Inverse Association between Prediagnostic IgE Levels and the Risk of Brain Tumors: A Systematic Review and Meta-Analysis

An inverse association between allergic conditions and glioma risk has been suggested in many epidemiological studies. However, the evidence is inadequate to draw robust conclusions for the association between prediagnostic IgE levels and brain tumors risk. The aim of this study was to provide more precise estimates for this association by meta-analysis of all published studies. Overall, 8 individual studies with 2,461 cases and 3,934 controls were included in our study. A decreased risk of brain tumors (RR = 0.73, 95% CI 0.61-0.86, P < 0.001) was observed in relation to elevated level of total IgE. The negative association was significant between elevated total IgE level and the risk of glioma (RR = 0.74, 95% CI 0.62-0.88, P = 0.001). However, no significant relationship was demonstrated between testing positive for respiratory allergen-specific IgE and brain tumors risk. In addition, the role of prediagnostic IgE levels in brain tumors risk did not alter in men and women. The present study suggests that increased level of total prediagnostic IgE but not respiratory allergen-specific IgE plays a protective role in brain tumors risk, glioma in particular. More studies are warranted for further elucidation of the meningioma risk related to prediagnostic IgE levels.