Repeat A2 Into B Kidney Transplantation After Failed Prior A2 Into B Transplant: A Case Report.

Kidneys from donors with blood type A2 can be successfully transplanted into blood type B and O recipients without the need for desensitization if the recipient's starting anti-A hemagglutinin titer is within an acceptable range. National kidney allocation policy now offers priority for eligible B recipients to receive A2 or A2B deceased donor kidneys, and therefore, the frequency with which A2 or A2B to B transplants will occur is expected to increase. The precise mechanisms by which antibody-mediated rejection is averted in these cases despite the presence of both circulating anti-A antibody and expression of the A2 antigen on the graft endothelium are not known. Whether this process mirrors proposed mechanisms of accommodation, which can occur in recipients of ABO incompatible transplants, is also not known. Repeated exposure to mismatched antigens after retransplantation could elicit memory responses resulting in antibody rebound and accelerated antibody-mediated rejection. Whether this would occur in the setting of repeated A2 donor exposure was uncertain. Here we report the case of a patient with history of a prior A2 to B transplant which failed owing to nonimmunologic reasons; the patient successfully underwent a repeat A2 to B transplant. Neither rebound in anti-A2 antibody nor clinical evidence of antibody-mediated rejection were observed after the transplant. Current kidney allocation will likely enable more such transplants in the future, and this may provide a unique patient population in whom the molecular mechanisms of incompatible graft accommodation may be investigated.

Antibody-mediated rejection: New approaches in prevention and management.

Despite the success of desensitization protocols, antibody-mediated rejection (AMR) remains a significant contributor to renal allograft failure in patients with donor-specific antibodies. Plasmapheresis and high-dose intravenous immunoglobulin have proved to be effective treatments to prevent and treat AMR, but irreversible injury in the form of transplant glomerulopathy can commonly manifest months to years later. There is an unmet need to improve the outcomes for patients at risk for AMR. Updated Banff criteria now take into account the increasing understanding of the complex and heterogeneous nature of AMR phenotypes, including the timing of rejection, subclinical and chronic AMR, C4d-negative AMR, and antibody-mediated vascular rejection. Treatment for AMR is not standardized, and there is little in the way of evidence-based treatment guidelines. Refining more precisely the mechanisms of injury responsible for different AMR phenotypes and establishing relevant surrogate endpoints to facilitate more informative studies will likely allow for more accurate determination of prognosis and efficacious intervention using new therapeutic approaches. In addition to plasma exchange and intravenous immunoglobulin, a number of other add-on therapies have been tried in small studies without consistent benefit, including anti-CD20, proteasome inhibitors, complement inhibitors, anti-interleukin-6 receptor blockers, and immunoglobulin G-degrading enzyme of Streptococcus pyogenes (called IdeS).

The Incremental Cost of Incompatible Living Donor Kidney Transplantation: A National Cohort Analysis.

Incompatible living donor kidney transplantation (ILDKT) has been established as an effective option for end-stage renal disease patients with willing but HLA-incompatible living donors, reducing mortality and improving quality of life. Depending on antibody titer, ILDKT can require highly resource-intensive procedures, including intravenous immunoglobulin, plasma exchange, and/or cell-depleting antibody treatment, as well as protocol biopsies and donor-specific antibody testing. This study sought to compare the cost and Medicare reimbursement, exclusive of organ acquisition payment, for ILDKT (n = 926) with varying antibody titers to matched compatible transplants (n = 2762) performed between 2002 and 2011. Data were assembled from a national cohort study of ILDKT and a unique data set linking hospital cost accounting data and Medicare claims. ILDKT was more expensive than matched compatible transplantation, ranging from 20% higher adjusted costs for positive on Luminex assay but negative flow cytometric crossmatch, 26% higher for positive flow cytometric crossmatch but negative cytotoxic crossmatch, and 39% higher for positive cytotoxic crossmatch (p < 0.0001 for all). ILDKT was associated with longer median length of stay (12.9 vs. 7.8 days), higher Medicare payments ($91 330 vs. $63 782 p < 0.0001), and greater outlier payments. In conclusion, ILDKT increases the cost of and payments for kidney transplantation.

