Submitted May 23, 2006
Accepted July 24, 2006
Hodgkin lymphoma and immunodeficiency in persons with HIV/AIDS
Robert J Biggar*, Elaine S Jaffe, James J Goedert, Anil Chaturvedi, Ruth Pfeiffer, and Eric A Engels
National Cancer Institute, National Institutes of Health, Dept of Health & Human Services, MD, USA
* Corresponding author; email: biggarb{at}mail.nih.gov.
In persons with HIV/AIDS (PWHA), Hodgkin lymphoma (HL) risk is increased. However, HL incidence in PWHA has unexpectedly increased since highly active anti-retroviral therapy (HAART) was introduced. We linked nationwide HIV/AIDS and cancer registry data from 1980 through 2002. Immunity was assessed by CD4 T-lymphocyte counts within -6 to +3 months of onset. Annual HL incidence rates were calculated for 4 through 27 months after AIDS onset. During 477,368 person-years (py) of follow-up in 317,428 persons with AIDS (PWA), 173 HL cases occurred (36.2 per 105 py). Incidence was significantly higher in 1996-2002 than earlier. Incidence peaked in PWA with 150-199 CD4 cells/
L (53.7 per 105 py), whereas it was 20.7 in PWA with <50 CD4 cells/L (ptrend= 0.002). For each HL subtype, incidence decreased with declining CD4 counts, but nodular sclerosing decreased more precipitously than mixed cellularity incidence, thereby increasing the proportion of mixed cellularity HL seen in PWA. HL incidence is lower with severe immunosuppression than with moderate immunosuppression. With more severe immunosuppression, nodular sclerosing HL becomes infrequent, explaining the higher proportion of mixed cellularity HL found in PWA. Thus, HAART-related improvements in CD4 counts likely explain the increasing HL incidence in PWHA observed since 1996. With more severe immunosuppression, nodular sclerosing HL becomes infrequent, explaining the higher proportion of mixed cellularity HL found in PWA. Pathogenesis implications are discussed.
