The clinical profile of systemic sclerosis without a ‘scleroderma pattern’ at nailfold capillaroscopy: results from the multicenter SPRING registry of the Italian Society of Rheumatology

Background Microvascular alterations can be detected with nailfold videocapillaroscopy, useful for systemic sclerosis (SSc) diagnosis upon identification of the “scleroderma pattern” (NVC-SP). However, this pattern is missing in a subset of SSc patients. Methods This retrospective analysis on the multicenter Italian SPRING cohort of SSc patients assessed the prevalence and characteristics of patients without NVC-SP. Associations with demographic and clinical features were evaluated using logistic regression (cross-sectional) and mixed-effects models (longitudinal). Results Out of 1,689 SSc patients with available NVC information, 90 (5.3%) did not have the NVC-SP. These patients were older at SSc onset (53 vs. 49 years) and more frequently sine scleroderma (31% vs 12%, p<0.001). The overall burden of vascular complications was milder in this subset, with a lower prevalence of pitting scars (33% vs 48%), telangiectasias (52% vs 74%), and calcinosis (3.4% vs 12%). During the follow-up, mRSS remained lower (60-month mean 4 vs 7, p=0.002), as well as the estimated probability of vascular complications. Moreover, despite comparable values at baseline, DLCO remained significantly higher in patients without NVC-SP at the following time points (12, 24, and 60 months, p<0.05). The presence of “late” NVC-SP was independently associated with ILD (OR 1.83, 95% CI 1.05-3.18). Conclusions The absence of NVC-SP in 5.3% of SPRING SSc patients may identify a subset characterized by milder disease, with a lower burden of vascular and organ complications. Conversely, lung involvement was more frequently observed in patients with more severe NVC microangiopathy.