Pharmacokinetic Studies with FVIII/von Willebrand Factor Concentrate Can Be a Diagnostic Tool to Distinguish between Subgroups of Patients with Acquired von Willebrand Syndrome

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.

A new genetic isolate of gray platelet syndrome (GPS): clinical, cellular, and hematologic characteristics

Gray platelet syndrome (GPS) is a disorder characterized by thrombocytopenia and large platelets that lack alpha granules and their contents. We describe two siblings with GPS who are members of a Moslem Bedouin genetic isolate. The children, an 8-year-old girl and a 5-year-old boy, had characteristic pale blue platelets lacking alpha granules on electron microscopy. Platelet aggregation studies were normal. The girl underwent a bone marrow aspiration and biopsy which showed mild myelofibrosis and extensive emperipolesis, i.e., the passage of other hematopoietic cells through megakaryocytes. Both children lacked high-molecular-weight multimers of von Willebrand factor (vWF) and had reduced activity and antigens of vWf. Platelet activation was approximately normal when ADP was employed as agonist, but significantly impaired using the thrombin receptor-activating peptide (TRAP). These findings are explained in light of the mechanism of action of each agonist. In addition, we propose that the emperipolesis was caused by increased P-selectin in megakaryocytes, and resulted in release of fibroblastic growth factors, explaining the myelofibrosis. The detailed description of these cases provides a basis for future differentiation of the various types of GPS, and for our current attempts to isolate the gene causing GPS in this genetic isolate.

Pharmacokinetic studies with FVIII/von Willebrand factor concentrate can be a diagnostic tool to distinguish between subgroups of patients with acquired von Willebrand syndrome

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 (lambda or kappa), 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.

Myeloma ascites--a favorable outcome with cyclophosphamide therapy

A 71-year-old woman with multiple myeloma (MM) in remission was admitted for evaluation of recent abdominal distension and was diagnosed as having massive myeloma ascites. The fluid was characterized by a total nucleated cell count of 6,600/mm3 (67% plasma cells), with a plasma cell CD38+ phenotype. Chemical analysis of the fluid showed lactate dehydrogenase of 122 IU/L, total protein of 2.9 g/dL, albumin of 2.4 g/dL, diastase of 38 IU/dL, cholesterol of 46 mg/dL, and C-reactive protein of 3 g/dL. The serum-ascites albumin gradient (SAAG) was low (0.9). Electrophoresis of the ascitic fluid showed a monoclonal spike in the gamma region and immunoelectrophoresis confirmed the presence of lambda light chains similar to those seen in the urine. Further analysis of the ascitic fluid showed markedly elevated levels of beta2 microglobulin (11,161 microg/L) and interleukin-6 (146 pg/ml compared to serum level of 4.3 pg/ml). There was evidence of intraabdominal masses that completely resolved with continuous high-dose cyclophosphamide (750 mg/m2/day for four days) followed by clinical improvement and disappearance of the ascites. We stress the value of complete fluid characterization and intensive chemotherapy to achieve a favorable outcome.

Severe arterial thrombosis in a congenitally factor VII deficient patient

We report a patient with congenital factor VII deficiency who developed severe arterial thrombosis. A 63-year-old-woman presented low factor VII clotting activity, amidolytic activity and antigen level < 4%. Activated factor VII plasmatic level was < 0.03 ng/ml compared to 4 ng/ml for the control value. She developed severe aorto-iliac thrombosis. 7 d before the thrombotic event, factor VII replacement therapy had been infused. Successful low molecular weight heparin therapy led to total disappearance of the aorto-iliac thrombus without bleeding complications. This suggests that factor VII infusion might have a thrombogenic effect in vivo and might be responsible for thrombosis.