Neutrophil function assay
(DHR)

Sample type

WB Sodium Heparin

Uses

1. The dihydrorhodamine (DHR) test has the ability to assess neutrophil superoxide production, a risk indicator for serious infection. Diagnosis of chronic granulomatous disease (CGD).

Precautions

1. Do NOT centrifuge sample Keep at room temperature (18-22°C).

2. Unacceptable Conditions :- Frozen, clotted, hemolyzed or centrifuged specimens. Anticoagulants other than heparin. Specimens >48 hrs old.

3. Specimens are optimally tested within 24 hours of blood draw, though the stability of the assay is within 48 hours of collection. Specimens should be collected in sodium heparin.

Interfering factors

Hemolyzed specimens may give high background. Specimens with an absolute neutrophil count (ANC) below 200 will not be accepted for this assay. Complete myeloperoxidase (MPO) deficiency can yield a false-positive result.

Pre analytical errors

1. Factors affecting the test :- Temperature, delay in processing and sample type

Corrective action

1. Keep and transport the sample at room temperature.

2. Use the corrective anticoagulant for the sample.

Post analytical errors

1. reporting to the wrong health care provider

2. delay of the delivery of the results

Corrective action

1. Critical results must be reported within 30 minutes time of obtaining results.

2. The result is reported to the pathologist and then called to the ordering physician.

Reference ranges