BCL2/JH Translocation Assay; for identification of follicular cell
and other lymphomas and leukemias
This is to bring to the attention of the medical community of the University of Iowa that the Molecular Pathology division of the Clinical Laboratories has validated and introduced a new test to detect BCL2 t(14;18) translocations. The test is based on the research and development work of a pan-European collaborative effort, BIOMED-2 Concerted Action, involving 32 diagnostic PCR laboratories (see reference: van Dongen et al. 2003). The kit is produced and marketed by InVivoScribe.
Clinical indications for the test include:
A) Differentiation of reactive and neoplastic B-cell proliferations
B) Differential diagnosis of B-cell malignancies
The t(14;18) is present in 70-90% of follicular non-Hodgkin B cell lymphomas, 50% of undifferentiated B cell lymphomas, and 20-30% of large cell diffuse B cell lymphomas. It is not seen in other lymphomas.
C) Prognostication of large cell diffuse B-cell lymphomas
Presence of the translocation is an indicator of poor prognosis
D) Evaluation of the clonal relationship between two lymphoid malignancies in one patient or discrimination between a relapse and a second malignancy
The method entails PCR amplification of the patient’s DNA and analysis of the resulting fluorescently tagged PCR products by capillary electrophoresis using the ABI3130 sequencer. A total of 9 primer pairs are used that identify MBR, 3’MBR, 5’mcr and mcr translocation clusters. The current method only investigates the MBR locus. The latter three clusters represent 15-20 % of all t(14;18) translocations and testing for these translocations significantly improves clinical sensitivity. The analytical sensitivity of the assay is comparable to the previously used liquid hybridization methodology even without the use of radioactive isotopes. The kit is well suited to work with DNA from multiple sources including paraffin embedded formaldehyde fixed tissues. The exact sizing of the PCR product allows the positive identification of specific clones. The test offers increased reproducibility and a shorter turnaround time than our previous assay.
Questions concerning the procedure should be addressed to Peter L. Nagy, M.D., Ph.D., at 353-4594.