Allergies and childhood acute lymphoblastic leukemia: A case-control study and meta-analysis
Menée aux Etats-Unis à partir de données portant sur 977 enfants atteints d'une leucémie lymphoblastique aiguë et sur 1 037 témoins, ainsi qu'à partir des données de 12 études, cette méta-analyse évalue l'association entre des allergies et le risque de développer la maladie
Background: Allergic disease is suspected to play a role in the development of childhood acute lymphoblastic leukemia (ALL). Studies conducted over the last several decades have yielded mixed results. Methods: We examined the association between allergy, a common immune-mediated disorder, and ALL in the California Childhood Leukemia Study (CCLS), a case-control study of 977 children diagnosed with ALL and 1037 matched controls (1995-2015). History of allergies in the first year of life was obtained from interviews, mainly reported by mothers. Logistic regression analyses were conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs), controlling for birth order, day care attendance, and mode of delivery. In addition, we conducted meta-analyses with data from the CCLS and 12 published studies and employed a new method to estimate between-study heterogeneity (R_b). Results: Overall, no associations were observed between childhood ALL risk and specific allergy phenotypes or any allergy, as a group. However, having any allergy was associated with an increased risk of ALL among the youngest study participants. In the meta-analysis random-effect models, a reduced odds of ALL was associated with hay fever (metaOR=0.65, 95% CI: 0.47, 0.90); however, restricting the analysis to studies that used medical records for assessment of allergy or recently published studies, led to null or attenuated results. Conclusions: Overall, our findings do not support a clear association between allergy and childhood ALL. Impact: The degree to which epidemiological studies can inform the relationship between allergies and risk of childhood ALL is limited by between-study heterogeneity.