Recurrent IgA Nephropathy After Kidney Transplantation.

BACKGROUND: Immunoglobulin (Ig)A nephropathy is the most common primary glomerulonephritis worldwide, with a high recurrence rate after kidney transplantation. The aim of this study was to assess allograft survival, impact of recurrence on allograft function, and risk factors for post-transplant IgA recurrence. METHODS: We identified 104 patients with IgA nephropathy who underwent kidney transplantation at our center between 1993 and 2014. Fourteen patients underwent more than one allograft. RESULTS: IgA recurrence was documented in 23 (19%) allografts. Median time to recurrence was 6.75 years (interquartile range, 1.4-9.2 years). Twelve of the 23 recurrences were from living related donors (P = .07), and those with younger age at transplantation (37.7 ± 2.3 vs 44 ± 1.3, P = .05) were at higher risk of recurrence. Mean allograft survival was reduced in those with recurrence (6.5 ± 5.1 years) compared with those without recurrence (10.4 ± 7.5 years). At 6 years after transplant, allograft failure was documented in 52% of the recurrence group compared with 10% in the non-recurrence group (P = .002). CONCLUSIONS: IgA recurrence after transplant is an important cause of allograft loss. Living related donors and younger age at transplantation are associated with high recurrence rate. Close monitoring and treatment of recurrence are crucial.

Splenic Irradiation for the Treatment of Severe Antibody-Mediated Rejection.

Patients requiring desensitization prior to renal transplantation are at risk for developing severe antibody-mediated rejection (AMR) refractory to treatment with plasmapheresis and intravenous immunoglobulin (PP/IVIg). We have previously reported success at graft salvage, long-term graft survival and protection against transplant glomerulopathy with the use of eculizumab and splenectomy in addition to PP/IVIg. Splenectomy may be an important component of this combination therapy and is itself associated with a marked reduction in donor-specific antibody (DSA) production. However, splenectomy represents a major operation, and some patients with severe AMR have comorbid conditions that substantially increase their risk of complications during and after surgery. In an effort to spare recipients the morbidity of a second operation, we used splenic irradiation in lieu of splenectomy in two incompatible live donor kidney transplant recipients with severe AMR in addition to PP/IVIg, rituximab and eculizumab. This novel approach to the treatment of severe AMR was associated with allograft salvage, excellent graft function and no short- or medium-term adverse effects of the radiation therapy. One-year surveillance biopsies did not show transplant glomerulopathy (tg) on light microscopy, but microcirculation inflammation and tg were present on electron microscopy.

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.

Chimeric Allografts Induced by Short-Term Treatment With Stem Cell-Mobilizing Agents Result in Long-Term Kidney Transplant Survival Without Immunosuppression: A Study in Rats.

Transplant tolerance allowing the elimination of lifelong immunosuppression has been the goal of research for 60 years. The induction of mixed chimerism has shown promise and has been extended successfully to large animals and to the clinic; however, it remains cumbersome and requires heavy early immunosuppression. In this study, we reported that four injections of AMD3100, a CXCR4 antagonist, plus eight injections of low-dose FK506 (0.05 mg/kg per day) in the first week after kidney transplantation extended survival, but death from renal failure occurred at 30-90 days. Repeating the same course of AMD3100 and FK506 at 1, 2 and 3 mo after transplant resulted in 92% allograft acceptance (n = 12) at 7 mo, normal kidney function and histology with no further treatment. Transplant acceptance was associated with the influx of host stem cells, resulting in a hybrid kidney and a modulated host immune response. Confirmation of these results could initiate a paradigm shift in posttransplant therapy.

Chimeric Allografts Induced by Short-Term Treatment With Stem Cell Mobilizing Agents Result in Long-Term Kidney Transplant Survival Without Immunosuppression: II, Study in Miniature Swine.

