Polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR/DGGE)‐based detection of clonal T‐cell receptor γ gene rearrangements in paraffin‐embedded cutaneous biopsies in cutaneous T‐cell lymphoproliferative diseases*

Abstract

Polymerase chain reaction (PCR)-based amplification of T-cell receptor (TCR)-gamma genes is a novel technique that can detect a clone of T cells comprising less than 1% of the total T cells in a lymphoid infiltrate. Besides greater sensitivity than Southern blotting, this technique can be performed with smaller quantities of lower molecular weight genomic DNA as template. We retrospectively analyzed 12 paraffin-embedded biopsies of cutaneous T-cell lymphoma (CTCL), 1 case suspicious for CTCL, 1 case of granulomatous slack skin, and 8 cases of inflammatory skin diseases to determine if PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analysis can detect TCR-gamma gene rearrangements on paraffin-embedded specimens. We were able to amplify Vgamma1-8 TCR sequences in each case and detected a dominant clone in 9 of 12 cases of CTCL and in granulomatous slack skin. We analyzed Vgamma9 sequences in 9 cases of CTCL and detected a dominant clone in 4 cases. This study demonstrates that PCR-DGGE can easily be applied retrospectively to cutaneous biopsies of lymphoproliferative diseases when fresh tissue is not available.

T‐cell receptor‐γ gene analysis in evolving to advancing cutaneous T‐cell lymphoma

“…Comparison of our PCR positivity rates with previously published studies showed an agreement in the findings: 50–78% clonality for patch‐stage MF (present study 62.1%); 50–100% clonality for plaque‐stage MF (present study 85.7%); 50–70% clonality for prediagnostic inflammatory dermatoses suggestive of MF (present study 50%); and 16–73% clonality for prediagnostic inflammatory dermatoses non‐specific for MF (present study 25%) 9,12,14–17 . The wide variation in sensitivity rates of published data is no doubt related to diagnostic criteria used for the histological diagnosis of MF and the sensitivity of the PCR technique.…”

New insights into the applicability of T‐cell receptor γ gene rearrangement analysis in cutaneous T‐cell lymphoma

“…The PCR/DGGE was performed using the method described previously 6,15 . Briefly, PCR for the TCR γ gene rearrangement was performed using consensus primers V γ 1–8 /J γ and V γ 9/ J γ as published previously (Table 7).…”

“…The technique has also been successfully applied to archival, paraffin‐embedded skin tissues with variable sensitivity 9, 12, 13 . We have applied the PCR/denaturing gradient gel electrophoresis (DGGE) to detect clonal TCR γ gene rearrangement on paraffin tissues successfully 15 and performed TCR gene rearrangement study in 100 cases, either on fresh‐frozen or paraffin‐embedded tissue. In this paper, we present our data to further evaluate the value of TCR gene rearrangement studies by PCR as an adjunct tool to the histological diagnosis in CTCL, and the possible difference between fresh vs. paraffin‐embedded tissues in this PCR‐based study.…”

The APOPTOSIS of dermatopathology?

“…The use of PCR in the field of cutaneous T‐cell lymphoma is well established and many laboratories are offering it 9 . Molecular techniques are becoming popular in the diagnosis of Kaposi's sarcoma 10 .…”

“…The use of PCR in the field of cutaneous T-cell lymphoma is well established and many laboratories are offering it. 9 Molecular techniques are becoming popular in the diagnosis of Kaposi's sarcoma. 10 In time, more and more tumors, malignant melanoma in particular, will be investigated by these techniques.…”