Reporting and Representativeness of Race, Ethnicity, and Socioeconomic Status in Systemic Sclerosis Randomized Trials: An Observational Study

OBJECTIVE

To assess how and to what extent socioeconomic status and ethnicity/race of participants are reported in randomized controlled trials (RCTs) on systemic sclerosis (SSc), and to estimate the representativeness of different ethnic/racial groups in SSc RCTs.

METHODS

We searched all published RCTs on SSc indexed in PubMed. We retrieved information on main features of RCTs published from 2000 onward and recorded for each study whether race/ethnicity was reported; how ethnicity/race was defined and assigned; and the number of patients included for each racial/ethnic group. Multivariable logistic regression was used to identify factors associated with race/ethnicity reporting. Proportion of races/ethnicities included in US-based RCTs on SSc was examined and compared with US demographic data.

RESULTS

We included 106 studies, mostly conducted in Europe (42%) or North America (25%), published after 2010 (74%), and enrolling a total of 6,693 patients. About one-third of studies provided information about race/ethnicity, with no improved reporting over time. Only 2 papers reported patient's socioeconomic status. Study location (US or intercontinental) was the only significant factor associated with a better reporting of race/ethnicity in multivariable analysis. In studies where race/ethnicity was reported, White patients were mostly represented (79%), followed by Asian (7%), and African American (6%). In the sensitivity analysis limited to studies from the US, underrepresentation of African American patients was observed in the 2000-2010 time period, but not later.

CONCLUSION

Documentation of race/ethnicity and socioeconomic status is poor in RCTs on SSc. More effort should be made to document race/ethnicity and socioeconomic status and to promote diversity in SSc RCTs.

Trends in Systemic Sclerosis Mortality Over Forty-Eight Years, 1968-2015: A US Population-Based Study

OBJECTIVE

To identify secular trends associated with systemic sclerosis (SSc) mortality over a 48-year period.

METHODS

Using national mortality data compiled by the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research, and population data from the US Census Bureau, we calculated an age-standardized mortality rate (ASMR) for SSc and non-SSc (all other causes), and we also calculated the ratio of the SSc ASMR to the non-SSc ASMR for each year from 1968 to 2015. We then used a joinpoint regression model to evaluate mortality trends overall and by sex and race.

RESULTS

From 1968 to 2015, there were 46,798 deaths with SSc recorded as the "underlying" cause of death and 106,058,839 non-SSc deaths. There were an additional 9,063 deaths with SSc recorded as a "contributing" cause of death from 1999 to 2015. Whereas the non-SSc ASMR decreased throughout the 48-year time period, the SSc ASMR increased from 1968 to 2000, followed by decreases each year from 2001 to 2015. The SSc ASMR also decreased for deaths where SSc was a contributing cause from 1999 to 2015. Women and Black persons had higher SSc ASMRs and SSc ASMR to non-SSc ASMR ratios than men and White persons, respectively. Additionally, SSc ASMRs and SSc ASMR to non-SSc ASMR ratios increased at higher rates in women and White persons than in men and Black persons, respectively, during the initial three decades.

CONCLUSION

Mortality attributable to SSc increased from 1968 to 2000, followed by a steady decline from 2001 to 2015. However, SSc mortality relative to non-SSc mortality remains high. SSc mortality has disproportionately changed by sex and race over the 48-year period assessed in the present study.

Analysis of the genetic component of systemic sclerosis in Iranian and Turkish populations through a genome-wide association study

Objectives

SSc is an autoimmune disease characterized by alteration of the immune response, vasculopathy and fibrosis. Most genetic studies on SSc have been performed in European-ancestry populations. The aim of this study was to analyse the genetic component of SSc in Middle Eastern patients from Iran and Turkey through a genome-wide association study.

Methods

This study analysed data from a total of 834 patients diagnosed with SSc and 1455 healthy controls from Iran and Turkey. DNA was genotyped using high-throughput genotyping platforms. The data generated were imputed using the Michigan Imputation Server, and the Haplotype Reference Consortium as a reference panel. A meta-analysis combining both case-control sets was conducted by the inverse variance method.

Results

The highest peak of association belonged to the HLA region in both the Iranian and Turkish populations. Strong and independent associations between the classical alleles HLA-DRB1*11: 04 [P = 2.10 × 10-24, odds ratio (OR) = 3.14] and DPB1*13: 01 (P = 5.37 × 10-14, OR = 5.75) and SSc were observed in the Iranian population. HLA-DRB1*11: 04 (P = 4.90 × 10-11, OR = 2.93) was the only independent signal associated in the Turkish cohort. An omnibus test yielded HLA-DRB1 58 and HLA-DPB1 76 as relevant amino acid positions for this disease. Concerning the meta-analysis, we also identified two associations close to the genome-wide significance level outside the HLA region, corresponding to IRF5-TNPO3 rs17424921-C (P = 1.34 × 10-7, OR = 1.68) and NFKB1 rs4648133-C (P = 3.11 × 10-7, OR = 1.47).

Conclusion

We identified significant associations in the HLA region and suggestive associations in IRF5-TNPO3 and NFKB1 loci in Iranian and Turkish patients affected by SSc through a genome-wide association study and an extensive HLA analysis.

Association between the functional PTPN22 G788A (R263Q) polymorphism and susceptibility to autoimmune diseases: A meta-analysis

This study explored whether the functional protein tyrosine phosphatase nonreceptor 22 (PTPN22) G788A (R263Q) polymorphism is associated with susceptibility to autoimmune diseases. A meta-analysis was conducted using 23 comparative studies with a total of 16,719 patients and 17,783 controls. The meta-analysis showed an association between the A allele of the PTPN22 G788A polymorphism and decreased risk of autoimmune diseases in all subjects (p < 0.001). Analysis after stratification by ethnicity indicated that the PTPN22 788A allele was significantly associated with autoimmune diseases in Europeans (p < 0.001) but not in Latin Americans. Meta-analysis by autoimmune disease type showed a significant negative association between the PTPN22 788A allele and systemic lupus erythematous (SLE) (p = 001), rheumatoid arthritis (RA) (p = 0.008), ulcerative colitis (UC) (p = 0.016), but not Crohn's disease (CD). A single study for each showed no association between the PTPN22 788A allele and systemic sclerosis, giant cell arteritis, Henoch-schonlein purpura, uveitis, and Grave's disease. This meta-analysis demonstrates that the PTPN22 G788A polymorphism confers protection against SLE, RA, and UC, supporting evidence of association of the PTPN22 gene with a subgroup of autoimmune diseases.

Clinical and serological features of systemic sclerosis in a multicenter African American cohort: Analysis of the genome research in African American scleroderma patients clinical database

Racial differences exist in the severity of systemic sclerosis (SSc). To enhance our knowledge about SSc in African Americans, we established a comprehensive clinical database from the largest multicenter cohort of African American SSc patients assembled to date (the Genome Research in African American Scleroderma Patients (GRASP) cohort).African American SSc patients were enrolled retrospectively and prospectively over a 30-year period (1987-2016), from 18 academic centers throughout the United States. The cross-sectional prevalence of sociodemographic, clinical, and serological features was evaluated. Factors associated with clinically significant manifestations of SSc were assessed using multivariate logistic regression analyses.The study population included a total of 1009 African American SSc patients, comprised of 84% women. In total, 945 (94%) patients met the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for SSc, with the remaining 64 (6%) meeting the 1980 ACR or CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) criteria. While 43% were actively employed, 33% required disability support. The majority (57%) had the more severe diffuse subtype and a young age at symptom onset (39.1 ± 13.7 years), in marked contrast to that reported in cohorts of predominantly European ancestry. Also, 1 in 10 patients had a severe Medsger cardiac score of 4. Pulmonary fibrosis evident on computed tomography (CT) chest was present in 43% of patients and was significantly associated with anti-topoisomerase I positivity. 38% of patients with CT evidence of pulmonary fibrosis had a severe restrictive ventilator defect, forced vital capacity (FVC) ≤50% predicted. A significant association was noted between longer disease duration and higher odds of pulmonary hypertension, telangiectasia, and calcinosis. The prevalence of potentially fatal scleroderma renal crisis was 7%, 3.5 times higher than the 2% prevalence reported in the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) cohort.Our study emphasizes the unique and severe disease burden of SSc in African Americans compared to those of European ancestry.

African American race associated with body image dissatisfaction among patients with systemic sclerosis

OBJECTIVES

Studies have shown a high degree of body image dissatisfaction among patients with systemic sclerosis (SSc). We aimed to identify demographic and phenotypic characteristics that correlate with body image dissatisfaction.