Transplantation is now lifesaving therapy for patients with end-stage organ failure but requires lifelong immunosuppression with resultant morbidity. Current immunosuppressive strategies inhibit T cell activation and prevent donor-recipient engagement. Therefore, it is not surprising that few host cells are demonstrated in donor grafts. However, our recent small animal studies found large numbers of recipient stem cells present after transplantation and pharmacological mobilization, resulting in a chimeric, repopulated organ. We now confirm these findings in a well-characterized large animal preclinical model. Here, we show that AMD3100 and FK506 mobilization of endogenous stem cells immediately post kidney transplantation combined with repeat therapy at 1, 2, and 3 months led to drug-free long-term survival in maximally immunologically mismatched swine. Three long-term recipients have stable chimeric transplants, preserved antidonor skin graft responses, and normal serum creatinine levels despite withdrawal of all medication for 3 years.

Presentation and Outcomes of C4d-Negative Antibody-Mediated Rejection After Kidney Transplantation.

The updated Banff classification allows for the diagnosis of antibody-mediated rejection (AMR) in the absence of peritubular capillary C4d staining. Our objective was to quantify allograft loss risk in patients with consistently C4d-negative AMR (n = 51) compared with C4d-positive AMR patients (n = 156) and matched control subjects without AMR. All first-year posttransplant biopsy results from January 2004 through June 2014 were reviewed and correlated with the presence of donor-specific antibody (DSA). C4d-negative AMR patients were not different from C4d-positive AMR patients on any baseline characteristics, including immunologic risk factors (panel reactive antibody, prior transplant, HLA mismatch, donor type, DSA class, and anti-HLA/ABO-incompatibility). C4d-positive AMR patients were significantly more likely to have a clinical presentation (85.3% vs. 54.9%, p < 0.001), and those patients presented substantially earlier posttransplantation (median 14 [interquartile range 8-32] days vs. 46 [interquartile range 20-191], p < 0.001) and were three times more common (7.8% vs 2.5%). One- and 2-year post-AMR-defining biopsy graft survival in C4d-negative AMR patients was 93.4% and 90.2% versus 86.8% and 82.6% in C4d-positive AMR patients, respectively (p = 0.4). C4d-negative AMR was associated with a 2.56-fold (95% confidence interval, 1.08-6.05, p = 0.033) increased risk of graft loss compared with AMR-free matched controls. No clinical characteristics were identified that reliably distinguished C4d-negative from C4d-positive AMR. However, both phenotypes are associated with increased graft loss and thus warrant consideration for intervention.

Quantifying renal allograft loss following early antibody-mediated rejection.

Unlike antibody-mediated rejection (AMR) with clinical features, it remains unclear whether subclinical AMR should be treated, as its effect on allograft loss is unknown. It is also uncertain if AMR's effect is homogeneous across donor (deceased/live) and (HLA/ABO) antibody types. We compared 219 patients with AMR (77 subclinical, 142 clinical) to controls matched on HLA/ABO-compatibility, donor type, prior transplant, panel reactive antibody (PRA), age and year. One and 5-year graft survival in subclinical AMR was 95.9% and 75.7%, compared to 96.8% and 88.4% in matched controls (p = 0.0097). Subclinical AMR was independently associated with a 2.15-fold increased risk of graft loss (95% CI: 1.19-3.91; p = 0.012) compared to matched controls, but not different from clinical AMR (p = 0.13). Fifty three point two percent of subclinical AMR patients were treated with plasmapheresis within 3 days of their AMR-defining biopsy. Treated subclinical AMR patients had no difference in graft loss compared to matched controls (HR 1.73; 95% CI: 0.73-4.05; p = 0.21), but untreated subclinical AMR patients did (HR 3.34; 95% CI: 1.37-8.11; p = 0.008). AMR's effect on graft loss was heterogeneous when stratified by compatible deceased donor (HR = 4.73; 95% CI: 1.57-14.26; p = 0.006), HLA-incompatible deceased donor (HR = 2.39; 95% CI: 1.10-5.19; p = 0.028), compatible live donor (no AMR patients experienced graft loss), ABO-incompatible live donor (HR = 6.13; 95% CI: 0.55-67.70; p = 0.14) and HLA-incompatible live donor (HR = 6.29; 95% CI: 3.81-10.39; p < 0.001) transplant. Subclinical AMR substantially increases graft loss, and treatment seems warranted.

