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: Lysann Mauch, Andreas Lun, Maurice R G O'Gorman, John S Harris, Ilka Schulze, Arturo Zychlinsky, Tobias Fuchs, Uta Oelschlägel, Sebastian Brenner, Dolphe Kutter, Angela Rösen-Wolff, Joachim Roesler
• Journal: Clinical chemistry (Clin Chem) Vol. 53 Issue 5 Pg. 890-6 (May 2007) ISSN: 0009-9147 [Print] England
• PMID: 17384005 (Publication Type: Journal Article)

Chemical References

• Acridines
• Coloring Agents
• Luminescent Agents
• Recombinant Proteins
• Rhodamines
• dihydrorhodamine 123
• 10,10'-dimethyl-9,9'-biacridinium
• Peroxidase
• NADPH Oxidases

Topics

• Acridines
• Coloring Agents
• Diagnosis, Differential
• Eosinophils (enzymology)
• False Positive Reactions
• Female
• Flow Cytometry
• Granulomatous Disease, Chronic (diagnosis, enzymology)
• Humans
• K562 Cells
• Luminescent Agents
• Luminescent Measurements
• Male
• NADPH Oxidases (analysis, genetics)
• Neutrophils (enzymology)
• Peroxidase (analysis, deficiency)
• Recombinant Proteins (analysis)
• Rhodamines
• Transfection