Laparoscopic sleeve gastrectomy improves renal transplant candidacy and posttransplant outcomes in morbidly obese patients.

Morbid obesity is a barrier to kidney transplantation due to inferior outcomes, including higher rates of new-onset diabetes after transplantation (NODAT), delayed graft function (DGF), and graft failure. Laparoscopic sleeve gastrectomy (LSG) increases transplant eligibility by reducing BMI in kidney transplant candidates, but the effect of surgical weight loss on posttransplantation outcomes is unknown. Reviewing single-center medical records, we identified all patients who underwent LSG before kidney transplantation from 2011-2016 (n = 20). Post-LSG kidney recipients were compared with similar-BMI recipients who did not undergo LSG, using 2:1 direct matching for patient factors. McNemar's test and signed-rank test were used to compare groups. Among post-LSG patients, mean BMI ± standard deviation (SD) was 41.5 ± 4.4 kg/m2 at initial encounter, which decreased to 32.3 ± 2.9 kg/m2 prior to transplantation (P < .01). No complications, readmissions, or mortality occurred following LSG. After transplantation, one patient (5%) experienced DGF, and no patients experienced NODAT. Allograft and patient survival at 1-year posttransplantation was 100%. Compared with non-LSG patients, post-LSG recipients had lower rates of DGF (5% vs 20%) and renal dysfunction-related readmissions (10% vs 27.5%) (P < .05 each). Perioperative complications, allograft survival, and patient survival were similar between groups. These data suggest that morbidly obese patients with end-stage renal disease who undergo LSG to improve transplant candidacy, achieve excellent posttransplantation outcomes.

A Steady-State Head-to-Head Pharmacokinetic Comparison of All FK-506 (Tacrolimus) Formulations (ASTCOFF): An Open-Label, Prospective, Randomized, Two-Arm, Three-Period Crossover Study.

This two-sequence, three-period crossover study is the first pharmacokinetic (PK) study to compare all three innovator formulations of tacrolimus (twice-daily immediate-release tacrolimus capsules [IR-Tac]; once-daily extended-release tacrolimus capsules [ER-Tac]; novel once-daily tacrolimus tablets [LCPT]). Stable renal transplant patients were dosed with each drug for 7 days, and blood samples were obtained over 24 h. Thirty subjects were included in the PK analysis set. A conversion factor of 1:1:0.80 for IR-Tac:ER-Tac:LCPT was used; no dose adjustments were permitted during the study. The median (interquartile range) total daily dose was 6.0 (4.0-8.0) mg for IR-Tac and ER-Tac and 4.8 (3.3-6.3) for LCPT. Significantly higher exposure on a per milligram basis, lower intraday fluctuation and prolonged time (Tmax ) to peak concentration (Cmax ) were found for LCPT versus IR-Tac or ER-Tac. ER-Tac showed no differences versus IR-Tac in exposure, Cmax , Tmax or fluctuation. The observed exposure of IR-Tac was used to normalize exposure for LCPT and ER-Tac, resulting in the following recommended total daily dose conversion rates: IR-Tac:ER-Tac, +8%; IR-Tac:LCPT, -30%; ER-Tac:LCPT, -36%. After exposure normalization, Cmax was ~17% lower for LCPT than for IR-Tac or ER-Tac; Cmin was ~6% lower for LCPT compared with IR-Tac and 3% higher compared with ER-Tac.

Plasma-Derived C1 Esterase Inhibitor for Acute Antibody-Mediated Rejection Following Kidney Transplantation: Results of a Randomized Double-Blind Placebo-Controlled Pilot Study.

