Clinical and serological features of systemic sclerosis in a Chinese cohort

The diagnostic and prognostic value of a line immunoblot assay in Taiwanese patients with systemic sclerosis

BACKGROUND AND AIMS

We aimed to evaluate the diagnostic performance and prognostic value of disease-specific antibodies and anti-Ro52 using a commercial line immunoblot assay (LIA) in Taiwanese patients with systemic sclerosis (SSc).

MATERIALS AND METHODS

We retrospectively enrolledall individuals at the Taichung Veterans General Hospital. We evaluated the diagnostic performance of LIA, anti-nuclear antibody (ANA) by indirect immunofluorescence (IIF) and also the association between the autoantibodies and the clinical phenotype using multivariable logistic regression.

RESULTS

The LIA exhibited a sensitivity of 65.4% and a specificity of 65.4%, at the optimal cutoff values of 2+ signal intensity. By taking the result of ANA into consideration, the optimal cutoff point was redefined as 1+. We observed a higher risk of diffuse cutaneous SSc (dcSSc) in those with negative autoantibodies, positive anti-Scl-70, anti-RNA polymerase III, and anti-Ro-52. Interstitial lung disease (ILD) was associated with negative autoantibodies, and positive anti-Scl-70 and anti-Ro52. Anti-Ro52 positivity was also associated with pulmonary arterial hypertension (PAH) and gastrointestinal tract involvement.

CONCLUSION

The presence of anti-Ro52 or the absence of SSc-specific autoantibodies may potentially indicate advanced diseases in patients with SSc. The incorporation of both IIF and LIA testing may improve the diagnostic specificity of SSc.

Comparing clinical characteristics of systemic sclerosis with or without interstitial lung disease: A cross-sectional study from a single center of the Chinese Rheumatism Data Center

Background

We aimed to compare the clinical characteristics of patients with systemic sclerosis (SSc) with or without interstitial lung disease (ILD) to identify relationships with the presence of ILD in SSc at a single center in China.

Methods

A cross-sectional study was conducted using retrospective data from the Chinese Rheumatology Data Center. Patients diagnosed with SSc at the Second Affiliated Hospital of Nanchang University between 2013 and 2022 were included. Demographic and clinical characteristics were compared between patients with SSc with and without ILD. Logistic regression analyses were performed to explore these associations.

Results

A total of 227 patients with SSc were included (male:female ratio = 1:4.82), of which 121 (53.3%) were accompanied with ILD. SSc patients with ILD had a higher percentage of diffuse cutaneous systemic sclerosis (dcSSc), sclerodactyly, loss of finger pad, muscle involvement, left ventricular diastolic dysfunction (LVDD), and pulmonary hypertension (PAH), elevated Krebs von den Lungen-6 (KL-6), and elevated ferritin than those without ILD, and a higher modified Rodnan skin score (mRSS), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) (all P < 0.05). Antinuclear antibody (ANA) and anti-scleroderma-70 (anti-Scl-70) positivity was presented frequently in SSc patients with ILD, while SSc patients without ILD were more often anti-centromere antibody (ACA) positive (all P < 0.05). On the multivariable analysis, muscle involvement [OR 2.551 (95% CI 1.054-6.175), P = 0.038], LVDD [OR 2.360 (95% CI 1.277-4.361), P = 0.006], PAH [OR 9.134 (95% CI 2.335-35.730), P = 0.001], dcSSc [OR 2.859 (95% CI 1.489-5.487), P = 0.002], PLR [OR 1.005 (95% CI 1.001-1.008), P = 0.020], elevated KL-6 [OR 2.033 (95% CI 1.099-3.763), P = 0.024], and anti-Scl-70 [OR 3.101 (95% CI 1.647-5.840), P < 0.001] were statistically significant associations with SSc patients with ILD.

Conclusion

Systemic sclerosis was found mainly in females. Several important differences in clinical and laboratory characteristics have been demonstrated between SSc patients with or without ILD. Muscle involvement, LVDD, PAH, dcSSc, PLR, elevated KL-6, and Anti-Scl-70 antibody may be associated with SSc in patients with ILD.

Epidemiology and Treatment of Systemic Sclerosis in Korea

Systemic sclerosis (SSc), a rare, chronic progressive systemic autoimmune disease of unknown etiology, is characterized by autoimmunity, tissue fibrosis, and obliterative vasculopathy. SSc can affect all major organs including the skin, blood vessels, lung, heart, kidneys, and gastrointestinal tract. Our understanding of its pathogenesis has increased over the past few decades, leading to improved diagnosis and treatment. However, the mortality rate of SSc remains considerable, mainly due to cardiopulmonary causes. A growing body of evidence suggests that geographical, regional, and ethnic differences could affect the epidemiology, clinical characteristics and prognosis of SSc. Although Korean data of this issue are lacking, a considerable amount of research has been published by many Korean researchers. To establish treatment strategies for Korean patients, extensive Korean research data are needed. This review summarizes the prevalence, incidence, mortality, and clinical and laboratory manifestations of Korean patients with SSc and discusses the current trends in evidence-based treatment and recommendations.

Systemic sclerosis in Native Americans of the American Southwest

OBJECTIVE

Many indigenous non-Caucasian populations, including Native Americans, have been reported to have higher rates, distinct clinical phenotypes, increased complications, and greater severity of systemic sclerosis (SSc). However, little is known of SSc specifically in Native Americans of the American Southwest. This study compared the clinical and serologic manifestations and outcomes of SSc in Native Americans and non-Native Americans (non-Natives) of this region.

METHODS

This cross-sectional retrospective study included 137 SSc patients (109 [80%] were non-Native and 28 [20%] were Native Americans) followed over a mean of 11.5 ± 7.6 years. Participants were repetitively evaluated with medical history, physical examination, echocardiography, chest imaging, and serologic testing. Disease characteristics and outcomes were statistically compared between Native Americans and non-Native patients.

RESULTS

The estimated prevalence of SSc in Native Americans was 40.0 cases/100 000 vs 17.1 cases/100 000 for non-Natives (odds ratio 2.34, 95% confidence interval [CI] 1.55-3.55, P < .001). The cohorts were similar in terms age, age of onset, limited vs diffuse cutaneous SSc, telangiectasias, gastroesophageal reflux disease, Raynaud phenomenon, serologies, interstitial lung disease, pulmonary arterial hypertension, scleroderma renal crisis, cancer prevalence, and overall mortality (all P > .05). However, for Native Americans, mortality specifically from fatal infections was 3.94-fold that of non-Natives (hazard ratio 6.88, 95% CI 1.37-34.64; P < .001).

CONCLUSION

In Native Americans of the American Southwest, SSc is increased in prevalence but is phenotypically similar to SSc in non-Natives. However, mortality due specifically to infection is increased in Native Americans with SSc.

Systemic sclerosis in Asians: Are there racial differences?

Systemic sclerosis is a multisystemic autoimmune disease characterized by vasculopathy and fibrosis. Racial factors exert a significant influence on the epidemiology, clinical manifestations, antibody profile, mortality and genetic factors in systemic sclerosis. In this review, we examined Asian systemic sclerosis cohorts reported in Asia and multi-racial cohort studies to evaluate the disease characteristics and outcomes of systemic sclerosis in Asians. Asian patients have distinct genetic susceptibility to systemic sclerosis, younger age of systemic sclerosis onset, higher frequency of diffuse skin involvement, different autoantibody profiles such as higher frequency of anti-Scl70 and anti-U1-RNP antibodies, and more severe clinical phenotype. There was a suggestion of poorer survival among Asians that may be contributed by more severe disease, socioeconomic factors and differences in healthcare systems. Recognizing the influence of racial differences in systemic sclerosis disease course is important as it has implications for appropriate treatment, monitoring and prognostication.