METHODS

Ninety-eight patients with SSc were recruited from Georgetown University Medical Center 2003-2004. Anonymous surveys collected demographic information (age, race, gender, duration/type of SSc) and assessed degree of body image dissatisfaction on a scale of 0-3 in relation to phenotypic features of SSc (hand contractures, finger ulcers, pigmentation changes, lip wrinkling/thinning, telangiectasias). A composite total distress score was derived. Parametric and nonparametric T tests were used to compare groups.

RESULTS

Of 98 patients, 86 were female and 12 male. The majority of patients were 30-60 years old. The sample was 62% Caucasian, 27% African American, and the rest identified as "other". Twenty-seven percent had limited SSc, 48% diffuse, and 25% "other". African American patients had greater total body image dissatisfaction (p=0.002), specifically with respect to digital ulcers, pruritus, and pigmentation changes, than Caucasian participants. Patients with diffuse SSc had greater body image dissatisfaction than those with limited disease (p=0.002).

CONCLUSIONS

Our results suggest that African American patients with SSc and those with diffuse subtype suffer a higher degree of body image dissatisfaction. Screening for and addressing this issue in SSc patients is prudent. Further study is needed to understand racial differences in body image dissatisfaction among patients with SSc.

Examination of the association of sex and race/ethnicity with appearance concerns: a Scleroderma Patient-centered Intervention Network (SPIN) Cohort study

OBJECTIVES

Appearance concerns are common in systemic sclerosis (SSc) and have been linked to younger age and more severe disease. No study has examined their association with sex or race/ethnicity.

METHODS

SSc patients were sampled from the Scleroderma Patient-centered Intervention Network Cohort. Presence of appearance concerns was assessed with a single item, and medical and sociodemographic information were collected.

RESULTS

Of 644 patients, appearance concerns were present in 72%, including 421 of 565 women (75%), 42 of 79 men (53%), 392 of 550 patients who identified as White (71%), 35 of 41 who identified as Black (85%), and 36 of 53 who identified as another race/ethnicity (68%). In multivariate analysis, women had significantly greater odds of reporting appearance concerns than men (odds ratio (OR)=2.97, 95% confidence interval (CI)=1.78-4.95, p<.001). Black patients had significantly greater odds of appearance concerns than White patients in unadjusted (OR=2.64, 95% CI=1.01-6.34, p=.030), but not multivariate analysis (OR=1.76, 95% CI=0.67-4.60, p=.250). Compared to a general population sample, appearance concerns were substantially more common in SSc, particularly for men across all age groups and for younger women. The most commonly reported features of concern were related to the face and head, followed by the hands and fingers; this did not differ by sex or race/ethnicity.

CONCLUSIONS

Appearance concerns were common in SSc. Women were substantially more likely than men to have appearance concerns. Although non-significant in multivariate analysis, Black patients were more likely to have concerns than White patients, likely due to more severe changes in appearance.

A candidate gene study identifies a haplotype of CD2 as novel susceptibility factor for systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is a rare autoimmune disease (AID) with a complex genetic etiology. Evidence for a shared pathogenesis across AIDs is given by the well-known pleiotropism of autoimmune genes. Recently, several unbiased approaches have identified an association between polymorphisms of the CD2 gene, and rheumatoid arthritis (RA) susceptibility. The objective of this study was to investigate whether CD2 polymorphisms are associated with SSc.

METHODS

Two SNPs of CD2, rs624988 and rs798036, were genotyped in a total of 1,786 SSc patients and 2,360 healthy individuals from two European populations (France and Italy). Meta-analyses were performed to assess whether an association exists between CD2 polymorphisms or haplotypes and SSc or its main subtypes.

RESULTS

The combined analyses revealed an association between the rs624988 A allele and SSc susceptibility: padj=0.023, OR=1.14 (95%CI 1.04-1.25). Single marker analysis did not reveal any association between rs798036 and SSc. Haplotype analysis identified that the A-T haplotype, previously described in RA, was associated with higher susceptibility for SSc (padj=0.029, OR=1.14, 95%CI 1.04-1.25) and with the positive anti-centromere antibody sub-group of SSc patients (padj=0.009, OR=1.19 95%CI 1.07-1.32). Genotype-mRNA expression correlations revealed that the CD2 risk haplotype was associated with decreased CD2 mRNA expression in SSc patients.

CONCLUSIONS

Our study establishes CD2 as a new susceptibility factor for SSc, in a European Caucasian population, confirming the sharing of autoimmune risk factors by SSc and RA.

Confirmation of CCR6 as a risk factor for anti-topoisomerase I antibodies in systemic sclerosis

OBJECTIVES

The current knowledge of the influence of systemic sclerosis (SSc) risk loci in the clinical sub-phenotypes is still limited. The main limitation lies in the low frequency of some sub-phenotypes which could be solved by replication studies in independent cohorts and meta-analysis between studies. In this regard, CCR6 gene variants have been recently associated with anti-topoisomerase I positive (ATA+) production in SSc patients in a candidate gene study. This gene has been proposed to have a critical role in IL-17-driven autoimmunity in human diseases.

METHODS

In order to confirm the association between CCR6 and ATA+ SSc patients, we performed an independent replication study in populations of European ancestry. We studied two CCR6 genetic variants (rs968334 and rs3093024) in a total of 901 ATA+ SSc cases, 3,258 ATA- SSc cases and 7,865 healthy controls and compared allelic frequencies for those SNPs in ATA+ SSc with healthy controls and also with ATA- SSc patients.

RESULTS

The comparison performed between ATA+ SSc patients and healthy controls showed significant association with SNP rs968334 (p=4.88x10(-2), OR=1.11). When we compared ATA+ SSc cases with ATA- SSc, both SNPs, rs3093024 and rs968334, showed significant associations (p=2.89x10(-2), OR=1.13; p=1.69x10(-2), OR=1.15). Finally, in order to increase even more sample size and statistical power, we meta-analysed our study with the previous reported and found a significant association between SNP rs3093024 and ATA+ SSc patients (p=1.00x10(-4), OR=1.16) comparing with healthy controls.

CONCLUSIONS

Our work confirms the association of CCR6 gene and ATA+ SSc patients.

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.

Severity of systemic sclerosis-associated pulmonary arterial hypertension in African Americans

African Americans (AA) with systemic sclerosis (SSc) have a worse prognosis compared to Americans of European descent (EA). We conducted the current study to test the hypothesis that AA patients with SSc have more severe disease and poorer outcomes compared to EA patients when afflicted with pulmonary arterial hypertension (PAH). We studied 160 consecutive SSc patients with PAH diagnosed by right heart catheterization, comparing demographics, hemodynamics, and outcomes between AA and EA patients. The cohort included 29 AA and 131 EA patients with similar baseline characteristics except for increased prevalence of diffuse SSc in AA. AA patients had worse functional class (FC) (80% FC III-IV vs 53%; p = 0.02), higher brain natriuretic peptide (NT-pro-BNP) (5729 ± 9730 pg/mL vs 1892 ± 2417 pg/mL; p = 0.02), more depressed right ventricular function, a trend toward lower 6-minute walk distance (263 ± 111  m vs 333 ± 110  m; p = 0.07), and worse hemodynamics (cardiac index 1.95 ± 0.58 L/min/m vs 2.62 ± 0.80 L/min/m; pulmonary vascular resistance 10.3 ± 6.2 WU vs 7.6 ± 5.0 WU; p  < 0.05) compared with EA patients. Kaplan-Meier survival estimates for AA and EA patients, respectively, were 62% vs 73% at 2 years and 26% vs 44% at 5 years (p  > 0.05). In conclusion, AA patients with SSc-PAH are more likely to have diffuse SSc and to present with significantly more severe PAH compared with EA patients. AA patients also appear to have poorer survival, though larger studies are needed to investigate this association definitively.

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.

