Post-infection vaccination with human immunodeficiency virus type 1 (HIV-1) specific antigens has been hypothesized as a mechanism for generating a more effective immune response to the HIV-1 virus. Cutaneous reactions at the site of immunization may provide information on the pattern of immune activation induced by the vaccine.Objective
To evaluate exaggerated local cutaneous reactions in eight HIV-1+ patients enrolled in a phase I and II gp160 vaccine study.Methods
Cutaneous biopsy specimens were obtained and evaluated using routine histologic, immunofluorescence, and immunohistochemical techniques.Results
A mononuclear cell infiltrate with tissue eosinophilia, in some cases forming flame figures, was present on histologic sections. There was no evidence of immune complex deposition. Activated T-helper cells formed a major portion of the mononuclear cell infiltrate.Conclusions
A delayed-type hypersensitivity reaction, mediated by T cells with a T-helper 2 cytokine pattern, was favored by clinical and histologic features. The most likely antigen stimulating this reaction is residual lepidopteran used in the preparation of the vaccine; however, baculovirus antigens may also play a role. In addition, the adjuvant, aluminum phosphate, as well as the underlying patterns of immune dysregulation present in HIV-1 + patients, may potentiate these reactions.