At a glance
Also known as
T-cell Gene Clonality; TCGR; TCR gene Rearrangement
Why get tested?
To help diagnose a T-cell lymphoma
; sometimes to detect and evaluate residual cancer cells
When to get tested?
When a doctor thinks that you may have a T-cell lymphoma; when a doctor would like to assess whether treatment has been effective and/or whether lymphoma has recurred
A , tissue such as a lymph node (), or body fluid sample collected by your doctor; sometimes a blood sample drawn from a vein in your arm
Confused about genetics?
See our Genetics Information page
What is being tested?
This test detects characteristic changes (rearrangements) in specific in T-cells. This information can be helpful in diagnosing a T-cell lymphoma.
T-cells are a type of , one of the white blood cells (WBC) that helps protect the body against infection. There are two main types of lymphocytes, B-cells and T-cells. Whereas B-cells produce to attack , and other foreign substances, one of the main jobs of T-cells is to destroy the body’s own cells that have been infected by viruses or bacteria or damaged for example by becoming cancerous. Like almost all cells in the body, white blood cells contain . As the cells mature, their DNA is modified in a process called gene rearrangement. These rearrangements allow for the development of a large repertoire of diverse cells enabling them to protect against many different kinds of infections. Rearrangements in parts of the DNA of T-cells called receptor genes are a normal part of their development. The final order in which the genes are rearranged is called a gene rearrangement profile. Within any normal population (sample) of T-cells, the cells and their gene rearrangement profiles are very diverse.
Lymphomas arise when an abnormal T-cell begins to produce numerous identical copies of itself (). The cloned cells grow and divide uncontrollably, crowding out normal cells. If someone has lymphoma, the T-cells in affected tissue (such as blood, lymph node, or skin) are identical and their gene rearrangement profiles are likewise identical.
A T-cell receptor gene rearrangement test evaluates the T-cells in a person's sample to determine whether the majority of T-cell rearrangement profiles are diverse or identical. This information, along with clinical and and results of other laboratory tests, can help clarify a person's diagnosis, or evaluate for persistent or recurrent lymphoma.
T-cell lymphoma is rare in Australia with B-cell Lymphoma being by far the most common type. There are many different types of T-cell Lymphoma and each of them is rare. Statistics from the American Cancer Society show that in the US 85 per cent of non-Hodgkin lymphomas are B-cell lymphomas with T-cell lymphomas accounting for the remaining 15 per cent. In Australia, the figures can be expected to be similar.
For additional details about T-cells and this testing, read more.
How is the sample collected for testing?
A , lymph node, or other tissue sample is collected through a procedure. Body fluid samples are obtained through collection of the fluid in a container by inserting a needle into the body cavity and aspirating a portion of the fluid with a syringe. Sometimes, a blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.