Test ID: CPG
Chromosome Analysis, CpG Mitogen Study for B-Cell Disorder
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
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
Identifying chromosome abnormalities associated with B-cell disorders
Method Name A short description of the method used to perform the test
Cell Culture with CpG Mitogen
Includes 2 banded karyograms, analysis of 20 or more metaphases, and other banding techniques when required.
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
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.
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. Include pathology reports, if available.
Forms: If not ordering electronically, submit a Cytogenetics Hematologic Disorders Request Form (Supply T607) with the specimen.
Advise Express Mail or equivalent if not on courier service.
Submit only 1 of the following specimens:
Specimen Type: Blood
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.
Specimen Type: Bone marrow
Container/Tube: Green top (sodium heparin)
Specimen Volume: 2-3 mL
Collection Instructions:
1. It is preferable to send the first aspirate from the bone marrow collection.
2. Invert several times to mix bone marrow.
3. Other anticoagulants are not recommended and are harmful to the viability of the cells.
Specimen Type: Lymph node
Container/Tube: Sterile container with sterile Hank's balanced salt solution (Supply T132), Ringer's solution, or normal saline
Specimen Volume: 1 cm(3)
Additional Information: Spleen tissue or extranodal tissue may be submitted when a lymphomatous disorder is believed to involve these tissues.
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 | NA |
| 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) | |
| Refrigerated | ||
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Conventional chromosome studies of B-cell disorders are not always successful because B-cell lymphocytes do not proliferate well in cell culture. FISH is an informative method to detect common B-cell-associated chromosome abnormalities, but FISH-based assays do not detect all abnormalities.
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.
Different disorders have differing levels of response to CpG. In 1 study, B-cell chronic lymphocytic leukemia (CLL) and marginal zone lymphoma showed the strongest response, followed by small lymphocytic lymphoma, follicular lymphoma, mantle cell lymphoma, and large cell lymphoma.
It is likely that CpG-stimulated chromosome analysis and FISH will be complementary tests. For example, about half of the 13q deletions seen in CLL and some lymphomas are microdeletions that are detectable by FISH, but not by conventional metaphase analysis.
CpG-stimulation reveals an abnormal karyotype in approximately 80% of patients with B-cell 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.
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.
46,XX or 46,XY. No apparent chromosome abnormality.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
The abnormalities detected, as well as their known prognostic significance, will be provided in an interpretive report.
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.
On rare occasions, the presence of an abnormality may be associated with a congenital abnormality and, thus, would not be related to the malignant process. Follow-up with a medical genetics consultation is recommended.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Peripheral blood is preferred over bone marrow or lymph node specimens.
This test does not replace FISH testing as several abnormalities seen by FISH are cryptic (undetected) by conventional chromosome analysis; both FISH and chromosome analysis using CpG 7909 (CpG) cell culture techniques are recommended.
Interfering factors:
Technical
-Cell lysis caused by forcing blood quickly through the needle at collection
-Use of an improper anticoagulant (sodium heparin is best) or not mixing the blood with the anticoagulant
-Excessive transport time
-Exposure of the specimen to temperature extremes (freezing or >30 degrees C)
Biological
-Abnormalities may be missed due to statistical sampling error
-Subtle structural chromosome abnormalities may be missed (occasionally)
-Neoplastic cells not dividing or not circulating in the bloodstream
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Mayr C, Speicher MR, Kofler DM, et al: Chromosomal translocations are associated with poor prognosis in chronic lymphocytic leukemia. Blood 2006 Jan 15;107(2):742-751
2. Stockero KJ, Fink SR, Smoley SA, et al: Metaphase cells with normal G-bands have cryptic interstitial deletions in 13q14 detectable by fluorescence in situ hybridization in B-cell chronic lymphocytic leukemia. Cancer Genet Cytogenet 2006 Apr 15;166(2):152-156
3. Jahrsdorfer B, Muhlenhoff L, Blackwell SE, et al: B-cell lymphomas differ in their respectiveness to CpG oligodeoxynucleotides. Clin Cancer Res 2005 Feb 15;11(4):1490-1499
4. Dicker F, Schnittger S, Haferlach T, et al: Immunostimulatory oligodeoxynucleotide-induced metaphase cytogenetics detect chromosomal aberrations in 80% of CLL patients: a study of 132 CLL cases with correlation to FISH, IgVH status, and CD38 expression. Blood 2006 Nov 1;108(9):3152-3160
5. Blum KA, Wei L, Jones JA, et al: Activity of combined Flavopiridol and Lenalidomide in patients with cytogenetically high risk chronic lymphocytic leukemia (CLL): Updated results of a Phase I trial. Blood (ASH annual meeting abstracts), Nov 2011;118:3910
6. 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, in press, 2012
Method Description Describes how the test is performed and provides a method-specific reference
A portion of the whole blood, bone marrow, or lymph node is transferred to a flask containing media and CyG 7909 (CpG) mitogen. The cells are incubated for 72 hours at 37 degrees C. In the harvest process, the cells are exposed to colcemid and hypotonic solution, then fixed with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slides and stained with quinacrine or Leishman stain. Twenty metaphases are usually examined for structure and number of chromosomes. If a clone is suspected, but not confirmed within 20 metaphases, 30 metaphases may be analyzed. Minimal evidence for the presence of an abnormal clone is defined as 2 or more metaphases with the same structural abnormality or chromosome gain (trisomy), or 3 or more metaphases lacking the same chromosome. Five to 10 metaphases are captured using a computerized imaging system, and 1 or more karyograms from each clone are prepared to document the type of abnormality and to permit systematic interpretation of the abnormalities. (Unpublished Mayo method)
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.
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.
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.
88237-Tissue culture for neoplastic disorders; bone marrow, blood
88291-Interpretation and report
88299-Unlisted cytogenetic study (Refer to patient report to apply the appropriate CPT code below in place of this unlisted cytogenetic study CPT code)
Based on the total number of cells analyzed and counted, MML would recommend the following:
Chromosome analysis with less than 5 cells; CPT Code 88261 w/modifier 52
Chromosome analysis with 5 to 14 cells; CPT Codes 88261, 88285
Chromosome analysis with 15 to 19 cells; CPT Code 88262
Chromosome analysis with 20 to 25 cells; CPT Code 88264
Chromosome analysis with more than 25 cells; CPT Codes 88264, 88285
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 |
|---|---|---|
| 29637 | Specimen | 31208-2 |
| 29638 | Specimen ID | N/A |
| CG138 | Source | N/A |
| 29640 | Order Date | N/A |
| CG140 | Reason For Referral | 42349-1 |
| 29642 | Method | 49549-9 |
| 50465 | Banding Methods | 62359-5 |
| 29643 | Result | N/A |
| 29644 | Interpretation | N/A |
| 29645 | Amendment | N/A |
| 29646 | Reviewed By | N/A |
| 29647 | Release Date | N/A |
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