Comparison of lymphocyte subpopulations in the peripheral blood of patients with infectious mononucleosis and human immunodeficiency virus infection: a preliminary report.

The aim of this study was to analyse the lymphocyte subpopulations in the peripheral blood of HIV-1-infected adults to compare them with four patients with acute EBV infection. Lymphocyte subsets in 15 healthy controls, 40 HIV-1-infected adults and 4 EBV-infected patients with infectious mononucleosis were analysed by flow cytometry. The immunophenotyping of HIV-1-infected patients in different stages of disease showed a significant reduction in the percentage and absolute count of CD4+ T-lymphocytes, significantly increased percentage of CD8+ T-lymphocytes, inverted CD4/CD8 ratio and an increase in the expression of activation marker HLA-DR compared to controls. The immuno-phenotyping profiles of HIV and EBV infection share some similarities as they both result in the decreased percentage of CD4+ T-lymphocytes, increased CD8+ T-lymphocytes and an inverted CD4/CD8 ratio. Patients with HIV infection could be distinguished from patients with EBV infection by the absolute lymphocytosis and increased expression of HLA-DR seen in the patients with infectious mononucleosis. In conclusion, both HIV-1 and EBV profoundly change the distribution of lymphocyte subpopulations in the peripheral blood. It is our opinion that flow cytometry could be an aid in the rapid distinguishing of patients with suspected primary HIV-1 infection from those with infectious mononucleosis (before serology data are available).