Peripheral CD4+/CD8+T-lymphocyte counts estimated by an immunocapture method in the normal healthy south Indian adults and HIV seropositive individuals

Background: Flow cytometry is the standard method for the estimation of CD4/CD8 counts; but the high initial investment for this instrument and costly reagents make it unaffordable to most of the centers in a developing country like India. Objectives: To evaluate the feasibility of an alternate system for the estimation of CD4 and CD8 counts in normal south Indian adults and validate the usefulness of this assay to monitor the counts in HIV seropositive individuals. Study design: Forty-six normal healthy adults and 68 HIV seropositive individuals both belonging to south Indian linguistic groups were enrolled in this cross-sectional study. The HIV seropositive individuals included 54 HIV-1, 9 HIV-2 and 5 HIV 1&2 infected individuals serologically confirmed by one of the commercial Immunoblot kits. The Capcellia CD4:CD8 whole blood assay, an immune-capture ELISA based kit from Sanof DIAGNOSTICS Pasteur, (France) was used with a few modifications in the procedure to measure the CD4 and CD8 counts. Results: The mean CD4 cell counts were 1048 (central 95 centile only), 746 and 424 for the normal healthy adults, asymptomatic HIV seropositives and symptomatic HIV patients, respectively, and the mean CD8 counts were 595, 889 and 732, respectively. Statistically significant differences were observed in the CD4 cell counts between HIV seronegative healthy adults and asymptomatic (P < 0.001) as well as asymptomatic and symptomatic (P < 0.05) HIV infected individuals. The mean CD4 counts of asymptomatic HIV-2 infected individuals was significantly higher than the counts of asymptomatic HIV-1 infected individuals (P < 0.05). Conclusions: This is an user friendly test and can be an alternate to flow cytometry for the estimation of peripheral T-lymphocyte subsets in developing countries. The assay system has certain limitations inherent to ELISA techniques. (C) 2000 Elsevier Science B.V. Ail rights reserved.