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HelpTest ID: CHRHB Chromosome Analysis, Hematologic Disorders, Blood
Reporting Name
Chromosomes, Hematologic, BloodUseful For
Assisting in the classification and follow-up of certain malignant hematological disorders when bone marrow is not available
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 (CLL), 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.
See Laboratory Screening Tests for Suspected Multiple Myeloma in Special Instructions.
Interpretation
The presence of an abnormal clone usually indicates a malignant neoplastic process.
The absence of an apparent abnormal clone in blood may result from a lack of circulating abnormal cells and not from an absence of disease.
On rare occasions, the presence of an abnormality may be associated with a congenital abnormality and, thus, not related to a malignant process. When this situation is suspected, follow-up with a medical genetics consultation is recommended.
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.
This test is not appropriate for detecting constitutional/congenital chromosome abnormalities. If this test is ordered with a reason for referral indicating a concern for a constitutional/congenital chromosome abnormality, the test will be cancelled 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 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.
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 |
Special Instructions
Analytic Time
9 daysDay(s) and Time(s) Performed
Specimens are processed Monday through Sunday.
Results reported Monday through Friday, 8 a.m.-5 p.m.
Clinical Reference
1. Dewald GW, Ketterling RP, Wyatt WA, Stupca PJ: Cytogenetic studies in neoplastic hematologic disorders. In Clinical Laboratory Medicine, Second edition. Edited by KD McClatchey. Baltimore, Williams and Wilkens, 2002, pp 658-685
2. Rigolin GM, Cibien F, Martinelli S, et al: Chromosome aberrations detected by conventional karyotyping using novel mitogens in chronic lymphocytic leukemia with "normal" FISH: correlations with clinicobiological parameters. Blood 2012 Mar 8;119(10):2310-2313
Method Name
Cell Culture without Mitogens* followed by Chromosome Analysis*
*In addition to the cell culture without mitogens, a CpG stimulated culture will be added and 10 additional cells will be analyzed for any specimen received from a patient age 30 or older with a reason for referral of chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), lymphocytosis, Waldenstrom macroglobulinemia, or when CLLF / Chronic Lymphocytic Leukemia (CLL), FISH is ordered concurrently.
Specimen Type
Whole bloodNecessary Information
A pathology and/or flow cytometry report may be requested by the Genomics Laboratory to optimize testing and aid in interpretation of results.
Specimen Required
Provide a reason for referral 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.
Container/Tube: Green top (sodium heparin)
Specimen Volume: 5-10 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Other anticoagulants are not recommended and are harmful to the viability of the cells.
Additional Information: Advise Express Mail or equivalent if not on courier service.
Specimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | ||
| Refrigerated | |||
Reference Values
An interpretative report will be provided.
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
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 | 49549-9 |
| 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.
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