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Test Code LAB3607 Dihydrorhodamine Flow Cytometric Test, Blood

Important Note

CALL REFERRAL TESTING 843-792-2432 PRIOR TO COLLECTING OR CANCELLING THIS TEST. SAMPLES CAN ONLY BE DRAWN MONDAY-THURSDAY. Testing will be cancelled at MAYO if the samples cannot get to the MAYO Reference Lab before the 4pm cutoff time.

Additional Codes

DHR

Useful For

Evaluation of chronic granulomatous disease (CGD), X-linked and autosomal recessive forms, RAC2 deficiency, complete myeloperoxidase deficiency

 

Monitoring chimerism and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase function post-hematopoietic cell transplantation

 

Assessing residual NADPH oxidase activity pretransplant

 

Identifying female carriers for X-linked CGD

 

Assessing changes in lyonization with age in female carriers

Specimen Type

WB Sodium Heparin


Shipping Instructions


Testing is performed Monday through Friday. Specimens not received by 4 p.m. Central time on Friday may be canceled. Collect and package specimen as close to shipping time as possible. Ship specimen overnight in an Ambient Shipping Box-Critical Specimens Only (T668) following the instructions in the box.

 

Collect and package specimen as close to shipping time as possible. Ship specimen overnight in an Ambient Shipping Box-Critical Specimens Only (T668) following the instructions in the box.

 

It is recommended that specimens arrive within 24 hours of collection.

 

Specimens arriving on the weekend and observed holidays may be canceled.



Necessary Information


Ordering healthcare professional name and phone number are required.



Specimen Required


Two whole-blood sodium heparin specimens are required, one from the testing patient and the other from an unrelated healthy donor as a control.

 

Supplies: Ambient Shipping Box-Critical Specimens Only (T668)

 

Patient:

Container/Tube: Green top (sodium heparin)

Specimen Volume: 5 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.

 

Normal Control:

Container/Tube: Green top (sodium heparin)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a control specimen from the unrelated healthy donor within an hour of the patient's specimen collection time.

2. Label clearly with Normal Control and the corresponding patient information.

3. Send the whole blood specimen in the original tube. Do not aliquot.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
WB Sodium Heparin Ambient 48 hours GREEN TOP/HEP

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject

Reference Values

Result name

Unit

Cutoff for defining normal

% PMA ox-DHR+

%

≥95%

MFI PMA ox-DHR+

MFI

≥60

% fMLP ox-DHR+

%

≥10%

MFI fMLP ox-DHR+

MFI

≥2

Control % PMA ox-DHR+

%

≥95%

Control MFI PMA ox-DHR+

MFI

≥60

Control % fMLP ox-DHR+

%

≥10%

Control MFI fMLP ox-DHR+

MFI

≥2

 

PMA = phorbol myristate acetate

DHR = dihydrorhodamine

MFI = mean fluorescence intensity

fMLP = N-formyl-methionyl-leucyl-phenylalanine

 

The appropriate age-related reference values for Absolute Neutrophil Count will be provided on the report.

Interpretation

An interpretive report will be provided, in addition to the quantitative values.

 

Interpretation of the results of the quantitative dihydrorhodamine (DHR) flow cytometric assay has to include both the proportion of positive neutrophils for DHR after phorbol myristate acetate and/or N-formyl-methionyl-leucyl-phenylalanine stimulation, and the mean fluorescence intensity .Additionally, visual assessment of the pattern of DHR fluorescence is helpful in discriminating between the various genetic defects associated with chronic granulomatous disease and complete myeloperoxidase deficiency.

Method Description

A sodium heparin whole blood specimen is incubated at 37° C in the presence of DHR123. Phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulant is added and mixed with the whole blood specimen for additional incubation at 37° C. The specimen is then centrifuged, and the cell pellet is subsequently lysed with ammonium chloride at ambient temperature. Lysed specimens are then washed with azide-free phosphate buffered saline prior to staining with LIVE/DEAD viability marker and CD15 at ambient temperature. Finally, cells are washed, centrifuged, and resuspended in 1% paraformaldehyde prior to analysis. Viable neutrophils are identified by the use of the viability dye and further confirmed by the presence of CD15. Approximately 20,000 viable neutrophil events in the unstimulated specimen are used to set the limits for number of events collected for flow cytometry. The results are derived as delta % DHR-positive neutrophils after PMA or fMLP stimulation and mean fluorescence intensity for each stimulant for DHR flow cytometry.(O'Gorman MR, Corrochano V. Rapid whole-blood flow cytometry assay for diagnosis of chronic granulomatous disease. Clin Diagn Lab Immunol. 1995;2[2]:227-232; Kuhns DB. Diagnostic testing for chronic granulomatous disease. Methods Mol Biol. 2019;1982:543-571)

Day(s) Performed

Monday through Friday

Report Available

3 to 4 days

Specimen Retention Time

4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

86352 x2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DHR DHR Flow, B 98122-5

 

Result ID Test Result Name Result LOINC Value
ANC Absolute Neutrophil Count 751-8
PMAP % PMA ox-DHR+ 85376-2
PMAM MFI PMA ox-DHR+ 85374-7
FMPPP % FMLP ox-DHR+ 85373-9
FMPM MFI fMLP ox-DHR+ 85370-5
ANCC Control Absolute Neutrophil Count 85369-7
PMAPC Control % PMA ox-DHR+ 85377-0
PMAMC Control MFI PMA ox-DHR+ 85375-4
FMPPC Control % fMLP ox-DHR+ 85372-1
FMPMC Control MFI fMLP ox-DHR+ 85371-3
DHRI Interpretation 69052-9

Method Name

Flow Cytometry

Secondary ID

62764