Common immune-related risk factors and incident non-Hodgkin lymphoma: the multiethnic cohort.

Severe immune dysfunction is an established risk factor of lymphoma, but the role of moderate alterations of immunity is not clear and prospective investigations are needed. We examined several immune-related disorders and medications in relation to non-Hodgkin lymphoma (NHL) in the Multiethnic Cohort. Over 215,000 subjects of African American, Caucasian, Japanese American, Latino and Native Hawaiian ancestry aged 45-75 years completed a questionnaire, including information on medical history, in 1993-1996. After exclusions, we performed Cox regression among 193,050 cohort members including 939 incident NHL cases while adjusting for sex, age, ethnicity, education, body mass index and alcohol intake. Self-reported diabetes was not associated with NHL overall, but was positively associated with risk among Japanese Americans [hazard ratio (HR) = 1.55; 95% confidence interval (CI): 1.10-2.17]. Participants with a history of blood transfusion were at increased risk with HR = 1.39 (95% CI: 1.06-1.84) in men and HR = 1.22 (95% CI: 0.94-1.58) in women, especially for the diffuse large B-cell lymphoma subtype. History of asthma or other allergies was associated with elevated risk only among Latinos (HR = 1.46; 95% CI: 1.07-2.00) who also showed a significant relation between current use of antihistamines and NHL (HR = 1.80; 95% CI: 1.09-2.97). Use of nonsteroidal anti-inflammatory drugs was not associated with NHL. Our findings from this large prospective study support a moderate risk for NHL related to blood transfusions, current long-term antihistamine use and diabetes, but the associations were limited to certain ethnic groups and require further replications.