Allergy biomarker associated with reduced risk for glioma, glioblastoma
Elevated serum levels of IgE were associated with a decreased risk for developing glioma or glioblastoma in a recent study.
In the nested case-control study, researchers evaluated serum specimens from 594 blood donors diagnosed with glioma between January 1974 and December 2007, along with 1,177 matched controls. This cohort included 374 patients diagnosed with glioblastoma matched with 740 controls. Fluorescent assays measured total and respiratory allergen-specific IgE levels to determine relationships between the allergy biomarker and glioma diagnosis.
A reduced risk for glioma was associated with testing positive for total IgE levels (OR=0.75; 95% CI, 0.56-0.99), and the association between elevated total IgE and reduced risk for glioblastoma was found to be borderline statistically significant (OR=0.74; 95% CI, 0.52-1.05). These associations were not sex-specific, but was borderline significant among women (OR=0.52; 95% CI, 0.24-1.11 for glioblastoma; OR=0.62; 95% CI, 0.36-1.08 for glioma).
Testing positive for allergen-specific IgE was associated with reduced risk for glioblastoma in women only (OR=0.46; 95% CI, 0.23-0.93 for women; OR=1.02; 95% CI, 0.72-1.44 for men; OR=0.85; 95% CI, 0.62-1.16 for both). No association was found between testing positive for allergen-specific IgE and risk for glioma for women (OR=0.78; 95% CI, 0.50-1.23), men (OR=1.03; 95% CI, 0.78-1.38) or both (OR=0.95; 95% CI, 0.75-1.22).
Investigators also observed significant or borderline-significant associations between decreased glioma and glioblastoma risk and total IgE levels regardless of the time between IgE tests and tumor diagnosis. Among patients who tested positive for IgE 20 years before diagnosis, investigators calculated an OR for glioblastoma of 0.50 (95% CI, 0.25-1.02) and an OR of 0.54 (95% CI, 0.30-0.99) for glioma.
“In addition to finding associations between both allergen-specific and total IgE and glioma risk, we are first to observe the presence of this association long before tumor diagnosis,” the researchers wrote. “If our findings can be replicated, basic research is needed to identify biological mechanisms that account for the observed associations. Whether this mechanism represents a form of immune surveillance or is a correlate of serum IgE concentration remains to be determined.”