Prevalence and risk factors of systemic sclerosis-associated interstitial lung disease in East Asia: A systematic review and meta-analysis

Objective

Interstitial lung disease (ILD) is a common and potentially life‐threatening complication for individuals with systemic sclerosis (SSc). The purpose of this study was to complete a systematic review and meta‐analysis on prevalence and risk factors of SSc‐ILD in East Asia.

Methods

Medline, EMBASE, and Cochrane Library were searched up to January 22, 2021. The Reporting of Observational Studies in Epidemiology (STROBE) statement was applied to access the methodological quality of the eligible studies. Study characteristics and magnitude of effect sizes were extracted. Then, we calculated the pooled prevalence, weighted mean differences (WMDs), pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs), and performed subgroup analysis, sensitivity analysis, and publication bias with Egger's test.

Results

Twenty‐seven of 1584 articles were eligible and a total of 5250 patients with SSc were selected in the meta‐analysis. The pooled prevalence of SSc‐ILD in East Asia was 56% (95% CI 49%‐63%). The SSc‐ILD prevalence was higher in China (72%) than in Japan (46%) and Korea (51%). Longer disease duration (WMD = 1.97, 95% CI 0.55‐3.38), diffuse SSc (OR = 2.84, 95% CI 1.91‐4.21), positive anti‐topoisomerase I antibody (ATA) (OR = 4.92, 95% CI 2.74‐8.84), positive anti‐centromere body antibody (ACA) (OR = 0.14, 95% CI 0.08‐0.25), positive anti‐U3 ribonucleoprotein (RNP) antibody (OR = 0.17, 95% CI 0.04‐0.66), and higher erythrocyte sedimentation rate (ESR) (WMD = 6.62, 95% CI 1.19‐12.05) were associated with SSc‐ILD in East Asia.

Conclusion

Through this systematic review and meta‐analysis, we found that ILD occurs in up to approximately 56% of patients with SSc in East Asia. Longer disease duration, diffuse SSc, positive ATA, negative ACA, negative anti‐U3 RNP antibody, and higher ESR were risk factors for SSc‐ILD.

Classical Disease-Specific Autoantibodies in Systemic Sclerosis: Clinical Features, Gene Susceptibility, and Disease Stratification

Systemic sclerosis (SSc) is an autoimmune disease characterized by abnormalities in microcirculation, extracellular matrix accumulation, and immune activation. Autoantibodies are markers of immune abnormalities and provide diagnostic and predictive value in SSc. Anti-topoisomerase antibodies (ATAs), anticentromere antibodies (ACAs), and anti-RNA polymerase antibodies (ARAs) are the three classical specific antibodies with the highest availability and stability. In this review, we provide an overview of the recent progress in SSc research with respect to ATAs, ACAs, and ARAs, focusing on their application in distinguishing clinical phenotypes, such as malignancy and organ involvement, identifying genetic background in human leukocyte antigen (HLA) or non-HLA alleles, and their potential roles in disease pathogenesis based on the effects of antigen-antibody binding. We finally summarized the novel analysis using ATAs, ACAs, and ARAs on more detailed disease clusters. Considering these advantages, this review emphasizes that classical SSc-specific autoantibodies are still practical and have the potential for patient and risk stratification with applications in precise medicine for SSc.

Increased expression of GAB1 promotes inflammation and fibrosis in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease mainly characterized by persistent inflammation and fibrosis. The receptor tyrosine kinase (RTK) signal pathway plays an important role in the process of SSc, and Grb2-associated binding protein (GAB) is crucial in activating RTK signalling. A previous study found elevated levels of GAB1 in bleomycin (BLM)-induced fibrotic lungs, but the effects of GAB1 in SSc remain unclear. Our aim was to investigate whether GAB1 was dysregulated and its potential role in SSc. Compared with healthy donors, we found GAB1 expression was 1.6-fold higher in peripheral blood mononuclear cells (PBMC), 2.5-fold higher in CD4 + T cells, and 2-fold higher in skin from of SSc patients (P < .01). At the same time, the levels of type one collagen (COLI) were also significantly increased (1.8-fold higher) in SSc skin. Additionally, BLM-induced SSc mice showed mRNA levels of Gab1 2-fold higher than saline-treated controls, and Gab1 expression correlated positively with collagen content. A further in vitro study showed silencing of GAB1 suppressed inflammatory gene expression in TNF-α induced fibroblasts. Additionally, GAB1 deficiency prominently inhibited cell proliferation and reduced COLI protein levels in TGF-β induced fibroblasts. Taken together, these data suggest that GAB1 has a relatively high expression rate in SSc, and knockdown of GAB1 may attenuate SSc by stimulating inflammatory and fibrotic processes.

Exome-Wide Association Analysis Suggests LRP2BP as a Susceptibility Gene for Endothelial Injury in Systemic Sclerosis in the Han Chinese Population

Genetic factors play a key role in the pathogenesis of autoimmune diseases, whereas the disease-causing variants remain largely unknown. Herein, we performed an exome-wide association study of systemic sclerosis in a Han Chinese population. In the discovery stage, 527 patients with systemic sclerosis and 5,024 controls were recruited and genotyped. In the validation study, an independent sample set of 479 patients and 1,096 controls were examined. In total, we found that four independent signals reached genome-wide significance. Among them, rs7574865 (P_combined = 3.87 × 10^-12) located within signal transducer and activator of transcription 4 gene was identified previously using samples of European ancestry. Additionally, another signal including three SNPs in linkage disequilibrium might be unreported susceptibility loci located in the epidermis differentiation complex region. Furthermore, two SNPs located within exon 3 of IGHM (rs45471499, P_combined = 1.15 × 10^-9) and upstream of LRP2BP (rs4317244, P_combined = 4.17 × 10^-8) were found. Moreover, rs4317244 was identified as an expression quantitative trait locus for LRP2BP that regulates tight junctions, cell cycle, and apoptosis in endothelial cell lines. Collectively, our results revealed three signals associated with systemic sclerosis in Han Chinese and suggested the importance of LRP2BP in systemic sclerosis pathogenesis. Given the limited sample size and discrepancies between previous results and our study, further studies in multiethnic populations are required for verification.

Associated factors of early-onset pulmonary hypertension and clinical difference between early- and late-onset pulmonary hypertension in Thai systemic sclerosis

OBJECTIVES

Pulmonary hypertension (PH) is a major cause of death in systemic sclerosis (SSc). Detection of early-onset PH and its associated factors would be helpful for improving patient care. Our aims were to determine the factors associated with early-onset PH and to define the differences between early- and late-onset PH among SSc patients.

METHODS

A cohort study was conducted of 409 adult SSc patients who had followed-up between January 2014 and December 2016. Early-PH is defined when the onset of PH is diagnosed within 5 years of the disease. Logistic regression analysis was applied to determine the factors associated with early-PH.

RESULTS

In 3409 person-years, we diagnosed 50 cases with PH confirmation by right heart catheterization, of whom 26 were early-PH (incidence 0.7 per 100 person-years; 95%CI:0.5-1.1). Among SSc with early-PH, 69.2% had the diffuse cutaneous SSc subset and the most common PH classification was PH due to interstitial lung disease (18 cases;69.2%). According to a logistic regression analysis, early-PH was associated with a WHO functional class (WHO-FC) II and higher, cardiomegaly according to chest radiography, and tricuspid regurgitation jet maximum velocity (TRVmax)>2.8 m/s with the respective OR of 20.12 (95%CI:1.59-255.35), 7.42 (95%CI:1.35-40.88), and 8.20 (95%CI:1.17-57.64). To contrast, early-PH had a negative association with gastrointestinal involvement (OR 0.08; 95%CI:0.01-0.56).

