Hodgkin lymphoma risk following infectious and chronic inflammatory diseases: a large population-based case-control study from Sweden.

Patients with Hodgkin lymphoma (HL) have a well-characterized immune deficiency of T cell function, originally identified by increased susceptibility to certain infections. Epidemiological evidence has long pointed to infectious etiologies in younger HL patients. With the aim of expanding our knowledge on the potential role of pre-existing immune deficiency in HL and an infectious/inflammatory etiology, we conducted a comprehensive population-based case-control study in HL patients diagnosed in Sweden in the period 1965-2004, and their matched controls. In a large population-based study including 7,414 HL patients and 29,240 matched controls, we evaluated the subsequent risk of HL in relation to a broad range of infectious and inflammatory conditions, using unconditional logistic regression. A previous history of any reported infection was associated with an 11 % increased risk of HL (P < 0.05). More specifically, we found sinusitis (odds ratio = 1.81; 95 % confidence interval = 1.06-3.07), tuberculosis (1.76; 1.01-3.07), encephalitis (7.88; 1.97-31.5), and herpes zoster (2.20; 1.11-4.35) to be associated with excess HL risk. A personal prior history of chronic inflammatory condition was not associated with an increased risk of HL (0.94; 0.71-1.14). Our results suggest that underlying immune deficiency is a primary phenomenon in HL. Alternatively, certain infectious agents may be potential HL triggers.