Anti-centromere Autoantibodies Research Articles

Prognostic value of anti-IFI16 autoantibodies in pulmonary arterial hypertension and mortality in patients with systemic sclerosis

ObjectivesTo determine the diagnostic value of anti-interferon gamma inducible protein 16 (IFI16) autoantibodies in systemic sclerosis (SSc) patients negative for all tested SSc-specific autoantibodies (SSc-seronegative patients) and to evaluate the clinical significance of these autoantibodies, whether isolated or in the presence of anti-centromere autoantibodies (ACA). MethodsOverall, 58 SSc-seronegative and 66 ACA-positive patients were included in the study. All patients were tested for anti-IFI16 autoantibodies by an in-house direct ELISA. Associations between clinical parameters and anti-IFI16 autoantibodies were analysed. ResultsOverall, 17.2% of SSc-seronegative and 39.4% of ACA-positive patients were positive for anti-IFI16 autoantibodies. Anti-IFI16 autoantibodies were found only in patients within the limited cutaneous SSc (lcSSc) subset. A positive association between anti-IFI16 positivity and isolated pulmonary arterial hypertension (PAH) was found (odds ratio [OR]=5.07; p=0.014) even after adjusting for ACA status (OR=4.99; p=0.019). Anti-IFI16-positive patients were found to have poorer overall survival than negative patients (p=0.032). Cumulative survival rates at 10, 20 and 30 years were 96.9%, 92.5% and 68.7% for anti-IFI16-positive patients vs. 98.8%, 97.0% and 90.3% for anti-IFI16-negative-patients, respectively. Anti-IFI16-positive patients also had worse overall survival than anti-IFI16-negative patients after adjusting for ACA status in the multivariate Cox analysis (hazard ratio [HR]=3.21; p=0.043). ConclusionAnti-IFI16 autoantibodies were associated with isolated PAH and poorer overall survival. Anti-IFI16 autoantibodies could be used as a supplementary marker of lcSSc in SSc-seronegative patients and for identifying ACA-positive patients with worse clinical outcome.

Specific Autoantibodies and Microvascular Damage Progression Assessed by Nailfold Videocapillaroscopy in Systemic Sclerosis: Are There Peculiar Associations? An Update.

Specific autoantibodies and nailfold videocapillaroscopy (NVC) findings are serum and morphological diagnostic hallmarks of systemic sclerosis (SSc) as well as useful biomarkers which stratify the microvascular progression and prognosis of patients. The aim of our narrative review is to provide an update and overview of the link between SSc-related autoantibodies, used in clinical practice, and microvascular damage, evaluated by NVC, by exploring the interaction between these players in published studies. A narrative review was conducted by searching relevant keywords related to this field in Pubmed, Medline and EULAR/ACR conference abstracts with a focus on the findings published in the last 5 years. Our search yielded 13 clinical studies and 10 pre-clinical studies. Most of the clinical studies (8/13, 61.5%) reported a significant association between SSc-related autoantibodies and NVC patterns: more specifically anti-centromere autoantibodies (ACA) were associated more often with an "Early" NVC pattern, whereas anti-topoisomerase autoantibodies (ATA) more frequently showed an "Active" or "Late" NVC pattern. Five studies, instead, did not find a significant association between specific autoantibodies and NVC findings. Among the pre-clinical studies, SSc-related autoantibodies showed different mechanisms of damage towards both endothelial cells, fibroblasts and smooth muscle vascular cells. The clinical and laboratory evidence on SSc-related autoantibodies and microvascular damage shows that these players are interconnected. Further clinical and demographic factors (e.g., age, sex, disease duration, treatment and comorbidities) might play an additional role in the SSc-related microvascular injury whose progression appears to be complex and multifactorial.