Antibody-mediated rejection (AMR) is typically treated with plasmapheresis (PP) and intravenous immunoglobulin (standard of care; SOC); however, there is an unmet need for more effective therapy. We report a phase 2b, multicenter double-blind randomized placebo-controlled pilot study to evaluate the use of human plasma-derived C1 esterase inhibitor (C1 INH) as add-on therapy to SOC for AMR. Eighteen patients received 20 000 units of C1 INH or placebo (C1 INH n = 9, placebo n = 9) in divided doses every other day for 2 weeks. No discontinuations, graft losses, deaths, or study drug-related serious adverse events occurred. While the study's primary end point, a difference between groups in day 20 pathology or graft survival, was not achieved, the C1 INH group demonstrated a trend toward sustained improvement in renal function. Six-month biopsies performed in 14 subjects (C1 INH = 7, placebo = 7) showed no transplant glomerulopathy (TG) (PTC+cg≥1b) in the C1 INH group, whereas 3 of 7 placebo subjects had TG. Endogenous C1 INH measured before and after PP demonstrated decreased functional C1 INH serum concentration by 43.3% (p < 0.05) for both cohorts (C1 INH and placebo) associated with PP, although exogenous C1 INH-treated patients achieved supraphysiological levels throughout. This new finding suggests that C1 INH replacement may be useful in the treatment of AMR.

Clinical implications of basic science discoveries: janus resurrected--two faces of B cell and plasma cell biology.

B cells play a complex role in the immune response. In addition to giving rise to plasma cells (PCs) and promoting T cell responses via antigen presentation, they perform immunoregulatory functions. This knowledge has created concerns regarding nonspecific B cell depletional therapy because of the potential to paradoxically augment immune responses. Recent studies now indicate that PCs have immune functions beyond immunoglobulin synthesis. Evidence for a new role for PCs as potent regulatory cells (via IL-10 and IL-35 production) is discussed including the implications for PC-targeted therapies currently being developed for clinical transplantation.

Equipoise: ethical, scientific, and clinical trial design considerations for compatible pair participation in kidney exchange programs.

Compatible living donor/recipient pair participation (CPP) in kidney exchange (KE) transplantation may substantially increase transplant volumes and significantly mitigate the O blood group donor shortage in KE. Initial ethical analysis did not support CPP for two primary reasons: (1) KE would be "unbalanced," and (2) the possibility of undue influence experienced by the compatible pair living donor. Recent developments with CPP (modeling studies and small clinical experiences), have demonstrated substantial potential for increasing KE volumes. This encouraged us to reconsider initial ethical concerns, with a focus on the potential for a design of a prospective CPP clinical trial. This ethical reconsideration led us to conclude that the concept of unbalanced kidney exchanges (manifested primarily by differential benefit between compatible and incompatible pairs) is no longer as clear cut as originally conceived. In addition, application of two concepts substantially diminishes ethical concerns including: (1) "quasi-compatible" pairs, and (2) a priori definition of mitigating factors. We conclude that genuine uncertainty exists regarding whether kidney exchange is best performed with or without compatible pair participation and that a clinical trial is therefore warranted.

New-Onset Diabetes After Transplantation: Results From a Double-Blind Early Corticosteroid Withdrawal Trial.

New-onset diabetes after transplantation (NODAT) is an important complication following kidney transplantation. Data from the 5-year early steroid withdrawal double-blind randomized trial were analyzed to determine if steroid avoidance reduced the NODAT risk. Incidence, timing and risk factors for NODAT were evaluated using eight definitions. By American Diabetes Association definition, 36.3% of patients on chronic corticosteroids (CCS) and 35.9% on early corticosteroid withdrawal (CSWD) were diagnosed with NODAT by 5 years. The definition combining fasting blood glucose ≥126 mg/dL on two occasions or treatment identified slightly more cases of NODAT: CCS (39.3%) and CSWD (39.4%). Through 5 years posttransplant, the proportion of NODAT patients requiring treatment were similar (CSWD 22.5% vs. CCS 21.5%); however, insulin therapy was lower with CSWD (3.7% vs. 11.6%; p = 0.049). By multivariate analysis, only age, but not corticosteroid use, was a significant risk factor for NODAT for more than one definition. Numerical, but not statistically significant trends toward lower NODAT rates with CSWD were observed through 5 years for insulin use, HbA1c ≥6.0% and ≥6.5% on two occasions. This prospective, randomized trial of CSWD indicates that CSWD has a limited impact in reducing NODAT when compared to low-dose prednisone (5 mg/day from month 6 to 5 years).

