SUPPRESSION OF ERYTHROID PROGENITOR CELLS DURING MALARIAL INFECTION IN THAI ADULTS CAUSED BY SERUM INHIBITOR

The bone marrows of 21 Thai adults infected with Plasmodium falciparum malaria were cultured for CFU-E and BFU-E by using AB serum, autologo us serum (parasitaemia) and autologous serum (post-parasitaemia). Six patients had no complication and 15 patients had pulmonary, renal or h aematologic complications. In the non-complicated cases, sera during p arasitaemia did not suppress the post-parasitaema CFU-E and BFU-E. Pos t parasitaemia, there was suppression of CFU-E by parasitaemia sera. I n the complicated cases, the autologous sera during parasitaemia suppr essed the growth of both CFU-E and BFU-E both during and after parasit aemia (P < 0.05). The post-parasitaemia sera had neither a suppressive nor a stimulating effect. In the complicated cases, the progenitor ce lls cultured from the bone marrow post-parasitaemia were fewer in numb er than those cultured from the bone marrow during parasitaemia using the same sera. Two possible mechanisms of suppression are postulated, namely the reduction of erythropoietin or the increased tumour necrosi s factor during malarial infection. Further studies to clarify this ar e being carried out.