Intraleucocytic malaria pigment and clinical severity of malaria in children

Abstract

Intraleucocytic malaria pigment has been suggested as a measure of disease severity in malaria. We have tested this hypothesis by studying 146 children aged 6 months to 14 years in 4 categories—cerebral malaria, mild malaria, asymptomatic malaria and ‘no malaria’—in Ibadan, Nigeria, an area of intense malaria transmission in Africa. Children with cerebral malaria were studied at the university hospital, those with mild malaria at 2 primary health centres and the other 2 groups were studied in a primary school.The proportion of pigment-containing neutrophils showed a clear rise across the spectrum no malaria—asymptomatic malaria—mild malaria—cerebral malaria (median values 2·0%, 6·5%, 9·0% and 27·0%, respectively; P < 0·0001).The proportion of pigment-containing monocytes did not differ significantly between the mild malaria, asymptomatic malaria and no malaria groups but the cerebral malaria group had a higher median value than the other 3 groups. The ratio of pigment-containing neutrophils to pigment-containing monocytes showed the same trend across the groups of subjects as was observed with the number of pigmentcontaining neutrophils. It is concluded that the pigment-containing neutrophil count is a simple marker of disease severity in childhood malaria in addition to the parasite count.