ENTEROPATHY-ASSOCIATED T-CELL LYMPHOMAS HAVE A CYTOTOXIC T-CELL PHENOTYPE

Aims: Enteropathy-associated T-cell lymphoma (EATCL) is a rare complic ation of coeliac disease. We investigated whether EATCLs are the neopl astic counterparts of activated cytotoxic T-cells (CTLs). Methods and results: Eight cases, clinically and histologically defined, were stai ned with monoclonal antibodies against components of the cytotoxic gra nules of CTLs, granzyme B and T-cell restricted intracellular antigen (TIA-1). It was found that all cases had a cytotoxic phenotype, i.e. e xpression of TIA-1 in most of the tumour cells, whereas granzyme B was found in six of eight cases, mostly in a smaller number of tumour cel ls compared to TIA-1, Since TIA-1 and granzyme B are expressed at diff erent stages of activation of CTLs it is hypothesized that differences in expression between granzyme B and TIA-1 in EATCL represent differe nt stages of activation in which the tumour cells are arrested. Clinic ally seven of the eight patients died within 10 months after diagnosis of EATCL. Conclusions: EATCL is a clinicopathological entity with a g rim prognosis and with tumour cells representing a unique neoplastic e quivalent of CTLs arrested in varying stages of activation.