Preferential type1-1 cytokine gene expressions in peripheral T-cell lymphomas

In this study, we have investigated whether a pattern of cytokine gene expr ession can be found in non-Hodgkin's peripheral T-cell lymphoma (PTCL). By using RNase protection assays and RT-PCR, we have systematically studied IL 1 alpha, IL1 beta, IL1-Ra, IL2, IL4, IL5, IL6, IL9, IL10, IL12p35, IL12p40, IL13, IL14, IL15, IFN gamma, IFN beta, TNF alpha, TNF beta, LT beta, and T GF beta 1, TGF beta 2 and TGF beta 3. Twenty-two cases of PTCL inclusive of three nasal NK-cell lymphomas were selected for the study; three cases of reactive lymphoproliferation were included for comparison. Results show tha t IFN gamma gene expression (key Type 1 cytokine) was frequently detected [ 18/22 (82 per cent)]. In contrast, IL4 (key Type 2 cytokine) was only detec ted in 4/22 (18 per cent) of cases (weaker than IFN gamma in three cases). This distinction was also found at the protein level by immunohistochemistr y. In addition, TNF beta and TNF alpha (strongly expressed by Type 1 cells) were almost complimentarily detected [4/19 (21 per cent)] and 12/19 (63 pe r cent), respectively). In contrast, neither IL5 nor IL13 (strongly express ed by Type 2 cells) were detected at all. However, 14/22 cases expressed IL 10, another Type 2 cytokine, which suggests that the autoregulatory feedbac k loop is stimulated. Compared to the tumour types, the cytokine profiles i n the reactive lymphoproliferative types also resembled a Type 1-like patte rn but was less striking. The overall result suggested a preferential expre ssion of certain cytokines, and these cytokines may play an important role in pathophysiologic progression in these T-cell disorders. Copyright (C) 19 99 John Wiley & Sons, Ltd.