Analyses of Pre-erythroid cells in peripheral blood of patients with different progression of HIV infection

Pre-erythroid cells, that normally are present in umbilical cord and in peripheral blood of infants where recently found to facilitate bacterial infections during early childhood but at the same time to suppress accompanying pro-inflammatory reactions through mechanisms dependent on the activity of arginase. HIV long term infected patients often exhibit hematopoietic syndroms through mechanisms that include direct effect of HIV on progentor cells, among those, erythroid cells. Increased arginase activity from PBMCs of HIV infected patients has been already shown to correlate with disease progression but whether it was accompanied with changes in population of pre-erythroid cells has not been demonstated before. The goal of our pilot study was to investiagate whether HIV infection is accompanied by hematopietic changes represented by increase of numbers of pre-erythroid cells and if these changes are associated with T cell activation profile. We have recruited to the study HIV infected patients with different pattern of disease progression. Among them were LTNP’s, naive from therapy HIV progressors and patient on ART and control, healthy group of volunteers. PBMC’s isolated from peripheral blood of these patients were used to assess the frequency of pre-erythroid cells and the expression of inflammatory marker (CD38) on CD8+ T cells by means of flowcytometry. We demonstrate that naïve from therapy, HIV progressors show significantly higher frequency of pre-erythroid cells than other groups tested. Patients on the antiretroviral therapy are not different in this regard from healthy controls, wherease LTNP’s show slightly increased number of thee cells. Frequency of pre-erythroid cells was conversly correlated with the frequency of CD38+ CD8+ T cells only in naïve HIV progressors. Our pilot study shows that potentially immunosuppressive pre-erythroid cells can be present in adults infected with HIV and this can be related to direct activity of virus as these cells are not present in significantly different numbers from healthy controls in patients receiving ART with undetectable VL. Farther analyses are necessary to explain the reason of incresed frequency of pre-erythroid cells in peripheral blood of HIV infected patients and to understand whether they have immunosuppressive properties.