Successful transplantation of kidney allografts in sensitized rats after syngeneic hematopoietic stem cell transplantation and fludarabine.

Current methods to remove donor-specific HLA antibody (DSA) from sensitized patients remain imperfect. We tested novel approaches to desensitization using an animal model of allogeneic sensitization with skin grafts from dark agouti (DA) to Lewis rats. At the peak IgG alloantibody response we transplanted DA kidneys into nephrectomized Lewis recipients (n = 6) and all died within 10 days from antibody-mediated rejection (AMR). Allogeneic hematopoietic stem cell transplants (HSCT) from DA donors failed to engraft after lethal or sub-lethal irradiation. Sensitized rats given lethal irradiation plus syngeneic green fluorescent protein (GFP) + HSCT had repopulation of blood, spleen, thymus and lymph nodes by GFP+ cells. At 2 months after HSCT, serum DSA levels were reduced 60-70% and DSA (IgG) production in cultured splenocytes was also significantly decreased. However, there was only a modest improvement in graft survival from an average of 6.5 to 13.9 (n = 9) days. Adding seven daily doses of fludarabine to the preconditioning regimen resulted in long-term survival (>90 days) in 7 out of 10 rat kidney allografts. We conclude that syngeneic HSCT performed after preconditioning with irradiation and fludarabine can reduce DSA, prevent DSA rebound and AMR, enabling successful transplantation in animals with strong antibody reactivity to the donor MHC.

Experiences obtaining insurance after live kidney donation.

The impact of kidney donation on the ability to change or initiate health or life insurance following donation is unknown. To quantify this risk, we surveyed 1046 individuals who donated a kidney at our center between 1970 and 2011. Participants were asked whether they changed or initiated health or life insurance after donation, and if they had any difficulty doing so. Among 395 donors who changed or initiated health insurance after donation, 27 (7%) reported difficulty; among those who reported difficulty, 15 were denied altogether, 12 were charged a higher premium and 8 were told they had a preexisting condition because they were kidney donors. Among 186 donors who changed or initiated life insurance after donation, 46 (25%) reported difficulty; among those who reported difficulty, 23 were denied altogether, 27 were charged a higher premium and 17 were told they had a preexisting condition because they were kidney donors. In this single-center study, a high proportion of kidney donors reported difficulty changing or initiating insurance, particularly life insurance. These practices by insurers create unnecessary burden and stress for those choosing to donate and could negatively impact the likelihood of live kidney donation among those considering donation.

Quantifying the risk of incompatible kidney transplantation: a multicenter study.

Incompatible live donor kidney transplantation (ILDKT) offers a survival advantage over dialysis to patients with anti-HLA donor-specific antibody (DSA). Program-specific reports (PSRs) fail to account for ILDKT, placing this practice at regulatory risk. We collected DSA data, categorized as positive Luminex, negative flow crossmatch (PLNF) (n = 185), positive flow, negative cytotoxic crossmatch (PFNC) (n = 536) or positive cytotoxic crossmatch (PCC) (n = 304), from 22 centers. We tested associations between DSA, graft loss and mortality after adjusting for PSR model factors, using 9669 compatible patients as a comparison. PLNF patients had similar graft loss; however, PFNC (adjusted hazard ratio [aHR] = 1.64, 95% confidence interval [CI]: 1.15-2.23, p = 0.007) and PCC (aHR = 5.01, 95% CI: 3.71-6.77, p < 0.001) were associated with increased graft loss in the first year. PLNF patients had similar mortality; however, PFNC (aHR = 2.04; 95% CI: 1.28-3.26; p = 0.003) and PCC (aHR = 4.59; 95% CI: 2.98-7.07; p < 0.001) were associated with increased mortality. We simulated Centers for Medicare & Medicaid Services flagging to examine ILDKT's effect on the risk of being flagged. Compared to equal-quality centers performing no ILDKT, centers performing 5%, 10% or 20% PFNC had a 1.19-, 1.33- and 1.73-fold higher odds of being flagged. Centers performing 5%, 10% or 20% PCC had a 2.22-, 4.09- and 10.72-fold higher odds. Failure to account for ILDKT's increased risk places centers providing this life-saving treatment in jeopardy of regulatory intervention.