CONCLUSIONS

Early-PH is prevalent among SSc patients and the most common cause is interstitial lung disease. A poor WHO-FC, cardiomegaly, and a high TRVmax are associated with early-PH. Gastrointestinal involvement is a protective factor for early-PH in SSc.

Myopathy is a Risk Factor for Poor Prognosis of Patients with Systemic Sclerosis: A retrospective cohort study

To compare clinical characteristics and identify long-term outcomes of Chinese patients with systemic sclerosis (SSc) with and without muscle involvement.We retrospectively investigated the medical records, laboratory results, and computed tomography images of 204 consecutive SSc patients. Kaplan-Meier analysis was performed to determine survival rates. Patients were allocated into groups with and without myopathy.The prevalence of myopathy was 21.6%. The myopathy group was more likely to develop diffuse cutaneous involvement (90.9% vs 56%, P = .006), interstitial lung disease (90% vs 56%, P < .001), digestive system involvement (56.7% vs 29.3%, P = .001), pulmonary hypertension (29.5% vs 10.5%, P = .004), and pericardial effusion (25% vs. 10%, P = .019). Patients with myopathy had lower single-breath diffusing capacity of the lung for carbon oxide (46.5 ± 11.1 vs 57.1 ± 13.4, P < .001).Further, the myopathy group has similar results in interstitial lung disease associated higher resolution computed tomography score (186.8 ± 64.5 vs 152.3 ± 45.5, P = .037), Valentini score for disease activity (3.4 ± 0.9 vs 2.0 ± 0.9, P < .001) and modified Rodnan total skin score (19.4 ± 6.1 vs 15.1 ± 7.7, P = .002), compared with non-myopathy group. Kaplan-Meier survival analysis revealed decreased overall survival rate of the myopathy group (P = .028).SSc Patients with myopathy had more severe clinical manifestations and higher disease activity compared with those without, which affected survival rates and indicated worse prognosis.

Clinical characteristics and outcomes of 566 Thais with systemic sclerosis: A cohort study

BACKGROUND

Most Thai patients with systemic sclerosis (SSc) have diffuse cutaneous SSc (dcSSc) unlike most Caucasians and some Asians. A longitudinal cohort study among Thai dcSSc is needed.

OBJECTIVES

We aimed to determine the overall clinical characteristics, define the clinical difference between limited cutaneous SSc (lcSSc) and dcSSc, and ascertain the mortality rate and the factors associated with mortality.

METHOD

We conducted a cohort study including 566 Thai adult SSc patients between January 2013 and June 2019. Clinical difference between lcSSc and dcSSc was investigated using generalized estimating equations (GEE).

RESULTS

Females presented more than males (356 vs 210 cases). The majority of cases were dcSSc (411; 72.6%). The median duration of disease at the time of pulmonary fibrosis (PF) detection was 2.5 years, pulmonary arterial hypertension 8.1 years, and renal crisis 4.1 years. By GEE analysis, dcSSc was significantly associated with salt-and-pepper skin, hand deformity, and every 1-point increase in modified Rodnan skin score (mRSS). A greater mortality risk was associated with age at onset >60 years (hazards ratio [HR] 5.5), a World Health Organization functional class (FC) III (HR 5.1), FC IV (HR 34.8), edematous skin (HR 11.4), early onset of PF (HR 1.7), each 5-point increase in the mRSS (HR 4.5), and ≥2 internal organ involvements (HR 10.1).

CONCLUSION

dcSSc is a common SSc subset among Thais. PF was an early complication in SSc and earlier PF detection was associated with a poorer prognosis. Elderly onset, high FC, severe skin tightness, and multiple organ involvements were associated with a greater mortality risk.

Increased Mortality in Asians With Systemic Sclerosis in Northern California

Objective

The objective of this study is to evaluate racial/ethnic differences in disease manifestations and survival in a US cohort of patients with systemic sclerosis (SSc), with a focus on Asian patients.

Methods

A retrospective cohort study was conducted among Kaiser Permanente Northern California adults with an incident SSc diagnosis by a rheumatologist from 2007 to 2016, confirmed by a chart review to fulfill 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria. Self‐reported race/ethnicity was categorized as non‐Hispanic white, Asian, Hispanic, and black. Disease manifestations and survival were compared, using white patients as the reference.

Results

A total of 609 patients with incident SSc were identified: 89% were women, and 81% had limited cutaneous SSc, with a mean age at diagnosis of 55.4 ± 14.8 years. The racial/ethnic distribution was 51% non‐Hispanic white (n = 310), 25% Hispanic (n = 154), 16% Asian (n = 96), and 8% black (n = 49). Compared with white patients, black patients had a greater prevalence of diffuse disease (14.5% vs. 44.9%; P < 0.001), and Asians had higher rates of anti‐U1‐RNP antibodies (32.1% vs. 11.9%; P = 0.005). Nine‐year overall survival rates following SSc diagnosis were lower in Asian (52.3%), black (52.2%), and Hispanic patients (68.2%) compared with white patients (75.8%). Pulmonary hypertension and infections were the leading causes of death in Asian patients. Asian race was associated with higher mortality on univariable (hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.08‐2.99]; P = 0.020) and multivariable analyses (HR 1.80 [95% CI 0.99‐3.16]; P = 0.047) when adjusting for age, sex, body mass index, cutaneous subtype, smoking status, interstitial lung disease, pulmonary hypertension, renal crisis, and malabsorption syndrome.

Conclusion

Asian patients with SSc in this US cohort had increased mortality compared with white patients. These patients warrant close monitoring for disease progression.

Characteristics of Systemic Sclerosis patients with positive anti-Th/To antibodies: About 6 patients and literature review

Among the antibodies described in Systemic Sclerosis (SSc), anti-Th/To antibodies (anti-Th/To) are rare and have been poorly studied. Thus, little is known about the profile of anti-Th/To positive patients. From our local Biobank (Marseille, France), we retrospectively selected data for 6 patients positive for anti-Th/To with an Immunodot assay. All of them suffered from SSc, sharing clinical and biological common features such as a limited cutaneous form of SSc, a decreased lung diffusing capacity and a speckled nuclear nucleolar immunofluorescence pattern of antinuclear antibodies screening on HEp-2 cells. In order to further characterize patients positive for anti-Th/To, we performed a thorough literature review. From 402 studied patients positive for anti-Th/To, we confirmed that these antibodies are associated with the limited cutaneous form of the disease (88% of the patients), and with an SSc related-pulmonary involvement (50%). The review analysis pointed out the rarity of the anti-Th/To with an estimated mean frequency of 3.4% of all SSc patients worldwide, their usual exclusivity with respect to the specific antibodies of scleroderma, and their high specificity (around 98%) for the diagnosis of SSc.

Mortality and hospitalization outcomes of interstitial lung disease and pulmonary hypertension in the Singapore systemic sclerosis cohort

OBJECTIVES

We compared mortality and hospitalization rates in four groups of patients with systemic sclerosis (SSc) [isolated pulmonary arterial hypertension (PAH) or interstitial lung disease (ILD), concomitant ILD-pulmonary hypertension (PH), and no/mild pulmonary involvement].

