AIM

To analyze the distribution of lymphocyte subsets in the peripheral blood of patients with infectious mononucleosis caused by Epstein-Barr virus (EBV) and cytomegalovirus (CMV) and to investigate the possible diagnostic usefulness of flow cytometry panel recommended by the Center for Disease Control and Prevention (CDC) for HIV-1 infection.

METHODS

The study included 130 immunocompetent adults with infectious mononucleosis caused by EBV (n=103) and CMV (n=27) and 50 controls. EBV-infected patients were divided into two groups based on typical (n=92) or atypical (n=11) clinical presentation of the disease. Lymphocyte subpopulations were determined by flow cytometry and a panel of monoclonal antibodies recommended by the CDC for the immunophenotyping of patients infected with human immunodeficiency virus (HIV).

RESULTS

Patients with typical and atypical presentation of EBV-induced infectious mononucleosis showed increased percentages of total T-cells, cytotoxic-suppressor CD8(+) T cells and activated HLA-DR(+) T cells compared to healthy controls. Percentages of CD4(+) T cells, as well as CD4/CD8 ratio, were significantly decreased. Absolute counts of CD4(+) T cells and percentages of B cells did not differ from healthy controls. Pattern of changes in CMV-infected patients was completely identical to that in healthy controls, although less pronounced.

CONCLUSION

Lymphocyte subpopulations represented in the CDC panel for HIV are sufficient for the recognition of patients with infectious mononucleosis caused by EBV and CMV. Flow cytometry can be useful support for reaching diagnosis in patients with atypical clinical presentation of EBV-induced infectious mononucleosis.