Autoimmunity and Susceptibility to Hodgkin Lymphoma: A Population-Based Case–Control Study in Scandinavia

Background: Personal history of autoimmune diseases is consistently associated with increased risk of non-Hodgkin lymphoma. In contrast, there are limited data on risk of Hodgkin lymphoma following autoimmune diseases and al most no data addressing whether there is a familial association between the conditions. Methods: Using population-based linked registry data from Sweden and Denmark, 32 separate autoimmune and related conditions were identifi ed from hospital diagnoses in 7476 case subjects with Hodgkin lymphoma, 18 573 matched control subjects, and more than 86 000 fi rstdegree relatives of case and control subjects. We calculated odds ratios (ORs) and 95% confi dence intervals (CIs) as measures of relative risks for each condition using logistic regression and also applied multivariable hierarchical regression models. All P values are two-sided. Results: We found statistically signifi cantly increased risks of Hodgkin lymphoma associated with personal histories of several autoimmune conditions, including rheumatoid arthritis (OR = 2.7, 95% CI = 1.9 to 4.0), systemic lupus erythematosus (OR = 5.8, 95% CI = 2.2 to 15.1), sarcoidosis (OR = 14.1, 95% CI = 5.4 to 36.8), and immune thrombocytopenic purpura (OR = ∞ , P = .002). A statistically signifi cant increase in risk of Hodgkin lymphoma was associated with family histories of sarcoidosis (OR = 1.8, 95% CI = 1.01 to 3.1) and ulcerative colitis (OR = 1.6, 95% CI = 1.02 to 2.6). Conclusions: Personal or family history of certain autoimmune conditions was strongly associated with increased risk of Hodgkin lymphoma. The association between both personal and family histories of sarcoidosis and a statistically signifi cantly increased risk of Hodgkin lymphoma suggests shared susceptibility for these conditions. [J Natl Cancer Inst 2006;98: 1321 – 30 ]