The killer cell immunoglobulin-like receptors (KIRs) form a group of regulatory molecules that specifically recognize HLA class I molecules. The aim of this study was to analyze the possible contribution of the KIR3DL1 and KIR3DS1 alleles, in addition to HLA-B27, in the susceptibility to ankylosing spondylitis (AS) in a population of individuals from Spain.
We genotyped the KIR3DS1 and KIR3DL1 alleles in 2 cohorts of patients with AS and healthy control subjects. In total, 270 patients with AS and 435 healthy, HLA-B27-positive matched control subjects from Spain were enrolled. The KIR3DS1 and KIR3DL1 alleles were genotyped by sequence-specific oligonucleotide probe-polymerase chain reaction, and their association with AS was analyzed. All individuals were typed for HLA-B.
The KIR3DS1*013 allele was solely responsible for the increased frequency of the activator receptor KIR3DS1 in patients with AS compared with healthy HLA-B27-positive control subjects (35.7% versus 22.6% [P = 10(-6)], odds ratio 1.90, 95% confidence interval 1.50-2.40). The increased frequency of the KIR3DS1*013 allele in patients with AS was independent of the presence or absence of the HLA-Bw4I80 epitope. Moreover, the null allele KIR3DL1*004 was a unique inhibitory KIR3DL1 allele that showed a negative association with AS in the presence of HLA-Bw4I80.
The increased frequency of the KIR3DS1*013 allele in patients with AS is clearly independent of the presence of the HLA-Bw4I80 epitope, whereas the presence of inhibitory allotypes such as KIR3DL1*004 demonstrated a negative association in patients with AS in the presence of HLA-Bw4I80. As a consequence, the influence of KIR genotypes on AS susceptibility would be mediated by a general imbalance between protective/inhibitory and risk/activating allotypes.
To analyze the effects of a novel compound, NK-007, on the prevention and treatment of collagen-induced arthritis (CIA) and the underlying mechanisms.
We determined the effect of NK-007 on lipopolysaccharide (LPS)-triggered tumor necrosis factor α (TNFα) production by murine splenocytes and a macrophage cell line (RAW 264.7) by enzyme-linked immunosorbent assay, intracellular cytokine staining, and Western blotting. The LPS-boosted CIA model was adopted, and NK-007 or vehicle was administered at different time points after immunization. Mice were monitored for clinical severity of arthritis, and joint tissues were used for histologic examination, cytokine detection, and immunohistochemical staining. Finally, stability of TNFα production and Th17 cell differentiation were studied using quantitative polymerase chain reaction and flow cytometry.
NK-007 significantly suppressed LPS-induced TNFα production in vitro. Administration of NK-007 completely blocked CIA development and delayed its progression. Furthermore, treatment with NK-007 at the onset of arthritis significantly inhibited the progress of joint inflammation. Administration of NK-007 also suppressed production of TNFα, interleukin-6 (IL-6), and IL-17A in the joint and reduced percentages of IL-17+ cells among CD4+ and γ/δ T cells in draining lymph nodes. We further demonstrated that NK-007 acted on the stability of TNFα messenger RNA and reduced Th17 cell differentiation. In addition, it significantly inhibited levels of IL-6 and IL-17A in human coculture assay.
For its effects on the development and progression of CIA and for its therapeutic effect on CIA, NK-007 has great potential to be a therapeutic agent for human rheumatoid arthritis.
To examine the distribution of HLA class II alleles in clinically distinct juvenile rheumatoid arthritis (JRA) subsets.
We typed 298 patients and 181 controls for HLA-DRB1, DQA1, DQB1, and DPB1 alleles using polymerase chain reaction and oligonucleotide probe techniques.
Each JRA subset was characterized by a distinct distribution of HLA class II alleles. For the persistently pauciarticular and rheumatoid factor-negative polyarticular JRA subsets, certain combinations of DRB1 and DPB1 alleles were characteristic. In patients without antinuclear antibodies and chronic iridocyclitis, there was an increase of DRB1*0101/02 and DQA1*0101.
Findings of HLA typing support clinical subdivisions of the disease and suggest the existence of a novel DRB1*0101/02 and DQA1*0101 associated disease subset.
To identify the peptide anchor motif for the rheumatoid arthritis (RA)-related HLA allele, DR10, and find shared natural ligands or sequence similarities with the other disease-associated alleles, DR1 and DR4.
The HLA-DR10-associated peptides were purified, and a proportion of these natural ligands were de novo sequenced by mass spectrometry. Based on crystallographic structures, the complexes formed by peptide influenza virus hemagglutinin HA306-318 with DR1, DR4, and DR10 were modeled, and binding scores were obtained.
A total of 238 peptides were sequenced, and the anchor motif of the HLA-DR10 peptide repertoire was defined. A large proportion of the DR10-associated peptides had the structural features to bind DR1 and DR4 but were theoretical nonbinders to the negatively associated alleles DR15 and DR7. Among the sequenced ligands, 10 had been reported as ligands to other RA-associated alleles. Modeling data showed that peptide HA306-318 can bind DR1, DR4, and DR10 with similar affinities.
The data show the presence of common peptides in the repertoires of RA-associated HLA alleles. The combination of the shared epitope present in DR1, DR4, and DR10 together with common putative arthritogenic peptide(s) could influence disease onset or outcome.
To examine the in vivo effects of PD-0200347, an alpha(2)delta ligand of voltage-activated Ca(2+) channels and a compound chemically related to pregabalin and gabapentin, on the development of cartilage structural changes in an experimental dog model of osteoarthritis (OA). The effects of PD-0200347 on the major pathways involved in OA cartilage degradation, including matrix metalloproteinases (MMPs) and the inducible form of nitric oxide synthase (iNOS), were also studied.
OA was surgically induced in dogs by sectioning the anterior cruciate ligament. OA dogs were randomly distributed into 3 groups and treated orally with either 1) placebo, 2) 15 mg/kg/day of PD-0200347, or 3) 90 mg/kg/day of PD-0200347. Dogs were killed 12 weeks after surgery. The severity of the lesions was scored macroscopically and histologically. Cartilage specimens from the femoral condyles and tibial plateaus were processed for RNA extraction and quantitative reverse transcription-polymerase chain reaction (RT-PCR) or immunohistochemistry. Specific probes and antibodies were used to study the messenger RNA and protein levels of iNOS, MMP-1, MMP-3, and MMP-13.
