In renal transplants with delayed graft function chemokines and chemokine receptor expression predict long-term allograft function.

BACKGROUND: Chronic loss of renal allograft function is associated with interstitial fibrosis and tubular atrophy (IF/TA). Independent of the underlying reason, one initial step in the development of fibrosis is chemokine-driven invasion of leukocytes from the blood vessels into the allograft. We studied the role of chemokines in kidney allografts with delayed graft function and the subsequent long-term outcome of renal function and fibrosis. METHODS: We examined repetitive biopsies of 30 patients without signs of acute rejection but with initially delayed graft function for IF/TA. In addition, we examined the expression of chemokine receptor (CCR)-1 and CCR2 on invaded leukocytes and macrophages and the corresponding ligands regulated upon activation, normal t-cell expressed, and secreted (RANTES) and monocyte chemotactic protein-1 on residential kidney cells. RESULTS: The initial expression of CCR1 positive invading cells and RANTES in glomerular cells correlated with the allograft function 12 months after transplantation and at last follow-up. The expression was independent of donor characteristics such as age, gender, infectious state, cause of death, or use of vasopressive agents. Furthermore, it did not correlate with the duration of cold ischemia time. Among the patients with the most progressive loss of allograft function follow-up biopsy specimen did not reveal any signs of rejection but showed increased CCR1 and RANTES expression in the interstitium suggesting ongoing inflammation and fibrosis. CONCLUSION: An early expression of RANTES in renal allografts with delayed graft function with consecutive invasion of CCR1 positive cells seems to promote ongoing IF/TA and to worse renal allograft outcome.

Uremia aggravates left ventricular remodeling after myocardial infarction.

BACKGROUND: Renal failure is a well-established cardiovascular risk factor. We hypothesized that uremia negatively affects post-myocardial infarction (MI) remodeling and left ventricular (LV) function and examined the pathohistological correlations. METHODS: Subtotally nephrectomized rats (SNX) and controls with MI only (MIC) were examined 1, 4 and 8 weeks after MI. MI size, ejection fraction (EF), cardiac fibrosis, vascular density and cardiomyocyte density were studied. RESULTS: The extension of MI was 0.08 +/- 0.02 in SNX versus 0.06 +/- 0.02 in MIC rats (p < 0.031). Prior to MI, EF was comparable in SNX and MIC (74 +/- 3 vs. 72 +/- 2%, n.s.). Despite a relatively small infarct size EF in SNX decreased to 58 +/- 4% 1 week after infarction and progressively worsened to 51 +/- 4% after 8 weeks. In MIC animals EF only slightly decreased 1 week after MI (70 +/- 3%) and remained unchanged at follow-up. In SNX animals LV end-diastolic diameter continuously increased following MI throughout the study period indicating accelerated remodeling. Furthermore, accelerated myocardial fibrosis was already notable 1 week after MI in SNX animals and the volume density of capillaries and cardiomyocytes was significantly lower in SNX rats. CONCLUSION: MI in experimental uremia is associated with progressive impairment of LV function, LV dilatation and accelerated myocardial fibrosis.

Role of FTY720 on M1 and M2 macrophages, lymphocytes, and chemokines in 5/6 nephrectomized rats.

Renal injury is accompanied by the presence of infiltrating inflammatory cells in the glomerulus and tubulointerstitium. FTY720 modifies lymphocyte migration into injured tissues by lymphocyte sequestration to secondary lymphoid organs. The purpose of this study was to examine the potential of FTY720 to influence the inflammatory response in a nonimmunological model of renal failure. Sham-operated and 5/6 nephrectomized (SNX) Sprague-Dawley rats received two different doses of FTY720 or vehicle orally for 14 wk. Treatment with FTY720 reduced glomerular and tubulointerstitial damage in SNX rats but failed to stabilize creatinine clearance. The increase in gene expression of chemokine receptors CCR1, CCR2, and CCR5 in kidneys of vehicle-treated SNX rats was significantly attenuated by high-dose FTY720. Treatment with high-dose FTY720 tended to normalize RANTES and MCP-1 renal gene expression. FTY720 affected not only glomerular and tubulointerstitial lymphocytes, but M1 and M2 phenotype macrophages were also reduced. FTY720 significantly reduced key mediators of renal inflammation and fibrosis. FTY720 also decreased immunoregulation of M2 macrophages, which are beneficial for tissue remodeling and repair.