[Show abstract][Hide abstract] ABSTRACT: TYK2 is a common genetic risk factor for several autoimmune diseases. This gene encodes a protein kinase involved in interleukin 12 (IL-12) pathway, which is a well-known player in the pathogenesis of systemic sclerosis (SSc). Therefore, we aimed to assess the possible role of this locus in SSc.
This study comprised a total of 7103 patients with SSc and 12 220 healthy controls of European ancestry from Spain, USA, Germany, the Netherlands, Italy and the UK. Four TYK2 single-nucleotide polymorphisms (V362F (rs2304256), P1104A (rs34536443), I684S (rs12720356) and A928V (rs35018800)) were selected for follow-up based on the results of an Immunochip screening phase of the locus. Association and dependence analyses were performed by the means of logistic regression and conditional logistic regression. Meta-analyses were performed using the inverse variance method.
Genome-wide significance level was reached for TYK2 V362F common variant in our pooled analysis (p=3.08×10(-13), OR=0.83), while the association of P1104A, A928V and I684S rare and low-frequency missense variants remained significant with nominal signals (p=2.28×10(-3), OR=0.80; p=1.27×10(-3), OR=0.59; p=2.63×10(-5), OR=0.83, respectively). Interestingly, dependence and allelic combination analyses showed that the strong association observed for V362F with SSc, corresponded to a synthetic association dependent on the effect of the three previously mentioned TYK2 missense variants.
We report for the first time the association of TYK2 with SSc and reinforce the relevance of the IL-12 pathway in SSc pathophysiology.
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Annals of the rheumatic diseases 09/2015; DOI:10.1136/annrheumdis-2015-208154 · 10.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
The current knowledge of the influence of systemic sclerosis (SSc) risk loci in the clinical sub-phenotypes is still limited. The main limitation lies in the low frequency of some sub-phenotypes which could be solved by replication studies in independent cohorts and meta-analysis between studies. In this regard, CCR6 gene variants have been recently associated with anti-topoisomerase I positive (ATA+) production in SSc patients in a candidate gene study. This gene has been proposed to have a critical role in IL-17-driven autoimmunity in human diseases.
In order to confirm the association between CCR6 and ATA+ SSc patients, we performed an independent replication study in populations of European ancestry. We studied two CCR6 genetic variants (rs968334 and rs3093024) in a total of 901 ATA+ SSc cases, 3,258 ATA- SSc cases and 7,865 healthy controls and compared allelic frequencies for those SNPs in ATA+ SSc with healthy controls and also with ATA- SSc patients.
The comparison performed between ATA+ SSc patients and healthy controls showed significant association with SNP rs968334 (p=4.88 x 10-2, OR=1.11). When we compared ATA+ SSc cases with ATA- SSc, both SNPs, rs3093024 and rs968334, showed significant associations (p=2.89 x 10-2, OR=1.13; p=1.69 x 10-2, OR=1.15). Finally, in order to increase even more sample size and statistical power, we meta-analysed our study with the previous reported and found a significant association between SNP rs3093024 and ATA+ SSc patients (p=1.00 x 10-4, OR=1.16) comparing with healthy controls.
Our work confirms the association of CCR6 gene and ATA+ SSc patients.
Clinical and experimental rheumatology 08/2015; 33(4). · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background Systemic sclerosis (SSc) is a chronic connective tissue disorder with the highest mortality of any autoimmune disease. SSc is a complex disease with a clear genetic component. This genetic susceptibility has been supported by a number of well-powered genetic association studies. In this regard, it is remarkable that several SSc genetic markers have been reported in the IL-12 pathway (IL12A, STAT4, IL12RB2, IL12RB1). Furthermore, multiple clinical and experimental evidences have shown that this pathway is altered in SSc patients. TYK2 encodes the Tyrosine kinase 2 enzyme, which mediates the signaling of IL-12 receptor.
Objectives We aimed to analyze the association of the TYK2 locus with SSc susceptibility.
