ABNORMAL PLATELET-FUNCTION AND ARACHIDONATE METABOLISM IN CHRONIC IDIOPATHIC THROMBOCYTOPENIC PURPURA

  • 1 January 1981
    • journal article
    • research article
    • Vol. 58  (2) , 326-329
Abstract
Several patients were observed with chronic idiopathic thrombocytopenic purpura (ITP) whose bleeding times were more prolonged than would have been expected from their platelet counts. In vivo and in vitro platelet function studies were performed, arachidonate metabolism was assessed and platelet-associated IgG (PAIgG) was measured in 7 patients with chronic ITP. The bleeding times of 3 of the patients were prolonged for greater than 7 min, and all of these patients had impaired platelet aggregation and abnormal platelet arachidonic acid metabolism as reflected by increased production of the lipoxygenase product HETE [12-hydroxy-5,8,10,14-eicosatetraenoic acid] and a concomitant decrease in the cyclooxygenase products, TXB2 [thromboxane A2] and HHT [12-hydroxy-5,8,10-heptadecatrienoic acid] (P < 0.001). The abnormalities noted were not due to concomitant drug ingestion, since they were present on repeated evaluation. There was no relationship between the platelet count and the bleeding time; there was a significant inverse correlation between the bleeding time and TXB2 production in all patients evaluated (r = 0.81; P < 0.05). There was no relationship between the level of platelet-associated IgG and any parameter of platelet aggregation or arachidonate metabolism. The abnormalities noted should be looked for in the individual patient with chronic ITP, since the bleeding tendency is exacerbated by the superimposed impairment of platelet function even at platelet counts of > 50,000/mm3, levels generally regarded as safe.

This publication has 0 references indexed in Scilit: