'Lethal' combination of Mycobacterium tuberculosis Beijing genotype and human CD209 -336G allele in Russian male population.

An interaction of different human alleles and endemic bacterial strains may be clinically manifested as different outcome of the disease in different hosts infected with the same genotype. The primary objective of this study was to investigate this issue in the model of Mycobacterium tuberculosis and human DC-SIGN encoding CD209 promoter SNP (rs4804803) in Russian Siberian population. We sought to find a possible combination of M. tuberculosis lineage and human host allele/genotype correlating with unfavorable outcome of the disease. The 101 paired DNA samples from patients with pulmonary TB (human and M. tuberculosis DNA) were studied by 12-loci MIRU-VNTR typing (M. tuberculosis strains) and CD209 -336 A/G typing (human DNA). Ninety autopsy DNA samples as a source of human and mycobacterial nucleic acids from persons who died from TB were also subjected to the same genotyping procedures. A human control group consisted of 177 healthy individuals. The Beijing genotype was more frequently identified in autopsy versus patient samples, in 70.0% and 51.5%, respectively (χ(2)=6.06, P=0.01). Regarding other M. tuberculosis genetic families, no significant difference in LAM family distribution among patient strains and autopsy samples has been found. In contrast, Ural genotype was significantly less frequently detected in the autopsy samples (χ(2)=6.12, P=0.01). Allelic and genotypic frequencies of the CD209 -336A/G did not differ significantly under global comparison when contrasting controls versus patients versus autopsy samples. However intriguing and contrasting significant associations were found in the male subgroup under M. tuberculosis genotype-stratified comparisons. Firstly, male carriers of -336AA genotype were more frequently infected with Beijing genotype (χ(2)=5.2, P=0.02). Secondly and remarkably, this association was inverted in the autopsy sample: male carriers of -336AA genotype died less frequently due to TB caused by a Beijing rather than a non-Beijing strain (χ(2)=5.37, P=0.02). In conclusion, we hypothesize that although carriers of CD209 -336A allele are more sensitive to infection with a Beijing strain, a combination of human CD209 -336G allele and M. tuberculosis Beijing genotype leads more frequently to the lethal outcome in pulmonary TB male patients in Russian (Caucasian) population.