No clinical signs of drug toxicity were noted in the treated animals. Treatment with PD-0200347 at both dosages tested (15 and 90 mg/kg/day) reduced the development of cartilage lesions. There was a reduction in the score of lesions, with a statistically significant (P = 0.01) difference when the highest dosage of the drug was administered. The reduction in the score was mainly related to a decrease in the surface size of the lesions. Quantitative RT-PCR showed that PD-0200347 significantly reduced the expression of MMP-13, a key mediator in OA. Immunohistochemical analyses showed that treatment with PD-0200347 significantly reduced the synthesis of all key OA mediators studied.
This study demonstrated the efficacy of PD-0200347 in reducing the progression of cartilage structural changes in a dog model of OA. It also showed that this effect is linked to the inhibition of the major pathophysiologic mediators responsible for cartilage degradation.
T cells are implicated in the production of anti-La/SSB and anti-Ro/SSA autoantibodies commonly associated with the DR3/DQ2 haplotype in systemic lupus erythematosus and Sjögren's syndrome. This study was undertaken to investigate the DR3/DQ2-restricted T cell response to wild-type human La (hLa) and a truncated form of mutant La.
Humanized transgenic mice expressing HLA-DRB1*0301/DQB1*0201 (DR3/DQ2) were immunized with recombinant antigen and examined for development of autoantibodies and T cell proliferation against overlapping peptides spanning the La autoantigen. HLA restriction and peptide binding of identified T cell epitopes to DR3 or DQ2 were determined using blocking monoclonal antibodies and a direct binding assay.
DR3/DQ2-transgenic mice generated an unusually rapid class-switched humoral response to hLa with characteristic spreading to Ro 52 and Ro 60 proteins following hLa protein immunization. Seven T cell determinants in hLa were restricted to the HLA-DR3/DQ2 haplotype. Six epitopes tested were restricted to HLA-DR and bound DR3 with semiconserved DR3 binding motifs. No DQ restriction of these epitopes was demonstrable despite efficient DQ binding activity in some cases. No neo-T cell epitopes were identified in mutant La; however, T cells primed with mutant La exhibited a striking increase in proliferation to the epitope hLa(151-168) compared with T cells primed with hLa.
Multiple DR3-restricted epitopes of hLa have been identified. These findings suggest that truncation of La produced by somatic mutation or possibly granzyme B-mediated cleavage alters the immunodominance hierarchy of T cell responsiveness to hLa and may be a factor in the initiation or maintenance of anti-La autoimmunity.
To determine whether there were differences in the circulating T lymphocyte subsets or clinical features of patients with primary Sjögren's syndrome (SS) who were positive for different HLA alleles.
Two- and three-color flow cytometry analyses were performed, using a whole blood lysing method.
Patients with SS who had the HLA alleles DRB1*0301, DQA1*0501, and DQB1*0201 had lower levels of circulating V delta 1-positive T cell receptor gamma/delta (TCR gamma/delta) cells and higher levels of circulating CD45RO-positive TCR gamma/delta cells compared with patients with SS who did not have these alleles. The patient subgroup with these alleles also had higher levels of anti-SS-A/Ro and anti-SS-B/La.
These results indicate that patients with primary SS may be immunologically divided into subgroups according to their HLA status. These immunologic changes in SS may also be typical of other autoimmune disorders in patients with the HLA-DR3 haplotype.
Patients with chronic periaortitis (CP) often show clinical and laboratory findings of a systemic autoimmune disorder. The aim of the present study was to investigate the role of the HLA system in CP.
Low-resolution genotyping for HLA-A, HLA-B, and HLA-DRB1 loci and genotyping of TNFA(-238)A/G and TNFA(-308)A/G single nucleotide polymorphisms were performed in 35 consecutive patients with CP and 350 healthy controls.
The HLA-DRB1*03 allele frequency was strikingly higher in patients with CP than in controls (24.28% versus 9.14%; chi(2) = 15.50, P = 0.000084, corrected P [P(corr)] = 0.0012, odds ratio [OR] 3.187, 95% confidence interval [95% CI] 1.74-5.83); the HLA-B*08 allele frequency was also higher in patients than in controls (17.14% versus 6.28%; chi(2)=11.12, P = 0.0008, P(corr) = 0.0269, OR 3.085, 95% CI 1.54-6.16). The A*01 allele frequency was significantly different (P = 0.0463), but the statistical significance was lost after correction for multiple testing (P(corr) = 0.5088). TNFA(-238)A allele and TNFA(-308)A allele frequencies were not significantly different (P = 0.512 and P = 0.445, respectively). Comparison of the main clinical and laboratory findings suggestive of a systemic autoimmune disease (e.g., acute-phase reactants, constitutional symptoms, other autoimmune diseases associated with CP) between the HLA-DRB1*03-positive and the HLA-DRB1*03-negative patients showed that the former group had significantly higher levels of C-reactive protein (P = 0.045) at disease onset, although this difference was not statistically significant after correction for multiple tests (P(corr) = 0.369).
The HLA system plays a role in susceptibility to CP. The strong association between CP and HLA-DRB1*03, an allele linked to a wide range of autoimmune conditions, further supports the view that CP may represent a clinical manifestation of an autoimmune disease.
To investigate 1) tumor necrosis factor (TNF) microsatellite allele frequencies in rheumatoid arthritis (RA), and 2) associations between TNF microsatellites and RA-associated HLA specificities in order to build up extended HLA haplotypes.
Eighty-five caucasoid patients with RA and 109 healthy caucasoid controls were typed for TNF microsatellites a-d using fluorescent-labeled primers and semiautomated genotyping. A further 56 RA patients who were selected for having certain HLA-DRB1 types were also typed for these TNF microsatellites. Linkage disequilibria between TNF and HLA alleles were calculated, and extended haplotypes were established.
