Treatment Of Chronic Antibody-mediated Rejection Research Articles

Granulomatous Tubulointerstitial Nephritis in a Kidney Allograft: Treatment with Interleukin-6 Receptor Antagonist Stabilises Kidney Function

Granulomatous tubulointerstitial nephritis (GTIN) attributed to early onset sarcoidosis is an ultrarare finding in an allograft kidney biopsy. We present the case of a young man with allograft dysfunction who had GTIN upon biopsy. We performed a thorough case review based on recovered records from early childhood and reassessed genetic testing results. We revised his underlying diagnosis from cryopyrin-associated periodic syndrome to early-onset sarcoidosis with wild-type NOD2 and established a rationale to use the interleukin-6 (IL-6) receptor blocker tocilizumab (TCZ). This suppressed his inflammatory disease and stabilised kidney function. We performed a literature review related to the emerging role of IL-6 pathway blockade in kidney transplantation. We identified 18 reports with 417 unique patients treated with TCZ for indications including HLA-desensitisation, transplant immunosuppression induction, treatment of chronic antibody-mediated rejection, and treatment of subclinical rejection. Both TCZ and the direct IL-6 inhibitor clazakizumab are being studied in ongoing randomised control trials.

Mechanism and treatment for chronic antibody-mediated rejection in kidney transplant recipients.

Chronic antibody-mediated rejection of kidney transplantation is a major cause of late-stage graft loss. Donor-specific antibodies are the main cause of antibody-mediated rejection; in particular, de novo donor-specific antibodies are a risk factor for chronic active antibody-mediated rejection. The level of de novo donor-specific antibodies tends to increase with time throughout long-term graft survival. Donor-specific antibodies induce humoral rejection through complement activation, which results in tissue injury and coagulation. Additionally, complement activation promotes the migration of inflammatory cells through the innate immune response, causing endothelial injury. This inflammatory response may cause persistent glomerulitis and peritubular capillaritis, leading to fixed pathological lesions that impair graft function. No treatment has been established for chronic antibody-mediated rejection, a condition in which antibody-mediated rejection becomes irreversible. Thus, antibody-mediated rejection must be detected and treated while it is still reversible. In this review, we discuss the development of de novo donor-specific antibodies and the mechanisms leading to chronic antibody-mediated rejection and summarize the current treatment options and the latest biomarkers for detecting chronic antibody-mediated rejection at an earlier stage.

MO1001: Tocilizumab in the Treatment of Chronic Antibody-Mediated Rejection Post Kidney Transplantation: Clinical and Histological Monitoring

Abstract BACKGROUND AND AIMS Chronic antibody-mediated rejection (cAMR) has very few effective therapeutic options. Interleukin-6 is an attractive target because it is involved in inflammation and humoral immunity. Therefore, the use of tocilizumab (anti-IL6 receptor, TCZ) is a potential valuable therapeutic option to treat cABMR in kidney-transplant (KT) recipients METHOD This single-centre retrospective study included all KT recipients that received monthly TCZ infusions in the setting of cABMR, between August 2018 and July 2021. We assessed 12-month renal function and KT histology during follow-up. RESULTS Forty patients were included. At 12-months, eGFR was not significantly different, 41.6 ± 17 versus 43 ± 17 mL/min/1.73 m2 (P = .102) in patients with functional graft. Six patients (15%) lost their grafts: Their condition was clinically more severe at the time of the first TCZ infusion. Histological follow-up showed no statistical difference in the scores of glomerulitis, peritubular capillaritis, and interstitial fibrosis/tubular atrophy (IFTA). However, the chronic glomerulopathy score, increased significantly over time, and conversely, arteritis and inflammation in IFTA ares improved in follow-up biopsies. CONCLUSION In our study, the addition of TCZ prevented clinical and histological worsening of cABMR in KT recipients, except for more severely ill patients. Randomized studies are needed to clarify the risk/benefit of TCZ in cABMR.

Tocilizumab in the Treatment of Chronic Antibody-Mediated Rejection Post Kidney Transplantation: Clinical and Histological Monitoring.

