Plasma cytokines and chemokines differentiate between active disease and non-active tuberculosis infection Adane Mihret a,b,c, *, Yonas Bekele a , Kidest Bobosha a , Martin Kidd d , Abraham Aseffa a , Rawleigh Howe a , Gerhard Walzl c a Armauer Hansen Research Institute, Addis Ababa, Ethiopia b Department of Microbiology, Immunology and Parasitology, School of Health Sciences, Addis Ababa University, Ethiopia c DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 19063, Francie van Zijl Drive, Tygerberg 7505, South Africa d Centre for Statistical Consultation, Department of Statistics and Actuarial Sciences, Faculty of Science, University of Stellenbosch, South Africa Accepted 10 November 2012 Available online 20 November 2012 KEYWORDS Cytokines; Active tuberculosis; Latent infection; Differentiation Summary Objectives: To analyse cytokines and chemokines from unstimulated plasma sam- ples 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 concentra- tions of EGF, fractalkine, IFN-g, IL-4, MCP-3 and IP-10 between contacts and TB patients. Sin- gle 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-g, IL-4, MCP-3, MIP-1b 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 di- agnosing active TB disease and for monitoring effective antituberculosis therapy. ª 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved. * Corresponding author. Armauer Hansen Research Institute, Addis Ababa, Ethiopia. Tel.: þ251 911408984. E-mail address: adane_mihret@yahoo.com (A. Mihret). 0163-4453/$36 ª 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jinf.2012.11.005 www.elsevierhealth.com/journals/jinf Journal of Infection (2013) 66, 357e365