Mannose binding protein deficiency is not associated with malaria, hepatitis B carriage nor tuberculosis in Africans.

ABSTRACT

PIP: Low serum mannose-binding protein (MBP), a calcium-dependent serum lectin that acts as an opsonin to promote phagocytosis, has been characterized as the most common immune deficiency. It has been suggested that MBP acts as a binding protein for mycobacteria and other intracellular pathogens, enabling them to enter host macrophages. The present study investigated the association between variant MBP alleles and malaria, tuberculosis, and hepatitis B virus (HBV) in adults and children in The Gambia. Of the 2041 Gambians screened for MBP mutations, 944 (46%) were homozygous for the wild-type allele, 922 (45%) were carriers of a single variant allele, and 175 (8.6%) possessed 2 mutant alleles. Compared to healthy controls, neither homozygotes nor heterozygotes for MBP genotypes were at increased risk of severe malaria (n = 504), HBV carriage (n = 337), or tuberculosis (n = 397). Stratification of patients by ethnic group did not alter this lack of relationship. However, the most common mutation in Africans--the codon 57 variant allele--was weakly associated with resistance to tuberculosis in both cases and controls. Although MBP deficiency may predispose to recurrent infections, this study failed to provide evidence that such a deficiency is a major risk factor for infectious diseases.