Epidemiological and Biological Study of Acquired Immunodeficiency Syndrome-related Lymphoma in the County of Los Angeles: Preliminary Results¹

A population-based case control study of intermediate- and high-grade lymphoma in the County of Los Angeles, CA, was initiated in 1989. Human immunodeficiency virus (HIV)-positive lymphoma patients are compared to HIV-negative lymphoma patients, to HIV-positive controls with acquired immunodeficiency syndrome but without lymphoma, and to HIV-positive asymptomatic individuals. The HIV-negative lymphoma cases are compared to neighborhood controls, who are matched in terms of age, sex, race/ethnicity, and socioeconomic status. All cases are reviewed for pathology by a single group of pathologists. All cases and controls are studied for HIV, Epstein-Barr virus (EBV), and human herpesvirus 6 antigens and antibodies. Tissues from HIV-positive and -negative cases are studied for immunoglobulin gene rearrangement, presence of EBV and HIV, c-myc oncogene rearrangements, and karyotypic analysis. To date, with 294 lymphoma cases and 181 control cases interviewed, high-grade lymphoma has been diagnosed in 82% of the HIV-positive cases versus 40% of the HIV-negative cases (P = 0.001). Although elevated titers of EBV-viral capsid antigen were demonstrated in 82% of HIV-positive versus 50% of HIV-negative lymphoma cases, the geometric mean titer of EBV-viral capsid antigen is similar among HIV-positive lymphoma cases and HIV-positive controls. The geometric mean titer of human herpesvirus 6 antibodies was similar in HIV-positive and HIV-negative lymphoma cases and in the control populations. Monoclonality was demonstrated in all cases of lymphoma. EBV genome was demonstrated within lymphoma DNA in 68% of HIV-positive and 15% of HIV-negative lymphoma cases. Further study will be required to elucidate the full mechanisms of pathogenesis of the acquired immunodeficiency syndrome-related lymphomas.