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Introduction Systemic sclerosis (SSc) is a heterogeneous autoimmune disease with racial and geographic variation in presentation and outcomes. While disparities among African American, Hispanic, and East Asian patients are documented, data on South Asians, particularly Indian patients, remain limited.Material and Methods We used de-identified data from two multi-center registries: the India-based Indian Progressive Systemic Sclerosis (IPSS) registry (n=247) and a US-based registry combining non-overlapping patients from the Stanford SSc Registry (n=219) and the Collaborative National Quality and Efficacy Registry (CONQUER) (n=1,113). Patients met 2013 ACR/EULAR criteria and had at least 5 years since first non-Raynaud’s symptom. Extracted variables included demographics, disease subtype, modified Rodnan Skin Score (mRSS), baseline forced vital capacity% predicted (FVC%), and presence of interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH), assessed by high-resolution computed tomography (HRCT) and right heart catheterization (RHC). Baseline characteristics and skin progression in diffuse cutaneous SSc (dcSSc) over three years were compared.Results The IPSS cohort was predominantly female (89.1% vs. 83.5%) with a lower proportion of dcSSc (54.3% vs. 62.9%), and younger age at baseline compared with the US (41.2 vs. 53.9 years). Baseline median FVC% (66.0 vs. 87.2) was lower in the IPSS group. ILD and PAH were assessed by HRCT and RHC in 64.4% and 22.2% of IPSS patients, and 79.1% and 20% of US patients. Among those who underwent testing, ILD and PAH were significantly more prevalent in the Indian cohort (ILD: 77.4% vs 61.3%; PAH: 65.5% vs 23.7%; both p<0.001). Digital ulcers and gangrene were more frequent in IPSS, while telangiectasias, calcinosis, tendon friction rubs, GERD, and renal crisis were more common in the US cohort ( tables 1-2).Although missing data increased over the three-year period, both cohorts showed improvement in mRSS among dcSSc patients. In the Indian cohort, the median mRSS decreased from 11 at baseline (n=119) to 6 (n=56) at one year, while in the US cohort, it decreased from 16 (n=805) to 13 (n=405) (table 3, figure 1).Conclusions Indian SSc patients in IPSS, compared to a US-based cohort, demonstrate a distinct phenotype with earlier disease onset, lower baseline lung function, and higher prevalence of lung disease (ILD and PAH) in those undergoing gold standard testing. MRSS improved over time in dcSSc patients in both cohorts. A key limitation was missing long-term follow-up data. These findings highlight the need for early diagnosis and standardized internal organ screening to improve outcomes in the Indian population.Abstract P.306 Figure 1Longitudinal trends in skin thickness (mRSS) over 36 months in diffuse cutaneous SSe patients from Indian (IPSS) and U.S cohortsAbstract P.306 Table 1Bascline demographicsAbstract P.306 Table 2Organ involvement at baseline visitAbstract P.306 Table 3Longitudinal modified rodnan skin score (mRSS) in diffuse cutaneous systemic sclerosis: comparison of Indian (IPSS) and U.S. Cohorts