Haematologic abnormalities in the acquired immunodeficiency syndrome.

During the clinical history of HIV infection, haematological abnormalities represent a common finding which not only contributes to worsening the clinical condition but also limit the use of antibacterial as well as antiviral agents. On the basis of the regulatory role played by the immune system on haemopoiesis, in the present review the foremost derangements of the immunoregulatory circuits are first discussed. The main functional and quantitative defects of peripheral blood erythrocytes, granulocytes, platelets and monocytes are then analysed, and the different bone marrow pictures observed during the progression of the disease are described. To elucidate the physiophatogenetic mechanisms responsible for bone marrow and peripheral cytopenia, the most relevant in vitro studies are reported and discussed. These studies suggest that both a direct cytopathic effect of HIV on haemopoietic progenitors and an immune system mediated mechanism are involved. In view of the HIV selective tropism for lymphocytes and macrophages, which are a major source of haemopoietic growth factors, the new therapeutical strategies for the treatment of cytopenias based on exogenous administration of these cytokines, alone or in combination with antiviral drugs, are briefly reported.