Note: All samples should be forwarded to LabPlus at room temperature within 24hours.
4 mL CPD Blood (Preferred) 4 mL EDTA Blood 2 mL EDTA Bone Marrow 2 mL CPD Bone Marrow Paraffin block Tissue Tissue Turnaround Time: Within 2 weeks, 4 days
Reporting may be delayed in specific cases due to complexity. Please contact the lab for more information.
Diagnostic Use and Interpretation
This test is used to detect the presence of a monoclonal T cell population in a blood or tissue samples.
Note: Although accurate in the majority of cases, molecular data should never be used in isolation to establish a diagnosis. The clinical setting, morphological findings and other ancillary tests should always be used in the final interpretation.
Immunoglobin Gene Rearrangement Analysis
To contact the Molecular Haematology team please call:
Auckland City Hospital (09) 307 4949 Lablink ext 22000 Prof. Peter Browett (Haematologist) ext 9090-86281 Nikhil Ghallayan (Section Leader) ext 22006 Molecular Haematology Lab ext 22005
For more inforamtion about the Molecular Haematology service at LabPLUS:
Molecular Haematology information page
During normal T cell development rearrangement processes occur in the T cell receptor (TCR) gene. The structure of the TCR gene consists of constant (C), joining (J) and variable (V) regions. Variability in structure is generated by a process of rearrangement of the DNA which involves splicing out and recombination of DNA segments. This process results in each T cell having its own specific combination of V and J segments which forms the basis of TCR diversity. Each cell has a characteristic rearrangement pattern which is present in all the progeny, therefore a clonal population consists of cells with the same pattern. The Southern blot technique is the 'gold-standard' for distinguishing between monoclonal and polyclonal lymphoproliferative disorders but this technique is time-consuming, requires large amounts of high-quality DNA and is technically difficult. PCR-based assays, which do not have these limitations, may be used instead. Most importantly, the PCR based assay can be used on paraffin-block extracted DNA samples, enabling analysis of histologically relevant samples.
PCR analysis of the TCRgamma gene recombination process may be used to asses T cell clonality as the rearrangement occurs in the majority of T cell neoplasms (irrespective of whether a functional TCRgamma receptor is expressed). Monoclonal TCRgamma rearrangements have been found in up to 90% of T cell neoplasms using the PCR method described below. Note, however, that 10-30% of T-cell malignancies may be missed by this method.