ADAMTS13 ACTIVITY and VON Willebrand FACTOR LEVELS IN PATIENTS with Livedoid VASCULOPATHY.

Abstract

Abstract 5064 IntroductionLivedoid vasculopathy is a rare skin disease caused by the extensive formation of microthrombi in dermis vessels, which leads to infarction and ulceration of the epidermis. The pathogenesis of livedoid vasculopathy is unknown, and hypercoagulation states have been implicated. Moreover, success using anticoagulation was reported in some patients. We hypothesized that decreased levels of ADAMTS13 activity and Von Willebrand factor (vWF) levels could contribute to the pathogenesis of local thrombus formation in livedoid vasculopathy. ObjectiveHere we evaluated the levels of ADAMTS13 activity and vWF in patients with livedoid vasculopathy. Patients and methodsFourteen patients (93% female) with livedoid vasculopathy, median age of 41.5 years (22 - 48) were included in the study. All patients were evaluated for the presence of classical acquired and hereditary thrombophilia markers. In addition, vWF antigen levels (Elisa) and activity (collagen binding assays), as well as ADAMTS13 activity (evaluated by residual collagen binding) were evaluated. Resultsnine patients (64%) were carriers of the MTHFR C677T mutation (6 heterozygous and 3 homozygous); 1 patient was a carrier of factor V Leiden mutation, and 1 patient was a carrier of the FII G20210A mutation. None of the patients presented deficiency of antithrombin, protein C or S, and antiphospholipid antibodies were not identified in our study population. ADAMTS13 and VWF activities were normal in all patients. Median vWF antigen was 120.5U/dl (reference value of 40.0 - 232.0%), and vWF activity was 102.3% (reference value of 45.5 - 203.7%). ADAMTS13 activity was 138.9% (reference value of 56.0 - 227.2 %). Two patients had a history of thromboembolic diseases: one patient with 2 strokes and one patient with central retinal artery occlusion. ConclusionWe show here that ADAMTS13 activity and vWF levels are not altered in patients with livedoid vasculopathy. The MTHFR C677T mutation is frequent in patients with livedoid vasculopathy but quantification of homocysteine levels is necessary to consider any relationship with this disease. DisclosuresNo relevant conflicts of interest to declare.