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.