IMMUNOMODULATION BY NITRITE INHALANTS MAY PREDISPOSE ABUSERS TO AIDS AND KAPOSIS-SARCOMA

Epidemiological studies indicating that nitrite inhalant abuse is a co -factor in HIV infection and in Kaposi's sarcoma are supported by rece nt experimental studies, described in this review. Inhalation exposure to the nitrites produce a nonspecific cytotoxicity, depleting many ce lls of the immune system. Apparently distinct from this cytotoxicity, inhalation of the nitrites impairs a variety of immune mechanisms, aff ecting both humoral and cell-mediated immunity. In addition, the inhal ant-increased macrophage production of the inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha), can directly stimulate HIV replica tion and can also stimulate the growth of Kaposi's sarcoma cells. Thus , nitrite inhalants may impair immune resistance to infection and acti vely promote viral replication and tumor growth. (C) 1998 Elsevier Sci ence B.V.