Correlation of clinical and laboratory surrogate markers of immunodepletion with T cell subsets (CD4 & CD8) determined flow cytometrically in HIV infected patients: a hospital based study.

CD4 count is established in HIV medicine as a marker of immune depletion. However, due to financial constraints this facility is not readily available in India. Therefore, this cross sectional study in the setting of a government hospital in Pune evaluated 72 HIV infected patients for the surrogate markers of CD4 count by correlating CD counts with clinical and easily available laboratory parameters. Using a data extraction Performa, the epidemiological and clinical data of these patients was noted. Routine hematological parameters were determined. T cell subsets were studied by 2-color flow cytometry. These included CD4 counts, CD4 percentage, CD8 counts, CD8 percentage and CD4/CD8 ratio. Status of cell-mediated immunity was determined using a Multi test CMI device and Mantoux reactivity. beta2 microglobulin levels were determined in 50 of the patients. Immunological parameters were correlated with the clinical profile and other simple laboratory markers. Statistical analysis was done using regression coefficients and paired t tests. Patients who had lesser weights had lower CD4 and CD8 counts, ALC (absolute lymphocyte counts) and CD4%. Fall in hemoglobin was associated with low CD4 count, low ALC and low CD8. ALC levels correlated well with CD4 counts below 500 cells / cmm. Patients with anergic skin response to Mantoux testing and impaired cell mediated immunity had lower CD4 counts than those who had intact cell mediated immunity. beta2 microglobulin levels did not correlate well with declining immune dysfunction. However a significant inverse correlation was established between beta2 microglobulin and CD4%.