Comprehensive analysis of the major histocompatibility complex in systemic sclerosis identifies differential HLA associations by clinical and serological subtypes

ObjectiveThe greatest genetic effect reported for systemic sclerosis (SSc) lies in the major histocompatibility complex (MHC) locus. Leveraging the largest SSc genome-wide association study, we aimed to fine-map this region...

Proteomics characterization of CENP-B epitope in Moroccan scleroderma patients with anti-centromere autoantibodies

BackgroundAnti-centromere auto-antibodies (ACA) have been described as a marker in Systemic sclerosis (SSc) disease. CENP-B is the major centromere auto-antigen recognized by SSc patients with positive ACA. Our aim was to characterize the major epitope involved in the anti-CENP-B immune response of Moroccan SSc patients. Patients and methodFor identification of SSc biomarkers, 80 sera from patients with SSc and systemic lupus erythematosus (SLE) were screened by indirect immunofluorescence test (IIF) to assess the presence of ANA reactivity. Immunoblotting analysis was performed for 11 sera with positive ACA using the N-terminal and C-terminal region of CENP-B protein as antigens. Results29 out of 30 (96, 66 %) patients with SSc had positive ANA. 11 out of 30 (36, 67 %) patients were ACA positive and 6 of them produced auto-antibodies against Nt-CENPB antigen. Two of these 6 Nt-CENPB positive sera produced also other auto-antibodies associated to primary biliary cirrhosis. None of all sera tested showed reactivity against Ct-CENPB. ConclusionOur data showed, for the first time in Morocco, that the Nt-CENPB contains a major epitope for Moroccan SSc patients. These findings could provide additional information that would contribute to improving the diagnosis and management of these patients.

Systemic sclerosis in sub-Saharan Africa: a systematic review.

Systematic studies on connective tissue disorders are scarce in sub-Saharan Africa. Our aim was to analyse the published clinical data on systemic sclerosis (SSc) in sub-Saharan Africa. A systematic review was carried out in accordance with the PRISMA guidelines. We screened the Embase, PubMed and African Health Sciences databases for literature published until March 2018. Searches produced 1210 publications. After abstract and full-text screenings, 91 publications were analysed, and epidemiological information and clinical features extracted. Publications were mostly publications case reports (36%), cross-sectional studies (26%) and case series (23%) and came predominantly from South Africa (45%), Nigeria (15%) and Senegal (14%). A total of 1884 patients were reported, 66% of patients came from South Africa. The patients were between 4 and 77 years old; 83% of patients were female. Overall, 72% had diffuse SSc. Raynaud´s phenomenon was reported in 78% and skin ulcerations in 42% of patients. Focal skin hypopigmentation was common and telangiectasia not frequent. Interstitial lung involvement was reported in 50%, pulmonary hypertension in 30%, heart involvement in 28% of patients. Oesophageal reflux was observed in 70% and dysphagia in 37% of patients. Antinuclear antibodies were positive in 65% of patients. Anti-centromere autoantibodies (9.2%) and RNA polymerase 3 antibodies (7.1%) were rare and anti-fibrillarin most frequent (16.5%). SSc presentations in sub-Saharan Africa differ from those reported in Europe and America by a frequent diffuse skin involvement, focal skin hypopigmentation and a high prevalence of anti-fibrillarin autoantibodies.

