Cytokine expression patterns distinguish HIV associated skin diseases

AIDS is known to cause a shift of cytokines in the periphery. However, predominant cytokines in skin of patients with HIV-associated skin diseases have not been clearly defined. We hypothesized that there are distinct cytokine profiles that distinguish among the different clinical manifestations of AIDS-related skin diseases. To test this hypothesis, lesional and non-lesional skin was biopsied from 53 HIV⁺ patients with Kaposi's sarcoma (KS), psoriasis, and pruritus due to eosinophilic folliculitis, and from HIV negative controls with psoriasis or KS prior to therapy. Immunohistochemistry was performed with antibodies to tumor necrosis factor (TNF)-α, interleukin (IL)-10, interferon (IFN)-γ, and interferon-inducible protein (IP)-10. HIV positive individuals included 10 with psoriasis, 14 with pruritus, and 15 with Kaposi's sarcoma. HIV negative controls included 12 with psoriasis and two with KS. Semi-quantitative analysis of cytokine staining was confirmed by optical density using a digital imaging system on four representative skin sections from each disease. Optical density analyses were conducted using ANOVA and t-tests. We found that epidermis overlying HIV⁺ Kaposi's sarcoma was hyperproliferative and was highest in IP-10, IFN-γ, and IL-10 (P=0.0001). HIV⁺ pruritus was significantly highest in TNF-α (P=0.0001) staining. HIV⁺ psoriasis represented an intermediate state for all four cytokines. Normal skin adjacent to lesions showed the same relative patterns, with lower intensities. Skin diseases seen frequently in the setting of HIV and immunodeficiency have relatively distinct levels and patterns of cytokine expression that may reflect immune dysfunction, reactivity to HIV and to opportunistic infections.