New Order Codes for BCR-ABL Testing
On November 16, 2021, Warde Medical Laboratory will begin performing in-house RT-PCR testing for the BCR-ABL molecular rearrangements characteristic of chronic myeloid leukemia (CML) and Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ALL). This testing was previously forwarded to Quest Diagnostics.
Although most aspects of the testing process will remain unchanged, this will involve a change to the way BCR-ABL testing is ordered. BCR-ABL rearrangements come in different forms, the most common of which encodes for a 210 kilodalton protein product (the so-called “p210” product), and the next most common of which encodes for a 190 kilodalton protein product (the so-called “p190” product). Nearly all cases of CML are associated with the p210 BCR-ABL protein. About half of Ph+ALL cases are associated with the p210 product and the rest with the p190 product. Until now, this test was offered under one test code– Quest performed initial testing for both products and, on subsequent submissions from the same patient, would follow up with only the specific product that had been previously identified on that patient. While convenient, this process was labor intensive, precluded the transmission of results directly through electronic interfaces, and may have resulted in unnecessary testing when previous results were unknown or performed at a different testing site. .
Effective November 16, 2021, this ordering process will change. Providers must specify one of three test codes when ordering, which will determine which combination of BCR-ABL testing takes place.
The first option is for patients with no previous BCR-ABL qPCR result. We recommend our BCR-ABL Reflex Test (BCRX) that first assesses p210 and then is reflexed to p190 when p210 is negative. The tests will be performed from a single tube of blood and will reduce unnecessary p190 tests for p210 positive patients.
The second and third options are for patients with a previous positive p210 result or p190 result, and are mainly used for treatment monitoring. The ordering physician must specify whether they wish to test for BCR-ABL1 Major p210 (Test Code: BCRMJ) or for BCR-ABL1 Minor p190 (Test Code: BCRMN). Both test codes can be ordered if a provider feels both results are necessary.
These changes mean that ordering physicians will want to be aware which product they are monitoring for each patient prior to ordering. For patients without prior BCR-ABL results, providers will have the choice to order both tests up front, or to order the p210 with reflex to p190 should p210 not be detected. To help with the change, patient samples will be preserved for several weeks in the event that additional tests need to be performed.
Samples should be collected in EDTA tubes and shipped refrigerated. We recommend shipping M-Th in order to prevent stability issues over the weekend. The p210 test will be performed Tuesdays and Thursdays. The p190 test will be performed Wednesdays and Fridays (as needed). Expected turn-around time is <6 business days and will vary depending on the day the sample is received. Samples received Thursday or Friday will take the longest amount of time. In general, we anticipate faster time to results with in-house testing compared to the send out.
Summary of New Test Codes:
|Test Code||Test Name||Recommended Utilization|
|BCRX||BCR-ABL1 Rearrangement, Quantitative PCR with Reflex||patient has never had a previous BCR-ABL1 test and/or previous test was negative|
|BCRMJ||BCR-ABL1 Major (p210) Rearrangement, Quantitative PCR||patient has a previous p210 detected result; treatment monitoring|
|BCRMN||BCR-ABL1 Minor (p190) Rearrangement, Quantitative PCR||patient has a previous p190 detected result; treatment monitoring|