Abstract IA22: Autoimmune rheumatic diseases and cancer

Abstract Some rheumatic disease autoantibodies are powerful markers of subgroups of patients who have distinct disease phenotypes and trajectories. Of particular interest are markers of several disease subgroups in whom cancer and rheumatic disease onset are clustered together in time. For example, a subgroup of scleroderma patients have coincident onset of cancer and scleroderma. This is observed in scleroderma patients with autoantibodies against RNA polymerase-3 (POLR3), and more recently with autoantibodies recognizing the minor spliceosome. In autoimmune myopathies, temporal clustering of diagnosis of cancer and myositis is associated with autoantibodies to NXP2 and components of the TIF1 complex. Interestingly, although the incidence of cancer is higher in patients with these autoantibodies, most patients with these autoantibodies do not manifest cancer, even with extended periods of follow-up. These observations provide an important opportunity to investigate the potential mechanisms which operate at the cancer-immune interface during development of rheumatic diseases. In cancers from anti-POLR3-positive scleroderma patients with a short scleroderma-cancer interval, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to POLR3 but not in eight patients without these antibodies. 3 antibody-positive patients had somatic mutations in POLR3A; 5 patients had loss of heterozygosity at the POLR3A locus. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations sparked cellular immunity and cross-reactive humoral immune responses. In a larger scleroderma cohort (>2300 patients), the incidence of cancer in various autoantibody subgroups was compared to data from the Surveillance, Epidemiology and End Results (SEER) Program. An increase in cancer incidence in scleroderma patients with POLR3 autoantibodies was observed compared to the general population; strikingly, patients with anti-centromere autoantibodies had a lower cancer incidence than observed in the general population. The finding that distinct serologic subgroups have different cancer risks suggests that cancer immunity may be a common principle across the scleroderma spectrum, with cancer emergence influenced by the effectiveness of the different immune responses. For example, in scleroderma patients with anti-centromere antibodies, cancer emergence may be inhibited, while inhibition of cancer emergence may only be partial for anti-POLR3. Prior studies in small cohorts of breast cancer patients have demonstrated that anti-centromere antibodies may be present, and may associate with improved disease-free and overall survival. Additionally, recent data also suggest that anti-DNA antibodies can have direct anti-cancer effects in cells with DNA repair defects, possibly explaining the decreased risk of breast and other cancers observed among patients with SLE.Taken together, these data suggest that at least some patients with autoimmune rheumatic diseases such as scleroderma may represent natural cancer immunoediting in humans. In the simplest model, somatic mutations in autoantigens in different cancers initiate an immune response to the mutated autoantigen, which spreads to include the wild type version, and exerts both an anti-cancer effect as well as causes damage or dysfunction of normal tissues. Understanding the mechanisms underlying the range of efficacies of the anti-cancer effects in different patients and subgroups may provide important insights into how the anti-cancer immune response in autoimmune diseases might be more effectively harnessed therapeutically. Citation Format: Livia Casciola-Rosen, Ami Shah, Antony Rosen. Autoimmune rheumatic diseases and cancer [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr IA22.

Evaluation of Anti-Centromere Antibodies, Anti-SSA and Anti-SSB in Serum and Saliva of Patients with Systemic Sclerosis

Background: Systemic sclerosis (SSc) is a chronic autoimmune illness, which is consider by three main features: Sclerotic changes in the skin and internal organs, Vasculopathy of small blood vessels, Particular autoantibodies (1). The most important autoantibodies appeared significantly in SSc patients are anti-topoisomerase I autoantibody (Scl-70), anti-centromere autoantibody (ACA), and anti-RNA polymerase III autoantibody (RNAP3) (2). Anti-centromere antibodies (ACA) are infrequent in rheumatic conditions and in healthy persons but occur commonly in limited systemic sclerosis (CREST syndrome), and rarely appeared in the diffuse form of systemic sclerosis (3). Anti-Ro/SSA and antiLa/SSB, antibodies directed against Ro/La ribonucleoprotein complexes, can serve as a diagnostic hallmark of autoimmune disease specially Sjogren’s syndrome (4). Materials and methods: This study was carried out during the period from the middle of November 2015 until the end of November 2016 in Baghdad city. The sample of this study was divided into two groups : Forty systemic sclerosis patients: Those patients were treated at Rheumatology department in Baghdad teaching hospital in Baghdad city as well as Forty healthy control subjects, age matched with no signs and symptoms of any systemic diseases. Results: The serum anti-SSA in SSc patient was significant increased as well as the salivary anti-SSA in SSc patient was highly significantly increased than in the control subjects by using t-test. The present study found that there no statically difference in salivary ACA, anti-SSB and serum anti-SSB while serum ACA was significantly increased. Conclusions: autoantibodies play a role in pathogenesis of SSc patients represented by increased serum (ACA and anti-SSA) that it considered reliable indicator for SSc patients while unpredicted marker in saliva except anti-SSA. Anti-La/SSB is unreliable marker in both serum and saliva SSc patients. The presence of Anti-Ro/SSA antibodies in serum and saliva of SSc patient has been predictive marker for SSc overlapped Sjogren’s syndrome.

