A new polymerase chain reaction-based method for the detection of T- cell clonality in patients with possible cutaneous T-cell lymphoma

Objective: To evaluate a new, rapid, and sensitive method for the detection of T-cell clonality in patients with lesions suggestive of cutaneous T-cell lymphoma (CTCL). Design: Skin specimens were obtained from 48 patients with possible CTCL. Polymerase chain reaction amplification of the T-cell receptor γ (TCRG) gene was performed using consensus primers to the V and J regions. Clonal populations having identical N-region sequences are detected by single-strand conformation polymorphism analysis using a semiautomated electrophoresis system with a silver-staining method for gel visualization. The results of clinicopathological assessment were compared with those of immunohistochemistry and polymerase chain reaction analysis. Setting: Cutaneous lymphoma clinic at a university medical center. Patients: Forty-eight patients with skin lesions suggestive of CTCL. Results: Based on the clinicopathological assessment, 26 patients were diagnosed as having CTCL. Of them, clonality was detected in 19 patients (73%) and an abnormal phenotype in 17 (68%) of 25 patients. Combining both tests, abnormal results were noted in 24 (92%) of 26 patients with CTCL. Clonality was also identified in 2 (12%) of 17 patients with presumably benign lesions on clinicopathological assessment. Conclusions: Polymerase chain reaction and single-strand conformation polymorphism analysis of the TCRG gene is a rapid and sensitive method that can contribute to the diagnosis of CTCL. The new method is especially useful when used in conjunction with immunophenotyping.