VALUE OF CLONALITY STUDIES OF CUTANEOUS T-LYMPHOCYTES IN THE DIAGNOSIS AND FOLLOW-UP OF PATIENTS WITH MYCOSIS-FUNGOIDES

Histological features of early mycosis fungoides (MF) can simulate num erous inflammatory lesions and histological confirmation of MF is ofte n delayed, compared with clinical diagnosis. Recently, using molecular techniques, the detection of a dominant T-lymphocyte clone has been r eported in cutaneous lesions of MF. The aim of the present study was t o determine the diagnostic value of a dominant T-lymphocyte clone as a ssessed by PCR-DGGE in early MF. Histopathological and molecular analy ses mere performed on cutaneous lesions from 104 patients clinically s uspected as having MF. In this population, the positive predictive val ue of a PCR gamma(+) was 0.86. In addition, four of six patients whose lesions were PCR gamma(+) (detectable dominant T-cell clone) but not histologically MF progressed to MF within 2-48 months. In order to eva luate the relevance of PCR gamma-DGGE in MF follow-up, serial biopsies mere performed in 24 patients, In 89 per cent of cases, the presence or absence of a PCR gamma(+) was constant during the course of the dis ease. When present, the DGGE imprint of PCR products was case-specific . These data demonstrate the diagnostic value in MF of T-lymphocyte cl onality assessed by PCR gamma-DGGE on cutaneous lesions and show that the technique can be used in MF follow-up to evaluate residual disease with high specificity. (C) 1998 John Wiley & Sons, Ltd.