Race and association with disease manifestations and mortality in scleroderma: a 20-year experience at the Johns Hopkins Scleroderma Center and review of the literature

Experience suggests that African Americans may express autoimmune disease differently than other racial groups. In the context of systemic sclerosis (scleroderma), we sought to determine whether race was related to a more adverse expression of disease. Between January 1, 1990, and December 31, 2009, a total of 409 African American and 1808 white patients with scleroderma were evaluated at a single university medical center. While the distribution by sex was virtually identical in both groups, at 82% female, African American patients presented to the center at a younger mean age than white patients (47 vs. 53 yr; p < 0.001). Two-thirds of white patients manifested the limited cutaneous subset of disease, whereas the majority of African American patients manifested the diffuse cutaneous subset (p < 0.001). The proportion seropositive for anticentromere antibody was nearly 3-fold greater among white patients, at 34%, compared to African American patients (12%; p < 0.001). Nearly a third of African American (31%) patients had autoantibodies to topoisomerase, compared to 19% of white patients (p = 0.001). Notably, African American patients experienced an increase in prevalence of cardiac (adjusted odds ratio [OR], 1.6; 95% confidence interval [CI], 1.3-2.2), renal (OR, 1.6; 95% CI, 1.2-2.1), digital ischemia (OR, 1.5; 95% CI, 1.4-2.2), muscle (OR, 1.7; 95% CI, 1.3-2.3), and restrictive lung (OR, 6.9; 95% CI, 5.1-9.4) disease. Overall, 700 (32%) patients died (159 African American; 541 white). The cumulative incidence of mortality at 10 years was 43% among African American patients compared to 35% among white patients (log-rank p = 0.0011). Compared to white patients, African American patients experienced an 80% increase in risk of mortality (relative risk [RR], 1.8; 95% CI, 1.4-2.2), after adjustment for age at disease onset and disease duration. Further adjustment by sex, disease subtype, and scleroderma-specific autoantibody status, and for the socioeconomic measures of educational attainment and health insurance status, diminished these risk estimates (RR, 1.3; 95% CI, 1.0-1.6). The heightened risk of mortality persisted in strata defined by age at disease onset, diffuse cutaneous disease, anticentromere seropositivity, decade of care at the center, and among women. These findings support the notion that race is related to a distinct phenotypic profile in scleroderma, and a more unfavorable prognosis among African Americans, warranting heightened diagnostic evaluation and vigilant care of these patients. Further, we provide a chronologic review of the literature regarding race, organ system involvement, and mortality in scleroderma; we furnish synopses of relevant reports, and summarize findings.

Clinical and serological features of systemic sclerosis in a Chinese cohort

Our goal was to study the prevalence of systemic sclerosis (SSc) subtypes, autoantibody profile, and pulmonary fibrosis in a large group of Han Chinese. Chinese SSc patients (n = 419) were recruited from a multicenter study including hospitals and outpatient clinics in China. All patients met the American College of Rheumatology classification criteria for SSc. Anti-topoisomerase (ATA), anti-centromere (ACA), anti-RNA polymerase III (anti-RNAP3), and anti-U1-ribonucleoprotein (anti-U1RNP) were detected utilizing commercially available kits. The clinical and autoantibody information in Chinese patients was compared to that in the US Caucasian patients (n = 834), recruited from the Genetics versus Environment in Scleroderma Outcome Study and Scleroderma Family Registry. Chi-square test was utilized for the abovementioned comparisons. Chinese patients showed 40.3 % limited (lcSSc) and 59.7 % diffuse (dcSSc) forms of SSc. ATA was found in 59.9 %, ACA in 13.4 %, anti-RNAP3 in 1.3 %, and anti-U1RNP in 18 % of Chinese SSc patients. Compared to US patients (65.1 % lcSSc, 34.9 % dcSSc, ATA in 18.7 %, ACA in 32.4 %, anti-RNAP3 in 17.4 %, and anti-U1RNP in 2.8 %), Chinese SSc patients are significantly higher in dcSSc and the frequencies of ATA and anti-U1RNP, but lower in ACA and anti-RNAP3. In addition, pulmonary fibrosis was observed in 78 % Chinese SSc patients and was strongly associated with the presence of ATA. The present study represents the first report of SSc features in a large group of Chinese patients. Clinical subtypes and the frequencies of SSc-related autoantibodies in Chinese SSc patients are significantly different from those in SSc patients of the US Caucasian descent.

Prevalence and clinical importance of gastroesophageal reflux in Chinese patients with systemic sclerosis

OBJECTIVES

To estimate the prevalence of gastroesophageal reflux (GER) and its clinical relevance with other manifestations in Chinese patients with systemic sclerosis (SSc).

METHODS

A prospective cross-sectional study of 205 Chinese patients with SSc was conducted at Peking Union Medical College Hospital (PUMCH). GER was diagnosed as mild heartburn or regurgitation ≥2 days per week, or moderate/severe heartburn or regurgitation ≥1 day a week. PAH was defined as pulmonary artery systolic pressure (PASP) >45mmHg at rest as estimated by transthoracic echocardiography (TTE). Demographic, clinical, and laboratory data were calculated between GER and non-GER groups, and relative examinations including a six-minute walk test, pulmonary function test and modified Rodnan skin score (mRSS) were also performed.

RESULTS

The prevalence of GER was 43.90% (90/205) among 205 Chinese patients with SSc. The presence of Raynaud phenomenon (98.9% vs. 92.2%), fingertip ulcers (56.7% vs. 51.3%), pulmonary arterial hypertension (PAH) (18.89% vs. 6.96%, respectively), and all gastrointestinal tract manifestations occurred significantly more frequent in patients with GER than in patients without GER, respectively (p<0.05). There were no differences in the development of any autoantibody between GER patients and non-GER patients (p>0.05). Echocardiography showed that the left ventricular ejection fraction (LVEF) was lower (62.27±10.48 vs. 70.09±5.26, respectively) and pericarditis was more frequent (22.6% vs. 11.0%, respectively) in SSc-related GER than in SSc patients without GER, respectively. The New York Heart Association (NYHA) functional class of SSc-related GER was worse than patients without GER (p=0.015). A pulmonary function test showed that forced vital capacity FVC% (78.93±17.90 vs. 84.55±17.45, respectively, p=0.042), forced expiratory volume FEV1% (77.12±15.65 vs. 84.30±16.25, respectively, p=0.004), and diffusing capacity DLCO% (4.76±1.76 vs. 5.63±2.12, respectively, p<0.001) were lower, and the FVC%/DLCO% ratio (1.46±0.42 vs. 1.28±0.27, respectively, p=0.001)was higher in SSc-related GER than non-GER patients (p<0.05). We also found that GER was an independent risk factor of PAH in SSc patients (p=0.030, OR=7.532).

CONCLUSIONS

GER is common in Chinese patients with SSc, and patients with GER are susceptible to microvascular damage. Therefore, SSc patients presenting with GER should be screened for PAH.

Association study of B-cell marker gene polymorphisms in European Caucasian patients with systemic sclerosis

BACKGROUND

BANK1 and BLK B-cell genetic markers have been reproducibly and convincingly found to contribute to susceptibility to systemic sclerosis (SSc).

OBJECTIVES

To determine whether other B-cell genetic markers including CD19, CD20, CD22 and CD24 polymorphisms affect susceptibility to SSc in the European Caucasian population.

METHODS

A case-control study was performed in 900 patients with SSc and 1034 healthy controls. Among the whole SSc population, 304 (34%) had the diffuse cutaneous subtype, 551 (61%) had the limited cutaneous subtype, 732 (81%) were positive for antinuclear antibodies , 331 (37%) were positive for anticentromere antibodies and 228 (25%) for the topo-isomerase I. Genotyping has been performed for CD19 rs35979293, CD19 rs2904880, CD20 rs7126354, CD20 rs3802954, CD20 rs105146, CD20 rs4939364, CD22 rs10406069, CD22 rs10413500, CD22 rs10419538, CD22 rs34826052 and CD24 ins-del polymorphisms.

RESULTS

Genotype frequencies were at the Hardy-Weinberg equilibrium in the control population for all the SNPs investigated and observed frequencies were very similar to those expected in the European population. Allelic and genotypic frequencies for all these tested SNPs were found to be similar in SSc patients and controls. Moreover, subphenotype analyses in particular for subgroups having the diffuse cutaneous subset or topo-isomerase I positive antibodies, which are the most associated with BANK1 variants, did not detect any difference between SSc patients and controls.

CONCLUSIONS

These results obtained through a large cohort of European caucasian patients with SSc do not support the contribution of CD19, CD20, CD22, CD24 variants to the genetic susceptibility of SSc.

Adenosine A2A receptor polymorphisms in Korean patients with systemic sclerosis

Adenosine A2A receptor (ADORA2A) regulates inflammation, promotes tissue repair and collagen production by human dermal fibroblasts. We investigated the genetic polymorphisms of ADORA2A in susceptibility to systemic sclerosis (SSc). We genotyped 142 Korean SSc patients and 150 controls for polymorphisms of -1751A/C (rs5996696) and 1976C/T (rs5751876), to cover the promoter and all exon sequences of ADORA2A in Koreans, using TaqMan fluorogenic 5' nuclease assay and single base primer extension assay. Neither -1751A/C nor 1976C/T polymorphism showed difference in the distribution of alleles or genotypes between patients and controls with allele frequency of 89.9% v 91.0% for -1751A (p=0.64) and 56.5% v 54.0% for 1976C (p=0.55). Our findings suggest that the role of ADORA2A in SSc may not be genetically related.

