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 count ry like India. Objectives: To evaluate the feasibility of an alternate syst em for the estimation of CD4 and CD8 counts in normal south Indian adults a nd validate the usefulness of this assay to monitor the counts in HIV serop ositive individuals. Study design: Forty-six normal healthy adults and 68 H IV seropositive individuals both belonging to south Indian linguistic group s were enrolled in this cross-sectional study. The HIV seropositive individ uals included 54 HIV-1, 9 HIV-2 and 5 HIV 1&2 infected individuals serologi cally confirmed by one of the commercial Immunoblot kits. The Capcellia CD4 :CD8 whole blood assay, an immune-capture ELISA based kit from Sanof DIAGNO STICS 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 1 048 (central 95 centile only), 746 and 424 for the normal healthy adults, a symptomatic HIV seropositives and symptomatic HIV patients, respectively, a nd the mean CD8 counts were 595, 889 and 732, respectively. Statistically s ignificant differences were observed in the CD4 cell counts between HIV ser onegative healthy adults and asymptomatic (P < 0.001) as well as asymptomat ic and symptomatic (P < 0.05) HIV infected individuals. The mean CD4 counts of asymptomatic HIV-2 infected individuals was significantly higher than t he counts of asymptomatic HIV-1 infected individuals (P < 0.05). Conclusion s: This is an user friendly test and can be an alternate to flow cytometry for the estimation of peripheral T-lymphocyte subsets in developing countri es. The assay system has certain limitations inherent to ELISA techniques. (C) 2000 Elsevier Science B.V. Ail rights reserved.