Genetic variants of SLC11A1 are associated with both autoimmune and infectious diseases: systematic review and meta-analysis

A systematic review and meta-analyses were undertaken to investigate the association of SLC11A1 genetic variants with disease occurrence. Literature searching indentified 109 publications to include in the meta-analyses assessing the association of 11 SLC11A1 variants with autoimmune and infectious disease. The (GT)(n) promoter alleles 2 and 3 (rs534448891), which alter SLC11A1 expression, were significantly associated with tuberculosis (OR = 1.47 (1.30-1.66), OR = 0.76 (0.65-0.89), respectively) and infectious disease (OR = 1.25 (1.10-1.42), OR = 0.83 (0.74-0.93), respectively). However, although no association was observed with autoimmune disease, a modest significant association was observed with type 1 diabetes (allele 2 OR = 0.94 (0.89-0.98)). On the basis of a stronger association of (GT)(n) allele 2 with tuberculosis, compared with the protective effect of allele 3, we hypothesise that allele 2 is likely the disease-causing variant influencing disease susceptibility. Significant associations were observed between the 469+14G/C polymorphism (rs3731865) and autoimmune disease (OR = 1.30 (1.04-1.64)) and rheumatoid arthritis (OR = 1.60 (1.20-2.13)) and between the -237C/T polymorphism (rs7573065) and inflammatory bowel disease (OR = 0.60 (0.43-0.84)). Further, significant associations were identified between the 469+14G/C, 1730G/A and 1729+55del4 polymorphisms (rs3731865, rs17235409 and rs17235416, respectively) and both infectious disease per se and tuberculosis. These findings show a clear association between variants in the SLC11A1 locus and autoimmune and infectious disease susceptibility.