Plasma cytokines and chemokines differentiate between active disease and non-active tuberculosis infection.

OBJECTIVES: To analyse cytokines and chemokines from unstimulated plasma samples for detection of active TB disease, latent TB, discriminating active TB cases from latently infected contacts and for monitoring anti TB treatment.
METHOD: We analysed ex vivo plasma samples from 33 TB patients (17 HIV negative and 16 HIV positive) and 30 healthy household contacts with Luminex. RESULT: We found statistically significant differences (p < 0.05) in median plasma concentrations of EGF, fractalkine, IFN-γ, IL-4, MCP-3 and IP-10 between contacts and TB patients. Single cytokines or chemokines predict with an area under the Receiver Operating Characteristic (ROC) curve of 0.59 for VEGF to 0.98 for IP 10 while a combination of fractalkine, IFN-g, IL-4, IP-10 and TNF identified 96.87% of TB cases and 100% of household contacts. However, none of the cytokines were significantly different in QFT positive and QFT negative contacts (p > 0.05). HIV does not affect the median plasma level of any of the cytokines or chemokines and there was not significant difference between HIV positive and HIV negative TB patients (p > 0.05) in any of the cytokines or chemokines. The median plasma concentrations of IFN-γ, IL-4, MCP-3, MIP-1β and IP-10 were significantly different (p < 0.05) before treatment and after treatment.
CONCLUSION: Plasma cytokines and chemokines could be used as immunological markers for diagnosing active TB disease and for monitoring effective antituberculosis therapy.