Occupational exposure to immunologically active agents and risk for lymphoma: The European Epilymph case-control study

Objectives: Allergies and asthma may be protective for the development of lymphoma. We evaluated whether occupational allergens that provoke immune reactivity and asthma through an IgE-mediated pathway are protective for lymphoma. Methods: The Epilymph study includes histologically or cytologically confirmed Hodgkin, B-cell, and T-cell lymphoma cases from six European countries (Spain, France, Germany, Italy, Ireland, and Czech Republic) recruited in 1998-2004. Controls were frequency matched to cases by age, gender, and study centre. Lifetime occupational exposure to seven high molecular weight (HMW) agents was evaluated through an asthma-specific job-exposure matrix. 2205 lymphoma cases and 2296 controls with complete occupational history could be included in the analysis. Associations between HMW exposures and lymphoma were evaluated using pooled unconditional logistic regression analyses. Results: Individuals exposed to HMW agents had a non-statistically significant decreased risk of any lymphoma (OR, 0.88: 95% CI, 0.74-1.05) and of B-cell lymphoma (OR, 0.91; 95% CI, 0.76-1.09), and a significantly decreased risk for Hodgkin lymphoma (OR, 0.62; 95% CI, 0.40-0.98). A decrease in risk for lymphoma was found for exposure to latex (OR, 0.74; 95% CI, 0.55-0.99). Conclusions: Further epidemiologic and mechanistic research is needed to confirm that occupational exposure to HMW agents predisposing to asthma can reduce the risk of lymphoma.