Bekir Tanriover

Donor-Specific Antibodies Adversely Affect Kidney Allograft Outcomes

The effect of low titers of donor-specific antibodies (DSAs) detected only by sensitive solid-phase assays (SPAs) on renal transplant outcomes is unclear. We report the results of a systematic review and meta-analysis of rejection rates and graft outcomes for renal transplant recipients with such preformed DSAs, defined by positive results on SPA but negative complement-dependent cytotoxicity and flow cytometry crossmatch results. Our search identified seven retrospective cohort studies comprising a total of 1119 patients, including 145 with isolated DSA-SPA. Together, these studies suggest that the presence of DSA-SPA, despite a negative flow cytometry crossmatch result, nearly doubles the risk for antibody-mediated rejection (relative risk [RR], 1.98; 95% confidence interval [CI], 1.36-2.89; P<0.001) and increases the risk for graft failure by 76% (RR, 1.76; 95% CI, 1.13-2.74; P=0.01). These results suggest that donor selection should consider the presence of antibodies in the recipient, identified by the SPA, even in the presence of a negative flow cytometry crossmatch result.

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.

Improvement in 3-Month Patient-Reported Gastrointestinal Symptoms After Conversion From Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium in Renal Transplant Patients

Background. The benefit of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in terms of gastrointestinal symptom burden has been evaluated previously using patient-reported outcomes. However, data are lacking concerning the sustained effect of conversion over time, and the potential impact of concomitant calcineurin inhibitor. Methods. In this 3-month, prospective, multicenter, longitudinal, open-label trial, MMF-treated renal transplant patients with gastrointestinal symptoms receiving cyclosporine or tacrolimus were converted to equimolar doses of EC-MPS. Change in gastrointestinal symptom burden was evaluated using a validated Gastrointestinal Symptom Rating Scale (GSRS). Results. A significant improvement in GSRS score was observed from baseline (2.61, 95% CI 2.54–2.68) to month 1 (1.87, 95% CI 1.81–1.93) after conversion to EC-MPS and was sustained to month 3 (1.81, 95% CI 1.74–188; both P<0.0001 versus baseline). The mean change in overall GSRS score from baseline to month 1 was −0.74 overall (cyclosporine: −0.73 and tacrolimus: −0.74; all P<0.0001 versus baseline), with a slight further improvement (−0.79) at month 3 (cyclosporine: −0.82 and tacrolimus: −0.78; all P<0.0001 versus baseline). A significant improvement in GSRS subscale scores was also observed in the total population regardless of calcineurin inhibitor at month 1, sustained to month 3 (all P<0.0001 versus baseline). The improvement in GSRS score postconversion was similar in African-American and non-African-American patients, and in diabetic and nondiabetic patients. Conclusions. This exploratory study in 728 patients demonstrates that following conversion from MMF to EC-MPS, regardless of concomitant calcineurin inhibitor, GSRS is improved and sustained over 3 months.

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.

Screening asymptomatic diabetic patients for coronary artery disease prior to renal transplantation.

Background. Coronary artery disease (CAD) is a significant contributor to excess mortality in renal transplant candidates with diabetes mellitus (DM). Prior studies relating to risk stratification for significant CAD in diabetics are confined to Caucasian type 1 DM patients. Methods. To assess the prevalence of clinically silent CAD and to identify variables that are associated with CAD, we retrospectively analyzed the cardiac catheterization data of 97 asymptomatic type 1 and 2 DM kidney and kidney-pancreas transplant candidates. Results. Thirty-three percent of type 1 and 48% of type 2 DM patients had significant stenosis (≥70%) in 1 or more coronary arteries. On multivariate logistic regression analysis, body mass index (BMI) >25 was significantly associated with CAD (relative risk = 4.8, P = 0.002). The age of the patient (7% increase in risk/year, P = 0.01; or relative risk = 3.0 if age >47 years, P = 0.032) and smoking history (2% increase in risk/pack-year of smoking, P = 0.10) were also associated with CAD. African American patients, who comprised 30% of the sample, had a 71% lower risk compared with Caucasian patients (P = 0.03). Factors that were not significantly associated with CAD included gender, type of diabetes, and whether dialyzed for >6 months prior to catheterization. Conclusions. We conclude that a notable proportion (approximately one-third to one-half) of asymptomatic type 1 and type 2 diabetic renal transplant candidates have significant CAD. Additionally, young African American DM patients with no smoking history and a BMI ≤25 are at reduced risk, and invasive tests may not be necessary in this group.

Analysis of kidney function and biopsy results in liver failure patients with renal dysfunction: a new look to combined liver kidney allocation in the post-MELD era.