Prospective iterative trial of proteasome inhibitor-based desensitization.

A prospective iterative trial of proteasome inhibitor (PI)-based therapy for reducing HLA antibody (Ab) levels was conducted in five phases differing in bortezomib dosing density and plasmapheresis timing. Phases included 1 or 2 bortezomib cycles (1.3 mg/m(2) × 6-8 doses), one rituximab dose and plasmapheresis. HLA Abs were measured by solid phase and flow cytometry (FCM) assays. Immunodominant Ab (iAb) was defined as highest HLA Ab level. Forty-four patients received 52 desensitization courses (7 patients enrolled in multiple phases): Phase 1 (n = 20), Phase 2 (n = 12), Phase 3 (n = 10), Phase 4 (n = 5), Phase 5 (n = 5). iAb reductions were observed in 38 of 44 (86%) patients and persisted up to 10 months. In Phase 1, a 51.5% iAb reduction was observed at 28 days with bortezomib alone. iAb reductions increased with higher bortezomib dosing densities and included class I, II, and public antigens (HLA DRß3, HLA DRß4 and HLA DRß5). FCM median channel shifts decreased in 11/11 (100%) patients by a mean of 103 ± 54 mean channel shifts (log scale). Nineteen out of 44 patients (43.2%) were transplanted with low acute rejection rates (18.8%) and de novo DSA formation (12.5%). In conclusion, PI-based desensitization consistently and durably reduces HLA Ab levels providing an alternative to intravenous immune globulin-based desensitization.

Addressing morbid obesity as a barrier to renal transplantation with laparoscopic sleeve gastrectomy.

Morbid obesity is a barrier to renal transplantation and is inadequately addressed by medical therapy. We present results of a prospective evaluation of laparoscopic sleeve gastrectomy (LSG) for patients failing to achieve significant weight loss with medical therapy. Over a 25-month period, 52 obese renal transplant candidates meeting NIH guidelines for metabolic surgery underwent LSG. Mean age was 50.0 ± 10.0 years with an average preoperative BMI of 43.0 ± 5.4 kg/m(2) (range 35.8-67.7 kg/m(2)). Follow-up after LSG was 220 ± 152 days (range 26-733 days) with last BMI of 36.3 ± 5.3 kg/m(2) (range 29.2-49.8 kg/m(2)) with 29 (55.8%) patients achieving goal BMI of <35 kg/m(2) at 92 ± 92 days (range 13-420 days). The mean percentage of excess weight loss (%EWL) was 32.1 ± 17.6% (range 6.7-93.8%). A segmented regression model was used to compare medical therapy versus LSG. This revealed a statistically significant increase in the BMI reduction rate (0.3 kg/m(2)/month versus 1.1 kg/m(2)/month, p < 0.0001). Patients also experienced a 40.9% decrease in anti-hypertensive medications (p < 0.001) and a 49.7% decrease in total daily insulin dose (p < 0.001). LSG is a safe and effective means for addressing obesity in kidney transplant candidates in the context of a multidisciplinary approach.

Should HLA mismatch acceptability for sensitized transplant candidates be determined at the high-resolution rather than the antigen level?

Defining HLA mismatch acceptability of organ transplant donors for sensitized recipients has traditionally been based on serologically defined HLA antigens. Now, however, it is well accepted that HLA antibodies specifically recognize a wide range of epitopes present on HLA antigens and that molecularly defined high resolution alleles corresponding to the same low resolution antigen can possess different epitope repertoires. Hence, determination of HLA compatibility at the allele level represents a more accurate approach to identify suitable donors for sensitized patients. This approach would offer opportunities for increased transplant rates and improved long term graft survivals.

The role of donor-specific HLA alloantibodies in liver transplantation.

