CD4(+) T-lymphocyte counts in HIV infection: Are European standards applicable to African patients?

CD4(+) lymphocyte count (CD4(+) LC) is a widely used marker of Human Immunodeficiency Virus (HIV) immune impairment. Physiological lymphocytosis is frequently encountered in Africans. Therefore, we tried to determine if given CD4(+) LC levels are of similar significance in European versus African HIV-infected individuals. Lymphocyte phenotyping of 750 HIV-infected adults was retrospectively analyzed. Three hundred and seventy patients were consecutively selected in Paris, France; 185 in Abidjan, Cote d'Ivoire; and 195 in Bobo-Dioulasso, Burkina Faso. In the three settings, lymphocyte phenotyping was performed by flow cytometry using similar protocols. Data from Abidjan and Bobo-Dioulasso were combined on the basis of geographic proximity and contrasted with those from Paris. Geometric mean levels of Total Lymphocyte Count (TLC), CD4(+) LC, CD8(+) lymphocyte count (CD8(+) LC), and CD4:CD8 ratio, adjusted for percentage of CD4(+) T-cells (%CD4(+)), were compared between Africans and Europeans. For a given %CD4+, TLC and CD4(+) LC but not CD8(+) LC tended to be about one third higher in West African than in French adults (p < 0.0001). Approximate equivalencies of absolute CD4(+) counts in French and West African HIV-infected adults suggest that where thresholds of 200 and 500 CD4(+) cells/mu l are applied in Europe, it might be appropriate to apply a threshold of similar to 250 and 700 CD4(+) cells/mu l in West Africa, respectively. Establishing indicators of progression of HIV infection with locally appropriate thresholds may represent important steps toward improvement of HIV disease management in Africa.