METHODS

In the Systemic Sclerosis Cohort Singapore (SCORE), ILD was diagnosed by HRCT and significant ILD was defined by forced vital capacity <70% predicted. Patients were classified as PAH if echocardiographic systolic pulmonary artery pressure (sPAP) ≥50 mmHg or right heart catheterization (RHC) mean PAP ≥25 mmHg. Multivariable regression analyses were performed to determine factors associated with mortality and hospital admissions per year. Cox proportional hazard model was used to analyze survival.

RESULTS

Of 490 SSc patients, 50 patients had PAH, 92 patients had ILD and 43 patients had ILD-PH. Of 93 patients with PAH or ILD-PH, 56 were based on echocardiography and 37 on RHC. Patients with ILD-PH (HR 3.77, 95% CI: 2.05-6.93) had the highest risk of death, followed by PAH (HR 3.03, 95% CI: 1.60-5.76) and ILD (HR 1.84, 95% CI: 1.04-3.28). After adjustment for confounders, PAH (HR 2.39, 95% CI: 1.13-5.07) remained independently associated with mortality, but not ILD-PH or ILD. Other factors associated with mortality were male gender, age at SSc diagnosis, malabsorption and digital ulcer/ gangrene. Increased hospitalization rate was associated with renal crisis, right heart failure and PAH medications, but not SSc groups.

CONCLUSION

PAH is an independent risk factor of mortality in SSc. Increased hospitalization rate was not associated with SSc groups. Other factors associated with increased mortality and hospital admissions were identified.

Unique clinical and autoantibody profile of a large Asian Indian cohort of scleroderma-do South Asians have a more aggressive disease?

AIM AND METHODS

A single-centre retrospective study was conducted using electronic medical records (EMR) of inpatients and outpatients with the diagnosis of "scleroderma" or "systemic sclerosis" visiting our clinic over the preceding 5 years.

RESULTS

A total of 327 patients' charts met our selection criteria; 301 were females. The median (IQR (inter quartile range)) age at onset of first non-Raynaud's symptom was 34.67 (27-43) years and median (IQR) disease duration prior to presentation to our department was 2.5 (1-5) years. Of these, 310 (94.8%) belonged to diffuse systemic sclerosis variety, 13 (4%) had limited systemic sclerosis, and 4 (1.2%) were of sine scleroderma type. A total of 289/302 (95.7%) patients were positive for ANA; of them, 245/327 (74.9%) were Scl-70 antibody-positive and 4% were CENP antibody-positive. Interstitial lung disease (ILD) was present in 288/327 (88.1%) patients. Among patients with available baseline forced vital capacity (FVC) data, 20% had a normal lung function and 28.4% had severe restriction. Pulmonary hypertension as assessed by echocardiography was present in 8.1% of patients. A significant association of Scl-70 antibody positivity with the presence of interstitial lung disease (ILD) (p = 0.000) and pulmonary hypertension (p = 0.035) was seen. On the other hand, presence of CENP antibody showed a protective trend against muscle weakness and/or muscle enzyme elevation (p = 0.052). Presence of arthritis was protective against development of digital ulceration (p = 0.021) and PAH (0.004). Patients younger than 40 years of age had significantly higher frequency of Scl-70 positivity (p = 0.038), whereas CENP antibody positivity was more likely in those aged > 40 years (p = 0.002).

CONCLUSION

Younger age of onset and high prevalence of Scl-70 antibody are unique South Asian features common with large Indian, Thai, and Chinese series. High prevalence of ILD is a feature common to Indian and Chinese series. Strong correlation of Scl-70 antibody with younger age and pulmonary hypertension were unique features of our cohort.

KEY POINTS

• Asian Indian scleroderma patients are younger by 2 decades compared to Caucasian series. • Higher prevalence of Scl-70 antibody, its association with young age, interstitial lung disease and pulmonary hypertension are features of our cohort. • High prevalence of interstitial lung disease (88.1%) was noted ; among those with baseline spirometry data (141/327), two thirds(66%) had moderate to severe restriction. • Younger age at onset, higher prevalence of Scl-70 antibody are features common to other Indian, Thai and Chinese series.

Clinical Manifestation and Incidence of Cardiopulmonary Complications in Early Systemic Sclerosis Patients with Different Antibody Profiles

Background

There has been no prior inception cohort study comparing clinical manifestations and incidence rate (IR) of cardiopulmonary involvement among early systemic sclerosis (SSc) patients by difference in autoantibody profiles. We compared the differences in the clinical presentation at study entry and cumulative organ complications at last visit, as well as the IR of cardiopulmonary complications between anti-topoisomerase I antibody-positive SSc patients (pATA), ATA-negative (nATA), and the positive anti-centromere antibody patients (pACA).

Methods

An inception cohort of early diagnosis SSc patients (disease duration ≤ 3 years) seen at the Rheumatology Clinic, Maharaj Nakorn Chiang Mai Hospital, between January 2010 and June 2016, was studied. SSc patients who had follow-up duration as less than 1 year and those diagnosed with an overlap syndrome were excluded. All participants underwent electrocardiography (ECG), echocardiography, and high-resolution computed tomography (HRCT) at the study entry and then annually.

Results

A total of 114 patients (90 diffuse cutaneous SSc (dcSSc), 69 women) with mean (standard deviation, SD) disease duration of 11.7 (8.8) months at cohort entry and an observational period of 3.8 (1.6) years, were recruited. There were 89 patients (78.1%) with pATA, 18 (15.8%) with nATA, and 7 (6.1%) with pACA. At enrollment, both pATA and nATA groups had a higher prevalence of dcSSc subtype, and interstitial lung disease (ILD) when compared with the pACA group. At the last visit, the pATA group had a higher cumulative prevalence of digital ulcers, joint contracture and tendon friction rub than the other groups. Both the pATA and nATA groups had a significantly higher IR of ILD compared to the pACA group (54.9 and 57.8 vs. 6.3 per 100 person-years). During the study period, no suspected myositis, systolic pulmonary artery pressure (sPAP) ≥ 50 mm Hg or cardiac complications was observed in the pACA group.

Conclusions

In our study cohort, the majority of which were dcSSc subtype with pATA, it was found that the presence of SSc-specific autoantibodies was associated with a distinctive clinical presentation and cumulative internal organ involvement, even in the early phase of the disease. Cardiopulmonary complications were rarely seen in the pACA group; whereas ILD complications were very common in both the pATA and nATA groups. A further study into the association of autoantibodies in nATA patients with ILD complications is needed.

Comparison of the clinical phenotype of systemic sclerosis patients in Iran and France in two university centers

Objectives:

Systemic sclerosis is a severe and rare chronic auto-immune multisystem disorder characterized by vasculopathy and skin stiffness. Ethnic and geographical origin can influence the outcomes. In this study, we compared the phenotypic characteristics of Iranian and French patients.

Methods:

This cross-sectional study was performed on 200 Iranian and 268 French systemic sclerosis patients. Iranian patients collected from the Iranian systemic sclerosis cohort of the Rheumatology Research Center, Shariati hospital, Tehran University of Medical Sciences. The French population was monocentric, and it was constituted by the patients included locally in the EUSTAR database in December 2016.

