Antibodies to Plasmodium falciparum merozoite protein protective.

2003 NOV 19 - (NewsRx.com & NewsRx.net) -- Serum IgG3 antibodies against the Plasmodium falciparum merozoite surface protein 2 is strongly associated with a reduced prospective risk of malaria.

"The merozoite surface protein 2 (MSP2) of Plasmodium falciparum is recognized by human antibodies elicited during natural infections, and may be a target of protective immunity. In this prospective study, serum IgG antibodies to MSP2 were determined in a cohort of 329 Gambian children immediately before the annual malaria transmission season, and the incidence of clinical malaria in the following five months was monitored," scientists in the U.K. and Gambia report.

"Three recombinant MSP2 antigens were used, representing each of the two major allelic serogroups and a conserved region," said Wolfram G. Metzger and collaborators at the London School of Hygiene and Tropical Medicine and University of Edinburgh in the U.K. and Medical Research Council Laboratories in Gambia. "The prevalence of serum IgG to each antigen correlated positively with age and with the presence of parasitemia at the time of sampling.

"These antibodies were associated with a reduced subsequent incidence of clinical malaria during the follow-up. This trend was seen for both IgG1 and IgG3, although the statistical significance was greater for IgG3, the most common subclass against MSP2."

"After adjusting for potentially confounding effects of age and ...