Department of Dermatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
Department of Dermatology, Kepler University Hospital, Linz, Austria
Institute of Statistics and Econometrics, Sofia University “St. Kliment Ohridski”, Faculty of Economics and Business Administration, 1113 Sofia, Bulgaria
Department of Dermatology, Lausanne University Hospital (CHUV) and the Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
These authors contributed equally.
Background: Early and precise diagnosis of cutaneous T-cell lymphomas (CTCL) is challenging. Currently, polymerase chain reaction (PCR)-based clonality assessment of the T-cell receptor (TCR) is a helpful tool for this diagnosis. Objectives: In this retrospective study, we aimed to assess the sensitivity and specificity of this method for the diagnosis of CTCL. Materials and Methods: Monoclonal rearrangement of the TCR was investigated retrospectively by PCR-based clonality assessment based on 292 DNA samples from skin biopsies of patients with a suspicion of CTCL. Algorithms were based on different ratios (three or five-fold difference) between the dominant PCR peak and the third highest PCR peak. Results: A PCR peak five-fold higher than the third highest PCR peak demonstrated significantly greater specificity (83.7% versus 76.4%) but lower sensitivity (59.8% versus 68.6%) compared to a cut-off of three-fold higher. Conclusion: Our results confirm the diagnostic value of TCR clonality analysis which may be used to define the ideal cut-off in order to optimize sensitivity and specificity.