DDAVP response and its determinants in bleeding disorders: a systematic review and meta-analysis.

Desmopressin (DDAVP) can be used to prevent or stop bleeding. However, large inter-individual variability is observed in DDAVP response and determinants are largely unknown. In this systematic review and meta-analysis we aim to identify the response to DDAVP, and the factors that determine DDAVP response in patients. We included studies with patients with any bleeding disorder receiving DDAVP. First and second screening round and risk of bias assessment were performed by independent reviewers. The main outcome was proportion of patients with complete (factor level > 50 U/dL), or partial (30-50 U/dL) response to DDAVP. Determinants of response including disease type, age, sex, Von Willebrand factor (VWF) and factor VIII (FVIII) mutations, and baseline factor levels were investigated. In total, 591 articles were found and 103 were included. Of these, 71 articles (1772 patients) were suitable for the study's definition of response. Meta-analysis showed a pooled response proportion of 0·71 [0·64;0·78] and a significant difference in response between disease subtypes. For hemophilia A, baseline FVIII:C was a borderline significant determinant of response. In von Willebrand disease (VWD) type 1 patients, VWF:Ag, VWF:Act and FVIII:C were significant determinants. A large variation in response was observed for specific mutations in VWF and F8. Response to DDAVP varied between disease subtypes, and was largely determined by the baseline levels of FVIII:C for hemophilia A and VWF:Ag for VWD. Our findings highlight the significant differences in response and emphasize the need for a standardized response definition and further research into response mechanisms.