The relevance of VDJ PCR protocols in detecting B-cell clonal expansion in lymphomas and other lymphoproliferative disorders

Abstract

Aims and background: The detection of immunoglobulin heavy chain variable (VH)-diversity (DH)-joining (JH) region gene rearrangement by polymerase chain reaction (VDJ PCR) has been recently proposed as a rapid approach to assess B-cell clonality in lymphoproliferative disorders. The aim of the present study was to determine the efficacy of VDJ PCR in a wide spectrum of lymphoproliferative disorders previously characterized by immunohistochemistry and Southern blot (SB).

Methods: 83 SB-rearranged B-cell non-Hodgkin's lymphomas (NHL) of different histotype, 22 cases of SB-unrearranged classical Hodgkin's disease (HD), 18 cases of HIV-related reactive lymphadenopathy, and 4 frankly pre-lymphomatous lesions (MESA) in the course of Sjögren's syndrome were investigated by 2 different VDJ PCR protocols (FR3, FR2).

Results: The detection rate in NHL was 64% and 71% using the protocols FR3 and FR2, respectively. However, the overall VDJ PCR efficacy increased to 81% by combining the results of both protocols. In addition, differences in the combined, as well as in the single FR3 or FR2 protocol efficacy, were noted in the different NHL subgroups. B-cell clonality was also detected in 4/22 (18%) SB-unrearranged classical HD cases and in 2/18 (11%) reactive lymphadenopathy cases, whereas it was demonstrated in all the MESA lesions, 2 of them being SB-negative.

Conclusions: VDJ PCR represents a useful and rapid technique to detect B-cell clonality in NHL, although with some differences depending on the NHL histotype and the panel of primers employed. The technique may also be of value to investigate the possible progression of early B-cell clonal expansion into frankly B-cell malignancy and to contribute to the controversy about the clonal lineage origin of the putative HD malignant cells.