Christina Krikke

Complement mediated renal inflammation induced by donor brain death : role of renal C5a-C5aR interaction

Kidneys retrieved from brain‐dead donors have impaired allograft function after transplantation compared to kidneys from living donors. Donor brain death (BD) triggers inflammatory responses, including both systemic and local complement activation. The mechanism by which systemic activated complement contributes to allograft injury remains to be elucidated. The aim of this study was to investigate systemic C5a release after BD in human donors and direct effects of C5a on human renal tissue. C5a levels were measured in plasma from living and brain‐dead donors. Renal C5aR gene and protein expression in living and brain‐dead donors was investigated in renal pretransplantation biopsies. The direct effect of C5a on human renal tissue was investigated by stimulating human kidney slices with C5a using a newly developed precision‐cut method. Elevated C5a levels were found in plasma from brain‐dead donors in concert with induced C5aR expression in donor kidney biopsies. Exposure of precision‐cut human kidney slices to C5a induced gene expression of pro‐inflammatory cytokines IL‐1 beta, IL‐6 and IL‐8. In conclusion, these findings suggest that systemic generation of C5a mediates renal inflammation in brain‐dead donor grafts via tubular C5a‐C5aR interaction. This study also introduces a novel in vitro technique to analyze renal cells in their biological environment.

Hypoxia and Complement-and-Coagulation Pathways in the Deceased Organ Donor as the Major Target for Intervention to Improve Renal Allograft Outcome.

Background In the last few decades, strategies to improve allograft survival after kidney transplantation have been directed to recipient-dependent mechanisms of renal injury. In contrast, no such efforts have been made to optimize organ quality in the donor. Optimizing deceased donor kidney quality opens new possibilities to improve renal allograft outcome. Methods A total of 554 kidney biopsies were taken from donation after brain death (DBD) and donation after cardiac death (DCD) kidneys before donation, after cold ischemia and after reperfusion. Healthy living donor kidney biopsies served as controls. Transcriptomics was performed by whole genome microarray analyses followed by functional pathway analyses. Results Before organ retrieval and before cessation of blood circulation, metabolic pathways related to hypoxia and complement-and-coagulation cascades were the major pathways enhanced in DBD donors. Similar pathways were also enriched in DCD donors after the first warm ischemia time. Shortly after reperfusion of DCD grafts, pathways related to prolonged and worsening deprivation of oxygen were associated with delayed graft function in the recipient. Conclusion In conclusion, this large deceased donor study shows enrichment of hypoxia and complement-and-coagulation pathways already in DBD donors before cessation of blood flow, before organ retrieval. Therefore, future intervention therapies should target hypoxia and complement-and-coagulation cascades in the donor to improve renal allograft outcome in the recipient.

Novel insights in localization and expression levels of C5aR and C5L2 under native and post-transplant conditions in the kidney

AIMS The complement system, and especially C5a, plays an important role in the pathophysiology of renal diseases and post-transplant renal injury. The two receptors for C5a are C5a receptor (C5aR) and C5a-like-receptor-2 (C5L2). Only renal C5aR expression has been reported, although exact localization and alterations in expression after transplantation are unknown. MATERIALS AND RESULTS Renal C5aR and C5L2 expression and localization were analyzed immunohistochemically. C5aR and C5L2 expression was analyzed in human kidney biopsies obtained from living donors and patients suffering from acute tubular necrosis, acute cellular and vascular rejection or IF/TA. C5aR was expressed in the thick ascending limb of Henles loop and first part of the distal convoluted tubule (DCT). Under inflammatory conditions, C5aR was de novo expressed in proximal tubuli. C5L2 was expressed in the kidney and localized to DCT1, DCT2 and connecting tubule. Persistent distal tubular expression of both receptors was demonstrated after renal transplantation. CONCLUSIONS This study shows distinct renal expression patterns for C5aR and C5L2. Our findings suggest a functional role for renal C5L2 rather than being a C5a decoy receptor. Future studies focusing on renal C5a-C5aR interaction should take differential C5aR and C5L2 expression into account, alongside abundant C5aR expression on infiltrating cells.