Introduction: Chronic antibody-mediated rejection (cAMR) has very few effective therapeutic options. Interleukin-6 is an attractive target because it is involved in inflammation and humoral immunity. Therefore, the use of tocilizumab (anti-IL6 receptor, TCZ) is a potential valuable therapeutic option to treat cABMR in kidney-transplant (KT) recipients.Materials and Methods: This single-center retrospective study included all KT recipients that received monthly TCZ infusions in the setting of cABMR, between August 2018 and July 2021. We assessed 12-month renal function and KT histology during follow-up.Results: Forty patients were included. At 12-months, eGFR was not significantly different, 41.6 ± 17 vs. 43 ± 17 mL/min/1.73 m2 (p = 0.102) in patients with functional graft. Six patients (15%) lost their graft: their condition was clinically more severe at the time of first TCZ infusion. Histological follow-up showed no statistical difference in the scores of glomerulitis, peritubular capillaritis, and interstitial fibrosis/tubular atrophy (IFTA). Chronic glomerulopathy score however, increased significantly over time; conversely arteritis and inflammation in IFTA ares improved in follow-up biopsies.Conclusion: In our study, the addition of TCZ prevented clinical and histological worsening of cABMR in KT recipients, except for more severely ill patients. Randomized studies are needed to clarify the risk/benefit of TCZ in cABMR.

New concepts in chronic antibody-mediated kidney allograft rejection: prevention and treatment.

Chronic antibody-mediated rejection (AMR) is a cardinal cause of transplant failure, with currently no proven effective prevention or treatment. The present review will focus on new therapeutic concepts currently under clinical evaluation. One interesting treatment approach may be interference with interleukin-6 (IL-6) signaling to modulate B-cell immunity and donor-specific antibody (DSA) production. Currently, a large phase III randomized controlled trial is underway to clarify the safety and efficacy of clazakizumab, a high-affinity anti-IL-6 antibody, in chronic AMR. A prevention/treatment strategy may be costimulation blockade using belatacept to interfere with germinal center responses and DSA formation. In a recent uncontrolled study, belatacept conversion was shown to stabilize renal function and dampen AMR activity. Moreover, preliminary clinical results suggest efficacy of CD38 antibodies to deplete plasma and natural killer cells to treat AMR, with anecdotal reports demonstrating at least transient resolution of active rejection. There are promising concepts on the horizon for the prevention and treatment of chronic AMR. The design of adequately powered placebo-controlled trials to clarify the safety and efficacy of such new therapies, however, remains a big challenge, and will rely on the definition of precise surrogate endpoints predicting long-term allograft survival. Mapping the natural history of AMR would greatly help the understanding of who would derive benefits from treatment.

COVID-19 in Kidney Transplantation: Outcomes, Immunosuppression Management, and Operational Challenges.

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2, has led to the death of hundreds of thousands of people worldwide. If infected, older individuals and those with diabetes, hypertension, cardiovascular disease, and compromised immune systems are at higher risk for unfavorable outcomes. These comorbidities are prevalent in patients with kidney disease, hence the significant burden of COVID-19 on kidney transplant programs. Multiple case series of kidney transplant recipients with COVID-19 have shown increased mortality compared to nontransplant patients. To date, we do not have high-level evidence to inform immunosuppression minimization strategies in infected transplant recipients. Most centers however have adopted early antimetabolite withdrawal in addition to other interventions. This review summarizes the published COVID-19 literature as it relates to outcomes and immunosuppression management in kidney transplant recipients. It also discusses challenges pertaining to pretransplant evaluation and wait-listed patients.

Longitudinal Changes in Donor-Derived Cell-Free DNA With Tocilizumab Treatment for Chronic Antibody-Mediated Rejection

Longitudinal Changes in Donor-Derived Cell-Free DNA With Tocilizumab Treatment for Chronic Antibody-Mediated Rejection

Correction to: Rabbit anti-human thymocyte immunoglobulin for the rescue treatment of chronic antibody-mediated rejection after pediatric kidney transplantation.

The article "Rabbit anti-human thymocyte immunoglobulin for the rescue treatment of chronic antibody-mediated rejection after pediatric kidney transplantation", written by Yasemen Cihan, Nele Kanzelmeyer, Jens Drube, Martin Kreuzer, Christian Lerch, Imke Hennies, Kerstin Froede, Murielle Verboom.

