Philip Alcabes

Use of a quantitative cytomegalovirus (CMV) antigenemia test in evaluating HIV+ patients with and without CMV disease

Cytomegalovirus (CMV) infection remains a life-threatening infection in patients with HIV disease. A rapid, quantitative diagnostic technique is needed to adi in the diagnosis of CMV disease. This study was undertaken to evaluate the CMV antigenemia test in patients with HIV disease who are at risk for CMV disease. The study included 22 patients who underwent ophthalmologic exams or selected diagnostic techniques in whom CMV cultures and CMV antigenemia tests were performed. All of 11 patients with CMV disease had positive CMV antigenemia assays [range, 48-1,000 positive cells/2 x 10(5) peripheral blood leukocytes (PBL)], and 10 were also CMV viremic. There was no clinical evidence of CMV disease in 11 patients, including seven in whom the CMV antigenemia assay was negative and who remained without evidence of CMV disease after a median follow-up of 159 days. Four patients had low antigenemia levels. Of these four, two subsequently developed CMV retinitis. In conclusion, a positive CMV antigenemia result with > or = 48 positive cells/2 x 10(5) PBL correlated with concurrent CMV disease. The CMV antigenemia test appears to be a valuable tool for the rapid diagnosis of CMV disease in HIV-infected individuals.

Characteristics of intravenous drug users by history of arrest and treatment for drug use

Typically, intravenous drug users are studied by drawing samples from drug treatment programs, from the criminal justice system, or by outreach into the street community via anthropological or ethnographic methods. Among 1405 subjects recruited through extensive community outreach, 46% reported no history of treatment for drug abuse and 16% said they had not been arrested in the preceding 10 years; 130 (9%) reported neither history. A history of arrest was higher among men and those with a history of: treatment for drug abuse, low educational attainment, having received public assistance, and unemployment. A history of drug treatment was higher among women and those of an older age with a history of: arrest, having received public assistance, and a greater duration and intensity of intravenous drug use. Intravenous drug users who had neither a history of arrest since 1977 nor of drug treatment were more likely to be women and more educated, to have not received public assistance, and to inject less than weekly. These data indicate that characteristics of intravenous drug users differ by history of arrest and treatment, substantiating reports of heterogeneity among intravenous drug users.

Laboratory markers and the risk of developing HIV-1 disease among injecting drug users

ObjectiveTo characterize the progression to HIV-1 disease among injecting drug users (IDU) according to laboratory markers. DesignProspective study of cohort of HIV-1-seroprevalent IDU, with case-comparison component. MethodsDifferent laboratory markers were examined as predictors of progression to HIV-1-associated diseases including AIDS in a cohort of 318 HIV-1-infected IDU. The cohort was enrolled from a methadone treatment program in the Bronx, New York, USA. The independent utility of non-CD4 cell markers was evaluated after adjustment for the association of low CD4 lymphocyte count with AIDS risk. Clinical events in the natural history of HIV-1 were related to changes in levels of two variables related to duration of infection, CD4 lymphocyte count and serum β2-microglobulin (β2M) concentration. ResultsOn univariate analysis, AIDS incidence measured from baseline increased with declining CD4 lymphocyte number and percentage, increasing serum β2M level, low platelet count, low leukocyte count and p24 antigenemia. Among HIV-1-related outcomes prior to any AIDS diagnosis, the relative risk of pyogenic bacterial infections conferred by these markers was similar to the relative risk of AIDS. For all HIV-1 outcomes, the elevated risk encountered at CD4 lymphocyte number ≤ 200x106/l was entirely due to the high risk at ≤150x106/l. On multivariate analysis, control for CD4 lymphocyte count eliminated the association of any other marker with increased AIDS hazard. HIV-1-related outcomes tended to occur in this order: multiple constitutional symptoms, oral candidiasis, pyogenic bacterial infections and AIDS. ConclusionsIn HIV-1-infected IDU, several laboratory markers may predict AIDS when analyzed individually. These are not, however, independently related to increased AIDS risk after adjustment for low CD4 lymphocyte count. A CD4 count ≤150×106/l is more strongly related to immediate risk of adverse outcome than a count of 200×106/l. A progressive series of clinical events is associated with markers of duration, of HIV-1 infection, prior to and including AIDS diagnosis.