Determination of T-Lymphocyte Subsets in a North African Population (Tunisia): Establishment of Normal Ranges and Results in HIV-Infected Individuals

Human Immunodeficiency Virus (HIV) infection is characterized by a depletion of the CD4+ T-lymphocytes. Absolute counts of CD3+CD4+ cells have been used in monitoring the progression of this disease and in assessing clinical trials of drugs developed to treat HIV infection and related complications [6,10]. In 1993, the definition of AIDS was revised to include HIV-infected persons whose CD4+ Tlymphocytes were ≤ 200 per μl, even in the absence of opportunistic infections or neoplasm. Both the CDC (Center for Disease Control) and WHO (World Health Organization) have emphasized the need to study lymphocyte subsets in normal populations [3]. It is thus necessary for a testing laboratory to establish normal ranges for these subsets in its local population. A number of studies have been done on lymphocyte subsets in healthy individuals. There is, however, a paucity of published data about Tunisians and North Africans in general. Therefore, our first objective in the present study was the establishment of normal ranges for CD3+CD4+ and CD3+CD8+ cells in a healthy Tunisian population. After that, the second step was the assessment of lymphocyte subsets in HIV infected individuals.