Desmopressin testing in haemophilia A patients and carriers: results of a multi centre survey.

INTRODUCTION: Desmopressin (DDAVP) testing (DT) in patients (pts) with haemophilia A (HA) and carriers (CHA) is up to now not standardized. This prompted us to evaluate results of DT carried out between 1996 and 2011 in centres of the Competence Network Haemorrhagic Diatheses East. PATIENTS AND METHOD: An increase of the factor VIII activity (FVIII) above 50% or at least the two fold of initial values within 120 min after DDAVP was defined as complete response (CR). Data from 80 patients (31 children, 49 adults) of whom 64 suffered from HA (sub-HA: n=48; mild: n=14; moderate: n=2) and 16 patients CHA were evaluated. RESULTS: In 34 patients DDAVP was given i.v. (dose range: 0.26-0.6 µg/kg body weight, mean: 0.33), in 31 intranasally (i.n. 300-600 µg) and in 15 s.c. (15-40 µg). The maximal FVIII increase was reached 60 min after DDAVP. For i.v. application the mean FVIII increase was 3.1-fold, for i.n. 2.1-fold and for s.c. 2.4-fold. A CR was detected in 71 patients, a non-response in 9. Mild side effects such as flush, headaches or nausea were observed in 11 patients (14%). CONCLUSION: For desmopressin testing in patients with haemophilia A and carriers i.v. application at 0.3 µg/kg body weight and the determination of FVIII before and 60 min after desmopressin infusion is recommended.

Evaluation of desmopressin effect on primary haemostasis in pediatric patients with aspirin-like defect as hereditary thrombocytopathy.

OBJECTIVES: Despite about 3 decades of clinical experience with the therapy of inherited thrombocytopathies (HTP) with desmopressin (DDAVP) the mechanisms of haemostatic effects of DDAVP in these diseases remain unclear. Therefore platelet function diagnostics was carried out in whole blood (WB) from children with aspirin-like defect as one of the clinically mild forms of HTP after DDAVP administration. DESIGN AND METHODS: 11 children (age range: 3-16 years) were treated with DDAVP i.v. (0.3 µg/kg as short infusion). Before, after 120, and 240 min of DDAVP administration the following parameters were measured: platelet aggregation (PA) and ATP release induced by ADP, collagen, ristocetin and thrombin; PFA-100 closure times (CT), factor VIII activity (FVIII:C), Von Willebrand factor antigen (VWF:Ag), collagen binding activity (VWF:CB) and blood count. RESULTS: PA, ATP release and blood count were not influenced by DDAVP administration. PFA-100 CTs were markedly reduced at 120 and 240 min after DDAVP, respectively. FVIII:C, VWF:Ag and VWF:CB were increased after 120 min. CONCLUSION: The DDAVP-induced improvement of primary haemostasis in patients with aspirin-like defect is mainly due to the marked increase of the VWF. For the evaluation of the clinical effect of DDAVP administration in patients with aspirin-like defect the investigation of a larger group of patients is needed.