DETECTION OF MINIMAL RESIDUAL DISEASE IN FOLLICULAR LYMPHOMAS USING PCR - VALUE OF CLONOSPECIFIC PROBES

Follicular lymphoma constitutes 30-40% of non-Hodgkin's lymphomas. Mos t patients have widespread disease at diagnosis. The clinical course i s generally indolent, and it is not usually curable With available tre atment The source of relapse in patients who achieve complete clinical remission is residual neoplastic cell that are present below the limi ts of detection wing standard techniques. With the development of PCR technology, the presence of these residual malignant cells [Minimal Re sidual Disease (MRD)] has been demonstrated clearly. Recently, an asso ciation of high-dose chemotherapy with autologous bone marrow or perip heral blood progenitor cell autograft appeared promising in the treatm ent of these lymphomas. In the search of clonal markers for the detect ion of MRD in follicular lymphomas, two strategies can be used. In the cases associated with the t(14;18)(q32;q21) chromosomal translocation , the bcl-2/J(H) junctional regions are amplified by PCR in similar or equal to 50% of cases and then sequenced in order to synthesize an an ti-junction oligonucleotide probe specific for each patient's malignan t clone (clonospecific probe). In the cases negative for this transloc ation, an alternative strategy consists in the amplification of immuno globulin high chain (IgH) gene rearrangement (similar or equal to 75% of cases). The present review highlights the value of molecular marker s such as bcl-2/J(H) and V-H/J(H) rearrangements to follow the neoplas tic clone and to detect MRD in patients with follicular lymphomas.