Results:

The mean age at onset was significantly lower in Iranian patients (35.58 ± 11.68 vs 47.06 ± 13.54, p-value < 0.001). The female-to-male ratio was approximately 5.2:1 and was not different in the two populations. The prevalence of diffuse cutaneous systemic sclerosis was significantly higher in Iranian patients (60.2% vs 42.85%, p-value < 0.001). Calcinosis cutis and joint synovitis were more prevalent in French patients ( p-value = 0.013, <0.001). The positivity of anti-topoisomerase antibody was higher in Iranian patients, whereas the anti-centromere antibody predominated in French cases ( p-value < 0.001). Restrictive pattern of pulmonary function test was more common in Iranian patients ( p-value < 0.001), while estimated pulmonary arterial pressure by echocardiography was higher in French patients ( p-value < 0.001).

Conclusion:

It seems that systemic sclerosis occurred in younger ages among Iranian female with the predominance of diffuse cutaneous subtype. In addition, lung interstitial disease appeared to be more prevalent and severe in Iranians than French patients.

Ethnic Variations in Systemic Sclerosis Disease Manifestations, Internal Organ Involvement, and Mortality

Objective.

A multiethnic systemic sclerosis (SSc) cohort study to evaluate ethnic variations in disease manifestations, internal organ involvement, and survival.

Methods.

Adults who fulfilled the American College of Rheumatology/European League Against Rheumatism classification criteria for SSc between 1970 and 2017 were included. Self-reported ethnicity was categorized as European-descent white, Afro-Caribbean, Hispanic, Arab, East Asian, South Asian, First Nations, or Persian. The primary outcome was the time from diagnosis to death from all causes. Survival probabilities and median survival times were determined using Kaplan-Meier survival curves.

Results.

There were 1005 subjects evaluated, the majority of whom were European-descent white (n = 745, 74%), Afro-Caribbean (n = 58, 6%), South Asian (n = 70, 7%), and East Asian (n = 80, 8%). Compared to European-descent white subjects, East Asians less frequently had calcinosis (29% vs 9%, p = 0.002) and esophageal dysmotility (88% vs 69%, p = 0.002); Afro-Caribbeans more frequently had interstitial lung disease (31% vs 53%, p = 0.007); and First Nations subjects more frequently had diffuse cutaneous disease (35% vs 56%, p = 0.02) and diabetes (5% vs 33%, p = 0.03). We found no difference in the short-term survival across ethnicities. Hispanic subjects have better longterm survival (81.3%, 95% CI 63–100) compared to European-descent white subjects (55%, 95% CI 51–60). East Asians appear to have the longest median survival time (43.3 yrs) and Arabs the shortest median survival time (15 yrs). There was no significant difference in median survival times between Afro-Caribbean and European-descent white subjects (22.2 vs 22.6 yrs).

Conclusion.

Ethnic variations in some SSc disease manifestations are observed. However, this does not result in significant differences in short-term survival but may affect longterm survival.

Prognostic profile of systemic sclerosis: analysis of the clinical EUSTAR cohort in China

BACKGROUND

Systemic sclerosis is a disease that has significant clinical heterogeneity. This study aims to determine the causes and risk factors of death in a single center European League Against Rheumatism Scleroderma Trials and Research Group (EUSTAR) cohort at the Peking Union Medical College Hospital (PUMCH) in China.

METHODS

Patients clinically diagnosed with systemic sclerosis (SSc) between Feb 2009 and Dec 2015 were prospectively recruited from the EUSTAR database and Chinese Rheumatism Data Center (CRDC) of the PUMCH. Baseline and follow-up data were collected. Kaplan-Meier analysis was used to estimate survival, and Cox proportional hazards regression analysis was used to identify factors associated with mortality.

RESULTS

A total of 448 patients were included in the cohort, of whom 56.7% had limited cutaneous systemic sclerosis (lcSSc). The average age at diagnosis was 42.8 ± 12.1 years. The prevalence of interstitial lung disease (ILD) was 382/447 (85.5%). Among 402 patients, 348 of them took glucocorticoid during the disease course; 374 patients received immunosuppressors. Across 2167 patient-years, 40 patients died. Of these, 27 deaths were attributable to SSc, with pulmonary arterial hypertension (PAH) being the leading cause of death. The median survival time was 53 months. Survival rates from disease diagnosis were 97.0%, 94.6%, 91.1% and 87.8% at 1, 3, 5 and 10 years, respectively. Independent prognostic factors for mortality were PAH (HR 6.248, 95% CI 2.855, 13.674) and arrhythmia (HR 4.729, 95% CI 1.588, 14.082). Tripterygium wilfordii Hook F (TwHF) (log-rank test 7.851, p 0.005) and methotrexate (MTX) (log-rank test 7.925, p = 0.005) were found in survival analysis to be protective treatments against mortality. Patients who used cyclophosphamide (CTX) during the disease course had poorer prognosis (log-rank test 5.177, p = 0.023).

CONCLUSIONS

In china, although there is a high prevalence of ILD in patients with SSc (85.5%), most of them have reserved pulmonary function, which means that interstitial lung disease (ILD) is not the most important factor in the death of patients with SSc and also is not a risk factor for poor prognosis. Only ILD with pulmonary dysfunction is associated with poor outcome. The 10-year cumulative rate (87.8%) in patients with SSc in China is slightly lower than the Europe, and pulmonary arterial hypertension (PAH) and arrhythmia at baseline are independent prognostic factors, whereas PAH instead of ILD is the leading cause of death in patients with SSc. Interestingly, the Chinese traditional medicine TwHF, as a protective factor for survival deserves further study.

Clinical and Laboratory Characteristics and Mortality in Korean Patients with Systemic Sclerosis: A Nationwide Multicenter Retrospective Cohort Study

Objective.

We aimed to investigate demographic and clinical features and predictors of mortality in Korean patients with systemic sclerosis (SSc).

Methods.

We performed a retrospective multicenter medical chart review in Korean patients diagnosed with SSc from 1986 to 2016 at 11 university hospitals representing each geographic area of Korea. SSc patients were defined according to the American College of Rheumatology preliminary classification criteria and subtyped as limited cutaneous (lcSSc) or diffuse cutaneous (dcSSc) SSc.

Results.

We enrolled 751 patients (female, 86.7%; mean age at diagnosis, 48.9 yrs). The most common organ involvement was interstitial lung disease (52.7%), followed by gastroesophageal reflux disease (32.9%) and pulmonary arterial hypertension (13.6%). Patients with lcSSc were more common than those with dcSSc (64.8 vs 35.2%), whereas anti-Scl-70 and anticentromere antibody positivity were identified in 302 (42.5%) and 175 (25.5%) patients, respectively. In the 46 (6.1%) patients who developed a malignancy, lung cancer (23.9%) was the most common diagnosis, followed by gastric (13%) and breast cancer (13%). During the study period, 57 (7.6%) patients died, and the 5- and 10-year survival rates were 94% and 87%, respectively. Increased age at diagnosis, cardiovascular involvement, and anti-Scl-70 antibody positivity were significant predictors of death.

Conclusion.

Clinical manifestations and survival rates in Korean SSc patients are similar to those of other populations. However, the prevalence of anti-Scl-70 antibody is higher in Korean SSc patients compared with whites, while the prevalence of anticentromere antibody is lower.

