Clinical and autoantibody profiles of systemic sclerosis patients: A cross-sectional study from North India

Abstract

Objectives This cross-sectional study was designed to assess the clinical profile and frequency of associated autoantibodies in all consecutive patients classified as systemic sclerosis (SSc) at Medanta—the Medicity Hospital, Gurgaon, India. Methods Between August 2017 and July 2019, we identified a total of 119 consecutive patients meeting the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2013 criteria for SSc and 106 patients consented to this study. Their clinical and serological data at the time of enrolment were analysed. Results Our cohort had a mean age at symptom onset of 40 ± 13 years with a median symptom duration of 6 years. We had 76 patients (71.7%) with interstitial lung disease (ILD), which was a higher proportion compared to European cohorts. 62 patients (58.5%) had diffuse cutaneous involvement which was significantly associated with anti-Scl70 antibodies (p < 0.001), digital ulcers (p = 0.039) and the presence of ILD (p = 0.004). 65 patients (61.3%) had anti-Scl70 and 15 patients (14.2%) had anti-centromere (anti-CENP) antibodies. Scl70 positivity was associated with the presence of ILD (p < 0.001) and digital ulcers (p = 0.01). Centromere antibodies had a negative association with ILD (p < 0.001), but was a risk factor for calcinosis (p < 0.001) and pulmonary arterial hypertension (PAH) (p = 0.01). The combination of diffuse cutaneous disease and Scl70 antibodies was the strongest predictor of ILD and digital ulcers (p = 0.015). sm/RMP, RNP68 and Ku antibodies correlated with musculoskeletal involvement (p < 0.01), while all seven of the patients with Pm/Scl antibodies had ILD. Renal involvement was noted in only two patients. Limitations A single-centre study may not capture the true prevalence of disease characteristics in the population. Referral bias for patients with diffuse cutaneous disease has been noted. Data on RNA-Polymerase antibodies have not been provided. Conclusion North Indian patients have some characteristic differences in disease phenotype as compared to their Caucasian counterparts with a larger proportion of patients presenting with ILD and Scl70 antibodies. Antibodies against Ku, RNP and Pm/Scl occur in a minority of patients, but may be associated with musculoskeletal features.