Identification of the B-cell tumor-specific molecular fingerprint using non-radiolabelled PCR consensus primers

Background: The complementarity determining region 3 (CDR3) of the immunoglobulin (Ig) heavy chain variable region (V-H) is the most reliable molecular fingerprint for most if not all human B cells. The nucleotide sequence encoding for any B-cell tumor-specific V-H CDR3 is currently identified by PCR sequencing based on procedures involving the usage of either radioactive materials, patient/family-specific primers, or bacterial cloning. Patients and methods: In six consecutive patients with follicular lymphoma we assessed the feasibility of a method that allows for identification of the tumor-specific V-H CDR3 using consensus primers while avoiding both radioactive materials and bacterial cloning procedures. Results: The tumor-specific V-H CDR3 was successfully identified in all six patients in nearly half the time typically required by any other method currently utilized. The feasibility of the proposed method was not significantly affected either by the tumor-specific Ig isotype, or by the tumor infiltration in the original biopsy specimen. In the three patients for whom tumor specimen-derived hybridomas were available, the tumor-specific V-H CDR3 was also found in at least 8 of 10 of them. Conclusions: The proposed method allows the ability to quickly identify the B-cell tumor-specific V-H CDR3 using consensus primers while avoiding radioactive materials and bacterial cloning procedures.