Methods The complete set of individuals included in this study reached 4,985 SSc patients and 11,621 healthy controls of European ancestry from Spain, Germany, The Netherlands, USA, Italy and United Kingdom. Initially, we analyzed all the polymorphisms located in the region that encompasses the TYK2 coding sequence and 20 kb up and downstream, in a previously published Immunochip-based dense genotyping study. We identified a common single nucleotide polymorphism (SNP), the V362F variant (rs2304256) and three rare variants: P1104A (rs34536443), A928V (rs35018800) and I684S (rs12720356), as the genetic markers that better explained the observed association in the region. Then, these variants were followed up in additional cohorts. Association and dependence relations were tested using logistic regression and conditional logistic regression, and pooled analyses were performed using the inverse variance method.
Results Our pooled analysis showed that V362F variant reached the genome-wide significance level (P=2.00x10-10, OR =0.84), while P1104A (rs34536443), A928V (rs35018800) and I684S (rs12720356) remained significant (P=8.61x10-3, OR=0.79; P=1.95x10-4, OR=0.49; Prandom=0.016, OR=0.84, respectively). The analyses carried out for the main clinical features revealed that the observed association signals relied on the whole disease. Furthermore, our results revealed that the association of TYK2 with SSc was dependent on the interaction between the P1104A, A928V and I684S rare variants and that the previously observed association for the autoimmune related V362F variant, corresponded to a synthetic association dependent on the association of the three previously mentioned rare variants.
Conclusions We report for the first time the association of TYK2 variants with SSc. Moreover, our data support that the highly significant association of a previously known autoimmune disease marker, the V362F variant (rs2304256), is dependent on the effect of three non-synonymous rare variants in this locus.
Disclosure of Interest None declared
Annals of the Rheumatic Diseases 06/2015; 74(Suppl 2):116.2-116. DOI:10.1136/annrheumdis-2015-eular.3859 · 10.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Common variable immunodeficiency disorder (CVID) is the most common symptomatic primary immunodeficiency in adults, characterized by B-cell abnormalities and inadequate antibody response. CVID patients have considerable autoimmune comorbidity and we therefore hypothesized that genetic susceptibility to CVID may overlap with autoimmune disorders. Here, in the largest genetic study performed in CVID to date, we compare 778 CVID cases with 10,999 controls across 123,127 single-nucleotide polymorphisms (SNPs) on the Immunochip. We identify the first non-HLA genome-wide significant risk locus at CLEC16A (rs17806056, P=2.0 × 10(-9)) and confirm the previously reported human leukocyte antigen (HLA) associations on chromosome 6p21 (rs1049225, P=4.8 × 10(-16)). Clec16a knockdown (KD) mice showed reduced number of B cells and elevated IgM levels compared with controls, suggesting that CLEC16A may be involved in immune regulatory pathways of relevance to CVID. In conclusion, the CLEC16A associations in CVID represent the first robust evidence of non-HLA associations in this immunodeficiency condition.
[Show abstract][Hide abstract] ABSTRACT: Immunoglobulin (Ig) replacement therapy is effective in reducing infections in patients with primary antibody deficiency (PAD). Diversity of specific antibodies is achieved by pooling plasma from over 1000 donors usually of a given geographic region. However, there is no agreement with regard to an optimal vaccination schedule for plasma donors. Especially for tick-borne encephalitis (TBE), regional vaccination rates differ widely among populations due to the epidemiology of the disease. We analyzed specific antibody titers against TBE in comparison to total IgG levels in 162 serum samples collected from 110 PAD patients substituted with polyvalent intravenous IgG or subcutaneous IgG. Some patients received different IgG products over time leading to a total number of 122 different patient-IgG product combinations. Positive TBE-specific IgG levels were detected in 35 cases when measured by standard ELISA and could be confirmed by demonstration of neutralizing antibodies in 31 cases. The detection of specific antibody levels correlated with the geographic origin of the IgG preparations. No titers were detectable in patients substituted with IgG products from North-American donors, whereas variable degrees of anti-TBE titers were observed in patients receiving products from different European countries. We suggest considering the patients' personal risk for TBE when selecting an appropriate Ig preparation. These data support regional plasma donation in order to address the diverse local infection profile.
