The association between SNPs in the IL-22 promoter region and TB susceptibility in pooled data stratified by age at diagnosis (≤25 and >25)
We further stratified our pooled data according to the age when the patients were admitted to the hospital for the experimental cohort. As shown in Table 4, out of five SNPs showing significant association in the pooled data, three SNPs (rs2227472, rs2227483, and rs2227485) showed more significant association in younger patients but not in elder patients, and two other SNPs (rs2227473 and rs2227478) showed significant association in elder patients but not in younger patients. Notably SNP rs2227485, which is marginally significant in the pooled data (p-value = 0.049), showed very significant association with decreased TB susceptibility in younger patients (age < = 25 years old) at p-value of 5.2E-5, with OR = 0.496 (95% CI = 0.303–0.663). But for the older group (age >25), this SNP did not show any association with TB susceptibility. A similar situation is true for SNP rs2227472.