Similarity In Joint Function Limitation In Type 3 Vwd And Moderate Hemophilia A

Type 3 von Willebrand Disease (VWD) is a rare bleeding disorder with markedly decreased or absent von Willebrand factor (VWF) antigen, and a parallel decrease in FVIII activity and VWF function. In addition to mucocutaneous bleeding, hemarthrosis and limited joint range of motion (ROM) have been reported. We have previously shown that lower FVIII level, increasing age, history of joint bleeding, and higher body mass index (BMI) are negatively associated with joint function in the Type 3 VWD population. The goal of this study was to compare subjects with similar FVIII levels (Type 3 VWD versus moderate Hemophilia A) in order to further isolate the role of FVIII and other variables in joint ROM loss. A previously validated cohort of subjects with Type 3 VWD and FVIII ≤ 5% were compared to subjects with moderate Hemophilia A (FVIII 1–5%) within the CDC-sponsored Universal Data Collection (UDC) database, which contains information on subjects with bleeding disorders followed at Hemophilia Treatment Centers in the U.S. Subjects with a history of an inhibitor were excluded. At each visit, a joint function score was calculated for each subject as the overall proportion of normal joint ROM based on measures taken of 10 joints. Longitudinal data analysis was performed to identify factors affecting joint ROM loss over time. Clinical characteristics of the two cohorts are as follows: Longitudinal data analysis revealed no significant difference in joint ROM loss over time between the Type 3 VWD and moderate Hemophilia A cohorts. Age, non-white race, lower FVIII level, BMI, use of prophylaxis, and history of an invasive joint procedure or orthopedic appliance were significantly associated with joint ROM loss over time. In the subgroup with age