[Show abstract][Hide abstract] ABSTRACT: To evaluate the prognostic significance of baseline electrocardiogram (ECG) abnormalities in a multiethnic cohort of patients with early systemic sclerosis (SSc) and to determine the serological, clinical, and echocardiogram correlates of ECG findings.
SSc patients with disease duration of≤5 years were enrolled in the GENISOS (Genetics versus Environment in Scleroderma Outcome Study) cohort. At the first visit, a standard 12 lead ECG was obtained along with demographic information, clinical data, and autoantibodies. The results of echocardiograms were also recorded. All ECGs were interpreted by a cardiologist unaware of the patients' clinical data.
Of 265 SSc patients with average disease duration at enrollment of 2.5 years, 140 (52.8%) had abnormal ECG findings. These findings were not associated with SSc disease type or autoantibody profile but were associated with more severe heart and lung involvement. A total of 75 patients (28.3%) died over a follow up time of 9.9 years. Complete right bundle branch block (± left anterior hemiblock) on ECG, present in 7 (2.6%) patients, predicted a higher risk of mortality (HR: 5.3; 95% CI: 2.1 to 13.4; p<0.001). The predictive significance of right bundle branch block was independent of age at enrollment, gender, ethnicity and risk factors for coronary artery disease.
ECG abnormalities are common in patients with early SSc and are associated with the severity of lung and heart involvement. Right bundle branch block is an independent predictor of mortality, and should be considered a marker of disease severity in SSc.
[Show abstract][Hide abstract] ABSTRACT: Objective:
There are no identified clinical markers that reliably predict long-term progression of interstitial lung disease (ILD) in systemic sclerosis (SSc; scleroderma). Elevated C-reactive protein (CRP) levels have been reported in SSc patients. We examined the predictive significance of CRP level for long-term ILD progression in a large early SSc cohort.
First, the CRP levels were compared between baseline samples of 266 SSc patients enrolled in the Genetics Versus Environment in Scleroderma Outcome Study cohort and 97 unaffected matched controls. Subsequently, the correlation between CRP levels and concomitantly obtained markers of disease severity was assessed. Serially obtained % predicted forced vital capacity (FVC) was used to examine the long-term ILD progression. The predictive significance of CRP level was investigated by a joint analysis of longitudinal measurements (serial FVCs up to 13 years) and survival data. This approach allowed inclusion of all 1,016 FVC measurements and accounted for survival dependency.
We confirmed that baseline CRP levels were higher in SSc patients than controls. CRP levels were associated with absence of anticentromere antibodies and correlated with the concomitant severity of lung, skin, and joint involvement. More importantly, higher baseline CRP levels were associated with shorter survival (P < 0.001) and predicted the long-term decline in FVC independent of potential confounders (age at baseline, sex, ethnicity, disease type, current smoking, body mass index, topoisomerase status, and treatment with immunosuppressive agents) in the multivariable model (P = 0.006).
Baseline CRP levels are predictive of long-term ILD progression. CRP level might aid clinicians in identifying patients that require more intensive monitoring and treatment.
[Show abstract][Hide abstract] ABSTRACT: Objective:
To examine the predictive significance of 2 pneumoproteins, surfactant protein D (SP-D) and CC-chemokine ligand 18 (CCL18), for the course of systemic sclerosis (SSc)-related interstitial lung disease.
The pneumoproteins were determined in the baseline plasma samples of 266 patients with early SSc enrolled in the GENISOS observational cohort. They also were measured in 83 followup patient samples. Pulmonary function tests were obtained annually. The primary outcome was decline in forced vital capacity (FVC percentage predicted) over time. The predictive significance for longterm change in FVC was investigated by a joint analysis of longitudinal measurements (sequentially obtained FVC percentage predicted) and survival data.
SP-D and CCL18 levels were both higher in patients with SSc than in matched controls (p < 0.001 and p = 0.015, respectively). Baseline SP-D levels correlated with lower concomitantly obtained FVC (r = -0.27, p < 0.001), but did not predict the short-term decline in FVC at 1 year followup visit or its longterm decline rate. CCL18 showed a significant correlation with steeper short-term decline in FVC (p = 0.049), but was not a predictor of its longterm decline rate. Similarly, a composite score of SP-D and CCL18 was a significant predictor of short-term decline in FVC but did not predict its longterm decline rate. Further, the longitudinal change in these 2 pneumoproteins did not correlate with the concomitant percentage change in FVC.