Sirtuin1 Protects against Systemic Sclerosis-related Pulmonary Fibrosis by Decreasing Proinflammatory and Profibrotic Processes

Pulmonary fibrosis is the leading cause of death in systemic sclerosis (SSc). Sirtuin1 (SIRT1) is a deacetylase with known antiinflammatory and antifibrotic activity in the liver, kidney, and skin. The role of SIRT1 in SSc-related pulmonary fibrosis is unknown. In the present work, we determined that the expression of SIRT1 in peripheral blood mononuclear cells of patients with SSc with pulmonary fibrosis is lower than that in patients with SSc without pulmonary fibrosis. In in vivo studies of bleomycin-induced lung fibrosis in mice, SIRT1 activation with resveratrol reduced collagen production when it was administered either prophylactically during the inflammatory stage or after the development of fibrosis. Furthermore, SIRT1 activation or overexpression inhibited tumor necrosis factor-α-induced inflammatory responses in vitro in human fetal lung fibroblasts, depletion of SIRT1 in fibroblasts enhanced inflammation, and these effects were related to changes in the acetylation of NF-κB. In addition, SIRT1 activation or exogenous overexpression inhibited collagen production in vitro, and these manipulations also inhibited fibrosis via inactivation of transforming growth factor-β/mothers against decapentaplegic homolog and mammalian target of rapamycin signaling. Taken together, our results show that a loss of SIRT1 may participate in the pathogenesis of SSc-related pulmonary fibrosis, and that SIRT1 activation is an effective treatment for both the early (inflammatory) and late (fibrotic) stages of pulmonary fibrosis. Thus, SIRT1 may be a promising therapeutic target in the management of SSc-related pulmonary fibrosis.

What have multicentre registries across the world taught us about the disease features of systemic sclerosis?

Introduction

The aim of this study is to compare the clinical features, mortality and causes of death of systemic sclerosis (SSc) patients in four large multicentre registries.

Methods

Patients seen at least once in the Australian Scleroderma Cohort Study (ASCS) (n = 1714), the Canadian Scleroderma Research Group (CSRG) (n = 1628), the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) Network (n = 13,996) and the Systemic Sclerosis Cohort in Singapore (SCORE) (n = 500) before August 2016 were included. Clinical manifestations and survival in cohorts and disease subtypes were compared.

Results

Among 17,838 SSc patients, most were female (86.1%), Caucasian (84.6%) and had the limited cutaneous subtype (lcSSc) (65.0%). The anti-centromere autoantibody was the most prevalent (37.6%). More patients in SCORE had the diffuse subtype (dcSSc) (49.3%) and Scl-70 autoantibody (38.8%) (p<0.001). Patients with dcSSc were more likely to be younger and male (p<0.001) and have shorter disease duration, more calcinosis, tendon friction rubs and synovitis (all p<0.001). Interstitial lung disease (ILD) occurred more frequently in dcSSc but prevalence of pulmonary arterial hypertension (PAH) was similar in both subtypes. More deaths occurred among SCORE patients who had the shortest median survival (p<0.001). The survival of patients with early disease, males and those with dcSSc was shorter than that of patients with prevalent disease, female gender and lcSSc, respectively. SSc-related complications accounted for more than 50% of deaths, with PAH and ILD being the most common.

Conclusions

This meta-cohort of SSc patients, the largest reported to date, provides insights into the impact of race and sex on disease manifestations and survival and confirms the early mortality in this disease.

[The influence of STAT4 rs7574865 (G/T) polymorphism on the risk of clinical and immunological phenotypes of systemic sclerosis in a Russian patient population: Results of a pilot study]

AIM

To examine the association of signal transducer and activator transcription 4 (STAT4) rs7574865 G/T polymorphism with a predisposition to systemic sclerosis (SSC) and associated clinical and autoimmune phenotypes in a Russian population.

SUBJECTS AND METHODS

A total of 102 patients with SSC and 103 healthy individuals as controls were examined. STAT4 rs7574865 polymorphism was investigated by real-time polymerase chain reaction.

RESULTS

The carriers of the T allele showed a statistically significant association with SSC, a diffuse form (DF), the presence of interstitial lung disease (ILD), cardiac injury (CI), and seropositivity for anti-topoisomerase I antibodies (ATA).

CONCLUSION

The findings results confirm the important role of STAT4 gene in the predisposition to SSC and its phenotypes, such as DF, ILD, CI, and ATA in the Russian population.

Relevance of clinical and autoantibody profiles in systemic sclerosis among Thais

OBJECTIVE

Autoantibody profiles in systemic sclerosis (SSc) and their relative clinical association vary between studies. The rate for being anti-topoisomerase-I (ATA) positive and the association with diffuse cutaneous the SSc subset (dcSSc) is higher among Thais than among Caucasians. The objective was to evaluate the relevance of clinical presentation, namely being positive for one or more autoantibodies among Thai SSc patients.

METHOD

A retrospective, cohort study was performed among SSc patients over 18 years of age at Srinagarind Hospital, Khon Kaen University, Thailand, during January 2006 to December 2013. Autoantibodies comprising 13 SSc-specific antigens were evaluated using the EUROIMMUN AG (Lübeck, Germany) in order to define their clinical association(s).

RESULTS

Two hundred and eighty-five scleroderma patients (200 female; 85 male) were included. The majority (66.7%) were dcSSc subset. ATA was the most common antibody profile in our patients (231 cases; 81.1%), followed by anti-Ro 52 (87 cases; 30.5%). Eleven of our patients (3.9%) were negative for all antibody profiles and 44 cases (15.4%) were negative for ATA and anti-centromere antibody (anti-CENP). Almost 40% (112 cases) were positive for at least two autoantibodies. There was an association between the presence of ATA and hand deformity (odds ratio [OR] 3.94; 95% CI 1.12-13.84), anti-CENP and hand deformity (OR 0.20; 95% CI 0.02-0.90), anti-Ku and scleroderma-polymyositis overlap syndrome (OR 6.58; 95% CI 2.16-19.39) and the absence of both ATA and anti-CENP with female sex (OR 2.90; 95% CI 1.12-7.51), limited cutaneous SSc subset (OR 2.70; 95% CI 1.30-5.55) and scleroderma-polymyositis overlap syndrome (OR 2.53; 95% CI 1.04-6.16). Neither ATA nor anti-CENP were associated with the SSc subset.

CONCLUSIONS

ATA and anti-CENP were not helpful in differentiating the SSc subset in Thai SSc patients, albeit they were good for predicting hand function. Coexisting ATA and anti-CENP negativity were associated with less extensive skin tightness and SSc overlap syndrome.

Survival and causes of death in systemic sclerosis patients: a single center registry report from Iran

The aims of the study were to determine prognostic factors for survival and causes of death in a cohort of patients with systemic sclerosis (SSc). This was a cohort study of SSc patients in single rheumatologic center from January 1998 to August 2012. They fulfilled the American College of Rheumatology classification criteria for SSc or had calcinosis Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia or sine sclerosis. Causes of death were classified as SSc related and non-SSc related. Kaplan-Meier and Cox proportional hazard regression models were used in univariate and multivariate analysis to analyse survival in subgroups and determine prognostic factors of survival. The study includes 220 patients (192 female, 28 male). Out of thirty-two (14.5 %) who died, seventeen (53.1 %) deaths were SSc related and in nine (28.1 %) non-SSc-related causes, and in six (18.8 %) of patients causes of death were not defined. Overall survival rate was 92.6 % (95 % CI 87.5-95.7 %) after 5 years and 82.3 % (95 % CI 73.4-88.4 %) after 10 years. Pulmonary involvement was a major SSc-related cause of death, occurred in seven (41.1 %) patients. Cardiovascular events were leading cause of in overall death (11) 34.3 % and 6 in non-SSc-related death. Independent risk factors for mortality were age >50 at diagnosis (HR 5.10) advance pulmonary fibrosis (HR 11.5), tendon friction rub at entry (HR 6.39), arthritis (HR 3.56). In this first Middle Eastern series of SSc registry, pulmonary and cardiac involvements were the leading cause of SSc-related death.