The impact of donor-specific HLA alloantibodies (DSA) on short- and long-term liver transplant outcome is not clearly defined. While it is clear that not all levels of allosensitization produce overt clinical injury, and that liver allografts possess some degree of alloantibody resistance, alloantibody-mediated adverse consequences are increasingly being recognized. To better define the current state of this topic, we assembled experts to provide insights, explore controversies and develop recommendations for future research on the consequences of DSA in liver transplantation. This article summarizes the proceedings of this inaugural meeting. Several insights emerged. Acute antibody-mediated rejection (AMR), although rarely diagnosed, is increasingly understood to overlap with T cell-mediated rejection. Isolated liver allograft recipients are at increased risk of early allograft immunologic injury when preformed DSA are high titer and persist posttransplantation. Persons who undergo simultaneous liver-kidney transplantation are at risk of renal AMR when Class II DSA persist posttransplantation. Other under-appreciated DSA associations include ductopenia and fibrosis, plasma cell hepatitis, biliary strictures and accelerated fibrosis associated with recurrent liver disease. Standardized DSA testing and diagnostic criteria for both acute and chronic AMR are needed to distil existing associations into etiological processes in order to develop responsive therapeutic strategies.

Randomized controlled pilot study of B cell-targeted induction therapy in HLA sensitized kidney transplant recipients.

Optimal induction regimens for patients at high risk for antibody and/or cell-mediated rejection have not been established. This pilot, prospective, randomized study evaluated addition of B cell/plasma cell-targeting agents to T cell-based induction with rabbit antithymocyte globulin (rATG) in high immunologic risk renal transplant recipients. Patients were randomized to induction with rATG, rATG + rituximab, rATG + bortezomib or rATG + rituximab + bortezomib. Inclusion criteria were: (1) current cytotoxic panel reactive antibody (PRA) ≥20% or peak cytotoxic PRA ≥50% or (2) T or B cell positive flow crossmatch with donor-specific antibody (DSA) or (3) historical positive serologic or cytotoxic crossmatch or DSA to donor or (4) prior allograft loss with more than one acute rejection. Median overall follow-up was 496 days: 1-year and overall acute rejection were 25% and 27.5%, and 25% of patients developed de novo DSA within 1 year. One-year and overall patient survival were 97.5% and 92.5%, and 1-year and overall death-censored allograft survival were 97.5% and 95%. Renal allograft function posttransplant was similar among all arms. Eight of nine cases of peripheral neuropathy were mild, whereas one case was moderate and required a narcotic prescription. In conclusion, addition of rituximab and/or bortezomib to rATG induction has an acceptable safety/toxicity profile in a high immunologic risk renal transplant population.

Effect of corticosteroid withdrawal on tacrolimus and mycophenolate mofetil exposure in a randomized multicenter study.

As corticosteroid-sparing protocols are increasingly utilized in kidney transplant recipients, it is crucial to understand potential drug interactions between tacrolimus (TAC) and the effect of corticosteroid withdrawal as well as to characterize dose adjustments of mycophenolate mofetil (MMF) in this setting. This prospective, multicenter, randomized, double-blind study included 397 patients who were randomized on posttransplant day 8 to receive either placebo (CSWD) or corticosteroid continuance (CCS). TAC trough levels at week two posttransplant were significantly greater in the CSWD group whereas TAC doses were comparable to the CCS group. This interaction was not observed in the African American subgroup. Higher serum creatinine and potassium levels were also observed in the CSWD group. MMF dose was significantly reduced in the CSWD group by the investigators because of decreased WBC counts, mostly outside of study protocol criteria, despite similar incidence of neutropenia and reported cytomegalovirus infection. Understanding TAC and MMF exposure in the context of corticosteroid-sparing protocols should allow for improved dosing of immunosuppressants and better management of posttransplant patients.

Efficacy of sotrastaurin plus tacrolimus after de novo kidney transplantation: randomized, phase II trial results.