Clinical and sociodemographic features of Puerto Ricans with systemic sclerosis

INTRODUCTION

Systemic sclerosis is an autoimmune disease of unknown etiology characterized by fibrotic changes in the skin, blood vessels, and various internal organs. The disease has a wide spectrum of presentation and a variable clinical course that includes limited skin involvement to life-threatening disease. Clinical manifestations and disease severity differs among ethnic groups. The objective of this study is to describe the clinical and sociodemographic features of patients with well-characterized systemic sclerosis from Puerto Rico.

METHODS

A structured questionnaire was completed for each patient to gather information about demographic factors, clinical manifestations, laboratory findings, diagnostic studies, and pharmacologic treatments.

RESULTS

Of the 24 patients with systemic sclerosis, 96% were females, 83% had Raynaud's phenomenon, 67% had gastrointestinal involvement, 63% had skin hypopigmentation, 50% had digital pitting scars, 46% had arterial hypertension, 11% had pulmonary hypertension, and 4.8% had renal involvement. The overall median modified Rodnan skin score was 24.5 (inter-quartile range 16.0-31.3). Pulmonary function tests resulted in abnormal in 60% of 14 patients, of which 57% had restrictive lung disease (FVC < 70%) and 42.9% had decreased diffusion capacity. Serologically, 66.7% were positive for antinuclear antibody and 62.5% were positive for anti-centromere.

CONCLUSIONS

In this study, the predominant clinical features of Puerto Ricans with systemic sclerosis were gastrointestinal involvement, Raynaud's phenomenon, digital pitting scars, and lung disease. Patients had a moderate severity of skin disease. The presence of renal involvement and pulmonary hypertension were low in our group. No significant differences were found between systemic sclerosis disease subsets.

Characterizing systemic sclerosis in Northern California: focus on Asian and Hispanic patients

OBJECTIVE

Previous studies suggest that Asian and Hispanic patients with systemic sclerosis (SSc) may have more severe disease than their Caucasian counterparts. The purpose of this study is to compare the clinical features of a group of Asian, Hispanic, and Caucasian patients with SSc in Northern California.

METHODS

We performed a cross-sectional study of patients receiving care at Stanford University Medical Center, Palo Alto Veterans Affairs Hospital, Santa Clara Valley Medical Center and San Francisco General Hospital between 1996 and 2006. Patients included in the analyses fulfilled the American College of Rheumatology criteria for SSc and could be classified as Caucasian, Asian, or Hispanic. Analyses using Caucasians as the reference group were performed.

RESULTS

One hundred and ninety-nine patients met the criteria for SSc, and 165 of these patients were classified as Caucasian (47%), Asian (26%), or Hispanic (27%). Disease subtype did not differ significantly among the three groups. Asian patients were less likely to have digital ulcers (26% vs. 47%, p=0.02) or anemia (26% vs. 45%, p=0.04) than Caucasians, and Hispanic patients had a lower frequency of lung disease than Caucasians (48% vs. 67%, p=0.04), but there were no other significant differences in disease manifestations.

CONCLUSION

In our cohort of SSc patients living in Northern California, clinical manifestations in Asian and Hispanic patients did not differ substantially from Caucasians. Further research is necessary to confirm these results and to investigate gene-environment interactions which may affect the clinical expression of disease in different racial groups.

Anti-chromatin and anti-histone antibodies in Egyptian patients with systemic lupus erythematosus

There has been a renewed interest in anti-chromatin and anti-histone antibodies in the last few years. To assess the prevalence of anti-chromatin and anti-histone antibodies in patients with systematic lupus erythematosus (SLE) and to correlate serum levels of these antibodies with clinical features of the disease, the presence of anti-chromatin and anti-histone antibodies in 38 patients with SLE was investigated by an enzyme-linked immunosorbent assay (ELISA). To determine the specificity of these antibodies, 15 patients with rheumatoid arthritis, 15 patients with systemic sclerosis, and 15 normal controls were also tested. Sensitivity of anti-chromatin antibodies in SLE patients was 89.5% and specificity was 80.0%, while sensitivity of anti-histone antibodies was 92.1% and specificity was 82.2%. Significant associations were found between the levels of anti-chromatin antibodies and arthritis, malar rash, oral ulcer, pulmonary affection (P < 0.05) also, lupus nephritis (P < 0.01), and disease activity score as measured by SLE disease activity index (SLEDAI; P < 0.001). Significant association was found between anti-histone antibodies and fatigue (P < 0.05). The incidence of positive anti-chromatin and anti-histone antibodies was significantly higher than that of anti-dsDNA antibodies in early stage of the disease. We conclude that anti-chromatin and anti-histone antibodies are both sensitive and specific for SLE and could be a useful addition to the laboratory tests that can help in the diagnosis of SLE. Anti-chromatin antibodies seem to be a promising marker useful in early diagnosis and assessment of disease activity in SLE patients especially in patients who are negative for anti-dsDNA antibodies.

Polymorphic markers of the fibrillin-1 gene and systemic sclerosis in European Caucasian patients

OBJECTIVE

Evidence suggests that systemic sclerosis (SSc) belongs to the fibrillinopathic disorders. Significant associations have been found with the fibrillin-1 gene (FBN1) in Choctaw and Japanese populations. We investigated FBN1 polymorphisms in cohorts of European Caucasian patients.

METHODS

We investigated 6 FBN1 polymorphisms in 2 cohorts: one with 399 French subjects (243 SSc patients/156 matched healthy controls), another with 319 Italian subjects (266 SSc patients/153 matched healthy controls). The 6 FBN1 polymorphisms included one single-nucleotide polymorphism (SNP) in intron C to replicate its genetic association and 5 microsatellite markers (D15S1028 in the 5' region, intragenic MTS2 and MTS3, and D15S123 and D15S143 in the 3' region). Then we investigated the French cohort enlarged to 362 SSc patients/162 matched healthy controls for 5 tagging single nucleotide polymorphisms (tagSNP) that account for the common genetic diversity according to HapMap data. We used Arlequin, Cocaphase, Phase 2 software, and Fisher's exact test for statistical analyses.

RESULTS

All markers were in Hardy-Weinberg equilibrium. No association was detected between polymorphic markers and disease in either the French or Italian cohorts, even for specific phenotypes. No significant differences between patients and controls were detected for the 5 tagSNP.

CONCLUSION

In contrast with data from Choctaw and Japanese patients, no association was detected between the polymorphic markers of FBN1 and SSc in 2 European Caucasian populations. These discrepancies may be explained by ethnic specificities and heterogeneity associated with this multigenic disease.

Systemic sclerosis in an Afro-Caribbean population: a review of demographic and clinical features

OBJECTIVE

To assess the clinical and selected demographic features of patients with systemic sclerosis (SS) seen over a 10-year period at the Rheumatology service of the Queen Elizabeth Hospital, Barbados. To compare these data with what is known to obtain in other ethnic populations.

DESIGN AND METHODS

A chart review involving all patients who were found to have SS based on the American College of Rheumatology clinical criteria was conducted between 1996 and 2006.

RESULTS

Twenty-seven patients with SS were identified in this predominantly Afro-Caribbean population. The prevalent and incident cases numbered 10 and 17 respectively. Twenty-six of these patients were female and the mean age at diagnosis was 37.3 years. Diffuse cutaneous involvement was seen in 63% of cases and limited cutaneous involvement in 37%. The most common clinical features in descending order of frequency were Raynaud's phenomenon, gastroesophageal reflux, pigmentary skin changes, digital pitting/ulceration, telangiectasia and pulmonary disease.

CONCLUSION

In a predominantly Afro-Caribbean population, SS was uncommonly seen, had a marked female preponderance and an earlier age of onset than that seen in Caucasian populations. As expected, diffuse disease was the more common subtype and digital pitting, pigmentary skin changes, and pulmonary disease were amongst the most frequent clinical features. Telangiectasia were found more frequently than the literature suggests is typical for patients of African descent.

Ethnic disparities among patients with pulmonary hypertension associated with systemic sclerosis

OBJECTIVE

To examine a cohort of patients with systemic sclerosis (SSc) and pulmonary hypertension (PH) for ethnic disparities in clinical presentation, disease detection, or management.

METHODS

Encounters of patients with SSc seen at the Medical University of South Carolina were recorded in a computerized database from November 1997 through January 2004. Patients were evaluated for discrepancy in disease manifestation and treatment. Evaluation criteria included patient ethnicity (by self report), age, disease duration from onset of first non-Raynaud's symptom, presence or absence of PH, incidence of diastolic dysfunction and left ventricular hypertrophy among patients with PH, severity of interstitial lung disease, and treatment course.

