Correlation of a quantitative videocapillaroscopic score with the development of digital skin ulcers in scleroderma patients

Background: Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and visceral organs. The microangiopathy is early detectable in the course of the disease by nailfold videocapillaroscopy (NVC), a non-invasive technique with a high diagnostic value. Objective: Aim of our study was to evaluate the feasibility of a quantitative score and its correlation with the digital skin ulcers, which frequently complicate SSc microangiopathy. Methods: We retrospectively analysed the NVC of 65 SSc patients, performed by 200x videocapillaroscopy connected to image analyse software (Videocap; DS MediGroup, Milan, Italy). The analysis of NVC images included: total number of capillaries in the distal row (N), maximum diameter (D) and number of giant capillaries (M), M/N ratio and percentage of M, presence/absence of micro-haemorrhages and tortuosity. Results: 21/65 SSc patients experienced digital ulcers within three months after the NVC examination. The N, D, M/N, and percentage of M significantly correlated with the appearance of ischemic ulcers. A multiple regression analysis showed a statistically significant correlation for N, M/N and D, while sensitivity and specificity of these parameters were unsatisfactory. A capillaroscopic score, according to the formula D·M/N2, showed a high specificity and sensibility (93.2% and 85.7% respectively; area under ROC curve: 0.918) to predict the appearance of digital ulcers. Conclusions: This capillaroscopic score may represent a feasible and simple tool in SSc patients’ assessment. The routinely use of this parameter might permit to recognize and to preventively treat SSc patients at high risk to develop digital ulcers.