SERPINA1 and infection: AAT prevalence differed between regions with higher infection in southern Nigeria (n = 24; χ2 = 2890.4, I2 = 99.1, 95% CI: 99.1–99.3, P < 0.0001), though more studies have been reported in northern Nigeria (n = 54; χ2 = 8311.1, I2 = 99.4, 95% CI: 99.3–99.4, P < 0.0001).