Platelet function disorders.

Platelet function disorders are a rare cause of bleeding in hematological practice. The inherited variety includes defects in platelet adhesion, aggregation, secretion and platelet procoagulant activities. The clinical presentation is usually mild with mainly mucocutaneous bleeds. Milder phenotypes may pass off unrecognized in childhood and present later in life. Testing includes a coagulation screen, which may show a prolonged bleeding time, followed by platelet aggregation tests with agonists. Flow cytometry for platelet surface markers, membrane glycoprotein analysis and facilities for identification of the genetic defect are usually available in research laboratories. Recent advances have opened vistas for antenatal testing. Bone marrow transplantation is the only curative therapeutic option available.

Immune functions in splenectomized thalassaemic children.

A prospective study to assess the immune functions in splenectomized thalassaemic children. Children were those registered in the Thalassemia major. There were 10 splenectomized children (Group 1), 10 non-splenectomized children and 6 age-matched control (Group 3). All children were shown to be HIV seronegative. The mean concentrations of serum IgG and IgA were higher in Group 1 as compared to Groups 2 and 3 but the differences were not statistically significant. Nitroblue tetrazolium (NBT) dye reduction by stimulated polymorphonuclear leukocytes was normal in both study and control groups and the differences were not statistically significant. However, NBT reduction in the unstimulated state was much higher in Group 2 as compared to Groups 1 and 3. Phytohaemagglutinin induced mitogen proliferation was normal in all 3 groups. Children in Group 1 not only had a significantly higher absolute lymphocyte count but also had a lower CD4/CD8 ratio as compared to Groups 2 and 3. Splenectomy does appear to alter the immune status of thalassemic children but the exact mechanism by which this occurrence is not clear.