Search for evidence of a Th2 profile in HIV plus patients

Background Hypersensitivity dermatoses are common in human immunodeficiency virus-positive (HIV+) patients, particularly as the disease progresses. St udies have shown that a switch to T-helper 2 (Th2) might represent a turnin g point in HIV. This study investigated whether increases in the number of skin mast cells, immunoglobulin E (IgE) serum levels, and eosinophilia, inv olved in the Th2 response in allergic disease, might also be present in HIV + patients. If so, these alterations might explain one of the mechanisms of skin hypersensitivity in these patients. Methods Forty-five skin biopsies from the normal skin of the upper arm of H IV+ patients and 15 controls were included in the study. HIV+ individuals w ere classified into three equal categories according to their immunologic s tatus: Category I (< 200/mu L), Category II (200-499/mu L), and Category II I (> 500/mu L). Anti-tryptase antibody was employed in tissue sections to s how mast cells; IgE serum levels and eosinophils in peripheral blood count were investigated; delayed-type hypersensitivity (DTH) skin tests (candidin , trichophytin, and PPD 2U) were evaluated. Results Normal cutaneous mast cell and eosinophil counts were the same in a ll categories and in the control group, but increased IgE levels (P < 0.01) and DTH skin test anergy (P < 0.006) were observed among acquired immunode ficiency syndrome (AIDS) patients. Conclusions The density of skin mast cells in HIV infection was not modifie d in the course of the disease. Mast cells do not seem to be primarily resp onsible for triggering hypersensitivity dermatoses among AIDS patients, alt hough data in support of the Th2 response, as seen in increased IgE serum l evels and DTH anergy, are present.