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BACKGROUND Acute antibody-mediated rejection (AMR) is responsible for up to 20% to 30% of acute rejection after kidney transplantation. New therapeutic agents have recently emerged, such as eculizumab, an anticomplement protein-C5 monoclonal antibody. In the setting of renal transplantation, eculizumab has so far proved effective both for preventive and curative treatments of AMR in sensitized patients and patients diagnosed with severe AMR. Unsuccessful eculizumab treatment has only been reported once in the literature by Stegall et al. (Am J Transplant 2011; 11: 2405). METHODS AND RESULTS We present two cases of AMR resistant to eculizumab after renal transplantation. One patient received the anti-C5 antibody curatively, and the other patient developed AMR while being treated with eculizumab after a relapse of atypical hemolytic uremic syndrome. The peculiarity of these two cases was the absence of C4d deposition in peritubular capillaries as well as the absence of C1q-binding donor-specific anti-human leukocyte antigen alloantibody, as determined retrospectively, suggesting that a complement-independent mechanism underlies the pathogenesis of these AMR. CONCLUSION The use of eculizumab in C4d-negative or C1q-negative AMR does not seem effective.

Background. Mycotic arteritis and/or aneurysms are infrequent complications of renal transplantation. They are mostly secondary to bacterial infection and rarely to Candida albicans. We report four cases of mycotic arteritis due to C. albicans after renal transplantation but which have been inoculated during organ harvesting or conservation. Methods. In all the four cases corresponding to two independent donors, C. albicans was isolated few days later in the systematic culture of the conservative liquid. We also review the clinical features and outcomes of 13 cases previously reported in the literature. Results. In two cases, the diagnosis of fungal arteritis was confirmed only during autopsy after the patient’s death due to massive bleeding. In the other two cases, the diagnosis was made on the arterial section of the anastomotic wall after detransplantation for massive bleeding for arterial leakage although an immediate antifungal treatment with fluconazole and caspofungin was given and was found to be inefficient. Conclusion. This is a serious complication of renal transplantation because it leads to graft loss in the majority of the cases and even to death in a few cases despite an efficient and rapid treatment. Routine fungal cultures of preservation media are important for early diagnosis and timely surgical interventions are life-saving.

Background. Chronic allograft nephropathy is the main cause of long-term kidney graft loss. The plasminogen activator inhibitor type 1 (PAI-1) is a potential fibrogenic molecule whose secretion is regulated by several metabolic, inflammatory, and genetic factors. We aimed to determine whether PAI-1 secretion in renal transplant patients is correlated with the decline in renal function after transplantation. Methods. Renal transplant patients (145 male/71 female) were included in the study 1-27 years after transplantation (median of follow-up: 7.35 years). At inclusion, routine clinical and biological data were collected, the 4G/5G polymorphism of the recipient PAI-1 gene was determined, and the PAI-1 plasma level was measured. Results. The mean rate of decline in renal function was -4.26±0.30 ml/min/year. By multiple linear regression analysis, the rate of decline in renal function was significantly correlated with proteinuria (P=0.0176), occurrence of late acute rejection episodes (P=0.0001), and PAI-1 plasma level (P=0.0051). In addition, PAI-1 plasma level was also significantly correlated with body mass index (P=0.038), insulin (P

BACKGROUND Plasminogen activator inhibitor type 1 (PAI-1) exerts antifibrinolytic and profibrotic activities. Inside the glomerulus, PAI-1 is mainly synthesized by mesangial cells. We hypothesized that thrombin, via its receptor protease activated receptor type 1 (PAR-1), present on the membrane of glomerular cells, is an important mediator of PAI-1 synthesis. METHODS Using the technique of Peten et al., we microdissected the glomeruli of 23 kidney transplanted patients admitted in our department from 1993 to 1997, and we followed-up these patients for up to 5 years, with sometimes iterative renal biopsies. With this technique, we also microdissected the glomeruli of three patients who have had a nephrectomy for cancer (control patients). We investigated mRNA expression of the PAI-1, the thrombin receptor PAR-1, the alpha2 chain of type IV (alpha2 IV) collagen, and of a housekeeping gene (cyclophilin) by reverse transcription-polymerase chain reaction. The results were correlated with the renal function and the histological findings classified into acute rejection (9 biopsies), chronic rejection (22 biopsies), or normal (8 biopsies). RESULTS A significant up-regulation of PAI-1 and alpha2 IV collagen mRNA was observed in acute rejection (P

BACKGROUND A widely used immunosuppressant, cyclosporine A (CsA), conveys long-term nephrotoxicity in some patients. However, no specific marker is presently available. In both native and transplanted human kidneys, epithelial phenotypic changes (EPCs) suggestive of epithelial to mesenchymal transition (EMT) are expressed in various diseases and are prognostic with respect to progression of interstitial fibrosis. We hypothesized that CsA is able to trigger these EPCs in tubular cells in vivo. METHODS We studied the kinetics of the EMT markers β-catenin, snail, vimentin, collagen III, and HSP47 at the messenger RNA and protein levels in the kidneys from rats injected with 15 mg/kg/day of CsA or its vehicle. We investigated several therapeutic strategies available to block EMT in this model. RESULTS By 2 weeks, CsA had induced histological changes (tubular dilatation and vacuoles) and overexpression of EMT-related genes. This up-regulation of the EMT program was associated with tubular, not interstitial, overexpression of mesenchymal markers. Angiotensin II and endothelin receptor antagonists failed to prevent this CsA-induced EMT. Interestingly, CsA withdrawal led to the gradual regression of histological lesions and EMT, demonstrating that it not only prevents progression but also allows healing of renal injury. CONCLUSION Our study suggests that detecting EPC could help to identify ongoing renal CsA-induced toxicity at an early and reversible stage.