Frontiers in Immunology 01/2015; DOI:10.3389/fimmu.2014.00675
[Show abstract][Hide abstract] ABSTRACT: Genome integrity is continuously challenged by the DNA damage that arises during normal cell metabolism. Biallelic mutations in the genes encoding the genome surveillance enzyme ribonuclease H2 (RNase H2) cause Aicardi-Goutières syndrome (AGS), a pediatric disorder that shares features with the autoimmune disease systemic lupus erythematosus (SLE). Here we determined that heterozygous parents of AGS patients exhibit an intermediate autoimmune phenotype and demonstrated a genetic association between rare RNASEH2 sequence variants and SLE. Evaluation of patient cells revealed that SLE- and AGS-associated mutations impair RNase H2 function and result in accumulation of ribonucleotides in genomic DNA. The ensuing chronic low level of DNA damage triggered a DNA damage response characterized by constitutive p53 phosphorylation and senescence. Patient fibroblasts exhibited constitutive upregulation of IFN-stimulated genes and an enhanced type I IFN response to the immunostimulatory nucleic acid polyinosinic:polycytidylic acid and UV light irradiation, linking RNase H2 deficiency to potentiation of innate immune signaling. Moreover, UV-induced cyclobutane pyrimidine dimer formation was markedly enhanced in ribonucleotide-containing DNA, providing a mechanism for photosensitivity in RNase H2-associated SLE. Collectively, our findings implicate RNase H2 in the pathogenesis of SLE and suggest a role of DNA damage-associated pathways in the initiation of autoimmunity.
[Show abstract][Hide abstract] ABSTRACT: Increased expression of IL-33 and its receptor ST2, encoded by the IL1RL1 gene, has been detected in the inflamed arteries of giant cell arteritis (GCA) patients. The aim of the present study was to investigate for the first time the potential influence of the IL33 and IL1RL1 loci on GCA predisposition.
A total of 1,363 biopsy-proven GCA patients and 3,908 healthy controls from four European cohorts (Spain, Italy, Germany and Norway) were combined in a meta-analysis. Six genetic variants: rs3939286, rs7025417 and rs7044343, within the IL33 gene, and rs2058660, rs2310173 and rs13015714, within the IL1RL1 gene, previously associated with immune-related diseases, were genotyped using predesigned TaqMan assays.
A consistent association between the rs7025417 polymorphism and GCA was evident in the overall meta-analysis, under both allele (PMH = 0.041, OR = 0.88, CI 95% 0.78-0.99) and recessive (PMH = 3.40E-03, OR = 0.53, CI 95% 0.35-0.80) models. No statistically significant differences between allele or genotype frequencies for the other IL33 and IL1RL1 genetic variants were detected in this pooled analysis.
Our results clearly evidenced the implication of the IL33 rs7025417 polymorphism in the genetic network underlying GCA.
PLoS ONE 11/2014; 9(11):e113476. DOI:10.1371/journal.pone.0113476 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The protein cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential negative regulator of immune responses, and its loss causes fatal autoimmunity in mice. We studied a large family in which five individuals presented with a complex, autosomal dominant immune dysregulation syndrome characterized by hypogammaglobulinemia, recurrent infections and multiple autoimmune clinical features. We identified a heterozygous nonsense mutation in exon 1 of CTLA4. Screening of 71 unrelated patients with comparable clinical phenotypes identified five additional families (nine individuals) with previously undescribed splice site and missense mutations in CTLA4. Clinical penetrance was incomplete (eight adults of a total of 19 genetically proven CTLA4 mutation carriers were considered unaffected). However, CTLA-4 protein expression was decreased in regulatory T cells (Treg cells) in both patients and carriers with CTLA4 mutations. Whereas Treg cells were generally present at elevated numbers in these individuals, their suppressive function, CTLA-4 ligand binding and transendocytosis of CD80 were impaired. Mutations in CTLA4 were also associated with decreased circulating B cell numbers. Taken together, mutations in CTLA4 resulting in CTLA-4 haploinsufficiency or impaired ligand binding result in disrupted T and B cell homeostasis and a complex immune dysregulation syndrome.
