Increased CD4-positive monocytes in HIV-infected haemophilic patients

The monocyte–macrophage system is known to play a central role in HIV infection, and expression of CD4 on the surface of monocytes/macrophages is important, since this molecule is a key factor for the entrance of HIV into susceptible cells. In this paper we evaluated the expression of CD4 in monocytes of haemophiliac patients (He) who had been infected with HIV (HIV+ He) through transfusion of contaminated plasma concentrates. Thirty seropositive patients (HIV+ He), 10 seronegative He patients (HIV− He) and 20 voluntary normal blood donors were studied. Phenotypic evaluation of monocytes was performed by flow cytometry of peripheral blood stained with anti‐CD45, ‐CD3, ‐CD4 and ‐CD14 monoclonal antibodies. The percentage of CD4 monocytes was increased in all HIV+ patient groups, but it was highest in those belonging to Groups III and IV A of the CDC classification. Furthermore, the median of fluorescence intensity of CD4+ monocytes from individual patients was shifted to the right, indicating expression of increased numbers of CD4 molecules on the cell membrane of monocytes. This could in turn favour HIV infection and viral persistence, facilitating in vivo dissemination of the virus.