B-cell stimulation and prolonged immune deficiency are risk factors for non-Hodgkin's lymphoma in people with AIDS.

OBJECTIVES: To identify risk factors for non-Hodgkin's lymphoma (NHL) in people with HIV infection. DESIGN AND SETTING: Case-control study in Sydney, Australia. PARTICIPANTS AND METHODS: Two hundred and nineteen patients with AIDS-related NHL were compared with 219 HIV-infected controls without NHL, matched for CD4 positive cell count and date of specimen collection. Data on demographic, infectious, treatment-related and immunological factors were abstracted by medical record review. The association between demographic factors, sexually transmissible diseases, HIV-related opportunistic infections, anti-viral therapy, duration of immune deficiency and indices of immune stimulation and risk of NHL were derived for these groups. RESULTS: In a multivariate model, there were two independent groups of predictors of NHL risk. The first was duration of immunodeficiency, as measured by longer time since seroconversion (P for trend 0.008), and lower CD4 positive cell count 1 year prior to the time of NHL diagnosis (P for trend 0.009). The second predictor was B-cell stimulation, as indicated by higher serum globulin (a surrogate marker for serum immunoglobulin, P for trend 0.044) and HIV p24 antigenaemia [odds ratio (OR) for p24 positivity, 1.82; 95% confidence interval (CI), 1.15-2.88]. Indices of B-cell stimulation preceded the diagnosis of NHL by several years. Factors not related to NHL risk included clinical indices of Epstein-Barr virus infection and receipt of individual nucleoside analogue antiretroviral agents. Combination therapy with these agents was associated with a non-significant reduction in NHL risk (OR, 0.68; 95% CI, 0.39-1.18). CONCLUSIONS: Markers of long-standing immune deficiency and B-cell stimulation were associated with an increased risk of developing NHL. Unless the strongest risk factor for NHL, immune deficiency, can be reversed, NHL is likely to become proportionately more important as a cause of morbidity and mortality in people with HIV infection.

HIV infection in sexually transmissible disease practice in Sydney: the effects of legislation, public education and changing clinical spectrum.

The experience with human immunodeficiency virus (HIV) infection of a private inner-city sexually transmissible diseases (STD) clinic in Sydney was quantified. Between February 1984 and March 1988, 2073 of the Clinic's patients were tested for antibodies to HIV on 5095 occasions. Of those tested, 538 (26%) were positive for antibodies to HIV: 532 (98.9%) of the seropositives had practised male homosexual intercourse. This is the highest reported seroprevalence of HIV for any primary care service in Australia. Those individuals seropositive because of other risk behaviours were detected by voluntary contact tracing rather than by screening. Female prostitution was not found to be a risk factor for HIV. In general, rates of first HIV antibody tests were adversely affected by threatening legislation, and temporarily stimulated (among lower-risk persons) by a national television campaign. These data suggest that much of the counselling, detection and management of HIV infection in Australia is occurring in private practice, and that STD services (private and public) are at the forefront of the HIV epidemic. This has implications for disease surveillance and control, health services planning and medical education.