T-cell receptor gene rearrangement analysis in the primary cutaneous T-cell lymphoma

Abstract

Object: The present paper is to evaluate the significance of T-cell receptor (TCR) gene rearrangements in primary cutaneous T-cell lymphomas (PCTCL) as detected by analysis of Southern Blot (SBA) and polymerase chain reaction (PCR). Patients and Methods: Skin specimens and peripheral blood samples were taken from 44 patients with PCTCL, including 30 patients with mycosis fungoides (MF), 2 patients with Sezary's syndrome (SS), and 12 patients with PCTCL other than MF and SS (PNCTCL). 11 patients with a presumptive diagnosis of MF, 23 patients with lymphoproliferative dermatoses including lymphomatoid papulosis (LyP) and 8 patients with benign cutaneous lymphoid infiltrates were simultaneously studied by the ampfification of junctional V (variable)-J (joining) sequences of the rearranged TCR T genes by PCR(TCRγPCR) and the analysis of TCRβ-chain genes by SBA(TCRβSBA) for detection of clonal gene rearrangements (GR). One lymph node specimen of a case with MF IIA was also detected by TCRγPCR and TCRβSBA. Results: In MF, GR were detected by TCRγPCR and TCRβSBA[3 in 83.3- 85.7% and 66.7%-71.4% of skin specimens of cases IIAliB and in 57.1%-70.0% and 14.3%-10.0% of those of cases IA-IB, respectively. GR were seen in 66.7%- 71.4% and 33.3%-43.0.% of blood samples of cases IIAliB, and 42.9%-40.0% and 0-10.0% of those of cases IAIB, respectively. GR was confirmed by TCRγPCR and TCRβSBA in one lymph node showing dermatopathic lymphadenopathy of a case with MF IIA. In 11 patients of clinically suspected MF, GR were present in skin specimens of 5 cases (45.4%) and in blood samples of 3 cases (27.3%) by TCRγPCR. In PNCTCL, GR were found in 9 skin specimens (90.0%) from 10 patients detected by TCRγPCR and in 6 skin specimens (75.0%) from 8 patients detected by TCRβSBA. GR were also seen in 6 blood samples (72.8%) from 11 patients detected by TCRγPCR, and in 7 blood samples (70.0%) from 10 patients by TCRβSBA. In SS and LyP, GR were detected by TCRγPCR and TCRβSBA in each of the two skin specimens of two cases with LyP and in each of the two blood samples of two cases with SS. GR were seen in one skin specimen of one case with SS and one blood sample of one case with LyP detected by TCRγPCR. Conclusions: This study demonstrated that TCRγPCR is a rapid, more sensitive tool than TCRβSBA, can be used in the analysis of T-cell clonality in skin, lymph node and blood samples of patients with PCTCL and indicated that this method forms a useful supplement to other methods for diagnosis of early and suspected MF, confirmation of PNCTCL and determination of extracutaneous involvement of lymph node and blood.