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HelpTest Code CHRHB Chromosome Analysis, Hematologic Disorders, Blood
Useful For
Assisting in the classification and follow-up of certain malignant hematological disorders when bone marrow is not available
This test is not useful for congenital disorders.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _ML20 | Metaphases, 1-19 | No, (Bill Only) | No |
| _M25 | Metaphases, 20-25 | No, (Bill Only) | No |
| _MG25 | Metaphases, >25 | No, (Bill Only) | No |
| _STAC | Ag-Nor/CBL Stain | No, (Bill Only) | No |
Testing Algorithm
This test includes a charge for cell culture of fresh specimens and professional interpretation of results. Analysis charges will be incurred for total work performed, and generally include 2 banded karyograms and the analysis of 20 metaphase cells. If no metaphase cells are available for analysis, no analysis charges will be incurred. If additional analysis work is required, additional charges may be incurred.
In addition to the cell culture, a CpG stimulated culture will be added, and 10 additional cells will be analyzed for any specimen received from a patient 30 years of age or older with a reason for testing of chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma, lymphocytosis, Waldenstrom macroglobulinemia, or any CLL fluorescence in situ hybridization test previously ordered or is ordered concurrently.
Special Instructions
Method Name
Cell Culture without Mitogens followed by Chromosome Analysis
Reporting Name
Chromosomes, Hematologic, BloodSpecimen Type
Whole bloodOrdering Guidance
This test is not appropriate for detecting constitutional/congenital chromosome abnormalities. If this test is ordered with a reason for testing indicating a concern for a constitutional/congenital chromosome abnormality, the test will be canceled and CHRCB / Chromosome Analysis, Congenital Disorders, Blood will be added and performed as the appropriate test.
If this test is ordered and the laboratory is informed that the patient is on a Children's Oncology Group (COG) protocol, this test will be canceled and automatically reordered by the laboratory as COGBL / Chromosome Analysis, Hematologic Disorders, Children's Oncology Group Enrollment Testing, Blood.
Consultation with personnel from the Cytogenetics Laboratory is recommended when considering blood studies for hematologic disorders. Call 800-533-1710 and ask for the Cytogenetics Genetic Counselor on call.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. A reason for testing should be submitted with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
2. A pathology and/or flow cytometry report may be requested by the laboratory to optimize testing and aid in interpretation of results.
Specimen Required
Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Green top (sodium heparin) or lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
Chromosomal abnormalities play a central role in the pathogenesis, diagnosis, and monitoring of treatment of many hematologic disorders. Whenever possible, it is best to do chromosome studies for neoplastic hematologic disorders on bone marrow. Bone marrow studies are more sensitive and the chances of finding metaphases are about 95%, compared with only a 60% chance for blood studies. When it is not possible to collect bone marrow, chromosome studies on blood may be useful.
When blood cells are cultured in a medium without mitogens, the observation of any chromosomally abnormal clone may be consistent with a neoplastic process.
Conventional chromosome studies of B-cell disorders are not always successful because B lymphocytes do not proliferate well in cell culture. The agent CpG 7909 (CpG) is a synthetic oligodeoxynucleotide that binds to the Toll-like receptor 9 (TLR9) present on B cells, causing B-cell activation. In the laboratory setting, CpG may be used as a mitogen to stimulate B cells in patient specimens, thus allowing identification of chromosome abnormalities. CpG stimulation reveals an abnormal karyotype in approximately 80% of patients with of chronic lymphocytic leukemia, and the karyotype is complex in 20% to 25% of cases. Several studies have reported that increased genetic complexity revealed by CpG-stimulated chromosome studies confers a less favorable time to first treatment, treatment response, and overall survival.
For more information see Multiple Myeloma: Laboratory Screening.
Cautions
Interfering factors:
Technical:
-Cell lysis caused by forcing blood quickly through the needle at collection
-Use of an improper anticoagulant or improperly mixing the blood with the anticoagulant
-Clotted blood specimen
-Excessive transport time
-Exposure of the specimen to extreme temperature
Biological:
-Abnormalities missed due to sampling error
-Subtle structural chromosome abnormalities may not be detected by conventional chromosome analysis
-Neoplastic cells not dividing or not circulating in the bloodstream
Day(s) Performed
Monday through Friday
Report Available
9 to 11 daysSpecimen Retention Time
3 weeksPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88237, 88291-Tissue culture for neoplastic disorders; bone marrow, blood, Interpretation and report
88264 w/ modifier 52-Chromosome analysis with less than 20 cells (if appropriate)
88264-Chromosome analysis with 20 to 25 cells (if appropriate)
88264,88285-Chromosome analysis with greater than 25 cells (if appropriate)
88283-Additional specialized banding technique (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CHRHB | Chromosomes, Hematologic, Blood | 62348-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 52391 | Result Summary | 50397-9 |
| 52393 | Interpretation | 69965-2 |
| 52392 | Result | 82939-0 |
| CG778 | Reason for Referral | 42349-1 |
| 52394 | Specimen | 31208-2 |
| 52395 | Source | 31208-2 |
| 52397 | Method | 85069-3 |
| 52396 | Banding Method | 62359-5 |
| 54633 | Additional Information | 48767-8 |
| 52398 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.