Research Article Increased Frequency of CD4+ CD25+ FoxP3+ T Regulatory Cells in Pulmonary Tuberculosis Patients Undergoing Specific Treatment and Its Relationship with Their Immune-Endocrine Profile Ariana Díaz, 1 Natalia Santucci, 1 Bettina Bongiovanni, 1 Luciano D’Attilio, 1 Claudia Massoni, 2 Susana Lioi, 2 Stella Radcliffe, 2 Griselda Dídoli, 1 Oscar Bottasso, 1 and María Luisa Bay 1 1 Institute of Immunology, School of Medical Sciences, National University of Rosario, Rosario, Santa Fe, Argentina 2 Central Laboratory, Centenary Provincial Hospital, Rosario, Santa Fe, Argentina Correspondence should be addressed to Ariana D´ ıaz; arianadiazd@gmail.com Received 24 October 2014; Revised 22 January 2015; Accepted 23 January 2015 Academic Editor: Marco Antonio Velasco-Vel´ azquez Copyright © 2015 Ariana D´ ıaz et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tuberculosis (TB) is a major health problem requiring an appropriate cell immune response (IR) to be controlled. Since regulatory T cells (Tregs) are relevant in IR regulation, we analyzed Tregs variations throughout the course of TB treatment and its relationship with changes in immune-endocrine mediators dealing with disease immunopathology. Te cohort was composed of 41 adult patients, 20 of them completing treatment and follow-up. Patients were bled at diagnosis (T0) and at 2 (T2), 4 (T4), 6 (T6), and 9 months following treatment initiation. Twenty-four age- and sex-matched healthy controls (HCo) were also included. Tregs (fow cytometry) from TB patients were increased at T0 (versus HCo  < 0.05), showing even higher values at T2 (versus T0  < 0.01) and T4 (versus T0  < 0.001). While IL-6, IFN-, TGF- (ELISA), and Cortisol (electrochemiluminescence, EQ) were augmented, DHEA-S (EQ) levels were diminished at T0 with respect to HCo, with cytokines and Cortisol returning to normal values at T9. Tregs correlated positively with IFN- ( = 0.868,  < 0.05) at T2 and negatively at T4 ( = −0.795,  < 0.05). Lowered levels of proinfammatory cytokines together with an increased frequency of Tregs of patients undergoing specifc treatment might refect a downmodulatory efect of these cells on the accompanying infammation. 1. Introduction According the World Health Organization one third of the world population is infected with Mycobacterium tuberculosis (Mtb), and the majority of afected people are found in developing countries. Te situation becomes even more problematical because of the increased susceptibility of HIV infected persons to develop the disease and the emergence of strains resistant to the antimicrobial therapy [1]. Most people infected with Mtb have a clinically latent infection and 10% of them further progress to active TB dur- ing their lifetime. Bacterial, host, and environmental factors infuence the development of active TB [1, 2]. Commonly, the host immune response (IR) controls Mtb replication, collaborating with the establishment of latent infection, which ultimately depends on a fne balance between the pathogen persistence and the specifc IR [3]. T cell-mediated immunity is the main response against TB, mainly through interferon-gamma (IFN-) production by antigen specifc T cells. However an exacerbated efector IR and the ensuing excessive secretion of infammatory mediators turn out to be detrimental damaging host tissues through immunopatho- logical processes. It follows that a properly balanced IR is essential to successfully cope with this pathogen [4]. Regulatory T cells which tend to modulate the anti- infectious host immunity are currently viewed as one of the suitable mechanisms for T-1-dependent immune response suppression. Among these T cell subpopulations, those Hindawi Publishing Corporation Journal of Immunology Research Volume 2015, Article ID 985302, 8 pages http://dx.doi.org/10.1155/2015/985302