The TNFa6 allele frequency was significantly increased in the RA patients compared with the controls (P = 0.0019, odds ratio [OR] 2.5, 95% confidence interval [95% CI] 1.3-4.6), an increase that was further evident in patients who were HLA-DRB1*0401 homozygous (P = 0.0003, OR 7.3, 95% CI 2.2-24.4). This increase was found to be due to association with HLA-DRB1*0401. No TNF microsatellite allele was found to be associated with HLA-DRB1*0404. Three HLA extended haplotypes were identified in the RA group: 1) HLA-DRB1*0401;TNFd4;TNFa6;TNFb5;HLA-B44; HLA-Cw5;HLA-A2, 2) HLA-DRB1*0301;TNFd2; TNFa2;TNFb3;HLA-B8;HLA-Cw7;HLA-A1, and 3) TNFd5;TNFc2;TNFa2;TNFb1;HLA-B62;HLA-Cw3.
TNF microsatellites found to be associated with RA do not appear to be independent of class II HLA associations.
To use molecular modeling tools to analyze the potential structural basis for the genetic association of rheumatoid arthritis (RA) with the major histocompatibility complex (MHC) "shared epitope," a set of conserved amino acid residues in the third hypervariable region of the DRbeta chain.
Homology model building techniques were used to construct molecular models of the arthritis-associated DRB1*0404 molecule and a T cell receptor (TCR) from T cell clone EM025, which is specific for DR4 molecules containing the shared epitope sequence. Interactive graphics techniques were used to orient the TCR on the DR molecule, guided by surface complementarity analysis.
The predicted TCR-MHC-peptide complex involved multiple interactions and specificity for the shared epitope. TCR residues CDR1beta D30, CDR2beta N51, and CDR3beta Q97 were positioned to potentially participate in hydrogen bond interactions with the shared epitope DRbeta residues Q70 and R71.
These results suggest a structural mechanism in which specific TCR recognition and possibly Vbeta selection are directly influenced by the disease-associated MHC polymorphisms.
To identify genetic determinants of granulomatosis with polyangiitis (Wegener's) (GPA).
We carried out a genome-wide association study (GWAS) of 492 GPA cases and 1,506 healthy controls (white subjects of European descent), followed by replication analysis of the most strongly associated signals in an independent cohort of 528 GPA cases and 1,228 controls.
Genome-wide significant associations were identified in 32 single-nucleotide polymorphic (SNP) markers across the HLA region, the majority of which were located in the HLA–DPB1 and HLA–DPA1 genes encoding the class II major histocompatibility complex (MHC) DPβ chain 1 and DPα chain 1 proteins, respectively. Peak association signals in these 2 genes, emanating from SNPs rs9277554 (for DPβ chain 1) and rs9277341 (DPα chain 1) were strongly replicated in an independent cohort (in the combined analysis of the initial cohort and the replication cohort, P = 1.92 × 10−50 and 2.18 × 10−39, respectively). Imputation of classic HLA alleles and conditional analyses revealed that the SNP association signal was fully accounted for by the classic HLA–DPB1*04 allele. An independent single SNP, rs26595, near SEMA6A (the gene for semaphorin 6A) on chromosome 5, was also associated with GPA, reaching genome-wide significance in a combined analysis of the GWAS and replication cohorts (P = 2.09 × 10−8).
We identified the SEMA6A and HLA–DP loci as significant contributors to risk for GPA, with the HLA–DPB1*04 allele almost completely accounting for the MHC association. These two associations confirm the critical role of immunogenetic factors in the development of GPA.
Antibodies toward the citrullinated form of the synovial antigen vimentin are specific for rheumatoid arthritis (RA) and are associated with HLA-DRB1*0401. This suggests that T cells specific for peptides derived from citrullinated vimentin presented in the context of HLA-DRB1*0401 may contribute to the etiopathogenesis of RA. The aim of this study was to identify immunodominant epitopes from citrullinated vimentin presented by HLA-DRB1*0401 and to characterize the resulting T cell responses.
We first predicted an HLA-binding T cell epitope from citrullinated vimentin based on the binding motif of HLA-DRB1*0401 and then confirmed its affinity. A class II major histocompatibility complex (MHC) tetramer loaded with the citrullinated form of vimentin aa 59-78 (cit-vimentin aa 59-78) was constructed and used to screen for specific T cells in HLA-DRB1*0401-transgenic mice, patients with RA, and healthy control subjects. Additionally, the cytokine output following cit-vimentin aa 59-78 challenge was analyzed in patients and healthy control subjects by multicolor flow cytometry and Luminex-based analysis.
The citrullinated form of vimentin aa 59-78 bound to HLA-DRB1*0401, but the native form could not. Subsequently, cit-vimentin aa 59-78-specific T cells were detected in immunized mice and in the periphery of both HLA-DR*0401-positive healthy control subjects and HLA-DR*0401-positive patients with RA, using class II MHC tetramers, CD154 up-regulation, and intracellular cytokine measurements. As demonstrated in cell culture supernatants, the production of cytokines (predominantly interferon-γ) in response to cit-vimentin aa 59-78 was significantly higher in patients compared with controls.
Here, we describe a posttranslational modification of an RA candidate autoantigen toward which HLA-DRB1*0401-restricted T cells can be detected in both patients with RA and healthy controls but for which a proinflammatory response is observed uniquely in patients with RA.
To identify critical residues involved in the binding of a selective peptide to DRB1*0401.
The binding of peptides to native or site-directed mutant DR molecules was evaluated using enzyme-linked immunosorbent assay and flow cytometry.
Amino acid substitutions at DR and peptide residues, which were predicted to contribute to interactions within the DR p4 pocket, had the greatest effects on the specificity of binding.
Differences in the peptide-binding repertoires of DR molecules may contribute to associations with autoimmune diseases.
Human interferon-alpha (IFNalpha) and IFNbeta are administered for treatment of several diseases, including viral infections, malignancies, and multiple sclerosis (MS). IFNalpha therapy has been associated with the production of autoantibodies and the development of a variety of autoimmune disorders, including polyarthritis. This report describes the development of seronegative, symmetric polyarthritis in a patient with relapsing-remitting MS, after 8 weeks of therapy with IFNbeta1a. HLA phenotyping analysis of the patient revealed the presence of HLA-DRB1*0404, an allele known to be associated with the development of rheumatoid arthritis. Therefore, IFNbeta1a may have induced arthritis in a patient who was genetically predisposed to develop arthritis on the basis of HLA determinants. The English-language literature regarding IFNalpha- and IFNbeta-induced polyarthritis is reviewed, and possible mechanisms for IFNalpha- and IFNbeta-induced autoimmunity, including the contribution of HLA determinants and nitric oxide overproduction, are discussed.
