Compared to the reference tertile (T2), participants in both the lowest (T1) and highest (T3) MPO tertiles exhibited elevated infection odds (T1: OR = 1.15, 95% CI: 1.05–1.25, p = 0.002; T3: OR = 1.18, 1.08–1.28, p < 0.001; Table 2). This evidence concerns the gene MPO and infection.