Platelet function disorders in north India.

ABSTRACT

BACKGROUND. Platelet function disorders are a fairly common cause of bleeding manifestations. Although their relative types and incidence are well documented, data from India are lacking. METHODS. Between 1970 and 1991, we studied the clinical and laboratory features of 144 north Indian patients who presented to our hospital with a bleeding diathesis in whom coagulation disorders, von Willebrand's disease and a history of drug ingestion were absent. RESULTS. Isolated platelet factor 3 availability defect was the commonest (56 cases) followed by the thrombasthenias (49 cases), arachidonic acid pathway defect (26 cases), storage pool disease (8 cases) and the Bernard-Soulier syndrome (3 cases). Isolated platelet factor 3 deficiency was rare (2 cases). Two varieties of thrombasthenia were seen--the classical Glanzmann's (13 cases) and thrombopathic (36 cases). The latter was characterized by absent or sub-normal platelet aggregation with agonists along with a reduced (to less than 50% of normal) total platelet factor 3 content. This has not been reported from western countries. Patients with classical Glanzmann's thrombopathic thrombasthenia with absent platelet aggregation and isolated platelet factor 3 deficiency were severe bleeders. Their family history suggested an autosomal recessive transmission in Glanzmann's and thrombopathic thrombasthenia and a possible autosomal dominant transmission in isolated platelet factor 3 availability defect and isolated platelet factor 3 deficiency. CONCLUSION. The frequency of various types of platelet function disorders in Indians is similar to that in western populations except that the incidence of thrombopathic thrombasthenias is higher in India.