To investigate the association of susceptibility and protective HLA-DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in an Asian population.
All RA patients (n = 574) and control subjects (n = 392) were Korean. HLA-DRB1 typing and further subtyping of all alleles was performed by polymerase chain reaction, sequence-specific oligonucleotide probe hybridization, and direct DNA sequencing analysis. We used a relative predispositional effects (RPEs) method and a false discovery rate correction method for multiple comparisons.
The DRB1*0405 and *0901 alleles showed the most significant associations with RA (P = 7.83 x 10(-24), odds ratio [OR] 4.40 [95% confidence interval (95% CI) 3.24-5.99], and P = 3.76 x 10(-9), OR 2.47 [95% CI 1.82-3.36], respectively). The RPEs test showed that the DRB1*0401 and *0410 alleles conferred susceptibility and that the DRB1*0701, *0802, *1301, *1302, *1403, and *1405 alleles showed significant protective effects. Susceptibility and protective alleles both showed a pattern consistent with additive genetic effects, and each influenced RA independently of the other. The compound heterozygote DRB1*0405/*0901 was associated with the highest risk of RA (corrected P = 1.81 x 10(-11), OR 58.2 [95% CI 7.95-425.70]). The mean age at disease onset was approximately 4 years earlier or was 3 years earlier, respectively, in patients with at least 1 copy of the DRB1*0405 or the DRB1*0901 allele. Radiographic changes (stages II-IV) were more frequent in patients with at least 1 copy of DRB1*0405 (P = 0.032, 92.6% versus 84.3%, OR 2.33 [95% CI 1.24-4.39]).
The DRB1*0405/*0901 heterozygote has the strongest association with RA, suggesting that this heterozygote enhances the susceptibility to RA in Koreans.
To analyze the associations of HLA class II antigens with rheumatoid arthritis (RA) in a Spanish population.
We used DNA oligotyping to determine DR types, DQA1 and DQB1 alleles, and DR4 variants in 70 unrelated seropositive RA patients and 189 healthy controls living in Spain.
A significantly higher frequency of DR4 was seen in RA patients compared with controls (relative risk [RR] = 2.40). The DR10 specificity correlated most strongly with disease susceptibility (RR = 3.84). A significant decrease in the frequency of DR7 was observed in the RA patients (RR = 0.48). DR4-Dw15 (DRB1*0405) was found to be the unique DR4 allele associated with RA (RR = 4.27, P < 0.05), whereas Dw4 (DRB1*0401) and Dw14 (DRB1*0404/0408) showed no association, and both Dw10 (DRB1*0402) and Dw13 (DRB1*0403/0407) were negative risk factors for the disease. Approximately one-third of the cases of RA could not be explained by the "shared epitope" hypothesis. Investigation of the DQ alleles associated with DR4 showed that the haplotype Dw15-DQ8 (DRB1*0405-DQB1*0302) was a susceptibility factor for RA (RR = 6.36, P < 0.05).
Our results suggest that HLA class II alleles involved in RA susceptibility can vary among different Caucasian populations.
To examine the predictive role of HLA genetic markers in scleroderma renal crisis (SRC), beyond the known clinical correlates, in a large population of patients with systemic sclerosis (SSc).
SSc patients from the Scleroderma Family Registry and DNA Repository, the Genetics versus Environment in Scleroderma Outcomes Study, and the rheumatology division registry at the University of Texas Health Science Center at Houston were included in the study. Relevant clinical data were obtained by chart review, and autoantibodies were detected utilizing commercially available kits. HLA class II genotyping was performed on extracted and purified genomic DNA.
Overall, 1,519 SSc patients were included in the study, of whom 90 (6%) had developed SRC. Among the 90 patients with SRC, the diffuse cutaneous disease subtype was found in 76%, antitopoisomerase antibodies (antitopo) in 9%, anticentromere antibodies (ACAs) in 2%, and anti-RNA polymerase III (anti-RNAP III) in 50% of patients. In multivariate analyses of clinical and demographic parameters, diffuse disease type and anti-RNAP III were strong risk factors for the presence of SRC, whereas ACAs and antitopo were protective. In the final multivariate analysis, which included HLA alleles, HLA-DRB1*0407 (odds ratio [OR] 3.21, 95% confidence interval [95% CI] 1.27-8.08; P = 0.013) and DRB1*1304 (OR 4.51, 95% CI 1.30-15.65; P = 0.018) were identified as independent risk factors for SRC. Only 3 clinical characteristics, diffuse disease type, anti-RNAP III, and ACAs, remained significantly associated with SRC in the final model.
The results of this study suggest that DRB1*0407 and *1304 are independent risk factors, beyond the known clinical correlates, for the development of SRC.
Systemic sclerosis (SSc) is uncommon in men, and relatively little is known about factors contributing to its pathogenesis in this population. In the current study, we investigated HLA class II alleles in men with SSc. We also investigated the hypothesis that HLA compatibility of the mother could be a risk factor for SSc in men.
Sequence-specific oligonucleotide probe typing was used to determine DQA1, DQB1, and DRB1 alleles of SSc patients (50 men and 36 parous women), healthy controls (59 men and 80 parous women), 26 mothers of men with SSc, and 44 mothers of healthy men. All study subjects were Caucasian, and allele frequencies were compared with those of Caucasian controls from the Eleventh International Histocompatibility Workshop as well as those of local controls.
The DQA1*0501 allele was significantly increased among men with SSc compared with healthy men (odds ratio [OR] 2.3, P = 0.006, Pcorr = 0.04). DQA1*0501 was associated with diffuse SSc in men (OR 3.0, P = 0.004, Pcorr = 0.03), but not with limited SSc in men. Maternal HLA compatibility was not a risk factor for SSc in men.
Previous studies have shown associations of DRB1 alleles with SSc, but have rarely determined DQA1 allele frequencies. Our findings indicate that a specific DQA1 allele is associated with SSc, and that DRB1 associations may be due to linkage disequilibrium with DQA1. Moreover, by analyzing genetic susceptibility according to sex, we found that the contribution of HLA genes to the risk of SSc was substantially greater in men than in parous women.
To investigate the relative contribution of HLA antigens in the susceptibility to psoriasis and to localize additional genetic factors involved in psoriatic arthritis (PsA).
DNA from 45 patients with psoriasis, 65 with PsA, and 177 healthy control subjects was examined by polymerase chain reaction (PCR) using sequence-specific oligonucleotide probes to determine HLA-C. To examine whether MICA (class I major histocompatibility complex chain-related gene A) confers additional susceptibility, trinucleotide repeat polymorphism in the transmembrane region of the MICA gene was investigated by radioactive PCR. Further analysis of MICA was made by PCR-single-strand conformational polymorphism to determine the allelic variant corresponding to MICA transmembrane polymorphism.
Our results reveal new findings: 1) the frequency of the Cw*0602 allele was significantly increased in both patient groups: psoriasis (corrected P [Pcorr] < 10(-5), relative risk [RR] 6.2), PsA (Pcorr < 10(-6), RR 6.3), 2) the trinucleotide repeat polymorphism MICA-A9 was present at a significantly higher frequency in PsA patients (Pcorr < 0.00035, RR 3.2), whereas a similar distribution was found in both the control and psoriasis population, 3) this polymorphism corresponds to the MICA-002 allele and was found to be overrepresented in patients with the polyarticular form (Pcorr < 0.0008, RR 9.35), 4) the increase in MICA-A9 in PsA patients is independent of linkage disequilibrium with Cw*0602, 5) this allele confers additional relative risk (RR 3.27, etiologic fraction 0.44; etiologic fraction is the proportion of disease cases among the total population that are attributable to 1 allele when the relative risk is > 1) in PsA patients who carry Cw*0602.
The data obtained in this study are consistent with the polygenic inheritance of psoriasis. Cw*0602 appears to be the stronger genetic susceptibility factor for psoriasis. Independent of the HLA-C association, MICA-A9 polymorphism corresponding to the MICA-002 allele is a possible candidate gene for the development of PsA.
To analyze the clinical and immunologic manifestations of antiphospholipid syndrome (APS) in a large cohort of patients and to define patterns of disease expression.
The clinical and serologic features of APS (Sapporo preliminary criteria) in 1,000 patients from 13 European countries were analyzed using a computerized database.
The cohort consisted of 820 female patients (82.0%) and 180 male patients (18.0%) with a mean +/- SD age of 42 +/- 14 years at study entry. "Primary" APS was present in 53.1% of the patients; APS was associated with systemic lupus erythematosus (SLE) in 36.2%, with lupus-like syndrome in 5.0%, and with other diseases in 5.9%. A variety of thrombotic manifestations affecting the majority of organs were recorded. A catastrophic APS occurred in 0.8% of the patients. Patients with APS associated with SLE had more episodes of arthritis and livedo reticularis, and more frequently exhibited thrombocytopenia and leukopenia. Female patients had a higher frequency of arthritis, livedo reticularis, and migraine. Male patients had a higher frequency of myocardial infarction, epilepsy, and arterial thrombosis in the lower legs and feet. In 28 patients (2.8%), disease onset occurred before age 15; these patients had more episodes of chorea and jugular vein thrombosis than the remaining patients. In 127 patients (12.7%), disease onset occurred after age 50; most of these patients were men. These patients had a higher frequency of stroke and angina pectoris, but a lower frequency of livedo reticularis, than the remaining patients.
APS may affect any organ of the body and display a broad spectrum of manifestations. An association with SLE, the patient's sex, and the patient's age at disease onset can modify the disease expression and define specific subsets of APS.
Although this report of the first 1,000 patients in a rheumatologic consultative private practice cannot necessarily reflect the general experience of rheumatology, certain conclusions may be valid and may help to guide the rheumatologist-in-training. Approximately 70% of our patients were categorized as having "inflammatory" or "connective tissue' disorders, rather than degenerative disorders. Internists and general practitioners were the principal referral sources. Over 80% of referrals came from a relatively small geographic radius of 10-15 miles. A population base of perhaps 200,000 people, therefore, may be necessary to support a purely rheumatologic practice. A relatively steady flow of 2 new patients per day was not significantly influenced by subsequent additional rheumatologists moving into the area. However, the pattern of referrals clearly changed to include more patient-to-patient referrals (nearly 30%), perhaps reflecting both loss of physician referral sources and the increasing number of referrals from satisfied patients over a period of time.
To devise a modified version of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) for use in children and adolescents with systemic lupus erythematosus (SLE), based on the frequency and distribution of damage in patients with juvenile-onset SLE and the sources of damage that are most suitable for inclusion in a pediatric damage index.
In this cross-sectional study, damage was assessed through the SDI. Clinical assessments included evaluation of growth failure and delayed puberty, which were believed to be important sources of damage that are not incorporated in the SDI but should be included in a pediatric version of the instrument.
A total of 1,015 patients with juvenile-onset SLE in 39 countries were enrolled in the study. Of these, 405 patients (39.9%) had an SDI score of > or =1 (mean +/- SD score 0.8 +/- 1.4). Renal damage (13%), neuropsychiatric damage (10.7%), and musculoskeletal damage (10.7%) were observed most frequently, followed by ocular damage (8.2%) and skin damage (7.6%). Growth failure and delayed puberty were recorded in 15.3% and 11.3% of patients, respectively. A pediatric version of the SDI was devised, with inclusion of growth failure and delayed puberty as new domains.
We propose a modified version of the SDI for use in patients with juvenile-onset SLE. This new instrument warrants prospective validation in other populations of patients seen in different clinical or research settings.
Although there is a strong relationship between depression, chronic pain, and physical activity, there are few findings regarding the prevalence and predictors of depression in patients with osteoarthritis (OA). The goal of the present study was to assess the prevalence and severity of depression in a large sample of patients with OA and to reveal predictors of depression.
Patients were approached consecutively in 75 general practices. Of 1,250 distributed questionnaires, 1,021 were returned and analyzed. Besides sociodemographic data, medication and comorbidities, depression, and arthritis were assessed using the Patient Health Questionnaire (PHQ-9) and the Arthritis Impact Measurement Scale. A stepwise multiple linear regression analysis with the PHQ-9 score as the dependent variable was performed.
