Red pulp of the spleen in autoimmune haemolytic anaemia and hereditary spherocytosis: morphometric light and electron microscopy studies.

Morphometric light and electron microscopy studies on perfusion-fixed spleens from 6 patients with autoimmune haemolytic anaemia and 18 patients with hereditary spherocytosis showed increased relative (and absolute) volumes of red pulp and absolute volumes of pulp cords when compared to 10 controls and 16 patients with immune thrombocytopenia without haemolysis. The mean erythrocyte volume density of the red pulp and mean erythrocyte area were significantly increased, and more of the erythrocytes' profiles were closer to being circular than in the controls. The changes within the splenic red pulp were qualitatively identical in the 2 cases of haemolytic disease, being quantitatively more pronounced, however, in hereditary spherocytosis than in autoimmune haemolytic anaemia.