[Utility of desmopressin in 4 cases of thrombocytopathies associated with giant platelets]. / Utilidad de la desmopresina en cuatro casos de trombocitopatías asociadas a plaquetas gigantes.

Shear-induced aggregation requires the platelet glycoprotein complexes (Gp), the von Willebrand factor (vWf) and ADP. The Bernard Soulier syndrome (BS) and the gray platelet syndrome (GPS) are platelet function defects characterized by absence of GP Ib/IX and alpha granules, respectively, with mucocutaneous hemorrhages, prolonged bleeding time (BT) and moderate thrombocytopenia in both syndromes. There are reports that desmopressin (DDAVP) shortens the BT in some patients with platelet dysfunction. The purpose of this study was to evaluate the response t(DDAVP) in four female patients (2 with GPS plus Marfan's disease and 2 BS). All had bleeding episodes, BTs > 10 minutes, platelet counts (PC) between 40-88 x 10(9)/L and defects in platelet aggregation. The DDAVP was administered at a dose of 0.3 microgram/kg in 15 to 30 mL of isotonic saline given by slow intravenous drip in 30 to 45 min. All patients were studied before and after DDAVP administration (BT, PC, platelet factor, mean platelet volume, factors F.VIII:C, FvW:Ag, FvW:RiC of, and platelet aggregation). After DDAVP infusion the patients had a BT < 6 min, and increased levels of F. VIII:C, FvW:Ag and FvW:RiC of (> 100 Ul/dL), and the bleeding disappeared. We conclude that there was a good response to DDAVP probably associated with improved platelet adhesion, and increases in the multimers of the von Willebrand factor.

Treatment of patients with hemophilia A and inhibitors to factor FVIII with cimetidine.

In this study, cimetidine was used to treat patients with hemophilia A and inhibitors to factor VIII who presented with acute hemorrhages (Group A) and those without hemorrhages (Group B). The dose of cimetidine was 15 mg/kg/day. Group A consisted of five patients with inhibitors between 156 and > 10,000 Bethesda Units (BU), all with serious hemorrhagic problems. The control of hemorrhaging was effective in 100% of these patients, although inhibitor levels remained high (25-380 BU). Group B consisted of seven patients who did not have hemorrhages, whose inhibitor levels were 41-358 BU. Five of these patients no longer had anamnestic responses to Factor VIII after several months of treatment with cimetidine. No difference in the response to cimetidine was seen between HIV positive and HIV negative patients. The results suggest that cimetidine is useful to suppress inhibitors to Factor VIII in patients with hemophilia A.

[Report of 2 cases with acquired von Willebrand disease and one with acquired hemophilia A]. / Informe de dos casos con enfermedad de von Willebrand adquirida y uno con hemofilia A adquirida.

We report three patients with acquired inhibitors against F VIII:C/F vW:Ag complex. Two patients had acquired hemophilia A. The three patients presented with bleeding diathesis. Case 1 was a 19 years old woman with Graves-Basedow disease; case 2 was a 40 years old woman with systemic lupus erythematosus of four years; and case 3 a 38 years old woman who had had rheumatoid arthritis for five years and was in her 3d month postpartum. The F VIII:C level was below 8 U/dL in all cases. The F vW:Ag, ristocetin cofactor and platelet aggregation with ristocetin were diminished in the two cases with von Willebrand. Inhibitor to F VIII:C was 50, 38 and 20 Bethesda units, respectively, for cases 1, 2 and 3. The three patients showed clinical response to DDAVP and cryoprecipitates with partial response in laboratory tests. All patients responded to corticosteroid treatment, but immunosuppressive treatment was necessary in case 3.

[Gray-platelet syndrome associated with Marfan disease in a Mexican family]. / Síndrome de la plaqueta gris asociado a enfermedad de Marfán en una familia mexicana.

Grey-platelet syndrome is a rare familial platelet impairment characterised by lack of alpha granules and giant vacuolated platelets. A Mexican family with grey-platelet syndrome associated to Marfan disease is presented. The family was comprised of 22 members, of whom 3 (the propositus and two of his nephews) could be studied. Two of them, with haemorrhagic symptoms since childhood, had moderate prolongation of the Ivy bleeding time which improved after DDAVP administration, plus moderate thrombocytopenia, giant platelets and abnormal platelet aggregation induced by adrenalin, ADP and collagen. Platelet factor 4 was normal. Electron microscope examination of platelets showed lack of alpha granules and increased dense bodies. The rarity of the casual association of two low-frequency genetic diseases, namely Marfan disease and the grey-platelet syndrome, is commented, along with the response attained with DDAVP in the two affected individuals.