RESUMO
The monoclonal dominant malignant T cells in mycosis fungoides (MF) carry identical TCR gamma rearrangements. Their detection is a useful diagnostic tool. Thus, in routine diagnosis we investigated the occurrence 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 sufficient DNA quality for PCR analysis was obtained. Applying a consensus PCR for the TCR gamma genes V gamma I and J gamma 1/2, we detected monoclonal T cells in 122 cases (65%). In the remaining 66 cases, we performed two multiplex-PCRs, covering rearrangements of the other TCR gamma genes. Here we found in 11 cases (6%) predominant clonal rearrangements of V gamma II-IV and J gamma 1/2 and in 2 (1%) those of V gamma I-IV and J gamma P 1/2. In patients with MF, detecting rearrangements of only V gamma I 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, chromosomal abberations or remaining of TCR in germline configuration.