Clinical Characteristics of Pruritus in Systemic Sclerosis Vary According to the Autoimmune Subtype.

Pruritus is a frequent symptom in systemic sclerosis (SSc), with a prevalence of 40-65%, but its pathophysiology is poorly understood. This study investigated the immunological component of pruritus. Fifty-six patients with SSc responded to a standardized questionnaire regarding both SSc disease and pruritus characteristics. Among patients with SSc, those with pruritus did not display a particular immunological profile (inflammatory, humoral, and/or cellular factors), but pruritus was, in most cases, concomitant with the development of SSc. Thus, pruritus characteristics were evaluated further, according to the detection of anti-centromere autoantibodies (ACA), into ACA+ (n = 17) and ACA- (n = 19). The ACA+ subgroup was characterized by a longer evolution of SSc and pruritus, pruritus present outside the sclerotic area, and a shorter daily duration of pruritus. In conclusion, the concomitant appearance of the 2 processes and the differences observed between ACA+ and ACA- subgroups support the presence of an immunological component in pruritus.

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.

Impact of anti-centromere antibodies on pulmonary function test results in patients with systemic sclerosis without established or suspected pulmonary disease.

Pulmonary arterial hypertension (PAH) occurs in approximately 15% of patients with systemic sclerosis (SSc). Annual screening with pulmonary function tests (PFT) is recommended to help identify those patients at risk of PAH. We have noted that patients with SSc who carry anti-centromere autoantibodies (ACA) often have PFT abnormalities, in the absence of clinical evidence of PAH. To evaluate this further, we undertook a retrospective case-control study evaluating PFT results in patients with SSc in whom pulmonary complications have neither been diagnosed nor suspected. Patients were divided according to ACA carriage and groups compared for PFT results. The median forced vital capacity (FVC) was higher in ACA-positive patients (106 vs. 93%, p=0.004). The gas transfer factor (TLco) was significantly lower in the ACA group (62.5 vs. 71%, p=0.013). The resulting FVC:TLco was significantly higher for ACA-positive vs. ACA-negative patients with SSc (1.70 vs. 1.29, p<0.001). Our findings suggest patients carrying ACA, without established or suspected pulmonary complications, have PFT abnormalities consistent with indolent increased pulmonary vascular resistance despite the majority of such patients not subsequently developing PAH. The long-term sequelae of PFT abnormalities in those patients with ACA who do not subsequently develop PAH are unknown.

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.

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.

AB0500 Treatment of digital ulcers in systemic sclerosis: a review of ten patients from a single center and discussion on outcome

BackgroundIn systemic sclerosis (SSc), digital ulcers (DU) are debilitating and sometimes recurrent complications. Treatment of DU is not dissociable from that of Raynaud’s phenomenon (RF), both express the same microvascular...

Genetic polymorphisms of FOXP3 in Italian patients with systemic sclerosis

A case control study to evaluate the possible influence of FOXP3 polymorphisms (rs3761548 and rs2280883) in the susceptibility of systemic sclerosis in an Italian Caucasian population. Subgroup analysis was also performed to test association between these SNPs and specific disease phenotypes. The study groups consisted of 467 individuals: 228 patients (194 with limited cutaneous form and 34 with diffuse cutaneous form of the disease) and 239 healthy control subjects. Genotyping was performed by high resolution melting analysis. Genotype distribution and allele frequency of the FOXP3 polymorphisms were analyzed statistically, using χ2 or Fisher exact test.Single-marker analysis of allelic and genotype frequencies revealed that SNP rs3761548 was not associated with systemic sclerosis susceptibility.Analysis of genotype and allele distributions of the rs2280883 genetic variant was associated, only in female subjects with systemic sclerosis, its limited subtype, and anti-centromere autoantibodies. Although these findings require replication in a larger set and other populations, FOXP3 rs2280883 may represent a novel susceptibility locus for systemic sclerosis in female subjects.