RESULTS

African Americans were more likely than Caucasians to have diffuse cutaneous SSc (dcSSc) (69.9% vs 42.9%, p < 0.001) and they presented with PH (defined as right ventricular systolic pressure > 40 mm Hg by echocardiogram or mean pulmonary artery pressure > 25 mm Hg by right heart catheterization (RHC) at a younger age (60.9 yrs vs 49.0 yrs, p < 0.001). There were no ethnic disparities in time from onset of the first non-Raynaud's symptom to detection of PH, method of PH detection, or treatment modalities. Patients with PH were more likely to have diastolic dysfunction than those without PH (52.3% vs 35.9%, p = 0.011).

CONCLUSION

In this cohort of patients, African Americans were more likely to have dcSSc. Among patients with PH, African Americans presented at a younger age than their Caucasian counterparts. Incidence of diastolic dysfunction was higher in the PH population. There were no significant ethnic disparities in time of progression to PH or in treatment modalities employed in our cohort.

An allograft inflammatory factor 1 (AIF1) single nucleotide polymorphism (SNP) is associated with anticentromere antibody positive systemic sclerosis

OBJECTIVE

To identify genetic associations between allograft inflammatory factor 1 (AIF1) and systemic sclerosis (SSc), or its subsets, using a single nucleotide polymorphism (SNP) in a replicate case-control study.

METHODS

The frequencies of alleles and genotypes of an SNP, rs2269475, for the AIF1 gene were examined in two large independent cohorts of SSc patients (n = 1015 total), and compared with two groups of normal controls (n = 893 total). Both cases and controls were stratified by ethnicity (Caucasian, African American and Hispanic) and by autoantibody status [anti-centromere antibodies (ACA) and anti-topoisomerase I antibody (ATA)].

RESULTS

The minor T allele and CT/TT genotype frequencies of the AIF1 SNP were not observed more frequently in SSc patients of the three ethnic groups (individually or combined) when compared with controls. On the other hand, T and CT/TT frequencies were significantly increased in ACA-positive Caucasian SSc patients, and all ACA-positive SSc patients (the three ethnic groups combined), when compared with ACA-negative SSc patients and with normal controls, with odds ratios of approximately 1.5.

CONCLUSION

The data demonstrate a genetic association between AIF1 and the ACA-positive subset of SSc. This polymorphism is a non-synonymous substitution and therefore likely to represent an important functional change in AIF1. Since vascular pathology is a prominent feature in ACA-positive SSc patients, the observed association with a vasculotrophic inflammatory gene is biologically plausible and warrants further research.

Pulmonary involvement in systemic sclerosis: associations with genetic, serologic, sociodemographic, and behavioral factors

OBJECTIVE

To determine the relative contributions of genetic, clinical, serologic, sociodemographic, and behavioral/psychological variables to early pulmonary involvement in the Genetics versus Environment in Scleroderma Outcome Study cohort.

METHODS

At the baseline visit (V0), 203 patients with systemic sclerosis (SSc) were examined (104 whites, 39 African Americans, and 60 Hispanics). We obtained sociodemographic, behavioral/psychological (illness behavior, social support, learned helplessness, smoking, drinking), clinical, serologic (autoantibodies), and genetic (HLA class II and FBN1 genotypes) factors; pulmonary function test results; electrocardiograms; and chest radiographs. Data analysis included Fisher's exact test, chi-square test, Student's t-test, analysis of variance, and stepwise linear and logistic regression methods.

RESULTS

Significant pulmonary involvement was seen in 25% of patients within 2.8 years of SSc diagnosis. At V0, pulmonary fibrosis was significantly higher in African Americans compared with whites or Hispanics. African Americans had significantly lower percent predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) compared with whites and significantly lower percent predicted diffusing capacity for carbon monoxide (DLCO) compared with whites and Hispanics. Significant, independent associations impacting early pulmonary involvement included African American ethnicity, skin score, serum creatinine and creatine phosphokinase values, hypothyroidism, and cardiac involvement. Anticentromere antibody seropositivity was a significant, independent, protective factor for restrictive lung disease and FVC or DLCO values. African Americans had significantly increased frequencies of anti-topoisomerase I, fibrillarin, and RNP autoantibodies compared with whites. African Americans scored significantly lower on the Interpersonal Support Evaluation List and significantly higher on the Illness Behavior Questionnaire.

CONCLUSION

Early pulmonary involvement in SSc appears to be influenced by several factors delineated by ethnicity, including racial, socioeconomic, behavioral, and serologic determinants.

Results of the Health Assessment Questionnaire for Japanese patients with systemic sclerosis--measuring functional impairment in systemic sclerosis versus other connective tissue diseases

OBJECTIVE

To evaluate the physical functional impairment in patients with systemic sclerosis (SSc) using the Health Assessment Questionnaire (HAQ) and to estimate the correlation of HAQ scores with the severity of SSc.

METHODS

One hundred and twenty-four outpatients with connective tissue disease, including 50 patients with SSc, were evaluated using the HAQ. Twelve patients were classified as having diffuse cutaneous SSc (dSSc) and 38 limited cutaneous SSc (lSSc). The severity classification and the guidelines for treatment (2004) were applied to Japanese SSc patients in order to evaluate the relationship between HAQ scores and disease activity in patients with multiple organ involvement.

RESULTS

In dSSc the HAQ category scores for eating, walking, grip, activity and the HAQ-disability index (HAQ-DI) showed the greatest deficits in all disease groups. The severity of disease activity correlated significantly with the scores for walking, reach, and the HAQ-DI. The severity of joint, heart, and pulmonary hypertension were correlated independently with the HAQ-DI score by multiple linear regression analysis.

CONCLUSION

Patients with dSSc suffer greater functional impairment than patients with other connective tissue diseases, and improvements in hand use and walking represent very important targets for both drug development and rehabilitation. As improvement in organ involvement (joints, heart as well as pulmonary hypertension) can lead to reduced functional impairment, they constitute an important target for therapy in SSc.

Validation of a new immunoenzymatic method to detect antibodies to RNA polymerase III in systemic sclerosis

OBJECTIVE

To test the reliability of a new enzyme-linked immunosorbent assay (ELISA) to identify anti-RNA polymerase III (RNAP III) positive sera from Italian patients with Systemic Sclerosis (SSc) and other chronic inflammatory disorders.

METHODS

A comparison between the new ELISA for anti-RNAP III and the gold standard technique, immunoprecipitation (IP), was first performed on 106 SSc patients, 16 patients with other connective tissue diseases and 10 healthy subjects. A further ELISA evaluation was performed on 224 SSc patients, 120 subjects with other rheumatic or infectious diseases, and 81 healthy controls.

RESULTS

Plotting ELISA and IP data in a Receiver Operator Characteristic curve, the ELISA cut-off value providing the best specificity (99.1%) and sensibility (100%) was 28 U/ml (AUC=0.999; p<0.0001). Using this cut-off in the second analysis, anti-RNAP III positive results were found in 41 (18.3%) SSc patients, all negative for anticentromere or anti-topoisomerase I antibodies, while only 3 subjects tested positive among the 120 sera collected from other patients. All the healthy subjects were negative.

CONCLUSION

This new ELISA for anti-RNAP III is highly accurate when a proper cut-off value is employed and represents a valid substitute to IP in a clinical setting.

Profile of systemic sclerosis in a tertiary care center in North India

AIM

To study the clinical and immunological profile in patients of systemic sclerosis from North India and compare it with other ethnic groups.

METHODS

Patients presenting to us between the years 2001 and 2004 and fulfilling the American Rheumatism Association (ARA) criteria for systemic sclerosis were included. There were 84 females and 16 males with the mean age of 32.5 +/-11.62 years and a mean duration of 6.49 +/- 4.34 years. All patients were admitted to the dermatology ward for detailed history and examination including Rodnan score. Investigations including hemogram, hepatic and renal functions, serum electrolytes, urine for albumin, sugar, microscopy and 24h urinary protein estimation, antinuclear antibody, chest X-ray, barium swallow, pulmonary function test, electrocardiogram and skin biopsy were done.

RESULTS

The most common presenting symptoms were skin binding-down (98.5%), Raynaud's phenomenon 92.9%, pigmentary changes 91%, contracture of fingers 64.6%, fingertip ulcer 58.6%, restriction of mouth opening 55.5%, dyspnea 51.1%, joint complaints 36.7% and dysphagia in 35.2%. The mean Rodnan score was 25.81 +/- 10.04 and the mean mouth opening was 24.6 +/- 19.01 mm. The laboratory abnormalities included raised ESR in 87.8%, ANA positive in 89.1%, proteinuria in 6.0%, abnormal chest X-ray in 65.3%, abnormal barium swallow in 70.2% and reduced pulmonary function test in 85.8%.