SP-D correlated with concomitantly obtained FVC, while CCL18 was a predictor of short-term decline in FVC. However, neither SP-D nor CCL18 was a longterm predictor of FVC course in patients with early SSc.
No preview · Article · Apr 2013 · The Journal of Rheumatology
[Show abstract][Hide abstract] ABSTRACT: Objective:
Illness behaviors (cognitive, affective, and behavioral reactions) among individuals with systemic sclerosis (SSc; scleroderma) are of clinical concern due to relationships between these behaviors and physical and mental quality of life, such as pain and symptoms of depression. Self-report measures with good psychometric properties can aid in the accurate assessment of illness behavior. The Illness Behavior Questionnaire (IBQ) was designed to measure abnormal illness behaviors; however, despite its longstanding use, there is disagreement regarding its subscales. The goal of the present study was to evaluate the validity of the IBQ in a cohort of patients with SSc.
Patients with SSc (n = 278) completed the IBQ at enrollment into the Genetics Versus Environment in Scleroderma Outcome Study. Structural validity of previously derived factor solutions was investigated using confirmatory factor analysis. Exploratory factor analysis was utilized to derive SSc-specific subscales.
None of the previously derived structural models were supported for SSc patients. Exploratory factor analysis supported an SSc-specific factor structure with 5 subscales. Validity analyses suggested that the subscales were generally independent of disease severity, but were correlated with other health outcomes (i.e., fatigue, pain, disability, social support, and mental health).
The proposed subscales are recommended for use in SSc, and can be utilized to capture illness behavior that may be of clinical concern.
Full-text · Article · Apr 2013 · Arthritis Care and Research
[Show abstract][Hide abstract] ABSTRACT: Objective
To measure interferon (IFN)–inducible chemokines in the plasma of patients with systemic sclerosis (SSc) and investigate whether the chemokine levels are correlated with disease severity. Methods
Plasma levels of the IFN-inducible chemokines IFNγ-inducible protein 10 (IP-10/CXCL10), IFN-inducible T cell α chemoattractant (I-TAC/CXCL11), and monocyte chemoattractant protein 1 (CCL2) were measured in SSc patients and examined for correlation with the IFN gene expression signature. A composite IFN-inducible chemokine score was generated for chemokines showing a correlation with the IFN gene signature (IP-10 and I-TAC), and this score was compared between 266 patients with SSc enrolled in the Genetics versus Environment in Scleroderma Outcome Study (GENISOS) cohort and 97 matched control subjects. Subsequently, the correlation between the IFN-inducible chemokine score at baseline and markers of disease severity was assessed. In addition, the course of the IFN-inducible chemokine score over time was examined. ResultsThe plasma IFN-inducible chemokine score correlated with the IFN gene expression signature, and this score was higher in SSc patients compared to controls. The IFN-inducible chemokine score was also associated with the absence of anti–RNA polymerase III antibodies and presence of anti–U1 RNP antibodies, but not with disease duration, disease type, or other autoantibodies. The chemokine score correlated with concomitantly obtained scores on the Medsger Severity Index for muscle, skin, and lung involvement in SSc, as well as the forced vital capacity, diffusing capacity for carbon monoxide, and creatine kinase levels. The association of the chemokine score with disease severity was independent of the presence of anti–U1 RNP or other potential confounders (age, sex, ethnicity, disease duration, and treatment with immunosuppressive agents). Finally, there was not a significant change in the IFN-inducible chemokine score over time. Conclusion
The IFN-inducible chemokine score is a stable serologic marker of a more severe form of SSc and may be useful for risk stratification of patients, regardless of disease type (limited or diffuse) or duration of disease.
Full-text · Article · Jan 2013 · Arthritis & Rheumatology
[Show abstract][Hide abstract] ABSTRACT: The first genome-wide association study (GWAS) of systemic sclerosis (SSc) demonstrated three non-major histocompatibility complex (MHC) susceptibility loci. The goal of this study was to investigate the impact of these gene variants on survival and severity of interstitial lung disease (ILD) in SSc.
