Intra-graft Coagulation Events in Clinical Renal Transplantation and Delayed Graft Function

Study Overview
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Brief Summary
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The purpose of this study is to investigate local activation of the coagulation system in the kidney graft during organ preservation and during early reperfusion in adult kidney transplantation. Generation of thrombin and fibrin as well as activation and inhibition of fibrinolysis will be investigated. Influence of these events on delayed graft function (DGF) and acute cell-mediated rejection will be evaluated.

Detailed Description
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Background In clinical kidney transplantation organ retrieval, cold-preservation of the graft as well as restoration of the blood flow to the transplant cause tissue damage (ischemia/reperfusion injury). Clinically these events can manifest themselves as delayed graft function (DGF), which is usually defined as the need for dialysis during first week after transplantation. DGF increases the risk of developing chronic rejection and subsequently loss of the transplant. Ischaemia/reperfusion injury is biologically characterized by local profound inflammatory response, activation of the coagulation system and endothelial dysfunction in the transplanted organ. After reperfusion activated neutrophils cause tissue damage in the graft by production of reactive oxygen species (ROS) and release of proteolytic enzymes, which lead to plugging of the capillaries by accumulation of thrombocytes and fibrin. Blood flow is further diminished by increased blood viscosity and local vasoconstriction and swelling of the endothelial cells. Disorders of the microcirculation lead to no-reflow phenomenon whereby locally tissues remain ischemic, despite of good blood flow in the organ artery and vein. Coagulation is activated in the renal transplant during reperfusion, when circulating factor VIIa (FVIIa) comes into contact with the tissue factor (TF), which is expressed on the endothelium due to ischaemia. FVII-TF complex activates factor X (FX) and activated FX (FXa) cleaves thrombin (FII) from prothrombin. Thrombin activates thrombocytes, cleaves fibrin from fibrinogen and activates factor XIII( FXIII), which stabilizes fibrin clot. Fibrin has been demonstrated to accumulate in the kidney graft during reperfusion. Fibrin accumulation is aggravated by inhibition of fibrinolysis due to reperfusion. Furthermore, the investigators conducting this current research project, have previously gained indirect evidence in a small cohort study, that accumulation of fibrin occurs even before reperfusion, during donor care and organ retrieval. Most importantly, specifically this pre-reperfusion fibrin deposition was related to DGF. Patients and sample size There were several limitations in investigators previous study concerning intra-graft coagulation events in DGF. It was conducted as a part of a larger trial in renal transplantation and included only 30 patients in two study arms with different immunosuppressant regimens (peri-operative basiliximab and conventional triple therapy). Therefore, a new study, with larger sample size and standardized immunosuppression is warranted. Therefore, in this current prospective observational study surgical technique, anaesthesia and hemodynamic management, immunosuppressive medications are strictly standardized. Sample size is increased to 100. The investigators prospectively screen all adult patients receiving their first kidney transplant from cadaveric donor. Only patients scheduled to receive local standard triple immunosuppressant therapy with cyclosporine A, mycophenolate mofetil and methylprednisolone are included. Blood samples and prospective data collection Blood samples for assessment of intra-graft coagulation events (generation of thrombin and fibrin, activation and inhibition of fibrinolysis) are drawn peri-operatively. Predefined clinical and demographical data are collected preoperatively and prospectively during 3 months after kidney transplantation to assess the influence of these coagulation events on delayed graft function according to Halloran criteria (8) (primary outcome) and acute cell mediated graft rejection (primary outcome).

Official Title
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Activation of Coagulation Pathways in Clinical Renal Allotransplantation and Delayed Graft Function and Acute Rejection of the Graft

Conditions
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End Stage Renal Disease, Reperfusion Injury, Delayed Graft Function, Kidney Transplantation

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult person (over 18 years old) cadaveric transplantation conventional standard immunosuppression plan (methylprednisolone, cyclosporin A, mycophenolate mofetil) Exclusion Criteria: previous kidney transplant other than local standard immunosuppression panel reactive antibodies (PRA) >30% warfarin therapy dual anti-platelet therapy use of low molecular weight heparins (LMWH) or fondaparinux during last two weeks before surgery for other indication than hemodialysis

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Trans-renal difference/ratio of plasma concentrations of coagulation measurements | Trans-transplant difference/ratio is determined in order to correlate intra-graft coagulation events to the incidences of other primary outcomes. | Two minutes after reperfusion of the kidney transplant | 
| Delayed Graft Function | Delayed graft function is assessed by Halloran criteria: oliguria < 1000ml/24h for more than 2 days after transplantation or plasma creatinine >500 micromol/l during the first week after transplantation or more than one dialysis during the first week after transplantation (Halloran et al, Transplantation 1988;46:223-8.) | During 1 week after kidney transplantation | 
| Acute cell mediated graft rejection |  | During 3 months after kidney transplantation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma creatinine value (micromol/L) |  | At admission to the hospital, during the first week after transplantation and at 1 and 3 months after renal transplantation | 
| Plasma urea value (mmol/L) |  | At admission to the hospital, during the first week after transplantation and at 1 and 3 months after renal transplantation | 
| Estimated glomerular filtration rate (ml/min/1.73 m2) | Estimated glomerular filtration rate is calculated according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula | At admission to the hospital, during the first week after transplantation and at 1 and 3 months after renal transplantation | 
| Urine output (ml/24h) | Urine output (ml/24h) before the surgery and during the first week after transplantation will be recorded | Pre-operative urine output (ml/24h) and daily urine output (ml/24h) during the first week after transplantation | 
| Renal artery and renal vein blood flow (ml/min) | Renal artery and renal vein blood flow (ml/min) are measured intra-operatively immediately after blood sample retrieval using a specific probe | Immediately after blood sample retrieval during reperfusion | 
| Fluid balance during surgery and post-anesthesia care unit stay (ml) | All fluids infused from the start of the kidney transplantation surgery until discharge from the post-anaesthesia care unit (until discharge to the ward) are recorded. All fluids losses (blood loss, urine output) during this period are recorded. | From the start of the kidney transplantation surgery until the discharge from post-anesthesia care unit (up to 24 hours from the start of the surgery) | 
| Transfusion | All blood products used during this time frame are recorded and reported | From the start of the kidney transplantation surgery until the discharge from post-anesthesia care unit (up to 24 hours from the start of the surgery) | 
| Prothrombin fragment 1+2 (F1+2) | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess thrombin generation. | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Fibrinopeptide A | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess fibrin generation. | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| D-dimers | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess fibrin degradation | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Tissue type plasminogen activator | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess activation of fibrinolysis. | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Plasminogen activator inhibitor | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess inhibition of fibrinolysis. | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Syndecan-1 | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess degradation of endothelial glycocalyx | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Myeloperoxidase and/or lactoferrin | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess activation of neutrophiles | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Interleukin 6, interleukin 8, interleukin 10 | Preoperative value and the trans-transplant difference and/or ratio is determined in order to assess activation/inhibition of inflammation | Blood samples are taken at two timepoints: 1) immediately before the start of the surgery; 2) 2 minutes after reperfusion of the kidney transplant | 
| Number of hemodialyses and their indication after surgery | All dialysis sessions will be recorded during first post-operative week. Indication for dialysis (oliguria, hyperkalemia, hypervolemia, acidosis) will be recorded during first post-operative week. At 1 and 3 months after surgery only number of dialyses/week will be recorded | From the start of the surgery until 3 months after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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kidney transplantation, renal transplantation, fibrinolysis, cell mediated rejection, coagulation, delayed graft function, Halloran criteria, graft rejection, thrombin generation, fibrin generation