KCNA5 gene is not confirmed as a systemic sclerosis-related pulmonary arterial hypertension genetic susceptibility factor

IntroductionPotassium voltage-gated channel shaker-related subfamily member 5 (KCNA5) is implicated in vascular tone regulation, and its inhibition during hypoxia produces pulmonary vasoconstriction. Recently, a protective association of the KCNA5 locus with systemic sclerosis (SSc) patients with pulmonary arterial hypertension (PAH) was reported. Hence, the aim of this study was to replicate these findings in an independent multicenter Caucasian SSc cohort.MethodsThe 2,343 SSc cases (179 PAH positive, confirmed by right-heart catheterization) and 2,690 matched healthy controls from five European countries were included in this study. Rs10744676 single-nucleotide polymorphism (SNP) was genotyped by using a TaqMan SNP genotyping assay.ResultsIndividual population analyses of the selected KCNA5 genetic variant did not show significant association with SSc or any of the defined subsets (for example, limited cutaneous SSc, diffuse cutaneous SSc, anti-centromere autoantibody positive and anti-topoisomerase autoantibody positive). Furthermore, pooled analyses revealed no significant evidence of association with the disease or any of the subsets, not even the PAH-positive group. The comparison of PAH-positive patients with PAH-negative patients showed no significant differences among patients.ConclusionsOur data do not support an important role of KCNA5 as an SSc-susceptibility factor or as a PAH-development genetic marker for SSc patients.

The autoimmune disease-associated IL2RA locus is involved in the clinical manifestations of systemic sclerosis

Regulatory T cells (T(regs)) are crucial in the maintenance of the immune tolerance and seem to have an important role in systemic sclerosis (SSc). The interleukin 2 receptor α (IL2RA) is an important T(reg) marker, and polymorphisms of IL2RA gene are associated with a number of autoimmune diseases. Therefore, we aimed to investigate for the first time the association of the IL2RA locus in SSc. For this purpose, a total of 3023 SSc patients and 2735 matched healthy controls, from six European Caucasian cohorts, were genotyped for the IL2RA gene variants rs11594656, rs2104286 and rs12722495 using the TaqMan allelic discrimination technology. The overall meta-analysis reached statistical significance when the three polymorphisms were tested for association with SSc, the limited subtype (lcSSc) and anti-centromere auto-antibodies (ACAs). However, no significant P-values were obtained when the ACA-positive patients were removed from the SSc and lcSSc groups, suggesting that these associations rely on ACA positivity. The strongest association signal with ACA production was detected for rs2104286 (P(FDR)=2.07 × 10(-4), odds ratio=1.30 (1.14-1.47)). The associations of rs11594656 and rs12722495 were lost after conditioning to rs2104286, and allelic combination tests did not evidence a combined effect, indicating that rs2104286 best described the association between IL2RA and ACA presence in SSc.

Novel identification of the IRF7 region as an anticentromere autoantibody propensity locus in systemic sclerosis

ObjectiveSystemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are related chronic autoimmune diseases of complex aetiology in which the interferon (IFN) pathway plays a key role. Recent studies have reported...

