Anaemia of acute malaria infections in non-immune patients primarily results from destruction of uninfected erythrocytes

TLDR

Anaemia in acute malaria is known, but the relative contributions of parasite‑direct destruction, loss of uninfected erythrocytes, and altered erythropoiesis remain unclear. The study proposes that uninfected erythrocytes are destroyed by phagocytosis of merozoite‑bound cells during malaria paroxysms. Modeling of patient data revealed that each parasitized erythrocyte is accompanied by destruction of about 8.5 uninfected cells, dyserythropoiesis is negligible, and anaemia develops before a significant antibody response.

Abstract

While anaemia has long been recognized as a consequence of acute infections with malaria, the relative contributions of direct erythrocyte destruction by parasites, destruction of uninfected erythrocytes and changes in erythropoiesis have been unclear. Fitting of parasitaemia and anaemia data from neurosyphilis patients undergoing malaria therapy to a mathematical model shows that in these patients, an average of 8·5 erythrocytes were destroyed in addition to each erythrocyte observed to become parasitized. The model also showed that dyserythropoiesis plays an insignificant role in the resulting anaemia. The anaemia occurs before a substantial antibody response to parasites or erythrocytes could be generated. We postulate that uninfected erythrocyte destruction occurs through phagocytosis of erythrocytes bound to merozoites killed as a result of the accompanying malaria paroxysms.