T-cell clonality (TCR)
| Category | Specialist Integrated Haematological Malignancy Diagnostic Service (SIHMDS) >> Molecular Pathology |
|---|---|
| Test background |
Immunoglobulin gene rearrangements are formed from the earliest stages of B-cell and T-cell development onwards. Random coupling between one of many V, (D) and J genes results in the formation of a unique V(D)J exon that encodes the actual antigen-binding moiety of the Ig or TCR chain. Owing to the huge diversity in Ig/TCR rearrangements, the diversity of different Ig or TCR molecules is estimated to be in the order of 1012 Consequently each lymphocyte has a unique antigen receptor molecule on its membrane and the chance that two different lymphocytes coincidentally bear the same receptor is almost negligible. Hence, identical rearrangements are not derived from multiple independently generated cells, but rather reflect the clonal nature of the involved cell population. T-cell clonality studies can help to discriminate between malignant and reactive lymphoproliferations in patients with suspected lymphoproliferative disorder. Multiplex PCR is performed using BIOMED-2 primers followed by fragment analysis to detect presence of clonal rearrangements in T-cell receptor gamma gene (TCRG). |
| Clinical Indications |
For diagnostic testing in lymphoid malignancies such as lymphomas. |
| Sample & container required | A minimum of 1ml peripheral blood or bone marrow in EDTA (lavender/purple top). Please note that samples must be received within 72 hours of collection for lymphocyte separation to be performed. FFPE tissue curls, uncoated/uncharged slides. Minimal tumour content of 5% is required for clonality studies. The tumour content and the amount of tissue to be cut must be assessed by a histopathologist prior to sending the sample. |
| Sample volume | 1 mL blood OR bone marrow |
| Sample collection | Please ensure the sample is sent to the lab ASAP after collection as it must be received within 72 hours. |
| Turnaround time | 14 calendar days |