title: Chronic granulomatous disease (CGD) and complete myeloperoxidase deficiency both yield strongly reduced dihydrorhodamine 123 test signals but can be easily discerned in routine testing for CGD.
abstract: BACKGROUND
  The flow cytometric dihydrorhodamine 123 (DHR) assay is used as a screening test for chronic granulomatous disease (CGD), but complete myeloperoxidase (MPO) deficiency can also lead to a strongly decreased DHR signal. Our aim was to devise simple laboratory methods to differentiate MPO deficiency (false positive for CGD) and NADPH oxidase abnormalities (true CGD).
  
  
  METHODS
  We measured NADPH-oxidase and MPO activity in neutrophils from MPO-deficient patients, CGD patients, NADPH-oxidase-transfected K562 cells and cells with inhibited and substituted MPO.
  
  
  RESULTS
  Eosinophils from MPO-deficient individuals retain eosinophilic peroxidase and therefore generate a normal DHR signal. The addition of recombinant human MPO enhances the DHR signal when simply added to a suspension of MPO-deficient cells but not when added to NADPH-oxidase-deficient (CGD) cells. Lucigenin-enhanced chemiluminescence (LCL) is increased in neutrophils from MPO-deficient patients, whereas neutrophils from patients with CGD show a decreased response.
  
  
  CONCLUSIONS
  A false-positive result caused by MPO deficiency can be easily ascertained because, unlike cells from a CGD patient, cells from MPO-deficient patients (a) contain functionally normal eosinophils, (b) show a significant enhancement of the DHR signal following addition of rhMPO, and (c) generate a strong LCL signal.
authors: University Clinic Carl Gustav Carus, Department of Pediatrics, Dresden, Germany.
authors: Lysann
authors: L
authors: Mauch
authors: Andreas
authors: A
authors: Lun
authors: Maurice R G
authors: MR
authors: O'Gorman
authors: John S
authors: JS
authors: Harris
authors: Ilka
authors: I
authors: Schulze
authors: Arturo
authors: A
authors: Zychlinsky
authors: Tobias
authors: T
authors: Fuchs
authors: Uta
authors: U
authors: Oelschlägel
authors: Sebastian
authors: S
authors: Brenner
authors: Dolphe
authors: D
authors: Kutter
authors: Angela
authors: A
authors: Rösen-Wolff
authors: Joachim
authors: J
authors: Roesler
mesh_terms: D000166:Acridines; D004396:Coloring Agents; D003937:Diagnosis, Differential; D004804:Eosinophils / Q000201:enzymology; D005189:False Positive Reactions; D005260:Female; D005434:Flow Cytometry; D006105:Granulomatous Disease, Chronic / Q000175:diagnosis* / Q000201:enzymology; D006801:Humans; D020014:K562 Cells; D049408:Luminescent Agents; D008163:Luminescent Measurements; D008297:Male; D019255:NADPH Oxidases / Q000032:analysis / Q000235:genetics; D009504:Neutrophils / Q000201:enzymology; D009195:Peroxidase / Q000032:analysis / Q000172:deficiency*; D011994:Recombinant Proteins / Q000032:analysis; D012235:Rhodamines; D014162:Transfection
chemical_list: D000166:Acridines; D004396:Coloring Agents; D049408:Luminescent Agents; D011994:Recombinant Proteins; D012235:Rhodamines; C058319:dihydrorhodamine 123; C033472:10,10'-dimethyl-9,9'-biacridinium; D009195:Peroxidase; D019255:NADPH Oxidases