Prevalence and clinical relevance of digital ulcers in systemic sclerosis patients from the real-life: the experience of the SPRING Registry of the Italian Society for Rheumatology

Introduction: Digital ulcers (DU) are one of the most frequent manifestations in systemic sclerosis (SSc). The presence of DU seems to be a sentinel sign of internal organ involvement and is related to a poor prognosis of the disease. The aim of this study was to evaluate the prevalence and the relationship of DU with clinical manifestations/variants in a large SSc cohort from the SPRING registry. Methods: SSc patients fulfilling the ACR/EULAR 2013 classification criteria without missing data on digital ulcers were enrolled in a cross-sectional study. Logistic regression models were built to test the association between the presence of DU and SSc-related features. Results: Among 1873 eligible SSc patients, the presence of DU was significantly associated with gastrointestinal involvement (OR 1.88, 2.04 and 1.74; p < 0.001) and serum ATA positivity (OR 2.15; p < 0.001), as well as with telangiectasias, sclerodactyly, digital pitting scar, and calcinosis (OR 1.40, p = 0.005; OR 3.43, p < 0.001, OR 9.12, p < 0.001 and OR 2.77, p < 0.001; respectively). In the multivariable regression models, even after adjustment for covariates, ATA positivity (OR 1.76, p = 0.039), puffy fingers (OR 2.82, p < 0.001), and a higher revEUSTAR-AI (OR 6.63, p < 0.001) emerged as risk factors for the presence of DU. Moreover, a low presence of DU was recorded in SSc patients with a history of previous immunosuppressive treatments (OR 0.53, p = 0.032). Conclusion: In our Italian SSc cohort, DUs were significantly associated with the presence of puffy fingers, high revEUSTR-AI, and ATA seropositivity. Noteworthy, immunosuppressive treatments were associated with a low rate of DU, suggesting that they might contribute to the prevention of these harmful manifestations.