Abnormalities of Erythropoiesis During HIV-1 Disease: a Longitudinal Analysis

Background: Impaired erythropoiesis is a key abnormality described in untreated HIV-1 disease. Most of the available data on HIV-associated hematopoietic abnormalities were obtained using unfractionated bone marrow-derived mononuclear cells, thus resulting in significant inter (and intra)-individual variability in the number of cultured precursors. Aim of this study was to assess the erythropoietic capability of purified CD34+ progenitors through a longitudinal analysis of burst-forming units-erythroid (BFU-E) growth before and after antiretroviral therapy (ART).

Methods: Twelve HIV-infected individuals were studied before and after ART; 31 HIV-uninfected individuals were enrolled as controls. CD34+ progenitors were purified from peripheral blood by immunomagnetic sorting and cultured in methylcellulose-based medium containing stem cell factor, granulocyte-monocyte colony-stimulating factor, interleukin-3, and erythropoietin. Serum levels of iron, transferrin, transferrin saturation index, soluble transferrin receptor, ferritin, and erythropoietin were also evaluated.

Results: Baseline BFU-E levels were increased in untreated HIV-infected individuals when compared with controls but declined significantly after successful ART. In contrast, serum levels of erythropoietin and soluble transferrin receptor increased significantly after ART.

Conclusions: These findings suggest that, in untreated HIV-infected individuals, chronic inflammation and/or immune activation is associated with defective erythropoiesis and accumulation of erythroid precursors. ART-induced suppression of HIV-1 replication is associated with normalization of BFU-E levels.