Eculizumab prevents recurrent antiphospholipid antibody syndrome and enables successful renal transplantation.

Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor-specific antibodies. After follow-up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.

Social media and organ donor registration: the Facebook effect.

Despite countless media campaigns, organ donation rates in the United States have remained static while need has risen dramatically. New efforts to increase organ donation through public education are necessary to address the waiting list of over 100,000 patients. On May 1, 2012, the online social network, Facebook, altered its platform to allow members to specify "Organ Donor" as part of their profile. Upon such choice, members were offered a link to their state registry to complete an official designation, and their "friends" in the network were made aware of the new status as a donor. Educational links regarding donation were offered to those considering the new organ donor status. On the first day of the Facebook organ donor initiative, there were 13 054 new online registrations, representing a 21.1-fold increase over the baseline average of 616 registrations. This first-day effect ranged from 6.9× (Michigan) to 108.9× (Georgia). Registration rates remained elevated in the following 12 days. During the same time period, no increase was seen in registrations from the DMV. Novel applications of social media may prove effective in increasing organ donation rates and likewise might be utilized in other refractory public health problems in which communication and education are essential.

Identifying appropriate recipients for CDC infectious risk donor kidneys.

Over 10% of deceased donors in 2011 met PHS/CDC criteria for infectious risk donor (IRD), and discard rates are significantly higher for kidneys from these donors. We hypothesized that patient phenotypes exist for whom the survival benefit outweighs the infectious risk associated with IRDs. A patient-oriented Markov decision process model was developed and validated, based on SRTR data and meta-analyses of window period risks among persons with IRD behaviors. The Markov model allows patients to see, for their phenotype, their estimated survival after accepting versus declining an IRD offer, graphed over a 5-year horizon. Estimated 5-year survival differences associated with accepting IRDs ranged from -6.4% to +67.3% for a variety of patient phenotypes. Factors most predictive of the survival difference with IRD transplantation were age, PRA, previous transplant, and the expected time until the next non-IRD deceased donor offer. This study suggests that survival benefit derived from IRD kidneys varies widely by patient phenotype. Furthermore, within the inherent limitations of model-based prediction, this study demonstrates that it is possible to identify those predicted to benefit from IRD kidneys, and illustrates how estimated survival curves based on a clinical decision can be presented to better inform patient and provider decision-making.

Center-level utilization of kidney paired donation.

With many multicenter consortia and a United Network for Organ Sharing program, participation in kidney paired donation (KPD) has become mainstream in the United States and should be feasible for any center that performs live donor kidney transplantation (LDKT). Lack of participation in KPD may significantly disadvantage patients with incompatible donors. To explore utilization of this modality, we analyzed adjusted center-specific KPD rates based on casemix of adult LDKT-eligible patients at 207 centers between 2006 and 2011 using SRTR data. From 2006 to 2008, KPD transplants became more evenly distributed across centers, but from 2008 to 2011 the distribution remained unchanged (Gini coefficient = 0.91 for 2006, 0.76 for 2008 and 0.77 for 2011), showing an unfortunate stall in dissemination. At the 10% of centers with the highest KPD rates, 9.9-38.5% of LDKTs occurred through KPD during 2009-2011; if all centers adopted KPD at rates observed in the very high-KPD centers, the number of KPD transplants per year would increase by a factor of 3.2 (from 494 to 1593). Broader implementation of KPD across a wide number of centers is crucial to properly serve transplant candidates with healthy but incompatible live donors.