COMPARISON OF CYTOGENETIC ANALYSIS, SOUTHERN ANALYSIS, AND POLYMERASECHAIN-REACTION FOR THE DETECTION OF T(14-18) IN FOLLICULAR LYMPHOMA

This study was undertaken to compare the ability of cytogenetic analys is (CG), Southern analysis (SA) and the polymerase chain reaction (PCR ) to detect the t(14;18) in follicular lymphoma (FL). All methodologie s were performed by standard techniques. The probes used for SA includ ed major breakpoint region (mbr) and minor cluster region (mcr) probes . The primers for PCR were identical or similar to those used by other investigators. One hundred fifteen cases of FL were ascertained by mo rphologic criteria, from which sufficient fresh tissue was available f or both CG and molecular analysis. Eleven cases failed by both methods (nonrepresentative sampling). One hundred four cases showed evidence of an abnormal clone by CG and/or immunoglobulin gene rearrangement (I gH) studies. Cytogenetic analysis failed in 2 cases, was positive for t(14;18) in 91 of the remaining 102 cases (89%) and detected a non-t(1 4;18) close in 11 cases. An IgH clonal rearrangement was confirmed in all 104 cases, Southern analysis detected a mbr or mcr rearrangement i n 78 of 104 cases (75%). Polymerase chain reaction detected an mbr or mcr rearrangement in 68 of 104 cases (65%). The use of PCR as a clinic al test to detect t(14;18)-positive lymphomas, with single primer sets for the mbr and mcr, will result in a high false-negative rate. The u se of additional primers to detect uncommon breakpoints sites will be required to enhance the sensitivity of PCR for detection of t(14;18) i n malignant lymphoma.