Background. Renal dysfunction in the context of liver failure negatively impacts orthotopic liver transplantation (OLT) outcomes. Appropriate allocation of combined liver and kidney transplants (CLKT) is crucial with the current organ shortage and lack of standard selection criteria. Methods. We propose a practical workup algorithm for CLKT by using three variables: duration of renal insufficiency and glomerular filtration rate measured by the iodine-125 iothalamate (Glofil) test and renal biopsy findings. The study was divided into two phases. In the first phase, we retrospectively reviewed the clinical and laboratory database of all liver transplant patients (n=196) performed in our institution. In the second phase, we prospectively implemented the algorithm on 20 selected patients with liver failure and renal dysfunction (chronic kidney disease stage 3 and acute kidney injury) worked up for OLT. Results. Based on the workup algorithm, we recommended OLT for 12 patients and CLKT for eight patients. We were able to avoid CLKT for six patients without causing adverse renal outcomes among 11 patients transplanted by using this algorithm. The average 12-month renal outcomes of these transplanted patients seem to be favorable with the mean serum creatinine 1.3 mg/dL in OLT group and 1.1 mg/dL in CLKT group. Conclusion. The workup algorithm, which primarily uses duration of renal failure, glofil measurement, and renal biopsy findings, offers a practical approach to this complicated decision-making process regarding appropriate allocation of organs for CLKT.

Polyclonal antibody-induced serum sickness in renal transplant recipients: treatment with therapeutic plasma exchange.

Serum sickness is an immune-complex mediated illness that frequently occurs in patients after polyclonal antibody therapy (ATGAM or thymoglobulin). Serum sickness presents with significant morbidity but is self-limited and resolves with prolonged steroid therapy. We present five renal transplant patients who developed serum sickness after polyclonal antibody treatment with severe symptoms that persisted after being started on systemic steroids. These patients underwent one or two courses of therapeutic plasma exchange (TPE) with subsequent complete resolution of their symptoms. Renal transplant recipients with serum sickness after polyclonal antibody therapy may benefit from TPE by accelerating their time to recovery and thereby reducing overall morbidity.

Induction Therapies in Live Donor Kidney Transplantation on Tacrolimus and Mycophenolate With or Without Steroid Maintenance

BACKGROUND AND OBJECTIVES Induction therapy with IL-2 receptor antagonist (IL2-RA) is recommended as a first line agent in living donor renal transplantation (LRT). However, use of IL2-RA remains controversial in LRT with tacrolimus (TAC)/mycophenolic acid (MPA) with or without steroids. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The Organ Procurement and Transplantation Network registry was studied for patients receiving LRT from 2000 to 2012 maintained on TAC/MPA at discharge (n=36,153) to compare effectiveness of IL2-RA to other induction options. The cohort was initially divided into two groups based on use of maintenance steroid at time of hospital discharge: steroid (n=25,996) versus no-steroid (n=10,157). Each group was further stratified into three categories according to commonly used antibody induction approach: IL2-RA, rabbit anti-thymocyte globulin (r-ATG), and no-induction in the steroid group versus IL2-RA, r-ATG and alemtuzumab in the no-steroid group. The main outcomes were the risk of acute rejection at 1 year and overall allograft failure (graft failure or death) post-transplantation through the end of follow-up. Propensity score-weighted regression analysis was used to minimize selection bias due to non-random assignment of induction therapies. RESULTS Multivariable logistic and Cox analysis adjusted for propensity score showed that outcomes in the steroid group were similar between no-induction (odds ratio [OR], 0.96; 95% confidence interval [95% CI], 0.86 to 1.08 for acute rejection; and hazard ratio [HR], 0.99; 95% CI, 0.90 to 1.08 for overall allograft failure) and IL2-RA categories. In the no-steroid group, odds of acute rejection with r-ATG (OR, 0.73; 95% CI, 0.59 to 0.90) and alemtuzumab (OR, 0.53; 95% CI, 0.42 to 0.67) were lower; however, overall allograft failure risk was higher with alemtuzumab (HR, 1.27; 95% CI, 1.03 to 1.56) but not with r-ATG (HR, 1.19; 95% CI, 0.97 to 1.45), compared with IL2-RA induction. CONCLUSIONS Compared with no-induction therapy, IL2-RA induction was not associated with better outcomes when TAC/MPA/steroids were used in LRT recipients. r-ATG appears to be an acceptable and possibly the preferred induction alternative for IL2-RA in steroid-avoidance protocols.

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

Future of Medicare Immunosuppressive Drug Coverage for Kidney Transplant Recipients in the United States

49,000. A combination of IVIG + RTX in late AMR may be beneficial but is an expensive treatment approach for selected renal transplant patients.