Relation of haemolytic anaemia and erythrocyte‐bound IgG in α‐ and β‐thalassaemic syndromes

There has been evidence that IgG‐mediated phagocytosis plays some part in destruction of erythroid cells and subsequent anaemia in thalassaemia. In this study using direct immunofluorescence and flow cytometry, erythrocyte‐bound IgG was studied in 53 and 33 β‐thal/Hb E and Hb H patients, respectively. The mean percentages of IgG‐positive erythrocytes in both nonsplenectomized (4.4%) and splenectomized (24%) β‐thal/Hb E patients were significantly higher than that in normal subjects (1.0%); p < 0.05 and < 0.001, respectively. Splenectomized β‐thal/Hb E patients had significantly higher percentages of IgG‐positive erythrocytes than the nonsplenectomized patients ( p < 0.001). The mean percentages of IgG‐positive erythrocytes in Hb H patients were comparable to those from normal controls. However, patients with α‐thal 1/Hb CS had significantly higher IgG‐positive erythrocytes than those with α‐thal 1/α‐thal 2 ( p = 0.008). Splenectomized Hb H patients also had higher IgG‐positive erythrocytes than nonsplenectomized Hb H patients ( p < 0.039). During haemolytic crisis in some Hb H patients, high percentages of IgG‐positive erythrocytes were also demonstrated. This study demonstrates the presence of increased IgG on erythrocytes in patients with β‐thal/Hb E and in those with Hb H disease following splenectomy or in haemolytic crisis.