The CARD9 Polymorphisms rs4077515, rs10870077 and rs10781499 Are Uncoupled from Susceptibility to and Severity of Pulmonary Tuberculosis

Genetic variants in the CARD9 gene predispose to inflammatory disorders and chronic infectious diseases. Tuberculosis (TB), a chronic infectious disease affecting the lung, is lethal in Card9-deficient mice. We hypothesized that polymorphisms in the CARD9 gene influence TB progression and disease-associated lung damage in humans. We tested genotype distributions of the CARD9 polymorphisms rs4077515, rs10781499 and rs10870077 in TB patients and healthy subjects in a Caucasian cohort. SNPs were in linkage disequilibrium and none of the haplotypes was significantly enriched in the TB group. We determined total and differential leukocyte count, erythrocyte sedimentation rate and plasma abundance of cytokines and chemokines as markers for systemic inflammation and scored chest X-rays to assess lung involvement in TB subjects. Most disease parameters segregated independently of the CARD9 haplotypes. In contrast to multifactorial chronic inflammation, selected genetic variants in the CARD9 gene leave host responses apparently unaffected in TB, at least in the population analyzed here.