CONCLUSION

The clinical and immunological profile of systemic sclerosis in North India is similar to that of other ethnic groups except that pigmentary changes are commoner and renal involvement is relatively uncommon.

Etrurians vs Greeks: May ACE I/D polymorphism still be considered as a marker of susceptibility to SSc?

OBJECTIVE

SSc is characterized by immune dysfunction and microvascular involvement. A different genetic background may determine a different polymorphic allele frequency between different populations, and data from literature reported conflicting results about the role of genetic components in predisposing to the disease. We carried out this study in order to compare the ACE I/D polymorphism genotype distribution and alleles frequency in two different populations from the Mediterranean area.

METHODS

Forty-eight Italian and 41 Greek SSc patients compared with 112 Italian and 93 Greek controls, have been studied. The ACE I/D polymorphism has been analysed.

RESULTS

The genotype distribution and allele frequency were in Hardy-Weinberg equilibrium for Italian and Greek SSc patients and controls. Among the Italian patients a significantly higher ACE D allele frequency than in the controls was found, whereas among the Greeks a higher prevalence was observed in the healthy subjects. A significant difference in ACE D allele frequency between Italian and Greek controls was observed (p = 0.04). ACE D allele was associated to the predisposition to SSc in Italians, but not in Greeks.

CONCLUSION

We confirm that Italian SSc patients have a higher ACE D allele frequency that is not present in the Greek patients. Thus, the two populations living in different Mediterranean areas and resulting from the Mediterranean civilization, do not show the same ACE-gene related allele frequencies. Other populations of the Mediterranean area must be investigated by using unlinked genetic markers to verify the homogeneity of the genetic background, and to test for a "true" difference in their ethnic origin.

Lack of association between three vascular endothelial growth factor gene polymorphisms and systemic sclerosis: results from a multicenter EUSTAR study of European Caucasian patients

INTRODUCTION

Systemic sclerosis (SSc) is characterised by disturbed vessel morphology and an overproduction of vascular endothelial growth factor (VEGF). The VEGF gene located on chromosome 6p21.3 has several polymorphisms.

OBJECTIVE

To test the hypothesis that disturbed angiogenesis may be related to the genetic background of the VEGF gene.

MATERIALS AND METHODS

EUSTAR centres included European Caucasian patients with SSc and matched controls with osteoarthritis. The VEGF gene was genotyped by polymerase chain reaction, followed by restriction enzyme analysis. The 634 C/T and 936 C/G mutations and an 18-base pair insertion/deletion at -2549 of the VEGF promoter region were tested.

RESULTS

416 patients with SSc and 249 controls were included in the study population. Of the patients with SSc, 42% had a diffuse cutaneous subtype, 16% had increased pulmonary arterial pressure and 61% had decreased carbon monoxide diffusion capacity. The genotype frequencies in the patients with SSc and in controls were in Hardy-Weinberg equilibrium. The allele and genotype frequencies of the polymorphisms did not differ between patients with SSc and controls. No association was found between these polymorphisms and disease phenotypes.

CONCLUSION

This study shows that there is no association between the three selected functional VEGF polymorphisms and SSc.

Systemic sclerosis mortality in the United States: 1979-1998

The US national mortality rates from systemic sclerosis (SSc) have not been reported since 1979. We studied age, gender and race specific time trends in US national mortality rates of SSc during the period 1979-1998 using poisson regression models. Over the 4.93 billion person-years of observation during the study period, there were 18,126 deaths from SSc, representing a mortality rate of 3.9 per million. The age adjusted mortality rates for men and women were 1.9 and 5.4 per million respectively. There were relatively few deaths in the extremes of age. SSc mortality rates increased with age in both genders and in all racial groups (p<0.001). In multivariable models adjusted for two-way statistical interactions, being African-American, female and of older age were associated with higher death rates. Over the 20 years of observation, overall (age-adjusted) SSc mortality rates showed a 36% increase (p<0.001) and subgroup analyses revealed that the increases were confined to women of both races. This rise occurred during a period in which post-diagnosis survival of SSc is known to have increased, suggesting an increasing incidence of this disease.

Racial variation in clinical and immunological manifestations of systemic sclerosis

OBJECTIVE

To clarify which racial differences in disease manifestations can be attributed to differences in other factors such as gender, education, disease classification, and disease duration.

METHODS

The study included white and black patients with systemic sclerosis (SSc) treated at a university hospital rheumatology clinic between November 1997 and April 2003. Demographic, clinical, and immunological measurements were obtained on each subject. Using multivariable statistical techniques we assessed differences in disease manifestations between white and black patients after adjusting for gender and classification and duration of disease.

RESULTS

Two hundred sixty-three patients (199 whites, 64 blacks) were enrolled in the study. Blacks experienced an earlier age at disease onset than whites and were significantly more likely to have diffuse disease, digital ulcers, digital pitting, impaired lung function, and anti-RNP, and anti-Ro antibodies. Whites were significantly more likely to have anti-centromere antibodies.

CONCLUSION

After adjusting for gender, disease classification, and disease duration, whites and blacks with SSc differ in some clinical and immunological manifestations of disease. Whether these differences can be attributed to genetic or environmental factors remains unknown.

Demographic and clinical factors associated with in-hospital death among patients with systemic sclerosis

OBJECTIVE

To examine demographic and clinical predictors of in-hospital death of patients with systemic sclerosis (SSc) and determine to what extent apparent racial differences may be attributed to socioeconomic factors.

METHODS

Data were obtained on all hospitalizations in South Carolina for patients who were ever hospitalized between 1996 and 2000 with a diagnosis of SSc. Multiple logistic regression was used to examine predictors of in-hospital death among whites, blacks, and other patients.

RESULTS

Proportions of in-hospital deaths among blacks (23.0%) and others (27.7%) were higher than among whites (15.6%), a finding that remained after adjustment for other sociodemographic and clinical factors (black/white odds ratio: 1.70, 95% confidence interval: 1.01-2.86; other/white OR 2.06, 95% CI 1.04-4.09). Other factors associated with in-hospital death included transfer status, emergency admission, length of stay, number of hospitalizations during the time period, and presence of congestive heart failure (OR 1.79; 95% CI 1.06-3.03) or hypertension (OR 0.41; 95% CI 0.23-0.71).

CONCLUSION

Black and other non-white patients with SSc appear to experience an elevated risk of death during their hospital stays. Further research is necessary to understand the reasons for these disparities.

Clinical characteristics of Japanese patients with anti-PL-7 (anti-threonyl-tRNA synthetase) autoantibodies

OBJECTIVE

The clinical and laboratory features of seven Japanese patients with anti-aminoacyl-tRNA synthetase (ARS) autoantibodies against PL-7 (anti-threonyl-tRNA synthetase) were analyzed and compared with previously published findings.

METHODS

Serum samples from 1,135 Japanese patients with various autoimmune diseases were screened for anti-PL-7 antibodies using RNA and protein immunoprecipitation assays. The patients whose sera contained anti-PL-7 antibodies were assessed regarding clinical symptoms and clinical course.

RESULTS

Sera from seven patients were found to have anti-PL-7 antibodies. These autoantibodies were associated with polymyositis/dermatomyositis (PM/DM) and/or interstitial lung disease (ILD). The clinical diagnoses of these seven patients were PM - systemic sclerosis (SSc) overlap (5 patients), DM (1 patient) and idiopathic pulmonary fibrosis (IPF) (1 patient). All patients had ILD with a chronic course and six also had arthritis (85%) and five sclerodactyly (71%).

CONCLUSIONS

These results indicate that anti-PL-7 autoantibodies are closely associated with PM-SSc overlap as well as ILD, arthritis and sclerodactyly in our series of Japanese patients.

Scleroderma in Australian Aborigines

Scleroderma (systemic sclerosis) has not been reported before in Australian Aborigines. We describe in detail a community middle-aged Aboriginal woman whose diffuse scleroderma terminated fatally with a renal crisis. Moreover, we have identified a further five Aboriginal patients on the South Australian Scleroderma Register (two with diffuse, two with limited and one with overlap scleroderma), a number consistent with that expected from the 2001 census data for our state. However, an analysis of all antinuclear antibody (ANA) requests from the Top End of Australia over a 6-year period revealed only two Aborigines with low titre anticentromere antibody (despite frequent occurrence of ANA with other specificities). Neither of these Aborigines had features of scleroderma. In conclusion, scleroderma does occur in indigenous Australians but further studies are needed to confirm the apparent infrequency of centromere-associated limited scleroderma (which is the commonest form of scleroderma in our Caucasian population).

