CPT® Code 81341

TRB@ (T cell antigen receptor, beta) (eg, leukemia and lymphoma), gene rearrangement analysis to detect abnormal clonal population(s); using direct probe methodology (eg, Southern blot)

The CPT® Code 81341 pertains to the molecular genetic testing of the T cell antigen receptor beta (TRB@) gene, which is located on chromosome 7. This testing is crucial for identifying mutations that may be responsible for certain types of leukemia and lymphoma. The T cell antigen receptor plays a vital role in the immune system, as it enables T cells to recognize and respond to foreign antigens, which are small peptides presented by major histocompatibility complex (MHC) molecules on antigen presenting cells (APC). The structure of T cell antigen receptors is formed from various independent gene segments, similar to immunoglobulin genes. The TRB@ gene specifically encodes the beta chain of the T cell antigen receptor, which is predominantly composed of alpha/beta chains (approximately 95%) and a smaller proportion of gamma/delta chains (about 5%). The analysis performed under this code utilizes direct probe methodology, such as Southern blotting, to detect abnormal clonal populations of T cells. This method involves the use of a single-strand DNA probe that is either radioactively labeled or enzyme-bound, allowing for the identification of specific base pairings and the sequencing of the gene. The comprehensive gene expression analysis provided by this testing can evaluate the human T cell receptor beta variable (TCRBV) proteins, which are essential for understanding the body's immune response to various conditions, particularly those affecting blood cells and the lymphatic system. By identifying the presence of abnormal clonal populations, healthcare professionals can gain insights into the underlying mechanisms of certain hematological malignancies, thereby aiding in diagnosis and treatment planning.