The purpose of this thesis was to obtain more insight into T-cell clonality in blood of mycosis fungoides (MF) patients. Investigation of the frequency of blood T-cell clonality clearly indicated... Show moreThe purpose of this thesis was to obtain more insight into T-cell clonality in blood of mycosis fungoides (MF) patients. Investigation of the frequency of blood T-cell clonality clearly indicated early dissemination of neoplastic T-cells into skin and blood as a sign of physiological recirculation. Nevertheless, circulating clonal T-cells not associated with a cutaneous clone were found in substantial numbers of MF patients and controls. This phenomenon remained obscure; we termed it T-cell Expansion of Undetermined Significance (TExUS). Qualitative investigation of T-cell clonality in blood samples at the initial diagnosis of MF could not predict the clinical course. Chromosomal analysis confirmed previous data demonstrating an early dissemination of the T-cell clone. Complex chromosomal aberrations were found exclusively in clonal T-lymphocytes. Characteristic combinations of chromosomal aberrations were found; some alterations seemed to be prognostically significant. Comparison of our in-house TCR_ assay with the Biomed-2 protocol verified our findings. Since detection of T-cell clonality by PCR assays fails in a substantial portion of CTCL samples, but succeeds in various benign conditions, accurate integration of clinical, histomorphological, immunohistochemical data still represents the golden diagnostic standard. Demonstration of a T-cell clone only supplements the diagnosis of CTCL. Show less
