Quantitation of red cell membrane associated immunoglobulin in children with Plasmodium falciparum parasitaemia

Erythrocyte-associated IgG was measured on washed red cells from 26 children with P. falciparum parasitaemia using an immunoradiometric assay. The values obtained were compared with 15 age-matched controls living in the same area who did not have malaria. The amount of red cell-associated IgG was related to the haemoglobin concentration, degree of parasitaemia and serum immunoglobulin level. The mean red cell-associated immunoglobulin for patients with malaria was 629 molecules per red cell (range 215-1770) which was significantly higher than the control group, who had a mean of 395 molecules per red cell (range 190-930). A statistically significant correlation was established between red cell-associated IgG and the degree of anaemia in the infected patients. In contrast, there was no relationship between the red cell-associated IgG and the degree of parasitaemia or the serum immunoglobulin level. These observations support the hypothesis that an immunological mechanism could be involved in the anaemia associated with malarial infections.