Summary
Acquired von Willebrand syndrome (AVWS) has been associated mainly with monoclonal
gammopathy of uncertain significance (MGUS), clonal lymphoproliferative or myeloproliferative
disorders and autoimmunity. In the present work we studied 6 patients with AVWS: four
with MGUS IgG (λ or κ), one with small lymphocytic lymphoma and one with agnogenic
myeloid metaplasia (AMM). All the patients underwent a pharmacokinetic analysis at
presentation in order to study potential differences in recovery, clearance (CL) or
terminal half-life (THL) following administration of von Willebrand factor (VWF) concentrate.
In all the patients with AVWS an increase in clearance and a decrease in THL was observed
as compared to these parameters in patients with hereditary type 3 von Willebrand
disease (VWD). No difference in recovery was observed among the groups. The increase
in clearance and the decrease in THL were significantly more pronounced in the group
of MGUS patients (57.93 ± 25.6 ml/h/kg, and 1.39 ± 0.5 h, respectively) as compared
to these parameters in the AMM (8.06 ml/h/kg, and 6.96 h, respectively) or the lymphoma
(4.76 ml/h/kg, and 6.76 h, respectively) patients (p = 0.03 for clearance and 0.001
for THL). These data indicate that the pharmacokinetic analysis can be a useful tool
to distinguish between MGUS-related and other causes of AVWS, and to plan an appropriate
treatment accordingly.
Keywords Acquired von Willebrand - pharmacokinetics