What are other Names for this Test? (Equivalent Terms)
- B-Cell Gene Clonality Molecular Genetic Test
- BCGR Test
- Immunoglobulin Gene Rearrangement Test
What is B-Cell Gene Rearrangement Test? (Background Information)
- B-cells are a type of white blood cells called lymphocytes. They are responsible for making antibodies and defending the body against disease
- B-cells can make antibodies that target a vast array of different invaders because of gene rearrangements. As the name implies, gene rearrangements refer to shuffling of genetic information during maturation of B-cells
- Gene rearrangements result in the production of an endless number of B-cells, each with their own unique genetic profile, and hence, the ability to produce antibodies that target unique invaders
- Because of the frequent genetic shuffling of B-cells during their maturation, B-cells are susceptible to genetic and biochemical alterations that could derail their maturation pathways and cause them to grow and divide uncontrollably
- B-cells that have gained the ability to uncontrollably proliferate are cancerous. In such instances, the B-cell continually copies itself, with each copy having the same genetic profile (in contrast to other “normal” B-cells, which each have unique genetic profiles)
- Hence, the presence of a large number of B-cells with identical genetic profiles indicates a possible B-cell cancer, or B-cell lymphoma
- The B-Cell Gene Rearrangement Test is a genetic test that detects the presence of a large number of B-cell clones. It is used to diagnose and monitor treatment for non-Hodgkin B-cell lymphoma
The molecular testing, in general, can be performed using a variety of methods. Some of these methods include:
- In situ hybridization technique, such as fluorescence in situ hybridization (FISH)
- Immunohistochemistry (IHC)
- Next-generation sequencing (NGS)
- Polymerase chain reaction (PCR)
- Comparative genomic hybridization (CGH)
- Karyotyping including spectral karyotyping
- mRNA analysis
- Tissue microarrays (TMAs)
- Southern blot test
- Northern blot test
- Western blot test
- Eastern blot test
The methodology used for the test may vary from one laboratory to another.
Note: Molecular testing has limitations due to the molecular method and genetic mutational abnormalities being tested. This can affect the results on a case-by-case basis. Consultation with your healthcare provider will help in determining the right test and right molecular method, based on individual circumstances.
What are the Clinical Indications for performing the B-Cell Gene Rearrangement Test?
Following are the clinical indicators for performing the B-Cell Gene Rearrangement Test:
- Multiple swollen lymph nodes without pain
- Fever, night sweats
- Unexplained weight loss
In general, the molecular genetic testing is undertaken in the following situations:
- To assist (and in some cases, confirm) the initial diagnosis
- To distinguish other tumors/conditions that have similar histological features, when examined by a pathologist under the microscope
- To help in determining treatment options
- To confirm recurrence of the tumor: Tumor recurrence can either be at the original tumor site, or at a distant location (away from the initial site)
How is the Specimen Collected for B-Cell Gene Rearrangement Test?
Following is the specimen collection process for B-Cell Gene Rearrangement Test:
The specimen sample requirements may vary from lab to lab. Hence, it is important to contact the testing lab for exact specimen requirements, before initiating the testing process.
- Sample on which the test is performed may include:
- Fresh tumor tissue during biopsy
- Formalin-fixed paraffin-embedded solid tumor tissue (FFPE tumor tissue), often referred to as paraffin block of the tumor
- Unstained tissue slides
- Process of obtaining the sample: As outlined by the laboratory testing facility
- Preparation required: As outlined by the laboratory testing facility
- In some cases, a different source of specimen (such as peripheral blood, bone marrow biopsy specimen, or other body fluids) may be acceptable to the laboratory performing the test
- Occasionally, additional samples may be required to either repeat the test or to perform follow-up testing
- Depending on the location of testing, it may take up to 2 weeks’ turnaround time, to obtain the test results
- Many hospitals preserve the paraffin blocks for at least 7 years. In general, older paraffin blocks (over 5 years) may affect the detection of specific mutations, due to degradation of the tumor specimen over time
Cost of B-Cell Gene Rearrangement Test:
- The cost of the test procedure depends on a variety of factors, such as the type of your health insurance, annual deductibles, co-pay requirements, out-of-network and in-network of your healthcare providers and healthcare facilities
- In many cases, an estimate may be provided before the test is conducted. The final amount may depend upon the findings during the test procedure and post-operative care that is necessary (if any)
What is the Significance of the B-Cell Gene Rearrangement Test Result?
The significance of the B-Cell Gene Rearrangement Blood Test is explained below:
- A positive value for the test may point to a diagnosis of non-Hodgkin B-cell lymphoma
- A positive value for the test after initiating treatment may indicate remission, or that the cancer treatment was not entirely successful
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- B-cell lymphoma comprises 85% of non-Hodgkin lymphomas
- Many laboratories may not have the capability to perform this test. Only highly-specialized labs with advanced facilities and testing procedures may perform this test
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider of the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
What are some Useful Resources for Additional Information?
The following DoveMed website link is a useful resource for additional information:
Please visit our Laboratory Procedures Center for more physician-approved health information:
References and Information Sources used for the Article:
https://ghr.nlm.nih.gov/primer/testing/genetictesting (accessed on 05/10/2017)
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5806a1.htm (accessed on 05/10/2017)
http://www.nature.com/gim/journal/v10/n5/full/gim200852a.html (accessed on 05/10/2017)
http://pediatrics.aappublications.org/content/106/6/1494 (accessed on 05/10/2017)
Lab Tests Online (2014, May 13). Retrieved from http://labtestsonline.org/understanding/analytes/bcgr/
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