A human model of intra-abdominal hypertension: even slightly elevated pressures lead to increased acute systemic inflammation and signs of acute kidney injury

Intra-abdominal hypertension may have catastrophic effects in the critically ill, but its pathophysiology is only partially understood. In a human model of intra-abdominal hypertension of 12 mmHg, 50 living kidney donors were randomized between hand-assisted laparoscopic nephrectomy and open nephrectomy. In the laparoscopic group intra-abdominal hypertension of 12 mmHg was induced. Markers of inflammation and renal function were obtained in both groups peri-operatively. Slightly elevated intra-abdominal pressure leads to increased acute CRP, IL-6 and plasma NGAL.

A randomized clinical trial of living donor nephrectomy: a plea for a differentiated appraisal of mini-open muscle splitting incision and hand-assisted laparoscopic donor nephrectomy

A randomized controlled trial was designed to compare various outcome variables of the retroperitoneal mini‐open muscle splitting incision (MSI) technique and the transperitoneal hand‐assisted laparoscopic technique (HAL) in performing living donor nephrectomies. Fifty living kidney donors were randomized to MSI or HAL. Primary endpoint was pain experience scored on a visual analogue scale (VAS). After MSI living donors indicated lower median (range) VAS scores at rest than HAL living donors on postoperative day 2.5 [10 (0–44) vs. 15 (0–70), P = 0.043] and day 3 [7 (0–28) vs. 10 (0–91), P = 0.023] and lower VAS scores while coughing on postoperative day 3 [20 (0–73) vs. 42 (6–86), P = 0.001], day 7 [8 (0–66) vs. 33 (3–76), P < 0.001] and day 14 [2 (0–17) vs. 12 (0–51), P = 0.009]. The MSI technique also resulted in reduced morphine requirement, better scores on three domains of the RAND‐36, reduced costs and reduced CRP and IL‐6 levels. The HAL technique was superior in operating time and postoperative decrease of hemoglobin level. The MSI technique is superior to the HAL technique in performing living donor nephrectomies with regard to postoperative pain experience. This study reopens the discussion of the way to go in performing the living donor nephrectomy.

Early Conversion to Prednisolone/Everolimus as an Alternative Weaning Regimen Associates With Beneficial Renal Transplant Histology and Function: The Randomized-Controlled MECANO Trial

In renal transplantation, use of calcineurin inhibitors (CNIs) is associated with nephrotoxicity and immunosuppression with malignancies and infections. This trial aimed to minimize CNI exposure and total immunosuppression while maintaining efficacy. We performed a randomized controlled, open‐label multicenter trial with early cyclosporine A (CsA) elimination. Patients started with basiliximab, prednisolone (P), mycophenolate sodium (MPS), and CsA. At 6 months, immunosuppression was tapered to P/CsA, P/MPS, or P/everolimus (EVL). Primary outcomes were renal fibrosis and inflammation. Secondary outcomes were estimated glomerular filtration rate (eGFR) and incidence of rejection at 24 months. The P/MPS arm was prematurely halted. The trial continued with P/CsA (N = 89) and P/EVL (N = 96). Interstitial fibrosis and inflammation were significantly decreased and the eGFR was significantly higher in the P/EVL arm. Cumulative rejection rates were 13% (P/EVL) and 19% (P/CsA), (p = 0.08). A post hoc analysis of HLA and donor‐specific antibodies at 1 year after transplantation revealed no differences. An individualized immunosuppressive strategy of early CNI elimination to dual therapy with everolimus was associated with decreased allograft fibrosis, preserved allograft function, and good efficacy, but also with more serious adverse events and discontinuation. This can be a valuable alternative regimen in patients suffering from CNI toxicity.

Multiple Renal Arteries in Kidney Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND The use of grafts with multiple renal arteries (MRA) in renal transplantation has not been clearly established. MATERIAL/METHODS A systematic literature review used predefined terms to search PubMed, EMBASE, and the Cochrane Library for all studies since 1985 that included more than 50 MRA grafts. A total of 23 studies, comprising a total of 18,289 patients, were eligible to be included in the meta-analysis. RESULTS Patients who received an MRA graft compared to single renal artery (SRA) grafts showed significantly higher complication rates (13.8% vs. 11.0%, OR 1.393, p<0.0001), more delayed graft function (10.3% vs. 8.2%, OR 1.333, p=0.022), and had an associated significantly lower 1-year graft survival (93.2% vs. 94.5%, OR 0.819, p=0.034). Both the creatinine level and the warm ischemia time (WIT) were significantly higher in patients with MRA grafts but showed high heterogeneity (I² 98% for WIT and I² 70% for creatinine level). Although MRA grafts were associated with more complications compared to SRA grafts, long-term outcomes were similar for 5-year graft survival (81.4% vs. 81.6%) and 1- and 5-year patient survival (95.4% and 89.6% in MRA group vs. 95.4% and 87.0% in SRA group, respectively). CONCLUSIONS MRA grafts were associated with a higher risk of complication and delayed graft function but had comparable long-term outcomes for graft and patient survival.

