Early Infection Incidence and Risk of Acute Leukemia Development Among Mexican Children.

Background: The few epidemiologic studies of infection exposure in early life and acute leukemia (AL) risk in Latino children have yielded inconsistent results, suggesting a possible effect of ethnicity. Here, we examined the correlation between infection exposure and acute leukemia risk in children from Mexico City-One of the biggest Latino cities worldwide.

Methods: This study included 1455 Mexican children diagnosed with de novo AL (2002-2016), and 1455 control individuals frequency-matched by age and health institution. The AL population included acute lymphoblastic leukemia (ALL), Pre-B ALL, and acute myeloblastic leukemia (AML). Logistic regression analyses were performed to investigate direct and indirect proxies of infection in children or their mothers.

Results: Upper respiratory tract infections during the child's first year of life were a risk factor for AL (OR, 2.76; 95% CI, 1.48-5.15), including ALL (OR, 3.14; 95% CI, 1.67-5.89) and Pre-B (OR, 3.11; 95% CI, 1.63-5.96). Mother's infections before and during pregnancy were protective factors against AL (OR, 0.55; 95% CI, 0.47-0.64; and OR, 0.61; 95% CI, 0.52-0.72, respectively). These associations included ALL and Pre-B. In contrast, only mothers' infections before pregnancy and respiratory tract infections were protective factors against AML (OR, 0.45; 95% CI, 0.33-0.62; and OR, 0.50; 95% CI, 0.37-0.68, respectively).

Conclusions: Infections during the first year of life were associated with AL development in children of Mexico City. Additionally, mothers' exposure to respiratory tract infections before and during pregnancy reduced the AL risk in this Latino population.