title: IP-10, MCP-1, MCP-2, MCP-3, and IL-1RA hold promise as biomarkers for infection with M. tuberculosis in a whole blood based T-cell assay.
abstract: BACKGROUND
  IFN-gamma responses to M. tuberculosis antigens are used as in-vitro diagnostic tests for tuberculosis infection. The tests are highly specific but sensitivity may be impaired due to immuno-suppression. The objective of this small exploratory study was to compare three novel biomarkers for in-vitro diagnosis of tuberculosis - MCP-1, MCP-3 and IL-1RA - with the current established biomarker IFN-gamma and the newly described IP-10 and MCP-2.
  
  
  METHODS
  Whole blood from 8 patents with active tuberculosis and from 7 healthy controls was stimulated with M. tuberculosis specific antigens and mitogen in the Quantiferon In Tube test tubes. Levels of biomarkers were measured using Luminex and ELISA (IFN-gamma).
  
  
  RESULTS
  We found all five new biomarkers were expressed in significantly higher concentrations compared to IFN-gamma. IP-10 and MCP-3 levels in the un-stimulated samples were higher in patients compared with controls.
  
  
  CONCLUSIONS
  All biomarkers had diagnostic potential as they could differentiate between the patients and the controls. IP-10 and MCP-2 seemed most promising as they were expressed in high levels with antigen stimulation and were low in the un-stimulated samples. Further studies are needed to explore the potential of these highly expressed novel biomarkers individually and in combination.
authors.affiliation: Dep. of Infectious Diseases 144, Copenhagen University, Hvidovre Hospital, DK-2650 Hvidovre, Denmark. mruhwald@mail.dk
authors.forename: Morten
authors.initials: M
authors.lastname: Ruhwald
authors.forename: Morten
authors.initials: M
authors.lastname: Bjerregaard-Andersen
authors.forename: Paulo
authors.initials: P
authors.lastname: Rabna
authors.forename: Jesper
authors.initials: J
authors.lastname: Eugen-Olsen
authors.forename: Pernille
authors.initials: P
authors.lastname: Ravn