The significance of multiplex PCR/heteroduplex analysis-based TCR-γ gene rearrangement combined with laser-capture microdissection in the diagnosis of early mycosis fungoides

摘要

Background: The diagnosis of early mycosis fungoides (MF) is a big challenge to dermatologists and dermatopathologists because it lacks specific clinicopathologic features. Methods: Fifty-two paraffin-embedded skin samples from 50 patients, including 31 with suspected MF, 10 with typical MF and 9 with benign inflammatory dermatosis (BID), were obtained from our archives. DNA was extracted both by traditional phenol-chloroform method and by the laser-capture microdissection (LCM)-proteinase K approach. The T VG/T JG, V 2-5/V 8-12/JGT 1 and BIOMED-2-TCR-Iγ primers were used to assess TCR-Iγ monoclonal rearrangement as measured by polymerase chain reaction (PCR). Results: In the suspected MF group, clonal TCR-Iγ gene rearrangements were detected in 11/31 cases (35.5%) by phenol-chloroform DNA extraction and in 25/31 cases (80.7%) by LCM-proteinase K extraction (p 0.05). While T-cell clonality was detected in 8/10 cases (80%) by the phenol-chloroform method and 10/10 cases (100%) by LCM (p 0.05) in the typical MF group, no TCR-Iγ monoclonal rearrangement was detected in the BID group. Conclusions: The strategy of multiple PCR/heteroduplex analysis for TCR-Iγ gene rearrangement combined with LCM increases the detection rate of clonal TCR-Iγ gene rearrangement in early MF cases and could provide strong evidence to confirm the diagnosis of early MF.