Publications by authors named "Tabea Koch"

2 Publications

  • Page 1 of 1

Sensitivity and specificity of T-cell receptor PCR BIOMED-2 clonality analysis for the diagnosis of cutaneous T-cell lymphoma.

Eur J Dermatol 2020 Feb;30(1):12-15

Department of Dermatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland, Department of Dermatology, Lausanne University Hospital (CHUV) and the Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.

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.
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http://dx.doi.org/10.1684/ejd.2020.3698DOI Listing
February 2020

A new live-cell biobank workflow efficiently recovers heterogeneous melanoma cells from native biopsies.

Exp Dermatol 2015 May;24(5):377-80

Department of Dermatology, University Hospital Zürich and University of Zurich, Zürich, Switzerland.

Fibroblast contamination can make establishing primary melanoma cell cultures from native biopsies a major challenge, due to fibroblasts overgrowing the melanoma cells. Standard protocols therefore enrich for highly proliferative melanoma cells that grow well in vitro but may not represent the full range of in vivo tumor heterogeneity. Here we apply conditional methods that more effectively retrieve melanoma cells by differential trypsinization or by inducing fibroblast senescence through contact inhibition, serum starvation or deprivation of adhesion. Simple mixing experiments of melanoma and fibroblast cells demonstrated the efficacy of the new protocols in retrieving slow-growing melanoma cells. Applying our protocols to 20 cultures that had failed to grow by conventional methods, we could retrieve 12 (60%) validated melanoma cell cultures. Further application of the protocols in the live-cell biobank of 124 early passage cultures significantly improved recovery rates from 13% using standard protocols to 70% overall for the new workflow.
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http://dx.doi.org/10.1111/exd.12683DOI Listing
May 2015