COMPARISON OF DIFFERENT STRATEGIES OF MOLECULAR-GENETIC MONITORING FOLLOWING AUTOLOGOUS STEM-CELL TRANSPLANTATION IN PATIENTS WITH FOLLICULAR LYMPHOMA

Two different molecular genetic methods were compared for their suitab ility for monitoring minimal residual disease in patients with follicu lar lymphoma (FL) treated with high-dose therapy and autologous stem c ell transplantation. Fifteen patients were selected because of a speci fic PCR-amplifiable t(14;18) mbr translocation, PCR amplification of r earrangements of the complementary region III (CDRIII) of the immunogl obulin heavy chain gene was also carried out, After autologous stem ce ll transplantation, patients were prospectively monitored with both mo lecular genetic methods. Seven of the 15 patients with detectable t(14 ;18) prior to transplantation were persistently negative during follow -up to 32 months post transplant. None of these patients relapsed, whe reas four of eight patients with positive PCR signals post transplant relapsed. Comparing t(14;18) and PAGE results, we observed six patient s showing clonal signals in CDRIII PAGE in spite of persistent negativ ity of t(14;18) PCR, We concluded that in patients with FL, t(14;18) P CR is superior to CDRIII PCR in terms of sensitivity and specificity. A positive t(14;18) PCR during the first year post transplant is highl y predictive for disease recurrence. CDRIII PCR may be used for monito ring in t(14;18) negative lymphomas, However, due to the poor specific ity of conventional gel electrophoresis PCR, the use of clone-specific probes is highly desirable.