On the PHQ-9, 19.76% of men and 19.16% of women achieved a score of >or=15, indicating at least a moderately severe depression. Significant sex differences could not be revealed. The strongest predictor for depression severity was perceived pain (beta = 0.243, P < 0.001) and few social contacts (beta = 0.218, P < 0.001). Further predictors were physical limitation of the lower body (beta = 0.157, P < 0.001) and upper body (beta = 0.163, P < 0.001), age (beta = -0.168, P < 0.001), and body mass index (beta = 0.080, P = 0.020).
These findings suggest an increased prevalence of depression among patients with OA and emphasize the need for recognition and appropriate treatment. Most of the revealed predictors are influenceable and should be potential targets in a comprehensive treatment of OA to interrupt the vicious circle of pain, physical limitation, and depression.
To examine preferences for improved health in patients with rheumatoid arthritis (RA).
A survey was mailed to patients with RA enrolled in a county-based register. The questionnaire comprised a variety of health status measures (Medical Outcome Study Short Form-36, Arthritis Impact Measurement Scales 2 [AIMS2], Modified Health Assessment Questionnaire, and visual analog scale for pain and fatigue). The patients were asked to check 3 of 12 areas in which they would most like to see improvement (item 60 AIMS2). The number of respondents was 1,024 (mean age/disease duration 63.4/12.7 years, 78.7% female).
Pain was the preferred area for improvement in all subgroups of patients. Preference for improvement in pain was associated with lower age, higher levels of perceived pain, and lower scores for self efficacy related to pain. One-third of the patients with this preference did not report use of pain-relieving medication.
Pain is the area of health in which almost 70% of the patients would like to see improvement. This study suggests that more attention should be paid to the examination of patient preferences for improvement in health.
To investigate involvement in and satisfaction with health care among patients with rheumatoid arthritis (RA) and persons with chronic noninflammatory musculoskeletal pain, to identify target areas for improvement.
Data were collected from postal surveys carried out in 1994 in Oslo, Norway, with 1,542 patients with RA and 10,000 randomly selected adults. Patients with RA and persons with noninflammatory musculoskeletal pain were asked 3 questions about their involvement with treatment and 1 question about their satisfaction with health care. Levels of involvement and of satisfaction were related to demographic measures, health status measures, use of health services, and, for patients with RA, self-efficacy.
Of the respondents with RA (n = 1,024), 40% scored low on at least 1 question on involvement and 11% reported global dissatisfaction. Being young, well educated, physically disabled, in good mental health, and self-efficient and having visited a rheumatologist in the last 12 months were associated with a high level of involvement; being female and having a low pain level, good mental health, and high self-efficacy were associated with satisfaction with health care. Of persons with noninflammatory musculoskeletal pain of more than 5 years duration (n = 1,509), 57% scored low on at least 1 question on involvement and 27% reported global dissatisfaction. Being well educated, having visited a general practitioner in the last 12 months, and having ever visited a rheumatologist were associated with a high level of involvement. Being older and having a low pain level and good mental health were associated with satisfaction. A low score on involvement was a strong independent predictor of global dissatisfaction in both groups.
High education level and health service provided by rheumatologists were consistently associated with a high level of involvement. Good mental health and high involvement were associated with satisfaction with the care received. Efforts to achieve a higher level of patient involvement should especially be directed toward patients with low education, emotional distress, and a chronic physical disorder.
To determine whether there is familial aggregation of systemic lupus erythematosus (SLE) and/or other autoimmune diseases in SLE patients and to identify clinical differences between patients with and those without familial autoimmunity.
We interviewed members of the Grupo Latinoamericano de Estudio del Lupus Eritematoso (GLADEL) inception cohort of 1,214 SLE patients to ascertain whether they had relatives with SLE and/or other autoimmune diseases. Identified relatives were studied. Familial aggregation was tested using reported highest and intermediate population prevalence data for SLE, rheumatoid arthritis (RA), or all autoimmune diseases, and studies were performed to identify the genetic model applicable for SLE.
We identified 116 first-, second-, or third-degree relatives with SLE, 79 with RA, 23 with autoimmune thyroiditis, 3 with scleroderma, 1 with polymyositis, and 16 with other autoimmune diseases, related to 166 of the 1,177 SLE patients in the GLADEL cohort who agreed to participate. Forty-two SLE patients had 2 or more relatives with an autoimmune disease. We found a lambda(sibling) of 5.8 and 29.0 for SLE and of 3.2-5.3 for RA, when comparing with their reported high or intermediate population prevalence, respectively. We also found familial aggregation for autoimmune disease in general (lambda(sibling) = 1.5) and determined that for SLE, a polygenic additive genetic model, rather than a multiplicative one, is applicable.
In SLE there is familial aggregation of SLE, RA, and autoimmune disease in general. A polygenic additive model applies for SLE. American Indian-white Mestizo SLE patients and those with higher socioeconomic level were more likely to have familial autoimmunity.
To define the true risk of hydroxychloroquine (HCQ) retinal toxicity by studying the largest single group yet evaluated.
Retrospective chart review of all patients in the Kaiser Permanente Medical Care Program, Southern California Region, who had HCQ prescriptions filled from 1991 through 1993 (1,556 patients in 11 medical centers). Of 1,207 charts of patients who took HCQ and had documented ophthalmologic examinations, initial screening identified 21 charts (1.7%) that indicated possible HCQ toxicity.
We identified 1 patient with definite toxicity (1 of 1,207; 0.08%) and 5 other patients with indeterminate but probable toxicity (5 of 1,207; 0.4%). The incidence of definite HCQ retinal toxicity in patients treated with HCQ at <6.5 mg/kg/day was 0.
In HCQ-treated patients whose renal function is normal, routine ophthalmic screening is not indicated if the daily dosage is <6.5 mg/kg. In patients whose daily dosage is >6.5 mg/kg or who have taken HCQ continuously for > 10 years, annual screening may be appropriate.
To examine the immunologic mechanism by which 1,25-dihydroxyvitamin D(3) (1,25[OH](2)D(3)) may prevent corticosteroid-induced osteoporosis in patients with early rheumatoid arthritis (RA), with a focus on T cell biology.
