Prevalence of von willebrand disease among university students in Riyadh, Saudi Arabia

BACKGROUND: von Willebrand disease (vWD) is the most common hereditary bleeding disorder, affecting up to 1% of the general population. OBJECTIVES: Estimating the prevalence of vWD among adolescents. DESIGN: This study was conducted between February 2014 and January 2016 on Saudi students in Riyadh. SETTINGS: We conducted an epidemiological survey on university students, using the standardized questionnaire based on molecular and clinical markers for the diagnosis and management of type 1 VWD. MATERIALS AND METHODS: All blood samples were tested for complete blood count, prothrombin time, partial thromboplastin time (PTT), and platelet function analyzer (PFA-100). MAIN OUTCOME MEASURES: Samples had an abnormal result of PTT and/or PFA-100 were tested for von Willebrand factor (vWF) antigen and factor VIII (FVIII) activity. SAMPLE SIZE: 2000 university students aged between 17 and 22 years were included. RESULTS: Of these students, 730 (36.5%) had reported bleeding symptoms, 326 (44.6%) had agreed to give blood samples, 116 (35.5%) samples had prolonged PTT (>41 s), 48 (14.7%) had prolonged PFA-100 adenosine diphosphate, 39 (11.9%) had prolonged PFA-100 epinephrine, and 72 (22.0%) had abnormal results in both PTT and PFA-100. Out of 275 samples tested for vWF (Ag and activity) and FVIII, 13 (3.9%) had reduced levels or nonfunction of vWF and 5 (1.6%) had reduced FVIII levels. After correlation with ABO blood group, only 5 (1.6%) cases were confirmed for vWD. The prevalence of vWD among Saudi adolescents in the selected student population was 1.5%. CONCLUSION: In this study, we report for the first time epidemiological survey of bleeding disorders in Arab ethnicity. LIMITATIONS: As this is a prevalence study, we have no limitations to discuss