Transfusion-transmitted retrovirus infection.

This article reviews the history, classification, and disease associations of the known human retroviruses and outlines their profound effects on the practice of transfusion medicine. The immunodeficiency viruses, HIV-1 and HIV-2, produce a cytolytic effect on infected lymphocytes, and are the causative agents of AIDS. In contrast are the oncoviruses, including HTLV-I and HTLV-II, which are typically lymphoproliferative and able to induce cellular transformation. Human foamy viruses, more recently recognized as a potential human neuropathogen, resemble the other retroviruses with their complex genome organization and structure.