Pulmonary involvement in systemic sclerosis: A clinical profile

Background:

Systemic sclerosis is a generalized disorder of connective tissue affecting skin and internal organs. Lung involvement accounts for significant morbidity and is a leading cause of mortality in patients.

Objectives:

This study intends to study the frequency of occurrence of pulmonary involvement in progressive systemic sclerosis (PSS) and to describe the clinical and radiological picture of pulmonary involvement in PSS.

Materials and Methods:

This was a descriptive cross-sectional study. A detailed history, modified Rodnan score, clinical examination, routine investigation, antinuclear antibody, immuno biot, chest X-ray (CXR), pulmonary function test (PFT), and 6 min walk test (6MWT) were performed on all patients. High resolution computed tomography was done on those who consented.

Results:

Hundred subjects with PSS were included in the study; 90 were females and 10 were males. Common presenting complaints were skin thickening in 98% and Raynaud's phenomenon in 98%. Skin thickening of digits beyond metacarpo phalangeal was seen in 98%, face and neck in 92%, and hands in 92%. Chest wall thickening was seen in 40 subjects (40%). 90 (90%) of the studied subjects had pulmonary involvement, longer duration of disease was significantly associated with pulmonary involvement (P < 0.05). Dyspnea, cough, bilateral crepitations, CXR, Borg score, and Rodnan score was found to be significantly associated with severe pulmonary involvement (P < 0.05).

Conclusion:

The prevalence of pulmonary involvement in this cohort study was 90%. Almost 1/3^rd of patients, that is 29 (29%) were detected to have pulmonary involvement despite being asymptomatic for respiratory complaints, hence early screening and evaluation is recommended. PFT and 6MWT are noninvasive, cost-effective, and easily available screening tests which can be used in resource-limited settings.

Copy Number Variation of HLA-DQA1 and APOBEC3A/3B Contribute to the Susceptibility of Systemic Sclerosis in the Chinese Han Population

OBJECTIVE

Systemic sclerosis (SSc) is a systemic connective tissue disease caused by a genetic aberrant. The involvement of the copy number variations (CNV) in the pathogenesis of SSc is unclear. We tried to identify some CNV that are involved with the susceptibility to SSc.

METHODS

A genome-wide CNV screening was performed in 20 patients with SSc. Five SSc-associated common CNV that included HLA-DRB5, HLA-DQA1, IRGM, CDC42EP3, and APOBEC3A/3B were identified from the screening and were then validated in 365 patients with SSc and 369 matched healthy controls.

RESULTS

Three hundred forty-four CNV (140 gains and 204 losses) and 2 CNV hotspots (6q21.3 and 22q11.2) were found in the SSc genomes (covering 24.2 megabases), suggesting that CNV were ubiquitous in the SSc genome and played important roles in the pathogenesis of SSc. The high copy number of HLA-DQA1 was a significantly protective factor for SSc (OR 0.07, p = 2.99 × 10(-17)), while the high copy number of APOBEC3A/B was a significant risk factor (OR 3.45, p = 6.4 × 10(-18)), adjusted with sex and age. The risk prediction model based on genetic factors in logistic regression showed moderate prediction ability, with area under the curve = 0.80 (95% CI 0.77-0.83), which demonstrated that APOBEC3A/B and HLA-DQA1 were powerful biomarkers for SSc risk evaluation and contributed to the susceptibility to SSc.

CONCLUSION

CNV of HLA-DQA1 and APOBEC3A/B contribute to the susceptibility to SSc in a Chinese Han population.

Interpretation of an Extended Autoantibody Profile in a Well-Characterized Australian Systemic Sclerosis (Scleroderma) Cohort Using Principal Components Analysis

OBJECTIVE

To determine the relationships between systemic sclerosis (SSc)-related autoantibodies, as well as their clinical associations, in a well-characterized Australian patient cohort.

METHODS

Serum from 505 Australian SSc patients were analyzed with a commercial line immunoassay (EuroLine; Euroimmun) for autoantibodies to centromere proteins CENP-A and CENP-B, RNA polymerase III (RNAP III; epitopes 11 and 155), the 90-kd nucleolar protein NOR-90, fibrillarin, Th/To, PM/Scl-75, PM/Scl-100, Ku, topoisomerase I (topo I), tripartite motif-containing protein 21/Ro 52, and platelet-derived growth factor receptor. Patient subgroups were identified by hierarchical clustering of the first 2 dimensions of a principal components analysis of quantitative autoantibody scores. Results were compared with detailed clinical data.

RESULTS

A total of 449 of the 505 patients were positive for at least 1 autoantibody by immunoblotting. Heatmap visualization of autoantibody scores, along with principal components analysis clustering, demonstrated strong, mutually exclusive relationships between CENP, RNAP III, and topo I. Five patient clusters were identified: CENP, RNAP III strong, RNAP III weak, topo I, and other. Clinical features associated with CENP, RNAP III, and topo I were consistent with previously published reports concerning limited cutaneous and diffuse cutaneous SSc. A novel finding was the statistical separation of RNAP III into 2 clusters. Patients in the RNAP III strong cluster had an increased risk of gastric antral vascular ectasia, but a lower risk of esophageal dysmotility. Patients in the other cluster were more likely to be male and to have a history of smoking and a history of malignancy, but were less likely to have telangiectasia, Raynaud's phenomenon, and joint contractures.

CONCLUSION

Five major autoantibody clusters with specific clinical and serologic associations were identified in Australian SSc patients. Subclassification and disease stratification using autoantibodies may have clinical utility, particularly in early disease.

Association of the IRF5 SNP rs2004640 with systemic sclerosis in Han Chinese

Systemic sclerosis (SSc) is a complex disease involving multiple genetic factors. An association of the IRF5 polymorphism with SSc was reported in Caucasian populations of Europe and North America, as well as in Japanese populations. The present study aimed to examine whether the SSc-associated SNP rs2004640 of IRF5 gene confer susceptibility to SSc and clinical features of SSc in a Han Chinese population. A Han Chinese cohort consisting of 424 SSc patients and 502 healthy controls were examined in the study. TaqMan assays were carried out to examine the SNP. Exact p-values were obtained (Fisher’s test) from 2x2 tables of allele counts and disease status. SSc patients of Han Chinese showed increased homozygous TT genotype of the rs2004640 (p = 0.027, odds ratio (OR) = 1.4, CI =1.03-1.93), which was significantly associated with pulmonary fibrosis of SSc and ATA-positive SSc of Han Chinese. The lcSSc and ACA-positive SSc of Han Chinese appeared also in association with the increased T allele frequency. However, the Chinese dcSSc did not show any association with the rs2004640. The results were consistent with previous reports in other ethnic populations in supporting the notion that polymorphisms of IRF5 may play an important role in susceptibility to SSc.

Clinical differences between Thai systemic sclerosis patients with positive versus negative anti-topoisomerase I

BACKGROUND

Anti-topoisomerase I antibody (ATA) carries an increased risk of systemic sclerosis (SSc) internal organ involvement. There have been no published comparisons of the clinical characteristics of patients positive and negative for ATA in Thailand, where the positive rate for ATA is higher than among Caucasians.

OBJECTIVE

To define the clinical differences between SSc, positive versus negative, for ATA.

METHODS

A retrospective cohort study was performed among SSc patients over 18 at Srinagarind Hospital, Khon Kaen University, Thailand, during January 2006-December 2013. SSc-overlap syndrome was excluded.