Nature Medicine 10/2014; DOI:10.1038/nm.3746 · 27.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
Spondyloarthritis (SpA) is one of the most frequently observed inflammatory joint diseases in HIV-1-seropositive patients. T-cells were described frequently as one of the major driving forces in SpA, therefore we tried to look for T-cell aberrancies in our HIV-positive patients with SpA.MethodsA total of 1098 files for HIV-positive patients who attended the HIV out-patient clinic of the Department of Clinical Immunology and Rheumatology at the Medical University Hanover for at least one visit between January 2004 and December 2010 were screened for the presence of a diagnosis of SpA. A cross-sectional study was conducted to investigate aberrancies in T-cell homeostasis induced by HIV-1 in these subjects.ResultsThe prevalence of SpA in the HIV-positive patients was 1.6% (18 of 1098). Interestingly, the percentage of patients with SpA who were human leucocyte antigen (HLA)-B27 negative in our HIV-positive cohort was 80%. Despite combination antiretroviral therapy (cART) and viral suppression, an incomplete immune recovery of T-cell naïve/memory distribution and turnover, as identified by intracellular Ki-67 expression, was observed in HIV-positive patients with SpA.Conclusions
Independent of HLA-B27 status and despite cART, HIV-positive patients can develop SpA and exhibit an increased T-cell turnover rate.
HIV Medicine 10/2014; 16(4). DOI:10.1111/hiv.12199 · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
The diagnosis of extrapulmonary tuberculous infections and nontuberculous mycobacterial (NTM) infections is difficult because the symptoms are nonspecific and suitable specimens for bacterial culture are often not available. Recent publications reported the existence of autoantibodies in tuberculous infections. We screened for specific autoantibodies in mycobacterial infections.Methods
We screened four in 29 patients with active mycobacterial infections and different controls using protein array technology. We could identify autoantibodies against ubiquitin-fold modifier-conjugating enzyme 1 (Ufc1) and pleckstrin homology domain containing, family G (with RhoGef domain) member 2 (Plekhg2) in all four patients. Subsequently, we designed enzyme-linked immunosorbent assays (ELISAs) for the detection of autoantibodies binding to Ufc1 and Plekhg2.ResultsAutoantibodies binding to Ufc1 and Plekhg2 were found in 19 of 29 patients (66%) with active mycobacterial infections. In comparison, we found these autoantibodies in one of 31 patients (3%) with successfully treated mycobacterial infections, in three of 40 (8%) HIV-infected patients not receiving combination antiretorviral therapy (cART) and in six of 134 (5%) blood donors. Interestingly, six of eight (75%) patients with HIV-associated B-cell non-Hodgkin lymphoma (B-NHL) at the onset of disease had autoantibodies against Ufc1 and Plekhg2, but none of nine (0%) patients after treatment of HIV-associated B-NHL, none of seven patients with non-HIV-associated B-NHL and 11 of 115 (10%) patients with other malignant diseases had autoantibodies against both proteins.Conclusions
In view of the high frequency of these autoantibodies, we postulate that they might be of potential use for additional diagnostics for mycobacterial infections, and further studies may shed light on the pathomechanisms of these two autoantibodies.
HIV Medicine 10/2014; 16(2). DOI:10.1111/hiv.12194 · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Exploiting genotyping, DNA sequencing, imputation and trans-ancestral mapping, we used Bayesian and frequentist approaches
to model the IRF5–TNPO3 locus association, now implicated in two immunotherapies and seven autoimmune diseases. Specifically, in systemic lupus erythematosus
(SLE), we resolved separate associations in the IRF5 promoter (all ancestries) and with an extended European haplotype. We captured 3230 IRF5–TNPO3 high-quality, common variants across 5 ethnicities in 8395 SLE cases and 7367 controls. The genetic effect from the IRF5 promoter can be explained by any one of four variants in 5.7 kb (P-valuemeta = 6 × 10−49; OR = 1.38–1.97). The second genetic effect spanned an 85.5-kb, 24-variant haplotype that included the genes IRF5 and TNPO3 (P-valuesEU = 10−27–10−32, OR = 1.7–1.81). Many variants at the IRF5 locus with previously assigned biological function are not members of either final credible set of potential causal variants
identified herein. In addition to the known biologically functional variants, we demonstrated that the risk allele of rs4728142,
a variant in the promoter among the lowest frequentist probability and highest Bayesian posterior probability, was correlated
with IRF5 expression and differentially binds the transcription factor ZBTB3. Our analytical strategy provides a novel framework for
future studies aimed at dissecting etiological genetic effects. Finally, both SLE elements of the statistical model appear
to operate in Sjögren's syndrome and systemic sclerosis whereas only the IRF5–TNPO3 gene-spanning haplotype is associated with primary biliary cirrhosis, demonstrating the nuance of similarity and difference
in autoimmune disease risk mechanisms at IRF5–TNPO3.
