Relationship between NRAMP1 gene polymorphism and efficacy of BCG vaccine in a helminth-infected population.

Infection of mothers with schistosomiasis and filariasis has been shown to influence infant responses to neonatal Bacille Calmette-Guerin (BCG) immunization. The genetic makeup of infants is also considered an important determinant for the activity of BCG vaccine. The effect of natural resistance-associated macrophage protein 1 (NRAMP1) gene polymorphism on the efficacy of BCG vaccine was examined in neonates with helminth-infected mothers (63 infants) and the results were compared with neonates of uninfected mothers (187 infants). After BCG vaccination, assessment of scar presence, tuberculin test, stool analysis, and IgE level was performed. Polymorphism of the NRAMP1 gene was investigated by PCR amplification followed by RFLP analysis. We found that patients with heterozygosity of intron 4 (GC) and/or maternal infection with helminth parasites showed reduced efficacy of BCG vaccine against tuberculosis.