RELATION OF HEMOLYTIC-ANEMIA AND ERYTHROCYTE-BOUND IGG IN ALPHA-THALASSEMIC AND BETA-THALASSEMIC SYNDROMES

There has been evidence that IgG-mediated phagocytosis plays some part in destruction of erythroid cells and subsequent anaemia in thalassae mia. In this study using direct immunofluorescence and flow cytometry, erythrocyte-bound IgG was studied in 53 and 33 beta-thal/Hb E and Hb H patients, respectively. The mean percentages of IgG-positive erythro cytes in both nonsplenectomized (4.4%) and splenectomized (24%) beta-t hal/Hb E patients were significantly higher than that in normal subjec ts (1.0%); p<0.05 and <0.001, respectively. Splenectomized beta-thal/H b E patients had significantly higher percentages of IgG-positive eryt hrocytes than the nonsplenectomized patients (p<0.001). The mean perce ntages of IgG-positive erythrocytes in Hb H patients were comparable t o those from normal controls. However, patients with alpha-thal 1/Hb C S had significantly higher IgG-positive erythrocytes than those with a lpha-thal 1/alpha-thal 2 (p=0.008). Splenectomized Hb H patients also had higher IgG-positive erythrocytes than nonsplenectomized Hb H patie nts (p<0.039). During haemolytic crisis in some Hb H patients, high pe rcentages of IgG-positive erythrocytes were also demonstrated. This st udy demonstrates the presence of increased IgG on erythrocytes in pati ents with beta-thal/Hb E and in those with Hb H disease following sple nectomy or in haemolytic crisis.