The authors examined 1443 Caucasian SSc patients enrolled in the Genetics versus Environment In Scleroderma Outcome Study (GENISOS) and Scleroderma Family Registry (n = 914 - discovery cohort) and The Johns Hopkins Scleroderma Cohort (n = 529 - replication cohort). Forced vital capacity (FVC)% predicted was used as a surrogate for ILD severity. Five single nucleotide polymorphisms, IRF5 (rs10488631, rs12537284, rs4728142), STAT4 (rs3821236), CD247 (rs2056626) reached genome-wide significance in the SSc-GWAS and were examined in the current study.
Overall, 15.5% of the patients had died over the follow-up period of 5.5 years. The IRF5 rs4728142 minor allele was predictive of longer survival in the discovery cohort (p = 0.021) and in the independent replication cohort (p = 0.047) and combined group (HR: 0.75, 95% CI 0.62 to 0.90, p = 0.002). The association of this SNP with survival was independent of age at disease onset, disease type and autoantibody profile (anticentromere and antitopoisomerase antibodies). The minor allele frequency of IRF5 rs4728142 was 49.4%. Moreover, IRF5 rs4728142 minor allele correlated with higher FVC% predicted at enrolment (p = 0.019). Finally, the IRF5 rs4728142 minor allele was associated with lower IRF5 transcript expression in patients and controls (p = 0.016 and p = 0.034, respectively), suggesting that the IRF5, rs4728142 SNP, may be functionally relevant.
An SNP in the IRF5 promoter region (rs4728142), associated with lower IRF5 transcript levels, was predictive of longer survival and milder ILD in patients with SSc.
Full-text · Article · Mar 2012 · Annals of the rheumatic diseases
[Show abstract][Hide abstract] ABSTRACT: To investigate the association of cigarette smoking with susceptibility to systemic sclerosis (SSc) in a large, well-defined patient population.
We conducted a review of 1,379 patients with SSc enrolled in the Scleroderma Family Registry and DNA Repository and/or the Genetics versus Environment in Scleroderma Outcome Study cohort. Smoking history was obtained from chart review or via telephone interview. Patients with SSc were subsequently categorized as never smokers or ever smokers. Patients with SSc for whom smoking data were available were matched 2:1 by age, sex, ethnicity, and state of residence to control subjects, using the Behavioral Risk Factor Surveillance System.
The majority of patients were white (74.2%), with Hispanics and blacks representing 11.3% and 9.7%, respectively. Most patients had limited cutaneous involvement (54%). For our comparative analyses, 621 patients were matched with control subjects. There was no significant difference in age, sex, ethnicity, and SSc subtype between matched versus unmatched patients. The majority of patients had never smoked (57%), while 43% of patients were classified as ever smokers. The patients with SSc did not differ from control subjects in terms of their smoking behavior (odds ratio [OR] 1.020, 95% confidence interval [95% CI] 0.839-1.240, P=0.842). Anti-topoisomerase I antibody-positive patients were more likely to be never smokers (OR 0.648, 95% CI 0.421-0.998, P=0.049), whereas no such association was observed with anticentromere and anti-RNA polymerase III antibodies.
Unlike its role in rheumatoid arthritis, smoking does not confer a risk for development of SSc, although it may impact disease severity.
Full-text · Article · Oct 2011 · Arthritis & Rheumatology
[Show abstract][Hide abstract] ABSTRACT: Anti-U3-RNP, or anti-fibrillarin antibodies (AFA), are detected more frequently among African American (AA) patients with systemic sclerosis (SSc) compared to other ethnic groups and are associated with distinct clinical features. We examined the immunogenetic, clinical, and survival correlates of AFA in a large group of AA patients with SSc.
Overall, 278 AA patients with SSc and 328 unaffected AA controls were enrolled from 3 North American cohorts. Clinical features, autoantibody profile, and HLA class II genotyping were determined. To compare clinical manifestations, relevant clinical features were adjusted for disease duration. Cox proportional hazards regression was used to determine the effect of AFA on survival.
