Estimating Waiting Time for Deceased Donor Renal Transplantion in the Era of New Kidney Allocation System.

BACKGROUND: On December 4, 2014, a new deceased donor kidney allocation system (KAS) was implemented. The KAS was designed to improve organ equity and graft-recipient longevity matching. However, estimated wait-time to deceased donor transplantation is difficult to predict post-KAS. METHODS: Using the Kidney-Pancreas Simulated Allocation Model software (KPSAM), a program that the Organ Procurement and Transplant Network uses to assess policy proposals, we compared the kidney allocations of both the new (post-KAS) and old policies (pre-KAS) (10 iterations for each group; total N = 204,148) and estimated wait-time based on blood type, duration of dialysis exposure, and calculated panel-reactive antibody (CPRA). RESULTS: The simulations revealed that estimated median (25(th) and 75(th) percentile) waiting time in transplanted recipients decreased from 2.3 (1.2, 3.8) years in the old allocation to 1.8 (0.8, 3.4) years in the new allocation system. The rate of transplantations performed within the first year of wait-listing increased from 20.7% to 31.3%. The KPSAM resulted in more transplantations in recipients with more than 5 years of dialysis exposure (26.5% to 37.4%), longevity matching (12.2% to 17.5%), blood group B (12.6% to 17.2%), and high CPRA ≥98% (1.9% to 4.3%) in post-KAS compared with pre-KAS simulations. CONCLUSIONS: Based on the KPSAM results, it was projected that post-KAS wait-time in transplanted recipients might decrease approximately 6 months (22%) across all CPRA categories. It might be related to the KAS awarding waiting time points for prelisting dialysis time and priority points awarded based on CPRA (bolus effect).

Kidneys at higher risk of discard: expanding the role of dual kidney transplantation.

Half of the recovered expanded criteria donor (ECD) kidneys are discarded in the United States. A new kidney allocation system offers kidneys at higher risk of discard, Kidney Donor Profile Index (KDPI)>85%, to a wider geographic area to promote broader sharing and expedite utilization. Dual kidney transplantation (DKT) based on the KDPI is a potential option to streamline allocation of kidneys which otherwise would have been discarded. To assess the clinical utility of the KDPI in kidneys at higher risk of discard, we analyzed the OPTN/UNOS Registry that included the deceased donor kidneys recovered between 2002 and 2012. The primary outcomes were allograft survival, patient survival and discard rate based on different KDPI categories (<80%, 80-90% and >90%). Kidneys with KDPI>90% were associated with increased odds of discard (OR=1.99, 95% CI 1.74-2.29) compared to ones with KDPI<80%. DKTs of KDPI>90% were associated with lower overall allograft failure (HR=0.74, 95% CI 0.62-0.89) and better patient survival (HR=0.79, 95% CI 0.64-0.98) compared to single ECD kidneys with KDPI>90%. Kidneys at higher risk of discard may be offered in the up-front allocation system as a DKT. Further modeling and simulation studies are required to determine a reasonable KDPI cutoff percentile.

Availability, utilization and outcomes of deceased diabetic donor kidneys; analysis based on the UNOS registry.

The number of kidneys obtained from deceased diabetic donors available for transplantation has increased >eightfold increase in the past 15 years. We assessed allograft outcomes associated with deceased diabetic donors and compared them with that of standard and extended criteria donors (ECD) in the UNOS data registry. We identified 1982 recipients of diabetic standard criteria donors over a 10-year period from 1995 through 2004. Both overall and death-censored survival of organs from diabetic standard criteria donors was significantly better than that of organs obtained from nondiabetic ECD while inferior to that from nondiabetic standard criteria donors. Compared with ECD donors, diabetic donors had lower serum creatinine, less cold ischemia and these kidneys were less likely to be pump-perfused. Recipients of diabetic kidneys were younger and less likely to experience delayed graft function compared with recipient of ECD kidneys. More recently, many diabetic donor kidneys have been given to diabetic recipients with early graft survival being similar to that among nondiabetic recipients. These findings demonstrate the potential to expand and to improve utilization of this resource without compromising outcomes for recipients. Improved, evidence-based evaluation and allocation of deceased diabetic donor kidneys is needed to optimize their use.

Reduced fracture risk with early corticosteroid withdrawal after kidney transplant.

