Up-regulation of cyclooxygenase-2 in different grades of acute human renal allograft rejection

Abstract

Background: Cyclooxygenase-2 (COX-2) is up-regulated by a variety of stimuli that are associated with tissue injury and inflammation.Methods: the purpose of this study was to analyze COX-2 detection during different grades of acute human renal allograft rejection. COX-2 expressions were analyzed by immunohistochemistry in 74 samples obtained from biopsies with acute rejection of different grades (n = 48), tubular changes (n = 13) and from kidney allografts with stable function (n = 13).Results: in interstitial area, there was a significant correlation of COX-2 induction in acute rejection in comparison to tubular changes (1.67 vs. 0.76, p = 0.02) and stable function (vs. 0.07, p < 0.001), as well as in vessels in the group with acute rejection in relation to stable function (1.1 vs. 0, p = 0.04). When the group with acute rejection was analyzed in subgroups, there was a clear increase of COX-2 expression from acute rejection grade 1B to III in vessels, in inflammatory infiltrating cells in interstitial area and in glomeruli, while borderline and IA grades were intermediate.Conclusion: COX-2 is up-regulated during acute human renal allograft rejection according to the severity of acute rejection and could be used as a marker of inflammation in kidney transplantation. (c) 2007 Elsevier B.V. All rights reserved.