Neutrophil Function : Di-Hydrorhodamine Test ( DHR )

Immunology

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Description

The function of neutrophils is to ingest and destroy bacteria. This is brought about by efficient chemotaxis, phagocytosis and bacterial killing by production of free radicles by an oxidative burst. Chronic granulomatous disease ( CGD ) is caused by a genetic defect in 1 of the components of the NADPH-oxidase multienzyme complex that produces reactive oxygen intermediates ( ROIs ). In CGD, the inability to produce ROIs leads to recurrent life-threatening opportunistic infections and uncontrolled inflammation, often accompanied by granuloma formation [1]. There are X -linked and autosomal recessive forms. Infections with catalase -positive organisms ( Staph. aureus, Aspergillus, nocardia, & Serratia ), deep seated abscesses, osteomyelitis and chronic granulomata are the hallmark of this disease [1,2]. European Society for Immunodeficiencies ( ESID ) criteria use an abnormal response to DHR in the classification of CGD.

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Indications

To investigate Neutrophil Oxidative metabolism. Chronic granulomatous disorder. Recurrent Staphylococcal/ aspergillus infections.

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Sample Type

Fresh 5mL EDTA whole blood. A control sample from a healthy individual MUST be supplied together with the patients sample. Samples must be urgently transported to the laboratory. Requests from outside Sheffield: Please discuss transport requirements prior to requesting this test.

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Reference Range

Normal = normal response observed, see report.

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Turnaround Time

Within 3 days

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Testing Frequency

Please discus with the Immunology department prior to requesting this test.

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External Notes

Must be arranged with laboratory prior to taking any samples. Discuss with Clinical Scientists or Medical staff.

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References

Mauch L, et al. 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. Clin Chem. 2007. 53:890-896. [Ref 1]
Heyworth P, Cross A, and Curnutte J. Chronic granulomatous disease. Curr. Opin. Immunology. 2003. 15( 5 ):578-584. [Ref 2]

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.