Immunological markers of disease progression in human immunodeficiency virus type-l infection in Dar es salaam, Tanzania

Abstract

A cohort of HIV -1 seronegative individuals who were referents of HIV -1 seropositive individuals has been followed up for four years to study the sex difference and variability of lymphocyte subsets and levels of 8-2 M. Lymphocyte subsets determination was done using flow cytometry and levels of 8-2M were determined using an ELISA. Females had significantly higher mean CD4+T-lymphocyte counts and CD4:CD8lymphocyte ratios but significantly lower CD8+T-lymphocyte counts and concentration of 8-2M concentration than males. Percentage CD4+ and CD8+ T- lymphocytes were more reproducable than absolute counts. There was lack of correlation between percentage and absolute CD4+ T-Iymphocyte counts. Among the individuals CD3+ T -lymphocytes percentage, CD4+ T -lymphocyte counts, CD8+ T- lymphocyte counts and percentages and concentrations of 8-2M varied significantly in males in the different years of followup . However, in females only percent total lymphocytes and CD3+ T -lyrnphocytes varied significantly. Total lymphocyte counts, percent CD4+, CD8+ T -lymphocytes and CD4:CD8 lymphocyte ratios did not vary significantly in both sexes during the follow-up period. It is therefore important to consider the variations of these prognostic markers in normal individuals in relation to time and sex when evaluating these parameters in HIV -1 infected individuals. Haemoglobin levels, total peripheral white blood cell count, total lymphocytes, T-lymphocyte subsets and 8-2M concentrations were determined in 183 HIV -1 infected Tanzanian individuals in different clinical stages of HIV infection and in 119 healthy HIV-l seronegative Tanzanian blood donors. Haemoglobin concentration, CD4+ T- lymphocyte percentages and counts, CD8+ T-Iymphocyte percentages, CD4:CD8 lymphocyte ratios and concentration of 8-2M were strongly correlated with clinical stages of HIV -1 infection. However, total peripheral WBC counts, total lymphocyte counts, total T -lymphocyte counts and CD8+ T -lymphocyte counts were not

significantly different among individuals in the various clinical stages of HIV-l infection. In a longitudinal study, hotel workers were followed up for a period of four years to study the natural history of HIV infection. Among individuals with known approximate dates of HIV -1 seroconversion, there was a rapid fall of CD4+ T-lymphocytes, CD4:CD8 ratios and a rapid rise of the CD8+ T-Iymphocyte counts in the first year after HIV -1 seroconversion. There was also a gradual rise of 8-2M levels. The concentration of soluble CD30 doubled during the first year after seroconversion and remained high during the follow up period. Therefore, CD4 + T -lymphocyte counts and concentrations of soluble CD30 and 8-2M showed uniform changes during the follow up period of HIV infected individuals indicating that these parameters are important early markers of disease progression.