Exchange of Best Practices Within the European Union: Surgery Standardization of Abdominal Organ Retrieval

Considering the growing organ demand worldwide, it is crucial to optimize organ retrieval and training of surgeons to reduce the risk of injury during the procedure and increase the quality of organs to be transplanted. In the Netherlands, a national complete trajectory from training of surgeons in procurement surgery to the quality assessment of the procured organs was implemented in 2010. This mandatory trajectory comprises training and certification modules: E-learning, training on the job, and a practical session. Thanks to the ACCORD (Achieving Comprehensive Coordination in Organ Donation) Joint Action coordinated by Spain and co-funded under the European Commission Health Programme, 3 twinning activities (led by France) were set to exchange best practices between countries. The Dutch trajectory is being adapted and implemented in Hungary as one of these twinning activities. The E-learning platform was modified, tested by a panel of Hungarian and UK surgeons, and was awarded in July 2013 by the European Accreditation Council for Continuing Medical Education of the European Union of Medical Specialists. As a pilot phase for future national training, 6 Hungarian surgeons from Semmelweis University are being trained; E-learning platform was fulfilled, and practical sessions, training-on-the-job activities, and evaluations of technical skills are ongoing. The first national practical session was recently organized in Budapest, and the new series of nationwide selected candidates completed the E-learning platform before the practical. There is great potential for sharing best practices and for direct transfer of expertise at the European level, and especially to export this standardized training in organ retrieval to other European countries and even broader. The final goal was to not only provide a national training to all countries lacking such a program but also to improve the quality and safety criteria of organs to be transplanted.

Intra-Abdominal Localisation of a Buschke-Lowenstein Tumour: Case Presentation and Review of the Literature

Giant condyloma acuminatum or Buschke-Lowenstein tumour is a very rare disease which usually is located in the genital, anorectal, and perianal regions. It is regarded as a type of verrucous carcinoma occurring on anogenital mucosal surfaces where it is locally invasive but displays a benign cytology. We describe a case of a 24-year-old woman with persisting condyloma acuminata progressing to a large intra-abdominal Buschke-Lowenstein tumour. To our knowledge such an advanced stage has only been reported once before. The severity and extent of the tumour both determine the treatment and patient outcome. Treatment was impeded by cachexia, an immunosuppressive state after kidney transplantation and difficulties in establishing a reliable diagnose. Interferon treatment was started which initially led to tumour reduction but was complicated by an interferon-induced pancreatitis, pneumonia, and fasciitis necroticans resulting in death. We present a literature overview on the treatment options for a Buschke-Lowenstein tumour, with emphasis on interferon therapy, with all the advantages and disadvantages.

Urological Complications After Kidney Transplantation: Incidence And Risk-factors

Aims: The purpose of this study was to determine the incidence and management of urological complications. The possible risk factors from donor, graft and recipient for were ascertained for development of urological complications. Methods: Between 1992 and 2004, 974 patients underwent renal transplantation in our hospital. The patients with urological complications from this group were compared to a random sample of 357 patients without urological complications. Donor, graft and recipient characteristics, as well as implantantion procedure were scored. The incidence and type of complication were described and risk factors for urological complications were determined by chi-square tests and univariate analysis. Results: There were 78 (8.0 %) patients with urological complications. The complications were urinary leakage in 14 (1.4%), ureteral obstruction in 25 (2.6%), stenosis in 22 (2.3%) and hydronefrosis in 17 (1.7%). Age and cause of death were not related to urological complications. A relevant risk-factor for development of urological complications was mean systolic blood pressure of donor during last 24 hours. Two and threeway interactions were found for urine output in the last hour, systolic blood pressure and the occurence of hypotensive episodes. Ureter, venous and arterial abnormalities were not related to urological complications, nor were atherosclerosis, vascular problems or surgical bleeding. Conclusions: The incidence of urological complications was 8%. Urine output, systolic blood pressure and the occurence of hypotensive episodes of the donor combined have a strong additive effect on the occurence of urological complications. Donor and recipient characteristics and implantation problems showed no relation with the occurence of urological complications.