title: Effect of standard tuberculosis treatment on plasma cytokine levels in patients with active pulmonary tuberculosis.
abstract: BACKGROUND
  Sputum Mycobacterium tuberculosis (Mtb) culture is commonly used to assess response to antibiotic treatment in individuals with pulmonary tuberculosis (TB). Such techniques are constrained by the slow growth rate of Mtb, and more sensitive methods to monitor Mtb clearance are needed. The goal of this study was to evaluate changes in plasma cytokines in patients undergoing treatment for TB as a means of identifying candidate host markers associated with microbiologic response to therapy.
  
  
  METHODS
  Twenty-four plasma cytokines/chemokines were measured in 42 individuals diagnosed with active pulmonary TB, 52% were HIV co-infected. Individuals, undergoing a 26-week standard TB treatment, were followed longitudinally over 18 months and measurements were associated with HIV status and rates of sputum culture conversion.
  
  
  RESULTS
  Plasma concentrations of interferon-inducible protein-10 (IP-10) and vascular endothelial growth factor (VEGF) were significantly reduced upon TB treatment, regardless of HIV status. By the end of treatment, IP-10 concentrations were significantly lower in HIV negative individuals when compared to HIV-positive individuals (p = 0.02). Moreover, in HIV negative patients, plasma VEGF concentrations, measured as early as 2-weeks post TB treatment initiation, positively correlated with the time of sputum conversion (p = 0.0017). No significant changes were observed in other studied immune mediators.
  
  
  CONCLUSIONS
  These data suggest that VEGF plasma concentration, measured during early TB treatment, could represent a surrogate marker to monitor sputum culture conversion in HIV uninfected individuals.
authors.affiliation: Division of Immunology, Institute of Infectious Diseases and Molecular Medicine (IIDMM), Clinical Laboratory Sciences, University of Cape Town, Cape Town, Western Cape, South Africa.
authors.forename: Catherine
authors.initials: C
authors.lastname: Riou
authors.forename: Blas
authors.initials: B
authors.lastname: Perez Peixoto
authors.forename: Lindi
authors.initials: L
authors.lastname: Roberts
authors.forename: Katharina
authors.initials: K
authors.lastname: Ronacher
authors.forename: Gerhard
authors.initials: G
authors.lastname: Walzl
authors.forename: Claudia
authors.initials: C
authors.lastname: Manca
authors.forename: Roxana
authors.initials: R
authors.lastname: Rustomjee
authors.forename: Thuli
authors.initials: T
authors.lastname: Mthiyane
authors.forename: Dorothy
authors.initials: D
authors.lastname: Fallows
authors.forename: Clive M
authors.initials: CM
authors.lastname: Gray
authors.forename: Gilla
authors.initials: G
authors.lastname: Kaplan
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use*; D054357:Chemokine CXCL10 / Q000097:blood; D016207:Cytokines / Q000097:blood*; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D015658:HIV Infections / Q000150:complications; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000188:drug therapy* / Q000276:immunology* / Q000382:microbiology; D042461:Vascular Endothelial Growth Factor A / Q000097:blood; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; C114753:CXCL10 protein, human; D054357:Chemokine CXCL10; D016207:Cytokines; D018836:Inflammation Mediators; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A