title: Extra-pulmonary tuberculosis: a biomarker analysis.
abstract: BACKGROUND
  Studies on biomarkers in tuberculosis are focused on pulmonary forms of this disease (PTB), and only limited information is currently available on biomarkers of extra-pulmonary tuberculosis (EPTB).
  
  
  METHODS
  Serum samples from 24 patients with PTB, 29 patients with EPTB and 27 healthy controls were obtained, and the levels of interferon-gamma, chemokine ligand 9, mannose-binding lectin (MBL), tumor marker Ca-125 and adenosine deaminase were determined.
  
  
  RESULTS
  The circulating levels of all tested biomarkers in the serum were significantly higher in PTB and EPTB patients than in controls. However, there were no significant differences in the levels of the biomarkers between patients with PTB and EPTB, with the exception of serum levels of MBL which were significantly higher in patients with EPTB than in patients with PTB (p = 0.01). In patients with EPTB, no significant differences were observed in biomarker levels among patients with or without concomitant PTB involvement. Based on MBL serum levels, ROC curve analysis showed an AUC of 0.85 for EPTB versus non-EPTB. The optimal cut-off value of MBL serum levels for EPTB versus non-EPTB was 1,000 μg/ml, with a sensitivity and specificity of 79.3 and 78.0 %, respectively.
  
  
  CONCLUSIONS
  Biomarkers usually present as acute phase reactants and do not enable pulmonary forms to be differentiated from more serious or extra-pulmonary forms. MBL may be an exception.
authors.affiliation: Infectious Diseases Department, Ramon y Cajal Hospital, Ctra Colmenar km 9.1, 28034, Madrid, Spain, fortunabete@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Fortún
authors.forename: P
authors.initials: P
authors.lastname: Martín-Dávila
authors.forename: E
authors.initials: E
authors.lastname: Gómez-Mampaso
authors.forename: A
authors.initials: A
authors.lastname: Vallejo
authors.forename: C
authors.initials: C
authors.lastname: Cuartero
authors.forename: A
authors.initials: A
authors.lastname: González-García
authors.forename: J
authors.initials: J
authors.lastname: Rubí
authors.forename: E
authors.initials: E
authors.lastname: Pallarés
authors.forename: S
authors.initials: S
authors.lastname: Moreno
mesh_terms: D000243:Adenosine Deaminase / Q000097:blood; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D018394:CA-125 Antigen / Q000097:blood; D015331:Cohort Studies; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood; D008875:Middle Aged; D011446:Prospective Studies; D014376:Tuberculosis / Q000175:diagnosis* / Q000473:pathology*
chemical_list: D015415:Biomarkers; D018394:CA-125 Antigen; D016207:Cytokines; D037601:Mannose-Binding Lectin; D000243:Adenosine Deaminase