Cytokines in the pruritic papular eruption of HIV

Abstract

Background: The immunopathogenic mechanism of the pruritic papular eruption (PPE) of patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is poorly understood, and the objective of the present study was to determine the concentration of the serum cytokines interleukin-2 (IL-2), IL-4, IL-5, IL-10, IL-12, and gamma-interferon (gamma-IFN) in an attempt to recognize the pattern of CD4+/CD8+ lymphocytes occurring in this dermatosis.

Materials and methods: The study was conducted on 11 HIV-positive PPE patients, matched for sex and age with eight HIV-infected patients with no dermatosis and 10 healthy HIV-negative individuals. Cytokines were quantified by enzyme-linked immunoabsorbent assay (ELISA) using monoclonal antibodies (R & D Systems) and the data were analyzed by the Mann-Whitney, Kruskall-Wallis, and Spearman correlation tests.

Results: An increased concentration of IL-2 was observed in both the HIV-positive (77.65 pg/mL, P < 0.001) and PPE (20.42 pg/mL, P < 0.05) groups when compared with the HIV-negative group (9.50 pg/mL). The IL-2 concentration was significantly higher (P < 0.05) in the HIV-positive group than in the PPE group. Similarly, the gamma-IFN concentration was higher in the HIV-positive (14.97 pg/mL) and PPE (12.67 pg/mL) groups when compared with the HIV-negative group (8.58 pg/mL). The IL-12 concentration was similar in the PPE and HIV-positive groups (1.82 and 1.68 pg/mL, respectively), but higher than in the HIV-negative group (1.17 pg/mL). The same occurred with IL-5 (17.78, 17.79, and 15.74 pg/mL, respectively). There was no significant difference in IL-4 concentration among the PPE, HIV-positive, and HIV-negative groups (10.95, 7.88, and 10.16 pg/mL, respectively), and the same was observed for IL-10 (22.41, 21.13, and 20.92, respectively). There was a negative correlation between serum gamma-IFN concentration and peripheral CD4+ lymphocyte number (r = - 0.6256) in the PPE group (P < 0.05).

Conclusions: The lower levels of IL-2 and gamma-IFN and the negative correlation between gamma-IFN and peripheral CD4+ lymphocytes may indicate an early phase of immunosuppression in PPE.