Sotrastaurin, a novel immunosuppressant, blocks early T cell activation through protein kinase C inhibition. Efficacy and safety of sotrastaurin with tacrolimus were assessed in a dose-ranging non-inferiority study in renal transplant recipients. A total of 298 patients were randomized 1:1:1:1 to receive sotrastaurin 100 (n = 77; discontinued in December 2011) or 200 mg (n = 73) b.i.d. plus standard tacrolimus (sTAC; 5-12 ng/mL), sotrastaurin 300 mg (n = 75) b.i.d. plus reduced tacrolimus (rTAC; 2-5 ng/mL) or enteric-coated mycophenolic acid (MPA) plus sTAC (n = 73); all patients received basiliximab and corticosteroids. Composite efficacy failure (treated biopsy-proven acute rejection ≥ grade IA, graft loss, death or loss to follow up) rates at Month 12 were 18.8%, 12.4%, 10.9% and 14.0% for the sotrastaurin 100, 200 and 300 mg, and MPA groups, respectively. The median estimated glomerular filtration rates were 55.7, 53.3, 64.9 and 59.2 mL/min, respectively. Mean heart rates were faster with higher sotrastaurin doses and discontinuations due to adverse events and gastrointestinal adverse events were more common. Fewer patients in the sotrastaurin groups experienced leukopenia than in the MPA group (1.3-5.5% vs. 16.5%). Sotrastaurin 200 and 300 mg had comparable efficacy to MPA in prevention of rejection with no significant difference in renal function between the groups.

Donor-transmitted malignancies in organ transplantation: assessment of clinical risk.

The continuing organ shortage requires evaluation of all potential donors, including those with malignant disease. In the United States, no organized approach to assessment of risk of donor tumor transmission exists, and organs from such donors are often discarded. The ad hoc Disease Transmission Advisory Committee (DTAC) of the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) formed an ad hoc Malignancy Subcommittee to advise on this subject. The Subcommittee reviewed the largely anecdotal literature and held discussions to generate a framework to approach risk evaluation in this circumstance. Six levels of risk developed by consensus. Suggested approach to donor utilization is given for each category, recognizing the primacy of individual clinical judgment and often emergent clinical circumstances. Categories are populated with specific tumors based on available data, including active or historical cancer. Benign tumors are considered in relation to risk of malignant transformation. Specific attention is paid to potential use of kidneys harboring small solitary renal cell carcinomas, and to patients with central nervous system tumors. This resource document is tailored to clinical practice in the United States and should aid clinical decision making in the difficult circumstance of an organ donor with potential or proven neoplasia.

Immunosuppression with belatacept-based, corticosteroid-avoiding regimens in de novo kidney transplant recipients.

Current immunosuppressive regimens in renal transplantation typically include calcineurin inhibitors (CNIs) and corticosteroids, both of which have toxicities that can impair recipient and allograft health. This 1-year, randomized, controlled, open-label, exploratory study assessed two belatacept-based regimens compared to a tacrolimus (TAC)-based, steroid-avoiding regimen. Recipients of living and deceased donor renal allografts were randomized 1:1:1 to receive belatacept-mycophenolate mofetil (MMF), belatacept-sirolimus (SRL), or TAC-MMF. All patients received induction with 4 doses of Thymoglobulin (6 mg/kg maximum) and an associated short course of corticosteroids. Eighty-nine patients were randomized and transplanted. Acute rejection occurred in 4, 1 and 1 patient in the belatacept-MMF, belatacept-SRL and TAC-MMF groups, respectively, by Month 6; most acute rejection occurred in the first 3 months. More than two-thirds of patients in the belatacept groups remained on CNI- and steroid-free regimens at 12 months and the calculated glomerular filtration rate was 8-10 mL/min higher with either belatacept regimen than with TAC-MMF. Overall safety was comparable between groups. In conclusion, primary immunosuppression with belatacept may enable the simultaneous avoidance of both CNIs and corticosteroids in recipients of living and deceased standard criteria donor kidneys, with acceptable rates of acute rejection and improved renal function relative to a TAC-based regimen.

