Frontiers in Immunology · Oct 22, 2026
Ultra-low values of total serum immunoglobulin E and cancer risk: a systematic review and exploratory analysis of the Swedish AMORIS cohort
By Monroy-Iglesias MJ, George G, Reardon I et al.
Background: Immunoglobulin E (IgE) is increasingly recognized as a component of immune surveillance with potential relevance to cancer biology. While elevated IgE has been studied in relation to cancer risk, the implications of ultra-low or deficient total serum IgE remain unclear. Methods: We conducted a systematic review of observational studies examining ultra-low or deficient total serum IgE and cancer risk, searching PubMed/MEDLINE and Embase through September 2026. We additionally conducted exploratory analyses among 26,676 adults in the Swedish Apolipoprotein-related Mortality RISk (AMORIS) cohort with baseline total serum IgE measurements. Cancer risk was assessed using Cox proportional hazards models adjusted for age, sex, and education. IgE was analyzed using clinically defined categories (<2, 2–10, 10–20, 20–100, 100–<1,000, ≥1,000kU/L). Results: Seven observational studies met inclusion criteria. Several studies reported higher cancer prevalence or risk among individuals with ultra-low or deficient IgE, although studies were heterogeneous and largely retrospective or unadjusted. In exploratory AMORIS analyses, there was no evidence of an increased overall cancer risk among individuals with IgE deficiency (<2kU/L). Conclusion: Existing studies suggest a possible association between ultra-low total serum IgE and cancer risk, but current evidence is limited. In exploratory AMORIS cohort analyses, there was no evidence of an increased overall cancer risk among individuals with IgE deficiency. Further prospective studies with repeated IgE measurements and comprehensive covariate data are needed to clarify this understudied association.