In press. Capillaroscopic findings in individuals with Sjögren's syndrome, systemic sclerosis, and primary Raynaud's phenomenon at a capillaroscopy referral centre in Medellin, Colombia

Introduction: Nailfold capillaroscopy is a fundamental technique for studying systemic autoimmune diseases such as Sjögren's syndrome, particularly in patients with Raynaud's phenomenon and sclerodermiform features. However, in this condition, studies are scarce and often use less precise instruments than digital videocapillaroscopy, limiting the available evidence. Objective: To compare capillaroscopic findings among individuals with Sjögren's syndrome, primary Raynaud's phenomenon, and systemic sclerosis at a national referral centre for nailfold videocapillaroscopy in Medellin, Colombia, between 2016 and 2022. Materials and methods: An analytical cross-sectional observational study that included individuals over 18 years old with Sjögren's syndrome, systemic sclerosis, and primary Raynaud's phenomenon. Clinical and capillaroscopic characteristics information was obtained from capillaroscopy reports at an expert centre. Pearson's χ² test was used to compare qualitative variables, and the Kruskal-Wallis test for quantitative variables. A P value < .05 was considered statistically significant. Results: A total of 195 patients were included. Subjects with Sjögren's syndrome had a lower prevalence of abnormal capillaroscopic variables than patients with systemic sclerosis (P < .001). All abnormal capillaroscopic variables were more frequent in the Sjögren's syndrome group compared to primary Raynaud's phenomenon. There were statistically significant differences among the 3 patient groups in the capillaroscopic pattern (P < .001). The main capillaroscopic finding in Sjögren's syndrome was the presence of dilated capillaries (55.4%; 36/65). In the Sjögren's syndrome group, an early scleroderma pattern was present in 4.6%, and an active scleroderma pattern in 13.8%, both findings less frequent than in systemic sclerosis but more common than in primary Raynaud's phenomenon group. Conclusions: In a population of Sjögren's syndrome patients with a high prevalence of secondary Raynaud's phenomenon and anticentromere antibodies, a high prevalence of capillaroscopic abnormalities was found. Although less frequent compared to the systemic sclerosis group, these abnormalities were more common than in the primary Raynaud's phenomenon group.