Sociated with changes in the distribution of immune cells in the peripheral blood of various clinical groups defined on the basis of TB status. An increase in FLIPs expression seemed to be associated with Mtb infection. In infected individuals who remained healthy, this FLIPs increase was associated with a higher ratio of lymphocytes to monocytes, while infected contacts who later developed TB-like symptoms showed the reverse pattern: a significant elevation of the ratio of monocytes to lymphocytes in the peripheral blood. TB index cases were also characterized by an elevated ratio of monocytes to lymphocytes and this reversed after successful treatment. Like infected contacts, TB patients had increased expression of FLIPs, when compared to healthy individuals but additionally displayed an increased level of expression of mRNA for TNFR2. Prior studies indicate that increased expression of the TNFR2 gene by TB patients is associated with increased levels of serum soluble TNFR2 [26]Apoptosis-Related Gene Expression in TuberculosisFigure 8. Peripheral blood cell proportions as a function of clinical status group. (A) Monocytes, (B) neutrophils and (C) lymphocytes. The data shown are the mean+SD of cell percentage. NI-CC = Non infected community control (CC with TST induration,5 mm), i-hHC = infected household contact (TST induration 14 mm), sHC = household contact that developed TB symptoms, IC = index TB case. Significant differences in gene expression between clinical groups are indicated. doi:10.1371/journal.pone.0061154.gFigure 9. FLIPs and TNFR2 expressions in combination with lymphocyte and monocyte proportions to characterize clinical status. NICC = Non-infected community control (CC with TST induration ,5 mm), i-hHC = infected household contact (TST induration 14 mm), sHC 11967625 = household contact developing TB symptoms, IC = index TB case. In dark gray: significant increase; in light gray: significant increase in community control; in black: significant increase in sHCs, hatched: non particular pattern of response identified. Significant differences are indicated with stars. doi:10.1371/journal.pone.0061154.gApoptosis-Related Gene Expression in Tuberculosiswhich acts as a TNF-a antagonist, suggesting the same is likely true in this study. While 
these data are the first to suggest that FLIPs might be a promising marker of 1662274 Mtb infection, and that the combination of apoptotic genes and monocyte/lymphocyte markers may allow us to predict risk of progression from infection to full-blown TB, further studies are required to ascertain the usefulness of the observed parameters as surrogate markers of TB clinical status. Other factors influencing apoptosis and immune responses should be studied in a more integrative manner, with parallel studies of the genetics of human populations or Mtb strains, to improve our understanding of the disease and facilitate the development of new tools for combating tuberculosis.ing ELISPOT assays. We thank the Centre de Biologie Clinique of the Institut Pasteur de Madagascar for blood tests, the clinical physicians of the Dispensaire Anti-Tuberculeux SMER 28 site d’Antananarivo, the Radiology Department of the Institut d’Hygiene Sociale in Antananarivo, the staff of the Cucurbitacin I web National Mycobacterial ` Laboratory of the Ministry of Health and the National TB Control Program of the Ministry of Health for their contribution to the study. We also thank Dr Louise Kim from the Division of Infection and Immunity, University College London.Sociated with changes in the distribution of immune cells in the peripheral blood of various clinical groups defined on the basis of TB status. An increase in FLIPs expression seemed to be associated with Mtb infection. In infected individuals who remained healthy, this FLIPs increase was associated with a higher ratio of lymphocytes to monocytes, while infected contacts who later developed TB-like symptoms showed the reverse pattern: a significant elevation of the ratio of monocytes to lymphocytes in the peripheral blood. TB index cases were also characterized by an elevated ratio of monocytes to lymphocytes and this reversed after successful treatment. Like infected contacts, TB patients had increased expression of FLIPs, when compared to healthy individuals but additionally displayed an increased level of expression of mRNA for TNFR2. Prior studies indicate that increased expression of the TNFR2 gene by TB patients is associated with increased levels of serum soluble TNFR2 [26]Apoptosis-Related Gene Expression in TuberculosisFigure 8. Peripheral blood cell proportions as a function of clinical status group. (A) Monocytes, (B) neutrophils and (C) lymphocytes. The data shown are the mean+SD of cell percentage. NI-CC = Non infected community control (CC with TST induration,5 mm), i-hHC = infected household contact (TST induration 14 mm), sHC = household contact that developed TB symptoms, IC = index TB case. Significant differences in gene expression between clinical groups are indicated. doi:10.1371/journal.pone.0061154.gFigure 9. FLIPs and TNFR2 expressions in combination with lymphocyte and monocyte proportions to characterize clinical status. NICC = Non-infected community control (CC with TST induration ,5 mm), i-hHC = infected household contact (TST induration 14 mm), sHC 11967625 = household contact developing TB symptoms, IC = index TB case. In dark gray: significant increase; in light gray: significant increase in community control; in black: significant increase in sHCs, hatched: non particular pattern of response identified. Significant differences are indicated with stars. doi:10.1371/journal.pone.0061154.gApoptosis-Related Gene Expression in Tuberculosiswhich acts as a TNF-a antagonist, suggesting the same is likely true in this study. While these data are the first to suggest that FLIPs might be a promising marker of 1662274 Mtb infection, and that the combination of apoptotic genes and monocyte/lymphocyte markers may allow us to predict risk of progression from infection to full-blown TB, further studies are required to ascertain the usefulness of the observed parameters as surrogate markers of 
TB clinical status. Other factors influencing apoptosis and immune responses should be studied in a more integrative manner, with parallel studies of the genetics of human populations or Mtb strains, to improve our understanding of the disease and facilitate the development of new tools for combating tuberculosis.ing ELISPOT assays. We thank the Centre de Biologie Clinique of the Institut Pasteur de Madagascar for blood tests, the clinical physicians of the Dispensaire Anti-Tuberculeux d’Antananarivo, the Radiology Department of the Institut d’Hygiene Sociale in Antananarivo, the staff of the National Mycobacterial ` Laboratory of the Ministry of Health and the National TB Control Program of the Ministry of Health for their contribution to the study. We also thank Dr Louise Kim from the Division of Infection and Immunity, University College London.