Search

SummaryMycosis fungoides (MF) is a cutaneous T cell lymphoma, clinically characterized by patches, plaques and tumors occuring in successive stages of the disease. In early MF, an infiltrate consisting of mainly reactive T cells is seen in the papillary dermis while tumor cells are mostly confined to the epidermis. By contrast, later stages show nodular infiltrates formed mostly of tumor cells in the dermis while the epidermis is relatively devoid of tumor cells; however, knowledge of the localization of clonal T cells has been based on histomorphologic features and immunohistochemical stainings visualizing certain V-β subfamilies of the T cell receptor (TCR). As these techniques do not allow for an unequivocal identification of clonal tumor cells, we used micromanipulation and single cell PCR amplifying the TCR chain gene rearrangement. A total number of 387 single T cells was isolated from six skin biopsies in five patients in patch, plaque, and tumor stages. Of these, 180 T cells were picked from the epidermis and 207 from the dermal infiltrate. The rearranged TCR-γ DNA could be sequenced from 181 of 387 T cells. In three of six patients representing all three stages, epidermal T cells with a clonal rearrangement could be amplified. In early plaque stage a higher degree of epidermal T lymphocytes was found than in initial patch, later plaque, and tumor stages with an inverse distribution found for reactive T lymphocytes. In two patients a biallelic rearrangement was demonstrated that had not been detected in prior PCR analysis from blood and skin samples. These data show that clonal (neoplastic) and non-clonal (reactive) T lymphocytes in MF preferentially infiltrate different microanatomical compartments of the skin, depending on the stage of disease. The microanatomically distinct localization of reactive and clonal T cells suggests that the absence of direct contact between tumor and host-defense lymphocytes may contribute to tumor persistence and progression in epidermis, peripheral blood, and deep dermal tumor cell nests, respectively. [ABSTRACT FROM AUTHOR]

Analyzes CD30[sup+] cells in four patients with primary cutaneous CD30[sup+] large T cell lymphoma by single cell polymerase chain reaction of T cell receptor-gamma genes followed by sequencing. Observation related to the presence of T cell receptor-gamma gene in large CD30[sup+] atypical cells; Findings of comparative genomic hybridization among patients; Observation related to CD30[sup+] population in T cell lymphoma.

Abstract: For diagnosis and monitoring of Sézary syndrome flow cytometric quantification of CD7− and CD26− T-cells is widely used. Because antigen loss is a characteristic but not disease-specific finding we investigated the significance of this approach. Therefore we analyzed the prevalence of tumor cells in FACS-sorted CD7+/− as well as CD26+/− circulating T-cells applying a clone-specific qualitative and quantitative T-cell receptor PCR. Tumor cells varied considerably in the CD7+ and CD7− cell subset but were largely confined to the CD26− population. We conclude that quantification of CD26− T-cells reflects the tumor cell amount more accurate and should be preferred in the clinical setting. [Copyright &y& Elsevier]