Mortality in systemic sclerosis: an international meta-analysis of individual patient data

PURPOSE

Studies on mortality associated with systemic sclerosis have been limited by small sample sizes. We aimed to obtain large-scale evidence on survival outcomes and predictors for this disease.

METHODS

We performed a meta-analysis of individual patient data from cohorts recruited from seven medical centers in the United States, Europe, and Japan, using standardized definitions for disease subtype and organ system involvement. The primary outcome was all-cause mortality. Standardized mortality ratios and predictors of mortality were estimated. The main analysis was based only on patients enrolled at each center within 6 months of diagnosis (incident cases).

RESULTS

Among 1645 incident cases, 578 deaths occurred over 11,521 person-years of follow-up. Standardized mortality ratios varied by cohort (1.5 to 7.2). In multivariate analyses that adjusted for age and sex, renal (hazard ratio [HR] = 1.9; 95% confidence interval [CI]: 1.4 to 2.5), cardiac (HR = 2.8; 95% CI: 2.1 to 3.8), and pulmonary (HR = 1.6; 95% CI: 1.3 to 2.2) involvement, and anti-topoisomerase I antibodies (HR = 1.3; 95% CI: 1.0 to 1.6), increased mortality risk. Renal, cardiac, and pulmonary involvement tended to occur together (P <0.001). For patients without adverse predictors for 3 years after enrollment, the subsequent risk of death was not significantly different from that for the general population in three cohorts, but was significantly increased in three cohorts that comprised mostly referred patients. Analyses that included all cases in each center (n = 3311; total follow-up: 19,990 person-years) yielded largely similar results.

CONCLUSION

Systemic sclerosis confers a high mortality risk, but there is considerable heterogeneity across settings. Internal organ involvement and anti-topoisomerase I antibodies are important determinants of mortality.

Prevalence of systemic sclerosis in a French multi-ethnic county

OBJECTIVE

To assess the prevalence of systemic sclerosis (SSc) in a French multi-ethnic population and to examine ethnic differences.

METHODS

This survey was conducted in Seine-Saint-Denis County, a suburb of Paris, home to 1,094,412 adults (>/=15 yr), among whom 26% are of non-European background with mainly northern and sub-Saharan African, Asian and Caribbean ancestries. The study period comprised the entire calendar year 2001. Patients were ascertained through four sources: public and private hospitals, general practitioners and community specialists, the French SSc patient support group, and the National Public Health Insurance System database. Only cases meeting either the 1980 ACR and/or LeRoy and Medsger's classification criteria were included and assigned to three clinical subsets: limited (normal skin) (l), limited cutaneous (lc) or diffuse cutaneous (dc) SSc. Capture-recapture (CR) analyses using log-linear modelling were performed to correct for incomplete case finding.

RESULTS

We retained a total of 119 patients with SSc, including 15 extrapolated from inaccessible files. CR analysis estimated that 54.2 additional cases were missed by all the sources. The overall SSc prevalence (per million adults) was 158.3 (95% confidence interval, 129-187); those of lSSc, lcSSc and dcSSc were, respectively, 32.3 (16-48), 83.1 (66-101) and 42.9 (25-60); and respective values for Europeans and non-Europeans were 140.2 (112-170) and 210.8 (128-293).

CONCLUSION

Regarding the heterogeneity of previously published estimates, this population-based survey using CR analysis might contribute to obtaining a better appraisal of SSc prevalence. Despite overlapping confidence intervals, the higher prevalence observed for non-Europeans could support potential influences of ethnic origin on the pathogenesis of SSc.

Ethnic differences in cytotoxic T lymphocyte associated antigen 4 genotype associations with systemic sclerosis

OBJECTIVE

To determine the role of cytotoxic T lymphocyte associated antigen 4 (CTLA-4) genetic polymorphisms in susceptibility to systemic sclerosis (SSc, scleroderma).

METHODS

The study population consisted of 293 African American and Caucasian patients with SSc and matched controls. Subjects were genotyped for allelic determinants at 4 polymorphic sites: 3 in the promoter region (positions -318, -1661, -1722) and one in the first exon (position +49) of the CTLA-4 gene, using polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) methods. Genotype frequencies were compared using Pearson's chi-square or Fisher's exact test.

RESULTS

In African American patients, the frequency of AG heterozygotes at position +49 was significantly higher than in controls (71% vs 36%, p = 0.003; OR = 4.37), while the frequency of AA homozygotes was significantly lower in patients than in controls (29% vs 61%, p = 0.007; OR = 0.26). The distribution of CTLA-4 alleles at other loci did not differ significantly between patients and controls. CTLA-4 genotypes were not associated with SSc in Caucasians. No differences in CTLA-4 genotype distributions were observed between patients with the limited and diffuse forms of the disease.

CONCLUSION

Our data show that the exon 1 (+49) polymorphism of the CTLA-4 gene is associated with systemic sclerosis in African Americans.

Genome-wide association study for regions of systemic sclerosis susceptibility in a Choctaw Indian population with high disease prevalence

OBJECTIVE

Systemic sclerosis (SSc) is a complex, multisystem connective tissue disease in which genetic factors contribute to disease susceptibility. The aim of this study was to localize chromosome regions associated with susceptibility to SSc in a relatively isolated and homogeneous population of Choctaw Indians with a high prevalence of SSc.

METHODS

A genome-wide microsatellite screen at 10 cM resolution (400 markers) was performed in 20 Choctaw patients with SSc and 76 ethically matched controls. Based on the results of the initial screen, fine-scale microsatellite mapping at < or =1 cM resolution was performed in 10 selected chromosome regions. Allele and marker haplotype frequencies were compared between SSc patients and controls.

RESULTS

From the genome-wide screen, 12 markers showed evidence of highly significant associations with SSc in this population (P < 0.01), while 5 other markers showed significant associations (0.01 < P < 0.05). Among these markers, loci D5S410, D6S422, D15S978, and D20S107 are near the SPARC, MHC, FBN1, and TOPOI genes, respectively, confirming the results of our previous studies, which used different markers. D1S2800 and D14S63 have been reported to show linkage to systemic lupus erythematosus (SLE) in family-based studies, and D1S206, D6S422, and D6S264 are loci on 1p21.2, 6p22.3, and 6q23-27, respectively, which are in regions reported as showing linkage to SLE and other autoimmune diseases. Other markers showing unique associations with SSc were D7S510 (7p12-11), D7S661 (7q35), D8S514 (8q24.12), D19S221 (19p13.2), D19S220 (19q13.2), D22S423 (22q13.1), DXS1068 (Xp11.4), and DXS8055 (Xq21-23). Further analysis with fine-scale microsatellite mapping revealed at least 14 potential haplotypes associated with SSc.

CONCLUSION

Our findings indicate that a number of genetic loci may contribute to the high prevalence of SSc in the Choctaw and are consistent with the paradigm that some autoimmune rheumatic diseases are likely to share genetic determinants.

Patterns of hospital admissions and emergency room visits among patients with scleroderma in South Carolina, USA

OBJECTIVE

Little research has examined patterns of hospitalization and use of emergency rooms (ER) among patients with systemic sclerosis (SSc). We compared the incidence of hospitalizations and ER visits across 3 race groups (non-Hispanic white, non-Hispanic black, other) and determined predictors of referral to the Medical University of South Carolina (MUSC), a major referral center for patients with SSc residing in the southeastern United States.

METHODS

Data were obtained on all South Carolina hospitalizations (1996-2000) for patients who were ever hospitalized for a diagnosis of SSc during that time period. Hospitalization and ER incidence rates were determined in conjunction with corresponding population sizes obtained from the 2000 US Census, and rates were compared across race, sex, and age groups using Poisson regression models. Logistic regression was used to determine predictors of being treated at MUSC.

RESULTS

The hospitalization incidence rate was significantly (p < 0.05) higher among blacks compared to whites (rate ratio 1.66; 95% confidence interval 1.41, 1.96), as was the ER incidence rate (rate ratio 1.78; 95% CI 1.50, 2.11). Even after adjusting for sex, age, median household income, primary insurance claim payor, county, and comorbidity, blacks were 60% less likely (p < 0.05) than whites to receive inpatient treatment at MUSC. Similar results were observed when comparing other non-whites to whites.

CONCLUSION

The increased hospitalizations and ER visits among non-whites provide additional evidence of greater disease burden among these population groups. Despite this increased burden, non-whites are less likely to receive care at a major SSc referral center.

