Three important articles1-3 in this issue of THE JOURNAL focus our attention on infection of monocytes by human T-cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), the virus that causes acquired immunodeficiency syndrome. These articles show that a cell with the characteristics of a monocyte/macrophage is the predominantly infected cell in the brain and lung. They provide strong support for the concept that direct viral infection of these organs by HTLV-III/LAV causes central nervous system disease and lymphocytic interstitial pneumonia.
Although often overshadowed by devastating immunologic deficiency disease, a high incidence of neurological diseases, characteristically dementia with subacute encephalopathy, has been seen in HTLV-III-infected patients. In the majority of these patients, the neurological diseases were not associated with opportunistic pathogens, suggesting that the neurological disease was caused by the HTLV-III/LAV itself. Convincing evidence of the presence of the virus in the brain was first provided by Southern blot hybridization and