ADAMTS13 deficiency and immunological abnormalities in patients with systemic sclerosis.

INTRODUCTION: Systemic sclerosis (SSc) is a chronic autoimmune connective tissue disorder characterized by immunological deviations and generalized microvascular damage. AIM: To determine the serum level of the von Willebrand factor cleaving protease (ADAMTS13) in 39 SSc patients and healthy controls. MATERIAL AND METHODS: ADAMTS13 serum level was determined in 39 SSc patients and 11 healthy controls. Complete history of the patients was recorded and thorough clinical, rheumatological, and dermatological examinations were performed. RESULTS: The serum levels of ADAMTS13 were significantly lower in SSc than in normal controls (455.47 ±128 vs. 702.01 ±142 ng/ml, p < 0.00001). However significant correlations among serum ADAMTS 13 levels and organ changes were not found in SSc patients. CONCLUSIONS: We demonstrate a decreased serum level of ADAMTS13 in SSc patients, which may contribute to the vessel microangiopathy observed in systemic sclerosis.