|Comprehensive T-Cell Clonality Analysis
||The Comprehensive T-Cell Clonality Analysis test is based on the detection of rearrangements of the T-Cell Beta and Gamma receptor genes that occur during T lymphocyte development. Both the T-Cell Receptor Beta (TRB@) and the T-Cell Receptor Gamma (TRG@) rearrangements generate DNA segments that are unique in length and sequence for a specific lymphocyte clone. Polymerase chain reaction (PCR) assays can be used to identify lymphocyte populations derived from a single cell (monoclonal populations) by detecting the unique gene rearrangements present within both antigen receptor loci. Reactive lymphocytic proliferations show a polyclonal rearrangement profile.The identification of a monoclonal population in the right clinical and pathological scenario, suggests the presence of a lymphoid neoplasm (leukemia or lymphoma). Non-neoplastic lymphocytic proliferations can also present with monoclonal populations. This test is used to detect the vast majority of clonal T-Cell malignancies. The combination of both TRB@ and TRG@ gene rearrangement assay is reported to identify 94%of T-cell malignancies (Brüggemann et al. Leukemia 2007, 21:215-221).
The T-Cell Receptor Beta and the T-Cell Receptor Gamma rearrangement assays are available as separate tests. Please see test codes #9200 (PB, BM, T) and #9225 (FFPE) for T-Cell Receptor Beta rearrangements and test codes #9215 (PB, BM, T) and #9235 (FFPE) for T-Cell Receptor Gamma rearrangements.
If the cell lineage is not known, this test can be combined with the Comprehensive B-Cell Clonality Analysis for detection of clonal B-cell proliferations. Please see test codes #9202 (PB, BM, T) or #9240 (FFPE).
To order this test on FFPE samples, please see test code #9245.
||This assay employs multiple consensus DNA primers that target conserved genetic regions within the TRB@ and TRG@ gene loci. The methodology used (Invivoscribe ASR reagents, TRB@ VDJ recombination and TRG@ VJ recombination) is based on data produced by independent testing centers throughout Europe in a collaborative study known as the BIOMED-2 Concerted Action. Unique rearrangements products are amplified by PCR followed by size determination using capillary electrophoresis. A clonal population of cells will produced one or two prominent amplicons within the expected size range. In contrast, DNA from normal polyclonal populations will produce amplicon products that reflect the heterogeneous population of rearrangements in a Gaussian distribution.