CORRELATION BETWEEN CLONOTYPIC T-CELL RECEPTOR-BETA CHAIN VARIABLE REGION (TCR-V-BETA) GENE-EXPRESSION AND ABERRANT T-CELL ANTIGEN EXPRESSION IN CUTANEOUS T-CELL LYMPHOMA

Immunohistochemical studies can augment the clinicopathologic diagnosi s of cutaneous T-cell lymphoma (CTCL). Our goal was to determine wheth er a panel of 11 T-cell receptor (TCR) beta chain variable region (V-b eta) monoclonal antibodies (moAbs) could consistently identify clonal T-cell populations within CTCL skin infiltrates, and whether these cel ls exhibited aber-rant T-cell antigen expression, Biopsies from 24 CTC L and 3 parapsoriasis patients were analyzed. Of the 27 patients, 4 (1 5%) demonstrated T-cell clonality by restricted TCR-V-beta moAb staini ng. The V-beta(+) restricted cells expressed aberrant antigen profiles , Overall, aberrant antigen profiles were detected in 18/24 (75%) CTCL patients, V(beta)18 moAb crossreacted with a 85 kD protein produced b y basal and suprabasal keratinocytes. We conclude: 1) Restricted TCR-V -beta expression correlated with aberrant T-cell antigen profiles; 2) In the absence of a complete panel of TCR-V-beta moabs, localization o f aberrant T-cell antigen expression can be useful in identifying mali gnant T-cells within CTCL skin infiltrates; 3) The detection sensitivi ty and specificity of the currently available TCR-V-beta moAbs may lim it their utility to consistently detect clonal T-cell populations in C TCL skin biopsies 4) A 85 kD protein present on basal and suprabasal k eratinocytes is recognized by V(beta)18 moAb and may be related to imm une function(s) of the epidermis.