Peripheral blood mononuclear cells (PBMCs) and CD4+CD45RO+ (memory) and CD4+CD45RO- (non-memory) T cells separated by fluorescence-activated cell sorting (FACS) from treatment-naive patients with early RA were stimulated with anti-CD3/anti-CD28 in the absence or presence of various concentrations of 1,25(OH)(2)D(3), dexamethasone (DEX), and 1,25(OH)(2)D(3) and DEX combined. Levels of T cell cytokines were determined by enzyme-linked immunosorbent assay and flow cytometry.
The presence of 1,25(OH)(2)D(3) reduced interleukin-17A (IL-17A) and interferon-gamma levels and increased IL-4 levels in stimulated PBMCs from treatment-naive patients with early RA. In addition, 1,25(OH)(2)D(3) had favorable effects on tumor necrosis factor alpha (TNFalpha):IL-4 and IL-17A:IL-4 ratios and prevented the unfavorable effects of DEX on these ratios. Enhanced percentages of IL-17A- and IL-22-expressing CD4+ T cells and IL-17A-expressing memory T cells were observed in PBMCs from treatment-naive patients with early RA as compared with healthy controls. Of note, we found no difference in the percentage of CD45RO+ and CD45RO- cells between these 2 groups. Interestingly, 1,25(OH)(2)D(3), in contrast to DEX, directly modulated human Th17 polarization, accompanied by suppression of IL-17A, IL-17F, TNFalpha, and IL-22 production by memory T cells sorted by FACS from patients with early RA.
These data indicate that 1,25(OH)(2)D(3) may contribute its bone-sparing effects in RA patients taking corticosteroids by the modulation of Th17 polarization, inhibition of Th17 cytokines, and stimulation of IL-4.
For approximately 2 years, bone loss was measured in women with early stages of rheumatoid arthritis (RA) and in control subjects, using serial computed tomography and dual photon absorptiometry. Rapid trabecular bone loss from the distal radius was observed in the RA patients but not the controls. The bone loss correlated with initial plasma levels of parathyroid hormone and 1,25-dihydroxyvitamin D3 (calcitriol) concentrations. It has been suggested that these humoral factors may interact with cytokines or other mediators produced in the adjacent wrist joint. Losses of the cortical bone of the radial midshaft and the lumbar spine were modest and were comparable in the 2 groups. Indices relating to both bone formation and bone resorption predicted bone loss at these 2 sites, but changes in the parathyroid hormone and calcitriol concentrations did not.
Twenty-three rheumatic disease patients with glucocorticoid-induced osteopenia (defined by measurement of forearm bone mass) completed an 18-month double-blind, randomized study to assess the effect of oral calcium and 1,25-dihydroxyvitamin D (1,25-OH2D) or calcium and placebo on bone and mineral metabolism. Intestinal 47Ca absorption was increased (P less than 0.05) and serum parathyroid hormone levels were suppressed (P less than 0.01) by 1,25-OH2D (mean dose 0.4 micrograms/day); however, no significant gain in forearm bone mass occurred, and bone fractures were frequent in both groups. In the 1,25-OH2D group, histomorphometric analysis of iliac crest biopsy specimens demonstrated a decrease in osteoclasts/mm2 of trabecular bone (P less than 0.05) and parameters of osteoblastic activity (P less than 0.05), indicating that 1,25-OH2D reduced both bone resorption and formation. We conclude that 1,25-OH2D should not be used for treatment of glucocorticoid-induced osteopenia. Since patients receiving calcium and placebo did not exhibit a loss of forearm bone mass, elemental calcium supplementation of 500 mg daily might be useful to maintain skeletal mass in patients receiving long-term glucocorticord therapy.
We conducted a 6-month open-label trial in which 10 patients with active psoriatic arthritis received 2 micrograms of oral 1,25-dihydroxyvitamin D3 daily. Statistically significant improvement was noted in the tender joint count and physician global impression. Of these 10 patients, 4 had substantial (greater than or equal to 50%) improvement, and 3 had moderate (greater than or equal to 25%) improvement in the tender joint count. Two patients were unable to receive therapeutic doses because of hypercalciuria. High-dose vitamin D may be a useful therapeutic agent for psoriatic arthritis.
Treatment of rheumatoid arthritis (RA) with cyclosporin A (CsA) has been successful, but the adverse effects of the drug have limited its use. We investigated the capacity of another immunosuppressive agent, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], to augment the effects of CsA on in vitro T cell functions. Exposure of CD4+ cells from RA patients or from normal subjects to either molecule alone resulted in a dose-dependent inhibition of phytohemagglutinin stimulation and interleukin-2 (IL-2) production that was more pronounced in cells from RA patients than in cells from normal subjects. Moreover, the action of CsA and 1,25(OH)2D3 on RA patient T cell functions in vitro was synergistic. Thus, in the presence of the vitamin D3 metabolite, only one-hundredth the concentration of CsA was required to produce the same effect on IL-2 production as that produced by CsA alone. IL-2 receptor expression was also reduced by the addition of both drugs. In contrast, IL-1 production by RA monocytes was not affected by CsA and 1,25(OH)2D3, either together or alone, and addition of IL-1 did not restore the ability of CD4+ cells from RA patients to secrete IL-2. Exogenous IL-2 reversed a large part of the inhibitory effect induced by both CsA and 1,25(OH)2D3, indicating that the immunosuppressive properties of these agents are mediated by the inhibition of IL-2 secretion. This synergy between 2 molecules that are biochemically very different suggests the existence of one or several sites of interaction that take place during the early stages of T cell activation.
To determine whether hypoxia and hypoxia-inducible factor (HIF) proteins regulate expression of β-1,3-glucuronyltransferase 1 (GlcAT-1), a key enzyme in glycosaminoglycan synthesis in nucleus pulposus cells.
Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to measure GlcAT-1 expression. Transfections were performed to determine the effect of HIF-1α and HIF-2α on GlcAT-1 promoter activity.
Under hypoxic conditions there was an increase in GlcAT-1 expression; a significant increase in promoter activity was seen both in nucleus pulposus cells and in N1511 chondrocytes. We investigated whether HIF controlled GlcAT-1 expression. Suppression of HIF-1α and HIF-2α induced GlcAT-1 promoter activity and expression only in nucleus pulposus cells. Transfection with CA-HIF-1α as well as with CA-HIF-2α suppressed GlcAT-1 promoter activity only in nucleus pulposus cells, suggesting a cell type-specific regulation. Site-directed mutagenesis and deletion constructs were used to further confirm the suppressive effect of HIFs on GlcAT-1 promoter function in nucleus pulposus cells. Although it was evident that interaction of HIF with hypoxia-responsive elements resulted in suppression of basal promoter activity, it was not necessary for transcriptional suppression. This result suggested both a direct and an indirect mode of regulation, possibly through recruitment of a HIF-dependent repressor. Finally, we showed that hypoxic expression of GlcAT-1 was also partially dependent on MAPK signaling.