Fifty (18.5%) AA patients had AFA. After Bonferroni correction, HLA-DRB1*08:04 was associated with AFA, compared to unaffected AA controls (OR 11.5, p < 0.0001) and AFA-negative SSc patients (OR 5.2, p = 0.0002). AFA-positive AA patients had younger age of disease onset, higher frequency of digital ulcers, diarrhea, pericarditis, higher Medsger perivascular and lower Medsger lung severity indices (p = 0.004, p = 0.014, p = 0.019, p = 0.092, p = 0.006, and p = 0.016, respectively). After adjustment for age at enrollment, AFA-positive patients did not have different survival compared to patients without AFA (p = 0.493).
Our findings demonstrate strong association between AFA and HLA-DRB1*08:04 allele in AA patients with SSc. AA SSc patients with AFA had younger age of onset, higher frequency of digital ulcers, pericarditis and severe lower gastrointestinal involvement, but less severe lung involvement compared to AA patients without AFA. Presence of AFA did not change survival.
Full-text · Article · May 2011 · The Journal of Rheumatology
[Show abstract][Hide abstract] ABSTRACT: To determine the prevalence, correlates, and predictors of work disability (WD) in the Genetics versus ENvironment In Scleroderma Outcome Study (GENISOS). We hypothesized that WD in systemic sclerosis (SSc) is a function of demographic, clinical, and psychosocial factors.
Patients enrolled in the GENISOS cohort were subdivided in 3 groups: work disabled, working, and retired or homemakers. The latter group (n = 29) was excluded from further analysis. We used logistic regression analysis with a forward hierarchical variable selection strategy to investigate the independent correlates of WD at enrollment. Cox regression proportional Hazard's model with a similar variable selection strategy was utilized to determine the predictors of WD in those working at enrollment.
Overall, 284 patients with a mean age of 48.7 years and disease duration of 2.5 (±1.6) years were enrolled into the GENISOS cohort, consisting of 83.5% female, 46.8% white, 28.9% Hispanic, and 20.4% African American. Patients were longitudinally followed in 1438 study visits. At enrollment, 124 patients (43.7%) were work disabled, whereas 131 (46.1%) were working. Lower level of education (P < 0.001), higher Medsger Lung Severity Index (P = 0.012), higher Fatigue Severity Score (P = 0.008), and less social support (P < 0.001) correlated independently with WD. Of those working at baseline, 35 (26.7%) eventually developed WD. Non-white ethnicity (P = 0.038), lower DLCO % predicted value (P = 0.038), and higher Fatigue Severity Score (P = 0.009) at enrollment independently predicted WD on follow-up visits.
WD is a major problem among SSc patients and its prevalence is substantially higher than other rheumatic conditions. Demographic, clinical, and psychosocial factors correlate with WD cross-sectionally and predict WD longitudinally in these patients.
Full-text · Article · Mar 2011 · Seminars in arthritis and rheumatism
[Show abstract][Hide abstract] ABSTRACT: 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.
Full-text · Article · Feb 2011 · Arthritis & Rheumatology
[Show abstract][Hide abstract] ABSTRACT: The objective of the present study was to examine the association of baseline demographic and clinical characteristics with sequentially obtained measurements of forced vital capacity (FVC), expressed as a percentage of the predicted value, and to identify predictors of the decline rate in FVC over time in the Genetics versus Environment in Scleroderma Outcome Study (GENISOS).
To date, 266 patients have been enrolled in GENISOS, a prospective, observational cohort of patients with early systemic sclerosis. In addition to pulmonary function tests (PFTs), clinical and laboratory data were obtained from each patient. We analyzed 926 FVC measurements utilizing generalized linear mixed models. The predictive significance of baseline variables for the decline rate in FVC was investigated by the interaction term between the variable and the follow-up time within the first 3 years after enrollment as well as throughout the entire follow-up time.
The cohort consisted of 125 white, 54 African American, and 77 Hispanic patients with average disease duration of 2.5 years at enrollment. The mean follow-up time was 3.8 years, ranging up to 11.4 years. A number of baseline variables, including antibody status, African American ethnicity, disease type, baseline PFT values, modified Rodnan Skin Score, fibrosis on chest radiograph, and lung and skin subscores of the Severity Index, were associated with serially measured FVC levels. However, only the presence of anti-topoisomerase I antibodies (ATA) was associated with lower FVC levels (P < 0.001) as well as accelerated decline rate in FVC within the first 3 years of follow-up (P = 0.02). None of the baseline variables predicted the rate of decline in FVC on long-term follow-up. Patients with rapidly progressive ILD, however, were under-represented in the long-term follow-up group because the accelerated rate of decline in FVC was associated with poor survival (P = 0.001).
