MUC5AC genetic variation is associated with tuberculous meningitis CSF cytokine responses and mortality.

BACKGROUND: The purpose of this study was to assess if single nucleotide polymorphisms (SNPs) in lung mucins MUC5B and MUC5AC are associated with Mycobacterium tuberculosis outcomes.

METHODS: Independent SNPs in MUC5B and MUC5AC (genotyped by Illumina HumanOmniExpress array) were assessed for associations with TNF concentrations (measured by immunoassay) in cerebral spinal fluid (CSF) from tuberculous meningitis (TBM) patients. SNPs associated with CSF TNF concentrations were carried forward for analyses of pulmonary and meningeal tuberculosis susceptibility and TBM mortality.

RESULTS: MUC5AC SNP rs28737416 T allele was associated with lower CSF concentrations of TNF(p = 1.8*10-8) and IFNγ(p = 2.3*10-6). In an additive genetic model, rs28737416 T/T genotype was associated with higher susceptibility to TBM (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.03, 1.49; p = 0.02), but not pulmonary tuberculosis (OR 1.11, 95% CI 0.98, 1.25; p = 0.10). TBM mortality was higher among participants with the rs28737416 T/T and T/C genotypes (35/119, 30.4%) versus the C/C genotype (11/89, 12.4%; log-rank p = 0.005) in a Vietnam discovery cohort (N = 210), an independent Vietnam validation cohort (N = 87; 9/87, 19.1% vs 1/20, 2.5%; log-rank p = 0.02), and an Indonesia validation cohort (N = 468, 127/287, 44.3% vs 65/181, 35.9%, log-rank p = 0.06).

CONCLUSIONS: MUC5AC variants may contribute to immune changes that influence TBM outcomes.