Thymic stromal lymphopoietin and digital microvascular damage in systemic sclerosis patient. a pilot study

Background: Systemic sclerosis (SSc) is a complex autoimmune connective-tissue disease, characterised by vasculopathy and fibrosis of the skin and internal organs. Activation of microvascular endothelial cells (ECs) causes the intimal hyperplasia that characterises the vascular remodelling in SSc. The most frequent complication of SSc is the development of digital ulcers (DUs). Thymic stromal lymphopoietin (TSLP) may trigger fibrosis and sustain vascular damage. Aim of this study was to evaluate the correlation between serum level of TSLP and DUs. Methods: 75 consecutive SSc patients were enrolled and serum TSLP levels were measured. The presence of history of DUs (HDU) was evaluated. Recurrent new DUs were defined as the presence of at least 3 episodes of DUs in a 12-months follow up period. The risk of developing new DUs was calculated by applying the capillaroscopic skin ulcer risk index (CSURI). Results: The median value of TSLP was higher in patients with HDU than patients without HDU [181.67 pg/ml (IQR 144.67; 265.66) vs 154.67 pg/ml (IQR 110.67; 171.33), p < 0.01]. The median value of TSLP was higher in patients with an increased CSURI index than patients without an increased CSURI [188 pg/ml (IQR 171.33; 246.33) vs 159.33 pg/ml (IQR 128.67; 218), p < 0.01]. Kaplan-Meier curves demonstrated that free survival from new DUs was significantly (p < 0.01) lower in SSc patients with increased TSLP serum levels. Conclusion: TSLP might have a key role in digital microvascular damage of SSc patients.