Enhanced basophil releasability in subjects infected with human immunodeficiency virus

Spontaneous histamine release and basophil response to IgE-dependent (anti-IgE) and IgE-independent (formyl-methionine peptide, calcium ionophore A23187) stimuli were evaluated in 15 patients with acquired immunodeficiency syndrome (AIDS), 8 with AIDS related complex (ARC), 7 with lymphadenopathy syndrome (LAS), 11 seropositive asymptomatic subjects, 10 human immunodeficiency virus (HIV)-seronegative drug addicts, and 20 normal subjects. Both spontaneous histamine release and anti-IgE-induced histamine release were significantly increased in HIV-infected subjects, in comparison with seronegative drug addicts and normal controls. Basophil response to anti-IgE was higher in AIDS ARC patients than in seropositive asymptomatic subjects and LAS patients, although the difference was not statistically significant. When basophils were challenged with 0.1 μM formyl-methionine peptide, a significantly increased histamine secretion was found in HIV-infected subjects; conversely, at the higher formyl-methionine peptide concentration (10 μM), as well as at all calcium ionophore A23187 concentrations, histamine release was similar in all the studied groups. No correlation was found among anti-IgE-induced histamine release, total lymphocyte counts, CD4⁺ and CD8⁺ T cell counts, and total serum IgE levels. These findings indicate that infection with HIV is associated with an increased basophil releasability. This could be of some relevance in the increased incidence of allergic manifestations and adverse drug reactions observed in AIDS patients.