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Test Code PML/RARA Qnt PML/RARA Quantitative, PCR

Reporting Name

PML/RARA Quantitative, PCR

Useful For

Diagnosis of acute promyelocytic leukemia (APL)

 

Detection of residual or recurrent APL

 

Monitoring the level of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARA) in APL patients


Advisory Information


This assay may not detect rare, unusual PML/RARA fusions. Therefore, if the assay is going to be used for monitoring after treatment, the test should be performed at the time of diagnosis to ensure that the test gives a positive result.



Shipping Instructions


Refrigerated specimen must arrive within 5 days (120 hours of draw), and ambient specimens must arrive within 3 days (72 hours) of draw. Draw and package specimen as close to shipping time as possible.



Necessary Information


The following information is required:

1. Pertinent clinical history

2. Date of collection

3. Specimen source (blood or bone marrow)



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: EDTA (lavender top)

Acceptable: ACD (yellow top)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

3. Label specimen as blood.

 

Specimen Type: Bone marrow

Container/Tube:

Preferred: EDTA (lavender top)

Acceptable: ACD (yellow top)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix bone marrow.

2. Send specimen in original tube.

3. Label specimen as bone marrow.


Seattle Children's Hospital Note:

MUST ARRIVE @ MAYO WITHIN 72 HOURS. Samples collected on a Friday must be received in the SCH main lab before 7 pm. Samples can be collected on the weekend as long as the following Monday is not a holiday.

Specimen Type

Varies

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Varies Refrigerated (preferred) 5 days
  Ambient  72 hours

Day(s) and Time(s) Performed

Monday through Friday

Seattle Children's Hospital Note:

TAT: 6 - 10 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

Quantitative, Real-Time Polymerase Chain Reaction (PCR)

Method Description

Total RNA is extracted from blood or bone marrow using the QIAmp kit (Qiagen). cDNA is made using the Superscript III kit (Invitrogen). Quantitative, real-time PCR is performed using the LightCycler instrument (Roche) and the data analyzed using the supplied software for relative quantification with calibrator normalization and efficiency correction.(Instruction manual: Roche Applied Science LightCycler 2.0 Instrument. Version 4/1.2. 2003. Roche Diagnostics)

 

The normalized ratio is a relative quantification calculation as follows: 

Normalized ratio*=

PML/RARA (sample)

GUSB (sample)

PML/RARA (calibrator)

GUSB (calibrator)

 

*Where GusB mRNA is used to normalize variations in RNA quality and calibrator mRNA from a promyelocytic leukemia/retinoic acid receptor alpha (PML/RARA)-positive cell line is used to normalize variations in run conditions.

Reference Values

An interpretive report will be provided.

 

If positive, a value representing a ratio of PML-RARA fusion transcript to the control gene GusB expressed as a percentage will be reported.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

81315-PML/RARalpha (t(15;17)), (PML-RARA regulated adaptor molecule 1) (eg promyelocytic leukemia) translocation analysis; common breakpoints (eg, intron 3 and intron 6), qualitative or quantitative

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PMLR PML/RARA Quantitative, PCR In Process

 

Result ID Test Result Name Result LOINC Value
39469 PMLR Result In Process
MP012 Specimen Type 31208-2
19449 Final Diagnosis 34574-4

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

NA

Icterus

NA

Other

Moderately to severely clotted

Testing Algorithm

See Acute Promyelocytic Leukemia: Guideline to Diagnosis and Follow-up in Special Instructions.

Forms

1. Hematopathology Patient Information (T676) in Special Instructions

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request Form (T726) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/hematopathology-request-form.pdf)