Active Extrusion of Heinz Bodies in Drug-Induced Haemolytic Anaemia

S ummary . A patient with repeated episodes of sulphonamide-induced haemolytic anaemia is reported. The haemolytic episodes were associated with a high percentage of Heinz bodies which had the unique feature of being actively extruded from the erythrocytes. Detailed morphological and biochemical studies are outlined, but the basis for the tendency to form Heinz bodies remains unclear. It is suggested that the phenomenon of active extrusion may provide an alternative route, independent of the reticuloendothelial system, for the removal of Heinz bodies. The close resemblance between the active expulsion of the Heinz bodies and the physiological denucleation of the maturing erythroblast is noted and a similar mechanism postulated.