High detection rate of T-cell receptor beta chain rearrangements in T-celllymphoproliferations by family specific polymerase chain reaction in combination with the GeneScan technique and DNA sequencing

The distinction between benign polyclonal and malignant monoclonal lymphoid disorders by morphology or immunophenotyping is frequently difficult. Ther efore, the demonstration of clonal B-cell or T-cell populations by detectin g identically rearranged immunoglobulin (Ig) or T-cell receptor (TCR) genes is often used to solve this diagnostic problem. Whereas the detection of r earranged Ig genes is well established, TCR gamma (gamma) and beta (beta) g ene rearrangements often escape detection with the currently available poly merase chain reaction (PCR) assays. To establish a sensitive, specific, and rapid method for the detection of rearranged TCR-beta genes, we developed a new PCR approach with family-specific J beta primers and analyzed the res ulting PCR products by high-resolution Gene-Scan technique. The superior ef ficiency of this new method was demonstrated by investigating 132 DNA sampl es extracted from lymph node and skin biopsy specimens (mostly formalin fix ed) and blood samples of 62 patients who had a variety of T-cell lymphomas and leukemias. In all but 1 of the tumor samples (98.4%) a clonal amplifica te was detectable after TCR-beta PCR and the same clonal T-cell population was also found in 15 of 18 (83%) of the regional lymph nodes and in 7 of 11 (64%) of the peripheral blood samples. Direct comparison of these results with those obtained currently by the most widely applied TCR-gamma PCR reve aled an approximate 20% lower detection rate In the same set of samples tha n with the TCR-beta PCR method. These results indicate that the new TCR-bet a PCR is most suitable for a rapid and reliable detection of clonal T-cell populations. (C) 2000 by The American Society of Hematology.