DETECTION OF MONOCLONAL T-CELLS IN THE DIAGNOSIS OF MYCOSIS-FUNGOIDESBY TCR-GAMMA PCR AND TEMPERATURE-GRADIENT GEL-ELECTROPHORESIS

The monoclonal dominant malignant T cells in mycosis fungoides (MF) ca rry identical TCR gamma rearrangements. Their detection is a useful di agnostic tool. Thus, in routine diagnosis we investigated the occurren ce of monoclonal T cells in skin biopsy samples of MF-patients by TCR gamma-PCR, followed by temperature gradient gel electrophoresis (TGGE) . In 188 out of 208 MF patients, at least one skin sample with suffici ent DNA quality for PCR analysis was obtained. Applying a consensus PC R for the TCR gamma genes V gamma l and J gamma 1/2, we detected monoc lonal T cells in 122 cases (65%). In the remaining 66 cases, we perfor med two multiplex-PCRs, covering rearrangements of the other TCR gamma genes. Here we found in 11 cases(6%) predominant clonal rearrangement s of V gamma ll-IV and J gamma 1/2 and in 2 (1%) those of V gamma l-IV and J gamma P1/2. In patients with MF,detecting rearrangements of onl y V gamma l and J gamma 1/2 is sufficient for PCR screening analysis. In 53 of the patients (28%) the applied methods revealed no monoclonal T cells. This may be due to a low cell number, oligoclonal nature, ch romosomal abberations or remaining of TCR in germline configuration.