Ethnicity and race and systemic sclerosis: how it affects susceptibility, severity, antibody genetics, and clinical manifestations

Most studies have suggested that ethnic factors impact significantly on systemic sclerosis. Extensive epidemiologic studies have been carried out in white individuals, and limited data suggest that blacks are affected twice as frequently; Japanese patients have a lower prevalence than whites. This highest rate that has been described has been in Choctaw Native Americans. Blacks have a lower age at onset, as well as a higher frequency of diffuse skin involvement, pulmonary disease, and an overall worse prognosis than whites. Limited data in Hispanics and Native Americans suggest that they have more severe disease than whites. Whites have the highest frequency of anti-centromere antibodies (associated with limited skin involvement and less pulmonary fibrosis), whereas blacks have a higher frequency of anti-ribonucleoprotein and fibrillarin autoantibodies; the latter is a nucleolar antibody associated with a poorer prognosis. Ethnic differences are also seen for associations with non-major histocompatibility complex genes, such as FBN1 (fibrillin) genes, in Choctaws and Japanese and SPARC (osteonectin) in whites, Hispanics, and Choctaws. Although these facts do not entirely rule out socioeconomic factors associated with ethnicity, nevertheless ethnicity has an important impact on the pathogenesis of systemic sclerosis, perhaps because of genetic factors.

Association of CTLA-4 with systemic sclerosis in Japanese patients

OBJECTIVE

The contribution of CTLA-4 alleles to the pathogenesis of systemic sclerosis (SSc) was studied in Japanese patients.

METHODS

CTLA-4 typing in 2 dimorphic sites, +49 A/G and -308 C/T, was carried out in 62 SSc patients and 107 normal subjects by the PCR-RFLP (restriction fragment length polymorphism) method. HLA-DRB1*15 and *08 genotyping were carried out by the PCR-SSCP (simple-stranded DNA conformation polymorphism) method.

RESULTS

In SSc the frequency of the +49A allele increased slightly (40.3%), but was not significant. In SSc with diffuse scleroderma and SSc with anti-topoisomerase I antibody, the +49A also increased (43.8%, and 48.0%, respectively) but again was not significant. A significant increase in the +49A was not observed in SSc with HLA-DRB1*1502 or ORB1*0802. In contrast, the +49A had significantly increased in SSc with the anti-RNP antibody [52.9%, p = 0.0337, Odds ratio (OR) = 2.27 (95% confidential interval (CI) = 1.09-4.71)]. HLA-DRB1*1502 and *0802 had no influence on the association of anti-RNP antibody with the +49A. The +49AA genotype increased significantly in SSc without lung fibrosis [31.8%, p = 0.0456, OR = 3.37 (CI = 1.16-9.87)], especially in limited SSc without lung fibrosis [33.3%, p = 0.0319, OR = 3.62 (CI = 1.16-11.29)]. The dimorphism at -308 did not associate with SSc.

CONCLUSION

In Japanese scleroderma, the +49A allele of CTLA-4 increased in the presence of SSc with the anti-RNP antibody.

The genetics of systemic sclerosis

The etiopathogenesis of systemic sclerosis (SSc) is unclear. With no definitive evidence supporting an environmental cause, recent attention has focused on genetic factors. Familial clustering and ethnic influences have been demonstrated. Human leukocyte antigen (HLA) associations exist but are more related to the presence of particular autoantibodies rather than to the disease. In addition, no single major histocompatibility complex (MHC) allele predisposes to SSc in all ethnic groups. The role of microchimerism in SSc is a novel yet unproven hypothesis that may be related to intergenerational HLA compatibility. Recent studies investigating polymorphisms in genes coding for extracellular matrix proteins and cell-signaling molecules implicate non-MHC areas in SSc pathogenesis. The data reviewed suggest that SSc is a multigenic complex disorder.

Anti-fibrillarin antibodies in systemic sclerosis

OBJECTIVES

To investigate the nature and extent of organ involvement in anti-fibrillarin antibody (AFA)-positive patients within a UK systemic sclerosis (SSc) population.

METHODS

We investigated 1026 consecutive patients with SSc. AFA was identified by the characteristic clumpy nucleolar and coilin body pattern of staining in interphase cells and staining of fibrillarin in metaphase cells by indirect immunofluorescence using HEp-2 cells. Identity of the 34-kDa fibrillarin protein was confirmed by immunoprecipitation from [(35)S]methionine-labelled HeLa cell extract.

RESULTS

AFA was detected in 42 patients (4.1%) with early disease onset (mean age 36 yr). Sixteen (38%) patients had limited cutaneous (lcSSc) and 26 (62%) diffuse cutaneous SSc (dcSSc). All eight Afro-Caribbean patients with AFA had dcSSc whereas the Caucasians were equally divided between dcSSc and lcSSc. Within the dcSSc subgroup, 54% had myositis, 35% had pulmonary hypertension, 15% had cardiac involvement and 23% had renal involvement.

CONCLUSIONS

AFA identifies young SSc patients with frequent internal organ involvement, especially pulmonary hypertension, myositis and renal disease. In contrast to previous reports, AFA was not restricted to dcSSc patients in Caucasians.

Association of HLA class II genes with systemic sclerosis in Koreans

OBJECTIVE

To investigate HLA class II associations with systemic sclerosis (SSc) in Koreans according to anti-topoisomerase I (anti-topo I), anti-centromere antibody (ACA), and anti-U1 ribonucleoprotein (RNP) status.

METHODS

HLA class II alleles (DRB1, DRB5, DQB1) were determined by DNA typing in 200 healthy control subjects and 74 patients with SSc: 35 anti-topo I positive, 3 ACA positive, and 19 anti-U1 RNP positive; among them were 34 diffuse and 40 limited subtypes, and 16 overlap syndrome.

RESULTS

Anti-topo I positive SSc was strongly associated with DRB1*1502 compared with both controls (23% vs 5%; Pcorr = 0.003) and anti-topo I negative patients (23% vs 3%; p = 0.009); our study confirms observations in Japanese. HLA-DR 67FLEDR71, especially 38V-67FLEDR71 sequence (carried on DRB5*0102 in linkage disequilibrium with DRB1*1502, DRB1*0802, DRBI*1101), showed the strongest association with anti-topo I response (46% vs 16% in controls; Pcorr = 0.001), and 38L-67FLEDR71 group alleles were not associated with anti-topo I response. Anti-topo I response was not significantly associated with HLA-DQB1 alleles in Koreans. There were only 3 ACA positive patients, and all patients had DRB1*1501 and DQB1*0602 as heterozygotes. Anti-U1 RNP occurred at a high frequency (63%) among patients with overlap syndrome, and was not associated with HLA-DR or DQ genes. Among anti-topo I negative patients, diffuse and limited subtypes of SSc were significantly associated with DRB1*0803 (47% vs 15% in controls; Pcorr < 0.05) and DRB1*1501 (50% vs 17% in controls; Pcorr < 0.01), respectively. These HLA associations have not been reported in other ethnic groups and possible associations with certain autoantibody subsets remain to be confirmed.

CONCLUSION

HLA-DR gene has a primary association with anti-topo I response, and HLA-DR 38V-67FLEDR71 group alleles including DRB5*0102 (in linkage disequilibrium with DRB1*1502) show the strongest association with anti-topo I response in Korean patients with SSc.

Familial occurrence frequencies and relative risks for systemic sclerosis (scleroderma) in three United States cohorts

OBJECTIVE

To determine the frequency with which scleroderma (systemic sclerosis; SSc) recurs in families and the familial relative risk (lambda) in the US.

METHODS

Family histories of SSc were prospectively surveyed in 3 large US cohorts of SSc patients, 2 in Texas and 1 in Michigan. Diagnoses of familial SSc were verified by rheumatologist evaluation and/or review of medical records. Familial relative risks for first-degree relatives (lambda1) and siblings (lambdas) were calculated using actual reported counts of first-degree relatives in 2 cohorts and recent estimates of SSc prevalence in the US.

RESULTS

Compared with the estimated prevalence of SSc in the US (2.6 cases/10,000 population [0.026%]), the disease occurred in 1 or more first-degree relatives in 1.5-1.7% of SSc families in the 3 cohorts (or 11 of 703 families [1.6%]), a significant increase. Familial relative risks in first-degree relatives in the 3 cohorts ranged from 10 to 16 (13 combined), and in siblings they ranged from 10 to 27 (15 combined).

CONCLUSION

SSc occurs significantly more frequently in families with scleroderma (1.6%) than in the general population (0.026%). A positive family history of SSc is the strongest risk factor yet identified for SSc; however, the absolute risk for each family member remains quite low (<1%).