New PCR assay for Detecting Clonal Proliferations of B Lymphocytes

The Molecular Pathology Laboratory is pleased to announce the implementation of an improved method for the detection of B lymphocyte clonality, the IGH Clonality Assay from InVivoScribe Technologies. This multiplex PCR-based assay will replace our current Southern blot and IgH PCR tests for primary detection of clonal B cell proliferations.  The InVivoScribe IGH Clonality Assay is based on a pan-European collaborative effort involving 32 diagnostic high-complexity laboratories (the BIOMED-2 Concerted Action, see van Dongen et al. 2003).  The new assay has an improved clinical sensitivity (85-90%) and an analytic sensitivity of ~1% based upon Molecular Pathology Laboratory validation testing.  In addition, the new test allows for a much shorter turn-around time compared to Southern blotting.  However, since 10-15% of clonal B cell populations may be missed by this assay, follow-up testing by Southern blot is still recommended for cases in which there is a negative IGH Clonality Assay result and a strong remaining clinical suspicion of a clonal process. 

Clinical indications for the test include:
A) Any suspect B-cell proliferation when morphology and immunophenotyping are not conclusive;
B) Lymphoproliferations in immunodeficient patients;
C) Evaluation of the clonal relationship between two lymphoid malignancies in one patient or discrimination between a relapse and a second malignancy;
D) Occasionally, staging of lymphomas.
Acceptable specimens include fresh or frozen tissue, whole blood (collected in lavender or yellow top tubes), bone marrow, and formalin-fixed, paraffin-embedded tissue sections. 
The IGH Clonality Assay will be performed weekly; results are interpreted by qualified Molecular Pathology faculty.  For questions regarding this assay, please contact Beth Alden (384-9870), Dr. Peter Nagy (353-4594) or Dr. Jon Heusel (335-8217).