Hemostatic abnormalities in patients with Ehlers-Danlos syndrome

Background Ehlers-Danlos syndrome (EDS) includes a heterogeneous group of connective tissue disorders affecting skin, bones, vessels, and other organs. Patients with EDS have an increased risk of bleeding, but a comprehensive study of hemostasis in EDS patients is lacking. Objective To investigate the bleeding tendency of a cohort of patients with EDS by using the Bleeding Assessment Tool of the ISTH, the bleeding severity score (BSS). Methods The BSS was defined as abnormal when it was >= 4 in men and >= 6 in women. Patients with a bleeding tendency were compared with those without in terms of type and number of hemostatic abnormalities. Results Fifty-nine of 141 patients with EDS (41.7%) had an abnormal BSS. Prothrombin time and activated partial thromboplastin time were slightly prolonged in 10 patients (7.1%) because of mild coagulation factor deficiencies, which were not responsible for the bleeding diathesis. von Willebrand factor antigen, ristocetin cofactor, endogenous thrombin potential and platelet count were normal in all patients. At least one platelet function abnormality was found in 53 patients (90%) with an abnormal BSS and in 64 (78%) with a normal BSS (adjusted odds ratio [OR] 2.55, 95% confidence interval [CI] 0.87-7.48). The risk of bleeding progressively increased with the number of platelet function abnormalities, reaching an OR of 5.19 (95% CI 1.32-20.45) when more than three abnormalities were detected. Conclusions Our results show that nearly half of patients with EDS have an abnormal BSS, which, in 90% of cases, appear, at least in part, to be attributable to platelet function abnormalities. Abnormalities of primary hemostasis may contribute to the risk of bleeding in patients with EDS.