[Megaloblastic anemia and platelet function--a qualitative platelet defect in pernicious anemia].

In order to know the entities of platelet defect in pernicious anemia, we investigated platelet functions in ten cases with pernicious anemia. Three of the cases had total gastrectomy. Five cases showed thrombocytopenia and four cases revealed prolongation of Ivy bleeding time. Decreased adhesiveness was observed in three cases. Various abnormalities in platelet aggregation were observed. However, almost all of the cases showed remarkable improvement of decreased platelet functions after the therapy of Vitamin B12 injection. The results of adenine nucleotides in platelets and the release of them following collagen or epinephrine aggregation were analysed in comparison with normal platelets. The ADP was definitely decreased and the ATP/ADP ratio was increased. In addition, the release of ATP and ADP at collagen or epinephrine induced aggregation was markedly decreased, and after the therapy of Vitamin B12, the decrease of adenine nucleotide release remarkably increased. In summary, the acquired defects of platelet function in pernicious anemia are regarded as a secondary storage pool disease, and its defects improve after Vitamin B12 therapy.