Can hemozoin alone cause host anaemia?

Both schistosomes and malaria parasites produce hemozoin and cause host anaemia. However, the relationship between anaemia and hemozoin is unclear. Although some studies have proposed that hemozoin is related to anaemia in malaria patients, whether hemozoin alone can cause anaemia in patients infected by malaria parasites or schistosomes is uncertain. To investigate the effect of hemozoin on hosts, β-haematin was injected intravenously to normal mice. Then, liver and spleen tissues were observed. Mouse blood was examined. Red blood cells (RBCs), white blood cells (WBCs) and haemoglobin were analysed. Macrophage changes in the spleens and marrow cells were compared using immunofluorescence and H&E or Giemsa stain, respectively. We found that after 15 injections of β-haematin, a large amount of β-haematin was observed to deposit in the livers and spleens. Splenomegaly and bone marrow mild hyperplasia were detected. The average number of RBCs, average number of WBCs and average concentration of haemoglobin decreased significantly from 9.36 × 10¹² cells/L to 8.7 × 10¹² cells/L, 3.8 × 10⁹ cells/L to 1.7 × 10⁹ cells/L and 142.8 g/L to 131.8 g/L, respectively. In specific, the number of macrophages in the spleens greatly increased after β-haematin infection. The results showed that injections of β-haematin alone can cause anaemia possibly through hypersplenism.