BackgroundThe tubule-interstitial fibrosis is the hallmark of progressive renal disease and is strongly associated with inflammation of this compartment. Heme-oxygenase-1 (HO-1) is a cytoprotective molecule that has been shown to be beneficial in various models of renal injury. However, the role of HO-1 in reversing an established renal scar has not yet been addressed.AimWe explored the ability of HO-1 to halt and reverse the establishment of fibrosis in an experimental model of chronic renal disease.MethodsSprague-Dawley male rats were subjected to unilateral ureteral obstruction (UUO) and divided into two groups: non-treated and Hemin-treated. To study the prevention of fibrosis, animals were pre-treated with Hemin at days -2 and -1 prior to UUO. To investigate whether HO-1 could reverse established fibrosis, Hemin therapy was given at days 6 and 7 post-surgery. After 7 and/or 14 days, animals were sacrificed and blood, urine and kidney tissue samples were collected for analyses. Renal function was determined by assessing the serum creatinine, inulin clearance, proteinuria/creatininuria ratio and extent of albuminuria. Arterial blood pressure was measured and fibrosis was quantified by Picrosirius staining. Gene and protein expression of pro-inflammatory and pro-fibrotic molecules, as well as HO-1 were performed.ResultsPre-treatment with Hemin upregulated HO-1 expression and significantly reduced proteinuria, albuminuria, inflammation and pro-fibrotic protein and gene expressions in animals subjected to UUO. Interestingly, the delayed treatment with Hemin was also able to reduce renal dysfunction and to decrease the expression of pro-inflammatory molecules, all in association with significantly reduced levels of fibrosis-related molecules and collagen deposition. Finally, TGF-β protein production was significantly lower in Hemin-treated animals.ConclusionTreatment with Hemin was able both to prevent the progression of fibrosis and to reverse an established renal scar. Modulation of inflammation appears to be the major mechanism behind HO-1 cytoprotection.

Primeira submissão em 09/10/08 Última submissão em 16/12/08 Aceito para publicação em 20/12/08 Publicado em 20/12/08 artigo origiNal original article

Both chagasic groups present an autonomic impairment using linear methods. The nonlinear methods revealed that the ChHD group had a higher cardiovascular risk. Serum cytokine concentrations between chagasic patients were similar. However, ChHD showed higher concentrations of IL-10 and lower of IFN-γ, suggesting some established process of immune regulation.

The kidney transplant is the main therapeutic alternative for end-stage kidney disease, and rejection is a major complication. The expression of proinflammatory cytokines is related to graft loss, whereas anti-inflammatory cytokines are associated with graft protection. The objective of this study is to evaluate the "in situ" expression of cytokines T helper 1 (tumor necrosis factor α [TNF-α]), T helper 17 (interleukin 17 [IL-17]), and regulatory T cell (transforming growth factor β [TGF-β]) and the expression of forkhead box P3 (FoxP3) in allograft kidney. We evaluated in situ expression of cytokines in allograft kidney under rejection process by indirect immunohistochemistry. Eighteen renal graft biopsies were from patients with episodes of rejection. The in situ expression of IL-17, TNF-α, and TGF-β was significantly higher in patients with acute rejection when compared with the control group. In contrast, analysis of FoxP3 expression showed few positive cells in patients with acute rejection compared with the control group. The results suggest that the expression of proinflammatory cytokines (IL-17 and TNF-α) contributes to the mechanisms of kidney transplant rejection. The increase in TGF-β expression might be an attempt to establish a process of immunoregulation or even to induce higher production of IL-17. The last hypothesis is supported by the observation of a reduced expression of FoxP3 and elevated levels of IL-17.

Transplanted organs may act as a route of transmission of infectious diseases, such as Chagas' disease. The aim of this study was to describe the transmission of the Trypanosoma cruzi through a renal transplant and the anatomo-clinical evolution of the patient after treatment with benzonidazole. The patient was a 31-year-old white male from the State of Minas Gerais in Brazil. He had renal failure secondary to diabetes and later received a kidney from a cadaveric donor. The patient was undergoing immunosuppression therapy with azathioprine, cyclosporine A, and prednisone. After the transplant, he developed an acute phase of Chagas' disease and complications from diabetes and died 2 months later. In the autopsy, T cruzi amastigotes were found in the transplanted kidney, heart, bladder, liver, and pancreas. An important reduction in the parasitemia was obtained through the treatment of the infection with benzonidazole; however, the patient died due to complications from diabetes associated with tissue lesions caused by T cruzi.