title: Monitoring temporary immunodepression by flow cytometric measurement of monocytic HLA-DR expression: a multicenter standardized study.
abstract: BACKGROUND
  Single-center trials have shown that monocytic HLA-DR is a good marker for monitoring the severity of temporary immunodepression after trauma, major surgery, or sepsis. A new test for measuring monocytic HLA-DR is now available.
  
  
  METHODS
  We evaluated a new test reagent set for monocytic HLA-DR expression (BD Quantibritetrade mark HLA-DR/Monocyte reagent; Becton Dickinson) in single-laboratory and interlaboratory experiments, assessing preanalytical handling, lyse-no-wash (LNW) vs lyse-wash (LW) values, reference values, and the effect of use of different flow cytometers and different instrument settings on test variance.
  
  
  RESULTS
  For preanalytical handling, EDTA anticoagulation, storage on ice as soon as possible, and staining within 4 h after blood collection gave results comparable to values obtained for samples analyzed immediately after collection (mean increase of approximately 4% in monocytic HLA-DR). Comparison of LNW and LW revealed slightly higher results for LNW ( approximately 18% higher for LNW compared with LW; r = 0.982). Comparison of different flow cytometers and instrument settings gave CVs <4%, demonstrating the independence of the test from these variables and suggesting that this method qualifies as a standardized test. CV values from the interlaboratory comparison ranged from 15% (blood sample unprocessed before transport) to 25% (stained and fixed before transport).
  
  
  CONCLUSIONS
  For the BD Quantibrite HLA-DR/Monocyte test, preanalytical handling is standardized. Single-laboratory results demonstrated the independence of this test from flow cytometer and instrument settings. Interlaboratory results showed greater variance than single-laboratory values. This interlaboratory variance was partly attributable to the influence of transport and can be reduced by optimization of transport conditions.
authors.affiliation: Institute of Medical Immunology, Charité-Campus Mitte, Humboldt University of Berlin, and University Hospital, Charité Berlin, Germany.
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Döcke
authors.forename: Conny
authors.initials: C
authors.lastname: Höflich
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Davis
authors.forename: Karsten
authors.initials: K
authors.lastname: Röttgers
authors.forename: Christian
authors.initials: C
authors.lastname: Meisel
authors.forename: Paul
authors.initials: P
authors.lastname: Kiefer
authors.forename: Stefan U
authors.initials: SU
authors.lastname: Weber
authors.forename: Monika
authors.initials: M
authors.lastname: Hedwig-Geissing
authors.forename: Ernst
authors.initials: E
authors.lastname: Kreuzfelder
authors.forename: Peter
authors.initials: P
authors.lastname: Tschentscher
authors.forename: Thomas
authors.initials: T
authors.lastname: Nebe
authors.forename: Andrea
authors.initials: A
authors.lastname: Engel
authors.forename: Guillaume
authors.initials: G
authors.lastname: Monneret
authors.forename: Andreas
authors.initials: A
authors.lastname: Spittler
authors.forename: Kathrin
authors.initials: K
authors.lastname: Schmolke
authors.forename: Petra
authors.initials: P
authors.lastname: Reinke
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Volk
authors.forename: Dagmar
authors.initials: D
authors.lastname: Kunz
mesh_terms: D005434:Flow Cytometry / Q000379:methods*; D005786:Gene Expression Regulation; D006684:HLA-DR Antigens / Q000032:analysis* / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D009000:Monocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*
chemical_list: D006684:HLA-DR Antigens