AUTONOMIC NERVOUS-SYSTEM DYSFUNCTION ASSOCIATED WITH HIV-INFECTION IN INTRAVENOUS HEROIN USERS

Objective: To evaluate the presence of autonomic nervous system (ANS) involvement in HIV-positive drug users. Design: We investigated 37 HIV-positive (and 18 HIV-negative controls) intravenous heroin users who were without symptoms and signs of autonomic or peripheral neuropathy. Methods: The patients were clinically and immunologically assessed and subjected to a battery of five cardiovascular reflex function tests. Results: The tests revealed ANS involvement in 22 HIV-positive subjects but only in one HIV-negative subject. Immunoglobulin (lg) G and C1q immune complex levels were significantly higher in HIV-positive subjects with severe cardiovascular reflex function tests alteration compared to those with normal tests. In a follow-up of 17 HIV-positive subjects, nine presented deteriorated reflexes in the tests and higher lgG immune complex levels. Conclusions: The results confirm that, by using sufficiently sensitive tests, signs of preclinical autonomic neuropathy can frequently be found in HIV-positive intravenous heroin users, as previously observed in homosexual patients, and suggest the existence of an HIV-related autoimmune pathogenesis. Early diagnosis of ANS involvement could be important, since the presence of autonomic dysfunction could increase the risk of cardiorespiratory arrest during invasive procedures.