The MCP-1 (CCL2) -2518 GG genotype is associated with protection against pulmonary tuberculosis in Moroccan patients.

INTRODUCTION Both monocyte chemoattractant protein-1 (MCP-1), also designated officially as chemokine (C-C motif) ligand 2 (CCL2), and interleukin-12 p40 (IL-12 p40) molecules, encoded by polymorphic genes, are central components of the immune response to infection by Mycobacterium tuberculosis (Mtb). Their genetic diversity has previously been associated with the outcome of tuberculosis (TB) infection. We investigated whether the MCP-1 -2518 A/G and the IL-12B (p40) +1188 A/C polymorphisms influence susceptibility to or resistance against pulmonary tuberculosis (PTB) in a Moroccan population group. METHODOLOGY Genomic DNA from 337 patients along with 204 healthy controls were genotyped for the above-mentioned genetic variations using polymerase chain reaction-based restriction fragment length polymorphism assay. RESULTS We found a higher prevalence of homozygous MCP-1 -2518 G allele in healthy individuals than in patients (pc = 0.04; odds ratio  = 0.35; 95% confidence interval  = 0.13 - 0.86), suggesting a potential protective effect, whereas analysis of IL-12B +1188 variation failed to reveal any such association. CONCLUSION Our results are in agreement with recent findings in Ghanaian patients, complying with the known genetic admixture of the Moroccan population.