It was previously reported that ischemia-reperfusion injury initiates an inflammatory response and may significantly affect the transplanted organ function. The aim of this study was to assess changes of intragraft cytokine mRNA expression in kidneys after cold ischemia (CI) and following reperfusion. We examined mRNA of a product of activated T lymphocytes (IFN-gamma) and a monocyte product (IL-6). Eleven kidneys were transplanted after CI time ranging from 16 to 39 hours. Renal needle core biopsies were obtained from donors after cold ischemia and approximately after 20 minutes of reperfusion. Tubular and glomerular expression of IFN-gamma and IL-6 mRNA were assessed using semiquantitative evaluation of the RT-PCR in situ. After reperfusion an intense increase of IL-6 mRNA expression was observed in four specimens, a slight increase was noticed in five specimens, and a very slight decrease in two specimens. Changes in IL-6 mRNA expression were limited only to tubules. In contrast, the glomerular and tubular mRNA expression of IFN-gamma and glomerular of IL-6 remained stable. Mean CI time for patients with an intense increase was higher than for patients with a slight increase and with the decrease of IL-6 mRNA expression (32.0 +/- 6.8 vs 25.2 +/- 7.3 and 26.0 +/- 5.7 hours). Our results suggest that early inflammatory changes at the time of implantation of renal allografts depends mainly on monocyte/macrophage-associated products. The observed intensity of their expression in tubules was connected to longer CI time.