Corticosteroid use after kidney transplantation results in severe bone loss and high fracture risk. Although corticosteroid withdrawal in the early posttransplant period has been associated with bone mass preservation, there are no published data regarding corticosteroid withdrawal and risk of fracture. We hypothesized lower fracture incidence in patients discharged from the hospital without than with corticosteroids after transplantation. From the United States Renal Data System (USRDS), 77, 430 patients were identified who received their first kidney transplant from 2000 to 2006. Fracture incidence leading to hospitalization was determined from 2000 to 2007; discharge immunosuppression was determined from United Networks for Organ Sharing forms. Time-to-event analyses were used to evaluate fracture risk. Median (interquartile range) follow-up was 1448 (808-2061) days. There were 2395 fractures during follow-up; fracture incidence rates were 0.008 and 0.0058 per patient-year for recipients discharged with and without corticosteroid, respectively. Corticosteroid withdrawal was associated with a 31% fracture risk reduction (HR 0.69; 95% CI 0.59-0.81). Fractures associated with hospitalization are significantly lower with regimens that withdraw corticosteroid. As this study likely underestimates overall fracture incidence, prospective studies are needed to determine differences in overall fracture risk in patients managed with and without corticosteroids after kidney transplantation.

High-dose intravenous immunoglobulin and rituximab treatment for antibody-mediated rejection after kidney transplantation: a cost analysis.

Antibody-mediated rejection (AMR) generally occurs in highly sensitized patients. A pilot study was performed on 7 consecutive patients with AMR to assess the efficacy of high-dose intravenous immunoglobulin (IVIG; 2 g/kg) + rituximab (RTX; 375 mg/m(2)) without plasmapheresis. After a 24-month follow-up, 1- and 2-year allograft survivals were 86% and 58%, respectively. C4d became negative in 1 patient posttreatment. Donor-specific antibody (DSA) titers decreased to less than 1:4 in 2 cases. There were 4 infectious complications and 1 case of aseptic meningitis followed by cranial nerve VI palsy. The average hospital charge for 1 administration of IVIG + RTX, including hospital stay and renal biopsy expenses, was approximately $49,000. A combination of IVIG + RTX in late AMR may be beneficial but is an expensive treatment approach for selected renal transplant patients.

Aseptic meningitis and abducens nerve palsy as a serious side effect of high dose intravenous immunoglobulin used in a patient with renal transplantation.

Immune globulin intravenous (human) (IGIV) is effective in the treatment of various autoimmune and inflammatory disorders. Recently, high-dose IGIV 2 g/kg has been utilized in the treatment of antibody-mediated rejection in solid organ transplantation. We report a renal transplant recipient who developed aseptic meningitis and diplopia from abducens nerve (cranial nerve VI) palsy following IGIV administration for antibody-mediated rejection. Potential mechanisms of the IGIV-related aseptic meningitis are elaborated. Clinicians should be aware of aseptic meningitis and cranial nerve palsy as an adverse reaction to IGIV exposure and monitor for its signs and symptoms.

Bacteremia associated with tunneled dialysis catheters: comparison of two treatment strategies.

BACKGROUND: Tunneled dialysis catheters are often used for temporary vascular access in hemodialysis patients, but are complicated by frequent systemic infections. The treatment of bacteremia associated with infected tunneled catheters requires both antibiotic therapy and catheter replacement. We compared the outcomes of two treatment strategies for catheter-associated bacteremia: exchange of the existing catheter with a new one over a guidewire versus catheter removal with delayed replacement. METHODS: We retrospectively analyzed the outcomes of all cases of tunneled dialysis catheter-associated bacteremia during a two-year period. The infection-free survival time of the subsequent catheter was evaluated in two groups of patients: group A (31 catheters), exchange of the existing infected catheter with a new catheter over a guidewire, and group B (38 catheters), removal of the infected catheter followed by delayed catheter replacement 3 to 10 days later. Patients in both groups received three weeks of systemic antibiotic therapy. Cox proportional hazard models were used to evaluate the factors predictive of infection-free survival time of the replacement catheter. RESULTS: On univariate proportional hazard regression analysis, the infection-free survival time of the replacement catheter was similar for groups A and B (P = 0.72), whereas the hazard of infection was significantly greater for patients with hypoalbuminemia (serum albumin < 3.5 g/dL), as compared with patients with a normal serum albumin (hazard ratio 2.81, 95% CI, 1. 21, 6.53, P = 0.016). The infection-free survival time was not affected by patient age, sex, diabetic status, or type of organism (gram-positive coccus vs. gram-negative rod). CONCLUSIONS: The infection-free survival time associated with the subsequent catheter is similar for the two treatment strategies. However, exchanging the catheter for a new one over a guidewire minimizes the number of separate procedures required by the patient. Hypoalbuminemia is the major risk factor for recurrent bacteremia in the replacement catheter.