Differentiation between non-Hodgkin's lymphoma recurrence and second primary lymphoma by VDJ rearrangement analysis.

Relapses in non-Hodgkin's lymphomas (NHL) could be due to the reappearance of the initial neoplasm or new primary tumours. Discrimination between the two events would allow a more targeted therapeutic approach. VDJ rearrangement was used as marker of clonality in metachronous biopsy specimens from 10 patients with relapsed B-NHL. Complimentary determining region 3 was amplified and sequenced. D-JH was identical in eight matched primary/secondary tumours, confirming the diagnosis of recurrence. In contrast, primary and secondary tumours in two patients were of different clonal origin. Our data indicate that VDJ analysis is a fundamental tool for identification of relapses in NHL.