The Impact of Cytokine Levels in Young South African Children with and without HIV-associated Acute Lower Respiratory Infections.

Annamalay, Alicia A; Abbott, Salome; Khoo, Siew-Kim; Hibbert, Julie; Bizzintino, Joelene; Zhang, Guicheng; Laing, Ingrid; Currie, Andrew; Le Souëf, Peter N; Green, Robin J

BACKGROUND Altered host immune responses are considered to play a key role in the pathogenesis of ALRI. The existing literature on cytokine responses in ALRI is largely focussed on adults from developed countries and there are few reports describing the role of cytokines in childhood ALRI, particularly in African or HIV-infected populations. OBJECTIVES To measure systemic cytokine levels in blood plasma from young South African children with and without ALRI and with and without HIV to determine associations between cytokine responses and disease status and respiratory viral identification. METHODS Blood plasma samples were collected from 106 hospitalized ALRI cases and 54 non-ALRI controls less than two years of age. HIV status was determined. Blood plasma concentrations of 19 cytokines, 7 chemokines and 4 growth factors (EGF, FGF-basic, HGF and VEGF) were measured using The Human Cytokine 30-Plex Panel. Common respiratory viruses were identified by PCR. RESULTS Mean cytokine concentrations for G-CSF, IFN-γ, IL-5 and MCP-1 were significantly higher in ALRI cases than in non-respiratory controls.Within the ALRI cases, several cytokines were higher in children with a virus compared with children without a virus. Mean cytokine concentrations for IFN-α, IFN-γ, IL-4, IL-5, IL-13, TNF-α and MIP-1α were significantly lower in HIV-infected cases than in HIV-uninfected cases, while IP-10 and MIG were significantly higher in HIV-infected cases than in HIV-uninfected cases. CONCLUSIONS Certain cytokines are likely to play an important role in the host immune response to ALRI. HIV-infected children have impaired inflammatory responses to respiratory infections compared with HIV-uninfected children. This article is protected by copyright. All rights reserved.