Progression of Nailfold Microvascular Damage and Antinuclear Antibody Pattern in Systemic Sclerosis

Abstract

This study evaluates possible correlations between the pattern of antinuclear antibodies (ANA) on indirect immunofluorescence (IIF) testing and nailfold microangiopathy stage (early, active, and late stage) in systemic sclerosis (SSc). Patients with SSc were followed prospectively to monitor progression of microvascular damage. The ANA pattern on IIF was searched in 42 patients with SSc showing an early pattern of nailfold microangiopathy at baseline, and was followed using nailfold videocapillaroscopy (NVC) for a median time of 91 months. Among patients whose microangiopathy showed a rapid progression from early to late pattern on NVC, the IIF pattern was fine-speckled + nucleolar (Scl-70+) in 44%, centromeric in 33%, nucleolar in 11%, and homogeneous in 11% of patients with SSc. Antitopoisomerase I antibodies were significantly more frequent (57%) in patients with late pattern of microangiopathy on NVC. The median time of progression from early to active disease was significantly lower in patients with both fine-speckled + nucleolar and nucleolar ANA positivity. The severity of microangiopathy was higher in patients with the nucleolar pattern on IIF. Patients already showing a slight reduction of capillary number at baseline were likely to have either the nucleolar or the fine-speckled + nucleolar pattern on IIF. Of note, 37% of patients still showing the early microangiopathy pattern on NVC at the end of the followup were ANA-negative. ANA-negative patients with SSc display a slower progression of nailfold microangiopathy characterized by the early pattern on NVC. Progression to the late NVC pattern (more advanced stage of microvascular damage) seems to be associated with a different autoantibody pattern on IIF (fine-speckled + nucleolar pattern being the most prevalent).