Risk Factors and Prediction of Long-term Outcome in Primary Biliary Cirrhosis

The natural history of the disease varies greatly among individual patients with primary biliary cirrhosis (PBC). Some patients live long without any symptoms while other patients present jaundice and develop hepatic failure in early phases of the disease. Previous studies showed that the natural course of PBC is altered by the use of ursodeoxy cholic acid (UDCA). In this review we discuss variation in the natural course of the disease and it's alteration by UDCA, and risk factors that predict disease progression. Based on clinical observations, there are three types of clinical evolution in PBC: 1) minimal to slow progression over several years; 2) rapid progression to jaundice and hepatic failure, and 3) progression to portal hypertension without developing deep jaundice. Notably, based on our analyses accelerated progression to jaundice and liver failure are reflected by a sustained serologic presence of anti-gp210 antibodies whereas patients with portal hypertension in the absence of jaundice have anti-centromere autoantibodies. These observations highlight the clinical importance of antinuclear antibody analysis in patients with PBC.

Late-onset systemic sclerosis--a systematic survey of the EULAR scleroderma trials and research group database

The clinical course of SSc depends on subtype, organ involvement and age. Few data are reported on patients suffering from late-onset SSc. We analysed data from 8554 patients prospectively followed in the EULAR Scleroderma Trials and Research (EUSTAR) group database. Late-onset SSc was defined as onset of non-RP disease features at or beyond 75 years of age. Disease characteristics, clinical features, disease course and mortality were evaluated. A total of 123 patients with SSc onset at or beyond 75 years of age were identified. Compared with patients<75 years they had more frequently limited than diffuse SSc and a higher prevalence of anti-centromere autoantibodies. Fewer old patients had digital ulcers. The modified Rodnan's skin score, the prevalence of lung fibrosis and renal crisis did not differ significantly between groups. Pulmonary hypertension (PH) measured by echocardiography was more prevalent in the late-onset group, as well as arterial hypertension and diastolic dysfunction. Late-onset SSc remained a positive predictor for PH in multivariate analyses. No significant difference of the two groups in skin score or diffusion capacity was observed during follow-up. Mortality due to SSc was higher in the late-onset group, but the survival time from diagnosis was longer compared with the younger patients. Late-onset SSc shows a distinct clinical presentation and outcome. Patients with late-onset SSc suffer more frequently from the limited subtype and PH, but fewer patients have digital ulcers. PH may in part be determined by underlying cardiovascular disease.

HLA–DPB1 and DPB2 are genetic loci for systemic sclerosis: A genome‐wide association study in Koreans with replication in North Americans

To identify systemic sclerosis (SSc) susceptibility loci via a genome-wide association study. A genome-wide association study was performed in 137 patients with SSc and 564 controls from Korea using the Affymetrix Human SNP Array 5.0. After fine-mapping studies, the results were replicated in 1,107 SSc patients and 2,747 controls from a US Caucasian population. The single-nucleotide polymorphisms (SNPs) (rs3128930, rs7763822, rs7764491, rs3117230, and rs3128965) of HLA-DPB1 and DPB2 on chromosome 6 formed a distinctive peak with log P values for association with SSc susceptibility (P=8.16x10(-13)). Subtyping analysis of HLA-DPB1 showed that DPB1*1301 (P=7.61x10(-8)) and DPB1*0901 (P=2.55x10(-5)) were the subtypes most susceptible to SSc in Korean subjects. In US Caucasians, 2 pairs of SNPs, rs7763822/rs7764491 and rs3117230/rs3128965, showed strong association with SSc patients who had either circulating anti-DNA topoisomerase I (P=7.58x10(-17)/4.84x10(-16)) or anticentromere autoantibodies (P=1.12x10(-3)/3.2x10(-5)), respectively. The results of our genome-wide association study in Korean subjects indicate that the region of HLA-DPB1 and DPB2 contains the loci most susceptible to SSc in a Korean population. The confirmatory studies in US Caucasians indicate that specific SNPs of HLA-DPB1 and/or DPB2 are strongly associated with US Caucasian patients with SSc who are positive for anti-DNA topoisomerase I or anticentromere autoantibodies.