Biochip array-based analysis of plasma cytokines in HIV patients with immunological and virological discordance

Assessment of cytokines in body fluids or cells provides important information in understanding the disease process and designing treatment strategies. Recent introduction of antibody-based protein arrays have provided investigators simultaneous and specific detection of multiple analytes in a single sample using minimum volumes. In this study, we used a biochip array system capable of measuring 12 cytokines and growth factors (IL-2, IL-4, IL-6, IL-8, IL-10, IL-1alpha, IL-1beta, IFN-gamma, TNF-alpha, monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF)) in HIV patients with immunological and virological discordance (discordant) to find out differences if any, in their plasma cytokine profiles when compared with concordant HIV-infected individuals. A sandwich chemiluminescent assay was performed with plasma specimens of 110 HIV patients (55 discordant, 55 concordant) and 22 normal healthy individuals followed by enzyme-linked immunosorbent assay (ELISA) to the confirm levels of cytokines and growth factors that showed significant differences in the two groups. The discordant HIV patients showed significantly higher levels of plasma VEGF (P = 0.001) and EGF (P = 0.034) levels when compared with concordant patients. Overall, the patients showed significantly higher levels of TNF-alpha, MCP-1 and VEGF when compared with the normal healthy controls (P < 0.05). ELISA for VEGF (P < 0.001) and EGF (P = 0.004) confirmed the comparison obtained with biochip array, between the discordant and concordant patients. The results of cytokine quantitation by biochip array and ELISA confirmed that this technology is not only comparable but also has a good potential in the future applications involving measurement of multiple cytokines with limiting specimens.