Presence of ATA was the only baseline variable associated with differential FVC levels, predicting the rate of decline in FVC within the first 3 years of follow-up. The association of faster decline in FVC with poor survival further emphasizes the need for identification of predictive biomarkers by collection of genetic information and serial blood samples in cohort studies.
[Show abstract][Hide abstract] ABSTRACT: It is increasingly being appreciated that multiple autoimmune diseases share common susceptibility genes. The tumour necrosis factor ligand superfamily member 4 gene (TNFSF4, OX40L), which encodes for the T cell costimulatory molecule OX40 ligand, has been identified as a susceptibility gene for the development of systemic lupus erythematosus (SLE). Accordingly, the aim of the current study was to investigate the possible association of the TNFSF4 gene region with systemic sclerosis (SSc), an autoimmune disease that leads to the development of cutaneous and visceral fibrosis.
A total of 9 single nucleotide polymorphisms (SNPs) in the TNFSF4 gene region, previously associated with susceptibility to SLE, were tested for association with SSc in a collection of 1059 patients with SSc and 698 controls.
Case-control comparisons revealed a significant association between susceptibility to SSc and the minor alleles at SNPs rs1234314 (OR 1.20, 95% CI 1.04 to 1.4, p(FDR)=0.019), rs2205960 (OR 1.24, 95% CI 1.10 to 1.50, p(FDR)=0.019) and rs844648 (OR 1.16, 95% CI 1.01 to 1.30, p(FDR)=0.032). The minor allele at rs844644 was protective (OR 0.84, 95% CI 0.70 to 0.97, p(FDR)=0.038). Analysis of subsets of patients with SSc demonstrated significant associations of the TNFSF4 SNPs with limited and diffuse SSc as well as specific SNPs that were associated with SSc-associated autoantibodies. Finally, the analyses suggest a potential interaction between two TNFSF4 SNPs, rs2205960 and rs844648, with regards to SSc susceptibility.
Polymorphisms in the TNFSF4 gene region are associated with susceptibility to SSc and its clinical and autoantibody subsets. TNFSF4 may be another gene that confers risk to multiple autoimmune diseases.
Preview · Article · Sep 2009 · Annals of the rheumatic diseases
[Show abstract][Hide abstract] ABSTRACT: Genetic studies in the systemic sclerosis (SSc), an autoimmune disease that clinically manifests with dermal and internal organ fibrosis and small vessel vasculopathy, have identified multiple susceptibility genes including HLA-class II, PTPN22, IRF5, and STAT4 which have also been associated with other autoimmune diseases, such as systemic lupus erythematosus (SLE). These data suggest that there are common autoimmune disease susceptibility genes. The current report sought to determine if polymorphisms in the C8orf13-BLK region (chromosome 8p23.1-B lymphoid tyrosine kinase), which is associated with SLE, are associated also with SSc.
Two variants in the C8orf13-BLK region (rs13277113 & rs2736340) were tested for association with 1050 SSc cases and 694 controls of North Americans of European descent and replicated in a second series 589 SSc cases and 722 controls from Spain.
The "T" allele at rs2736340 variant was associated with SSc in both the U.S. and Spanish case-control series (P = 6.8 x 10(-5), OR 1.27, 95% CI 1.1-1.4). The "A" allele at rs13277113 variant was associated with SSc in the U.S. series only (P = 3.6 x 10(-4), OR 1.32, 95% CI 1.1-1.6) and was significant in the combined analyses of the two series (P = 2.0 x 10(-3); OR 1.20, 95% CI 1.1-1.3). Both variants demonstrated an association with the anti-centromere antibody (P = 2.2 x 10(-6) and P = 5.5 x 10(-4), respectively) and limited SSc (P = 3.3 x 10(-5) and P = 2.9 x 10(-3), respectively) in the combined analysis. Peripheral blood gene expression profiles suggest that B-cell receptor and NFkappaB signaling are dysregulated based on the risk haplotype of these variants.
We identify and replicate the association of the C8orf13-BLK region as a novel susceptibility factor for SSc, placing it in the category of common autoimmune disease susceptibility genes.
No preview · Article · Sep 2009 · Journal of Autoimmunity