Test ID: CHRGB
Chimerism-Recipient Germline (Pre)
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Determining the relative amounts of donor and recipient cells in a specimen
An indicator of bone marrow transplant success
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
Initial Chimerism Testing
Complete chimerism analysis requires 3 specimens. These specimens should be submitted when collected. An interpretive report will be provided once all specimens are received.
CHRGB/83186 Chimerism-Recipient Germline (Pre)
CHIDB/83182 Chimerism-Donor
CHEP/84427 Chimerism-Recipient Engraftment (Post)
Billing occurs with test codes CHRGB/83186 (for the Pre and Donor specimens) and CHMT/84468 (for the Post specimen). If an additional donor sample is submitted, ADDO/61910 Additional Donor will be performed at an additional charge.
See Chimerism-Recipient Germline Testing Algorithm in Special Instructions.
For Mayo Clinic Arizona and Mayo Clinic Florida ONLY:
Initial Chimerism Testing
Complete chimerism analysis requires 3 specimens. These specimens should be submitted when collected. An interpretive report will be provided once all specimens are received.
CHRGB/83186 Chimerism-Recipient Germline (Pre)
CHIDB/83182 Chimerism-Donor
CHEP/84427 Chimerism-Recipient Engraftment (Post)
Billing occurs with test codes CHRGB/83186 (for the Pre and Donor specimens) and the appropriate test for the Post specimen: CHMT/84468 or PCS1/61911 and/or PCS2/62138. If an additional donor sample is submitted, ADDO/61910 Additional Donor will be performed at an additional charge.
See Chimerism-Recipient Germline Testing Algorithm in Special Instructions.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Polymerase Chain Reaction (PCR) Amplification/Capillary Electrophoresis
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Chimerism evaluation
Pre transplant evaluation
Transplant analysis
Transplant evaluation
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Forms:
1. Chimerism Analysis Information Sheet (Supply T594) in Special Instructions.
2. If not ordering electronically, submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
The following information is required:
1. Pertinent clinical history
2. Specimen source
3. Donor identifier and donor date of birth
4. Donor date of collection
Specimen must arrive within 168 hours of collection.
Submit only 1 of the following specimens:
Specimen Type: Blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: ACD
Specimen Volume: 6 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: Lavender top (EDTA)
Acceptable: ACD
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send specimen in original tube.
3. Label specimen as bone marrow.
Specimen Type: Buccal swab
Container/Tube: Buccal Smear Collection Kit (Supply T543)
Specimen Volume: 2 Cyto-Pak brushes-1 per cheek
Collection Instructions:
1. Patient should rinse out mouth vigorously with mouthwash for approximately 15 seconds.
2. Remove Cyto-Pak brush from container only touching "stick" end. Save container.
3. Using medium pressure, rotate brush several times on inside of cheek.
4. Return brush to container and cap.
5. Repeat steps 2 through 4 on other cheek using second brush.
6. It is important that patient's buccal cells are not contaminated with cells from any other source. Do not touch bristles. Do not brush too vigorously. If blood appears, discard brush. Restart collection process.
7. Label each container with patient's name and order number or hospital/clinic number.
Additional Information: It is important that the cells do not dry out during shipping. Ensure that container is tightly sealed.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | 7 days |
| Refrigerated | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Patients who have had donor hematopoietic cells infused for the purpose of engraftment (ie, bone marrow transplant recipients) may have their blood or bone marrow monitored for an estimate of the percentage of donor and recipient cells present. This can be done by first identifying unique features of the donor's and the recipient's DNA prior to transplantation and then examining the recipient's blood or bone marrow after the transplantation procedure has occurred. The presence of both donor and recipient cells (chimerism) and the percentage of donor cells are indicators of transplant success.
Short tandem repeat (STR) sequences are used as identity markers. STRs are di-, tri-, or tetra-nucleotide repeat sequences interspersed throughout the genome at specific sites, similar to gene loci. There is variability in STR length among people and the STR lengths remain stable throughout life, making them useful as identity markers. PCR is used to amplify selected STR regions from germline DNA of both donor and recipient. The lengths of the amplified fragment are evaluated for differences (informative markers). Following allogeneic hematopoietic cell infusion, the recipient blood or bone marrow can again be evaluated for the informative STR regions to identify chimerism and estimate the proportions of donor and recipient cells in the specimen.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
An interpretive report is provided, which includes whether chimerism is detected or not and, if detected, the approximate percentage of donor and recipient cells.
It is most useful to observe a trend in chimerism levels. Clinically critical results should be confirmed with 1 or more subsequent specimens.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The test has less than perfect accuracy, and accuracy varies with the proportions of donor and recipient cells in the specimen. For this reason, results are reported as approximate and rounded to the nearest 5% or 10%, depending on the calculated percentage of donor cells. For example, if the percent donor is < or =10%, it is reported as 5% donor cells. If the percent donor cells are > or =90%, it is reported as 95% donor cells.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Antin JH, Childs R, Filipovich AH, et al: Establishment of complete and mixed donor chimerism after allogenic lymphohematopoietic transplantation: recommendations from a workshop at the 2001 Tandem Meetings. Biol Blood Marrow Transplant 2001;7:473-485
Method Description Describes how the test is performed and provides a method-specific reference
Genomic DNA is extracted from blood or bone marrow aspirate samples using an automated extraction machine (MagNa Pure Compact, Roche Diagnostics) and used in a commercial kit AmpFLSTR Profiler Plus PCR Amplification Kit (Applied Biosystems, Foster City, CA) following the manufacturer's instructions. Briefly, 10 different short tandem repeat (STR) marker regions are amplified in single multiplex PCR using primers labeled with fluorescent tags. The products are analyzed for size and amount using capillary electrophoresis on an ABI3100 genetic analyzer. For the initial sample on any patient, the test is performed on 3 separate DNA samples: donor germline DNA, recipient germline DNA, and recipient posttransplant sample for chimerism determination. The STR profile of the germline samples is used to identify markers that can distinguish between the donor and recipient. Based on these profiles, the percentage of donor and recipient DNA is then determined in the posttransplant sample using the assumptions and calculations outlined in Thiede, et al. Subsequent samples for chimerism evaluation do not need to be accompanied by samples for donor and recipient germline evaluation, as the profiles from the initial testing are kept on file for comparison.(MagNA Pure Compact System. User Manual 2004. Roche Diagnostics, Basel, Switzerland. www.roche-applied-science.com; AmpFLSTR Profiler Plus PCR Amplification Kit. User Bulletin 2004. Applied Biosystems, Foster City, CA. www.appliedbiosystems.com; Thiede C, Florek M, Bornhauser M, et al: Rapid quantification of mixed chimerism using multiplex amplification of short tandem repeat markers and fluorescence detection. Bone Marrow Transplant 1999;23:1055-1060)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 9 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells)
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| MP007 | Donor | N/A |
| MP014 | Specimen Type | In Process |
| 83186 | Chimerism-Recipient Germline | N/A |
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