Human Molecular Genetics 09/2014; 24(2). DOI:10.1093/hmg/ddu455 · 6.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background Takayasu arteritis (TA) may be difficult to diagnose since diagnostic biomarkers have not been established so far. In a previous study, we could show the presence of autoantibodies against the human ferritin heavy chain protein (HFC) in sera of patients with giant cell arteritis (GCA) and/or polymyalgia rheumatica (PMR) (1).
Objectives To study the prevalence of autoantibodies against HFC in TA.
Methods We established 7 ELISAs for the detection of autoantibodies against HFC. As autoantigen we used the full recombinant HFC expressed by E. coli or one of six different peptides of the HFC: 1-18Aa (purity 98.8%), 19-45Aa (purity 98.8%), 52-78Aa purity 98.3%), 79-104Aa (purity 98.8%), 105-143Aa (purity 98.4%), 145-183Aa (purity 98.5%). We collected sera of 51 patients with TA, 49 sera of fever patients with underlying chronic infectious and malignant diseases, which are known for having unspecific autoantibodies, and 100 blood donors’ sera served as controls.
Results The best results were obtained by using ferritin pedtides as antigens. By combining different ELISAs detecting autoantibodies against HFC peptide 19-44A, 79-104A and 105-144A, we were able to detect ferritin peptide antibodies in 31/51 (61%) TA patients. For early TA, the frequency was lower than in early GCA and PMR (previous study up to 92%). In the controls, 0/100 (0%) of the blood donors were positive and 11/49 (22%) of the fever patients were positive.
Conclusions Considering the lack of biomarkers for TA, autoantibodies against peptides of HFC could be helpful as a marker for TA.
Disclosure of Interest None Declared
Annals of the Rheumatic Diseases 09/2014; 33(10). DOI:10.1007/s10067-014-2764-2 · 10.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Heme oxygenase (HO)-1, the inducible isoform of HO, has immunomodulatory functions and is considered a target for therapeutic interventions. In the present study, we investigated whether modulation of HO-1 might have regulatory effects on in vitro T-cell activation. The study examined whether: (1) HO-1 induction by cobalt-protoporphyrin (CoPP) or inhibition by tin-mesoporphyrin (SnMP) can affect expansion and function of virus-specific T cells, (2) HO-1 modulation might have a functional effect on other cell populations mediating effects on proliferating T cells (e.g., dendritic cells (DCs), regulatory T cells (Tregs), and natural killer cells), and (3) HO-1-modulated antiviral T cells might be suitable for adoptive immunotherapy.Inhibition of HO-1 via SnMP in CMVpp65-peptide-pulsed PBMCs led to increased antiviral T-cell activation and the generation of a higher proportion of effector memory T cells (CD45RA– CD62L–) with increased capability to secrete IFN-γ and granzyme B. Treg depletion and SnMP exposure increased the number of antiviral T cells 15-fold.To test the possibility that HO-1 modulation might be clinically applicable in conformity with good manufacturing practice (GMP), SnMP was tested in isolated antiviral T cells using the cytokine secretion assay. Compared to control, SnMP treatment resulted in higher cell counts and purity without negative impact on quality and effector function (CD107a, IFN-γ, and TNF-α levels were stable).These results suggest an important role of HO-1 in the modulation of adaptive immune responses. HO-1 inhibition resulted in markedly more effective generation of functionally active T cells suitable for adoptive T-cell therapy.