These studies demonstrate that hypoxia regulates GlcAT-1 expression through a signaling network comprising both activator and suppressor molecules, and that this regulation is unique to nucleus pulposus cells.
To study the regulation of expression of β-1,3-glucuronosyltransferase 1 (GlcAT-1), an important regulator of glycosaminoglycan (GAG) synthesis, by Smad3 in nucleus pulposus (NP) cells.
GlcAT-1 expression was examined in rat NP and anulus fibrosus (AF) cells treated with transforming growth factor β (TGFβ). The effects of Smad signaling and Smad suppression on GlcAT-1 were examined in rat NP cells. GlcAT-1 expression was analyzed in the discs of Smad3-null mice and in degenerated human NP tissue.
TGFβ increased the expression of GlcAT-1 in rat NP but not rat AF cells. Suppression of GlcAT-1 promoter activity was evident with dominant-negative ALK-5 (DN-ALK-5). Cotransfection with Smad3 strongly induced promoter activity independent of TGFβ. Bioinformatics analysis indicated the presence of several Smad binding sites in the promoter; deletion analysis showed that the region between -274 and -123 bp was required for Smad3 response. DN-Smad3, Smad 3 small interfering RNA, and Smad7 strongly suppressed basal as well as TGFβ-induced promoter activity. Induction of promoter activity by Smad3 was significantly blocked by DN-Smad3; Smad7 had a very small effect. Lentiviral transduction of NP cells with short hairpin RNA Smad3 resulted in a decrease in GlcAT-1 expression and accumulation of GAG. Compared to wild-type mice, significantly lower expression of GlcAT-1 was seen in the discs of Smad3-null mice. Analysis of degenerated human NP tissue specimens showed no positive correlation between GlcAT-1 and TGFβ expression. Moreover, isolated cells from degenerated human tissue showed a lack of induction of GlcAT-1 expression following TGFβ treatment, suggesting an altered response.
Our findings demonstrate that in healthy NP cells, the TGFβ-Smad3 axis serves as a regulator of GlcAT-1 expression. However, an altered responsiveness to TGFβ during disc degeneration may compromise GAG synthesis.
To compare the singular and combined effects of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-17 on messenger RNA (mRNA) expression, translation, and secretion of IL-6, IL-8, and IL-1beta in fibroblasts.
Fibroblasts were stimulated with the relevant cytokine(s), pulse labeled with 35S-methionine, and the newly synthesized proteins were immunoprecipitated and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gene expression was determined by Northern blot analysis. Secreted proteins were detected by enzyme-linked immunosorbent assay (ELISA).
IL-17 alone was a weaker stimulator of the transcription, translation, and secretion of other interleukins than was TNFalpha or IL-1beta. IL-17 (10 ng/ml) stimulated the expression of IL-6 mRNA by 1.3-fold, while TNFalpha (1 ng/ml) increased it by 3.7-fold, and IL-1beta (0.1 ng/ml) increased it by >30-fold. Unlike TNFalpha and IL-1beta, IL-17 hardly affected the expression of IL-8 and IL-1beta mRNA. Translation of IL-6 was 6.2 times greater with IL-17, but TNFalpha and IL-1beta stimulated it 28.9- and 174-fold, respectively. ELISA-measured secretion of IL-6 and IL-8 increased by 6.7 and 5.8 times, respectively, with IL-17, compared with 52 and 269 times with TNFalpha stimulation and 1,356 and 1,084 times with IL-1beta stimulation. Yet, when IL-17 was combined with other cytokines, these activities were stimulated much beyond the sum of the individual effects. The combination of IL-17 and TNFalpha induced the expression of IL-6 or IL-1beta mRNA 7 times more than their additive stimulation, and that of IL-8 mRNA 3.8 times more. Likewise, the secretion of IL-6 and IL-8 was 20 times and 5 times higher, respectively, than expected. This synergism started after 4 hours of combined treatment, and decayed after 24-48 hours regardless of cytokine presence. It could be blocked with anti-IL-17 but not with anti-IL-1.
Our findings suggest that the primary role of IL-17 is to synergize with TNFalpha and to fine-tune the inflammation process. Therefore, IL-17 may be a potential target for therapeutic intervention.
To examine associations between labial salivary gland (LSG) histopathology and other phenotypic features of Sjögren's syndrome (SS).
The database of the Sjögren's International Collaborative Clinical Alliance (SICCA), a registry of patients with symptoms of possible SS as well as those with obvious disease, was used for the present study. LSG biopsy specimens from SICCA participants were subjected to protocol-directed histopathologic assessments. Among the 1,726 LSG specimens exhibiting any pattern of sialadenitis, we compared biopsy diagnoses against concurrent salivary, ocular, and serologic features.
LSG specimens included 61% with focal lymphocytic sialadenitis (FLS; 69% of which had focus scores of ≥1 per 4 mm²) and 37% with nonspecific or sclerosing chronic sialadenitis (NS/SCS). Focus scores of ≥1 were strongly associated with serum anti-SSA/SSB positivity, rheumatoid factor, and the ocular component of SS, but not with symptoms of dry mouth or dry eyes. Those with positive anti-SSA/SSB were 9 times (95% confidence interval [95% CI] 7.4-11.9) more likely to have a focus score of ≥1 than were those without anti-SSA/SSB, and those with an unstimulated whole salivary flow rate of <0.1 ml/minute were 2 times (95% CI 1.7-2.8) more likely to have a focus score of ≥1 than were those with a higher flow rate, after controlling for other phenotypic features of SS.
Distinguishing FLS from NS/SCS is essential in assessing LSG biopsies, before determining focus score. A diagnosis of FLS with a focus score of ≥1 per 4 mm², as compared to FLS with a focus score of <1 or NS/SCS, is strongly associated with the ocular and serologic components of SS and reflects SS autoimmunity.