RESULTS

Two hundred and ninety-four SSc patients were included (female : male 2.5 : 1). The majority (68.6%) were the diffuse cutaneous SSc subset (dcSSc). ATA was positive in 252 patients (85.7%), among whom 71.7% had dcSSc and 28.2% limited cutaneous SSc (lcSSc). Using a multivariate analysis, hand deformity had a significantly positive association with ATA (odds ratio [OR] 7.01; 95% CI 1.02-48.69), whereas being anti-centromere (ACA) positive had a negative association (OR 0.17; 95% CI 0.03-0.92). After doing a subgroup analysis of the SSc subset, the median duration of disease at time of pulmonary fibrosis detection among ATA positive dcSSc was significantly shorter than the ATA negative group (1.05 vs. 6.77 years, P = 0.01). Raynaud's phenomenon (RP) at onset was significantly more frequent in lcSSc sufferers who were ATA negative than those who were ATA positive (90.5% vs. 56.9%, P = 0.005).

CONCLUSIONS

A high prevalence of ATA positivity was found among Thai SSc patients and this was associated with a high frequency of hand deformity, ACA negativity, a short duration of pulmonary fibrosis in dcSSc and a lower frequency of RP in lcSSc.

Lack of Association of the CD247 SNP rs2056626 with Systemic Sclerosis in Han Chinese

Systemic sclerosis (SSc) is a complex disease involving multiple genetic factors. A recent genome-wide association study (GWAS) indicated that CD247 was strongly associated with SSc, which was subsequently confirmed in a SSc cohort of European population. However, genetic heterogeneity in different ethnic populations may significantly impact the complex trait of SSc. The studies herein aimed to examine whether the SSc-associated SNP rs2056626 of CD247 identified in Caucasian is also associated with Han Chinese SSc. A Han Chinese cohort consisting of 387 SSc patients and 523 healthy controls were examined in the studies. TaqMan assays were performed to examine the SNP. Exact p-values were obtained (Fisher’s test) from 2x2 tables of allele counts and disease status. The results showed that there was no association between rs2056626 of CD247 and SSc or any SSc subtypes of Han Chinese. The negative results are important in understanding genetics of SSc in different ethnic populations, which further suggest complex nature of genetics of SSc.

Association of the HLA-DRB1 with scleroderma in Chinese population

Multiple alleles of the Human leukocyte antigen (HLA) DRB1 have been strongly associated with systemic sclerosis (SSc) and its clinical or serological subsets. However, the associations vary in different ethnic populations. To define SSc-risk and/or -protective alleles of HLA-DRB1 in Chinese population, we studied a Han Chinese cohort containing 585 patients with SSc and 458 gender-matched, unrelated controls. The HLA-DRB1 genotyping was performed with sequence-based typing method. Exact p-values were obtained (Fisher’s test) from 2×2 tables of allele frequency and disease status. The major SSc-risk allele subtypes of HLA-DRB1 are the DRB1*15∶02 and *16∶02 in this Chinese cohort. Particularly, DRB1*15∶02 was most significantly associated with anti-centromere autoantibodies (ACA) positive, and DRB1*16∶02 with anti-topoisomerase I autoantibodies (ATA) positive patients. On the other hand, DRB1*01∶01 and *04∶06 were strong SSc-protective alleles in Chinese, especially in patients who were ACA positive and had diffuse cutaneous SSc (dcSSc), respectively. In addition, DRB1*11 and *07∶01 also showed significant association with SSc as a risk for and protection from SSc, respectively, and which is consistent with the studies of Spanish, US Caucasian and Hispanic populations. DRB1*15 was associated with ATA positive Chinese SSc that is consistent with Black South African and Korean SSc. These findings of HLA-DRB1 alleles in association with Chinese SSc provide the growing knowledge of genetics of SSc, and indicate that the genetic heterogeneity among ethnicities may significantly impact the complex trait of SSc.

Association of HLA-DQB1*0501 with scleroderma and its clinical features in Chinese population

Specific human leukocyte antigen (HLA) DQB1 alleles confer strong susceptibility to systemic sclerosis (SSc). However, the frequencies of specific DQB1 alleles and their associations with SSc vary according to ethnicity and clinical features of SSc. The aim of this study was to profile DQB1 alleles in a Chinese population and to identify specific DQB1 alleles in association with SSc of Han Chinese. A cohort containing 213 patients with SSc and 239 gender-matched and unrelated controls was examined in the study. The HLA-DQB1 genotyping was performed with sequence-based typing (SBT) method. Exact p-values were obtained (Fisher's test) from 2x2 tables of allele counts or allele carriers and disease status. Seventeen DQB1 alleles were found in the cohort. DQB1*03:03 was the most common allele in this cohort. DQB1*05:01 was significantly increased in SSc, and was strongly associated with anti-centromere autoantibodies (ACA). Compared with SSc in other ethnic populations, SSc patients of Han Chinese are distinct in association with DQB1*06:11, common in association with DQB1*05:01, but lack association with DQB1*03:01. In addition, DQB1*06:01 appeared more common in ATA-positive Chinese SSc, and marginally associated with pulmonary fibrosis, and an increased frequency of DQB1*03:03 was observed in anti-U1RNP-positive Chinese SSc patients.

Association of HLA-DPB1 with scleroderma and its clinical features in Chinese population

Human leukocyte antigen DPB1 was reported to contain singly nucleotide polymorphisms conferring the strongest susceptibility to systemic sclerosis in Korean population. However, associations of specific DPB1 alleles with SSc vary in different ethnic populations. The aim of this study was to profile DPB1 alleles in Chinese population and to identify specific DPB1 alleles in association with SSc and clinical and serological features of SSc in Han Chinese. A cohort containing 338 patients with SSc and 480 gender-matched and unrelated controls were examined in the study. The HLA-DPB1 genotyping was performed with sequence-based typing method. Exact p-values were obtained (Fisher's test) from 2×2 tables of allele counts or allele carriers and disease status. Thirty eight DPB1 alleles were found in the cohort. DPB1*05:01 was the most common allele in this cohort. DPB1*03:01 and *13:01 were significantly increased in SSc. DPB1*13:01 association had already been described in other ethnic populations, whereas DPB1*03:01 was specific to Han Chinese patients with SSc. In addition, comparisons between SSc subsets indicated that patients carrying DPB1*03:01 were more likely to develop pulmonary fibrosis, DPB1*04 carriers were increased in SSc patients with anti-centromere autoantibodies and in contrast, SSc patients with homozygous DPB1*05:01 showed an opposite association with marginal significance.

STAT4 is a genetic risk factor for systemic sclerosis in a Chinese population

Systemic sclerosis (SSc) is an immune-mediated and complex genetic disease. An association of single-nucleotide polymorphisms (SNPs) in the STAT4 gene with SSc has been reported in European Caucasians, North Americans and Japanese. We undertook the current study to examine whether the STAT4 SNPs are also associated with susceptibility to SSc and SSc subsets in a Han Chinese population. A total of 453 Han Chinese patients with SSc and 534 healthy controls were examined in the study. The SNPs rs7574865, rs10168266 and rs3821236 of the STAT4 gene were examined with SNP TaqMan assays. The T-allele carriers of rs7574865 and rs10168266 were strongly associated with the presence of anti-topoisomerase I (ATA) and pulmonary fibrosis in SSc patients, as well as with diffuse cutaneous SSc (dcSSc). The presence of anti-centromere (ACA) and limited cutaneous SSc (lcSSc) did not show significant association with any of the examined SNPs. The results were consistent with previous reports in other ethnic populations in supporting the notion that polymorphisms of STAT4 may play an important role in susceptibility to SSc. It also revealed different genetic aspects of SSc subsets in a Han Chinese population.