Sotrastaurin, a novel small molecule inhibiting protein-kinase C: randomized phase II study in renal transplant recipients.

Sotrastaurin, a selective protein-kinase-C inhibitor, blocks early T-cell activation through a calcineurin-independent mechanism. In this study, de novo renal transplant recipients with immediate graft function were randomized 1:2 to tacrolimus (control, n = 44) or sotrastaurin (300 mg b.i.d.; n = 81). All patients received basiliximab, mycophenolic acid (MPA) and steroids. The primary endpoint was the composite of treated biopsy-proven acute rejection (BPAR), graft loss, death or lost to follow-up at month 3. The main safety assessment was estimated glomerular filtration rate (eGFR); modification of diet in renal disease (MDRD) at month 3. Composite efficacy failure at month 3 was higher for the sotrastaurin versus control regimen (25.7% vs. 4.5%, p = 0.001), driven by higher BPAR rates (23.6% vs. 4.5%, p = 0.003), which led to early study termination. Median (± standard deviation [SD]) eGFR was higher for sotrastaurin versus control at all timepoints from day 7 (month 3: 59.0 ± 22.3 vs. 49.5 ± 17.7 mL/min/1.73 m(2) , p = 0.006). The most common adverse events were gastrointestinal disorders (control: 63.6%; sotrastaurin: 88.9%) which led to study-medication discontinuation in two sotrastaurin patients. This study demonstrated a lower degree of efficacy but better renal function with the calcineurin-inhibitor-free regimen of sotrastaurin+MPA versus the tacrolimus-based control. Ongoing studies are evaluating alternative sotrastaurin regimens.

Proteasome inhibitor therapy for antibody-mediated rejection.

AMR is being recognized with increasing efficiency, but continues to present a significant threat to renal allograft survival. Traditional therapies for AMR (IVIG, plasmapheresis, rituximab, and antilymphocyte preparations) in general have provided inconsistent results and do not deplete the source of antibody production, viz., the mature plasma cell. Recently, the first plasma cell-targeted therapy in humans has been developed using bortezomib (a first in class PI) for AMR treatment in kidney transplant recipients. Initial experience with bortezomib involved treatment of refractory AMR. Subsequently, the efficacy of bortezomib in primary therapy for AMR was demonstrated. In a multicenter collaborative effort, the initial results with bortezomib in AMR have been confirmed and expanded to pediatric and adult heart transplant recipients. More recently, results from a prospective, staged desensitization trial has shown that bortezomib alone can substantially reduce anti-HLA antibody levels. These results demonstrate the significant potential of proteasome inhibition in addressing humoral barriers. However, the major advantage of proteasome inhibition lies in the numerous potential strategies for achieving synergy.

Ethical considerations for participation of nondirected living donors in kidney exchange programs.

Kidneys from nondirected donors (NDDs) have historically been allocated directly to the deceased donor wait list (DDWL). Recently, however, NDDs have participated in kidney exchange (KE) procedures, including KE 'chains', which have received considerable media attention. This increasing application of KE chains with NDD participation has occurred with limited ethical analysis and without ethical guidelines. This article aims to provide a rigorous ethical evaluation of NDDs and chain KEs. NDDs and bridge donors (BDs) (i.e. living donors who link KE procedures within KE chains) raise several ethical concerns including coercion, privacy, confidentiality, exploitation and commercialization. In addition, although NDD participation in KE procedures may increase transplant numbers, it may also reduce NDD kidney allocation to the DDWL, and disadvantage vulnerable populations, particularly O blood group candidates. Open KE chains (also termed 'never-ending' chains) result in a permanent diversion of NDD kidneys from the DDWL. The concept of limited KE chains is discussed as an ethically preferable means for protecting NDDs and BDs from coercion and minimizing 'backing out', whereas 'honor systems' are rejected because they are coercive and override autonomy. Recent occurrences of BDs backing out argue for adoption of ethically based protective measures for NDD participation in KE.