A cohort of 344 children aged less than five years were followed for one year to establish the relationship between haptoglobin genotype, haptoglobin plasma level and malaria infection and susceptibility. Haptoglobin genotyping was undertaken using PCR, with plasma haptoglobin levels measured using indirect ELISA. The number of children carrying the genotypes Hp^1-1, Hp^1-2 and Hp^2-2 were 85, 171 and 88, respectively. The state of malaria infection was assessed using standard microscopy method to detect parasitemia. Higher plasma haptoglobin level tended to be associated with negative parasitemia (P=0.01). During malaria infection, haptoglobin level decreased in all individuals and, the decrease significantly varied by genotype, whereby the decrease was greater in Hp^2-2 individuals than the other genotypes. A longitudinal examination of blood smears revealed a slightly higher proportion of children carrying the Hp^2-2 genotype (12.4%) to be positive for malaria, as compared to children with the genotype Hp^1-1 (11.7%) and Hp^1-2 (11.6%). The present study has demonstrated that malaria infection in children affects the haptoglobin plasma level and the effect is influenced by haptoglobin genotype. The study has also revealed a limited influence of haptoglobin genotype to malaria infection and disease development.

Key words: Haptoglobin, malaria, parasitemia.