Evaluation of the PCR-based T Cell Receptor-β clonality test in the diagnosis of early Mycosis Fungoides
Poster
Aviv Barzilai
(Department of Dermatology, Sheba Medical Center, Tel Hashomer, Ramat Gan | Institute of Pathology, Sheba Medical Center, Tel Hashomer, Ramat Gan | Sackler Faculty of Medicine,
Tel Aviv University, Tel Aviv)
Background
T-cell receptor (TCR) clonality is important for mycosis fungoides (MF) diagnosis. Routine clonality analysis is performed using a polymerase chain reaction (PCR) TCR-γ assay; yet with this method 10%–50% of T-cell lymphomas escape detection. TCR-β gene rearrangement is an additional assay. Data about its efficacy is controversial.
Objective
Evaluate the role of TCR-β assay in the diagnosis of early MF.
Methods
A retrospective study of 61 skin biopsies, 20 from MF patients, 30 from patients suspected to have early MF, and 11 from patients with chronic inflammatory skin disease.
Results
Monoclonality was detected in 16/20 (80%) MF cases; 15 (75%) with TCR-β and 12 (60%) with TCR-γ assay. Of the 30 suspected early MF cases, 14 demonstrated monoclonality, all of which with TCR-β and 5 with TCR-γ assay. None of the chronic inflammatory condition samples showed monoclonality. Therefore, TCR-β clonality assay was more sensitive in early MF than TCR-γ (83% vs. 43%, P=0.002).
Limitations
A retrospective, relatively small study.
Conclusion
TCR-β demonstrated a higher sensitivity rate compared with TCR-γ in early-stage MF. The combined use of the TCR-β and TCR-γ clonality tests can significantly improve the diagnosis rate of early-stage MF.