Test Id : CHRHB

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.

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.

Advise Express Mail or equivalent if not on courier service.

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.

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.

• Multiple Myeloma: Laboratory Screening

If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

3 mL

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.

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.

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.

An interpretative report will be provided.

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, consultation with a Clinical Geneticist is recommended.

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

1. Swerdlow et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. IARC Press:Lyon, 2017

2. Dewald GW, Ketterling RP, Wyatt WA, Stupca PJ. Cytogenetic studies in neoplastic hematologic disorders. In: McClatchey KD, ed. Clinical Laboratory Medicine. 2nd ed. Williams and Wilkens; 2002:658-685

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;119(10):2310-2313

A cell count is performed to establish a plating volume. Based on the cell count, a corresponding volume of blood is added to 2 culture flasks containing culture medium and incubated for 24 to 48 hours at 37 degrees C. In the harvest process, the cells are exposed to Colcemid and hypotonic solution and then fixed with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slides and are stained by G-banding. Other staining methods are employed as needed. Twenty metaphases are usually examined. If a clone is suspected, but not confirmed within 20 metaphases, 30 metaphases will 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. All cells analyzed are captured using a computerized imaging system, and 1 or more karyograms from each clone are prepared to document the abnormality and to permit systematic interpretation of the abnormalities

When a specimen is received from a patient 30 years of age or older with a reason for testing of chronic lymphocytic leukemia, small lymphocytic lymphoma, lymphocytosis, or Waldenstrom macroglobulinemia, a CpG-stimulated culture will be added and 10 additional cells will be analyzed. Additional metaphases may be analyzed from the unstimulated or CpG-stimulated cell cultures if necessary to provide an accurate interpretation. All 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.(Arsham, Marilyn S., et al. eds. The AGT Cytogenetics Laboratory Manual. 4^th ed. Wiley-Blackwell, 2017)

Monday through Friday

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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.

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)