Background & objectives: The enumeration of CD4 and CD8 positive cells, surrogate markers for HIV disease progression, is helpful in management and follow up of immunocompromised HIV-positive patients. In assessing the degree of immune deficiency in HIV-positive patients of a particular region, knowledge of reference range of T-cell subset counts of healthy individuals of that particular region is essential. The present cross-sectional study was undertaken to determine the reference range of T-cell subsets in healthy north Indians and to compare the values with those in HIV-positives.
Methods: Blood samples from 125 HIV seronegative healthy volunteers comprising group I (88 males, 37 females) and 452 HIV- positive patients, divided into group II of asymptomatic (n=137; 93 males, 44 females) and group III of AIDS patients (n=315; 253 males, 62 females) in the age group of 17-60 yr, were analysed for enumeration of CD4+, CD8+ cells/microl by flow cytometry.
Results: In group I, the CD4 and CD8 levels were 687 +/- 219 and 611 +/- 288 cells/microl in males and 740 +/- 255 and 546 +/- 246 cells/microl in females. Overall, a significant depressed level of CD4 (525 +/- 207 cells/microl) and elevated level of CD8 (1174 +/- 484 cells/microl) in group II and (170 +/- 115 and 1051 +/- 586 cells/microl) respectively in group III were observed. Group II patients had highest level of CD8 cells. No asymptomatic women had CD4 count of <200 cells/microl.
Interpretation & conclusion: Our findings on T-cell subset reference ranges of normal healthy north Indians validate the utility of determination of CD4 cell count as a useful predictor of AIDS in Indian conditions and confirm that a significant per cent of AIDS patients had CD4 cell count below 200/microl.