Rabbit anti-human thymocyte immunoglobulin for the rescue treatment of chronic antibody-mediated rejection after pediatric kidney transplantation.

Chronic antibody-mediated rejection (cAMR) is the leading cause of late kidney graft loss, but current therapies are often ineffective. Rabbit anti-human thymocyte immunoglobulin (rATG) may be helpful, but its use is virtually undocumented. Data were analyzed retrospectively from nine pediatric kidney transplant patients with cAMR were treated with rATG (1.5mg/kg × 5days) at our center after non-response to pulsed prednisolone, intravenous immunoglobulin, rituximab, and increased immunosuppressive intensity (including switching to belatacept in some cases), with or without bortezomib. The median time from diagnosis to cAMR was 179days. rATG was started 5-741days after diagnosis. Median estimated glomerular filtration rate (eGFR) increased from 40mL/min/1.73m2 when rATG was started to 62mL/min/1.73m2 9months later (p=0.039). Four patients showed substantially higher eGFR after 9months and 2 patients showed a small improvement; eGFR continued to decline in 3 patients after starting rATG. No grafts were lost during follow-up. At last follow-up, donor-specific antibodies (DSAs) were no longer detectable in 4 out of 8 patients for whom data were available, median fluorescence intensity had decreased substantially in 1 out of 8 patients; anti-HLA DQ DSAs persisted in 2 out of 8 patients. No adverse events with a suspected relation to rATG, including allergic reactions, leukocytopenia or infections, were observed in any of the patients. In this small series of patients, rATG appears a promising treatment for unresponsive cAMR. Further evaluation, including earlier introduction of rATG, is warranted.

Assessment of Tocilizumab (Anti-Interleukin-6 Receptor Monoclonal) as a Potential Treatment for Chronic Antibody-Mediated Rejection and Transplant Glomerulopathy in HLA-Sensitized Renal Allograft Recipients.

Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.

Antibody-mediated rejection: analyzing the risk, proposing solutions.

Antibody-mediated rejection: analyzing the risk, proposing solutions.

Monoclonal antibody therapy and renal transplantation: focus on adverse effects.

A series of monoclonal antibodies (mAbs) are commonly utilized in renal transplantation as induction therapy (a period of intense immunosuppression immediately before and following the implant of the allograft), to treat steroid-resistant acute rejections, to decrease the incidence and mitigate effects of delayed graft function, and to allow immunosuppressive minimization. Additionally, in the last few years, their use has been proposed for the treatment of chronic antibody-mediated rejection, a major cause of late renal allograft loss. Although the exact mechanism of immunosuppression and allograft tolerance with any of the currently used induction agents is not completely defined, the majority of these medications are targeted against specific CD proteins on the T or B cells surface (e.g., CD3, CD25, CD52). Moreover, some of them have different mechanisms of action. In particular, eculizumab, interrupting the complement pathway, is a new promising treatment tool for acute graft complications and for post-transplant hemolytic uremic syndrome. While it is clear their utility in renal transplantation, it is also unquestionable that by using these highly potent immunosuppressive agents, the body loses much of its innate ability to mount an adequate immune response, thereby increasing the risk of severe adverse effects (e.g., infections, malignancies, haematological complications). Therefore, it is extremely important for clinicians involved in renal transplantation to know the potential side effects of monoclonal antibodies in order to plan a correct therapeutic strategy minimizing/avoiding the onset and development of severe clinical complications.

Current Issues in the Treatment of Chronic Antibody-Mediated Rejection in Kidney Transplantation

Circulating alloantibodies are found in a substantial number of renal allograft recipients, and can induce chronic allograft injury, which is represented microscopically as transplant glomerulopathy and diffuse C4d deposition in peritubular capillaries (PTCs). Development of these injuries is significantly correlated with late allograft loss, and in this regard, it was included as a new disease entity named chronic antibody-mediated rejection (cAMR) in the updated Banff 05 classification. Usually, the prognosis of cAMR is poor and conventional immunosuppressants mainly targeting T cell-mediated immunity cannot prevent or reverse it. Therefore, some researchers have suggested that therapies directed at the humoral response may be required for the treatment of cAMR. Recently, some reports have suggested that the combined use of rituximab and intravenous immunoglobulin (IVIg) therapy may be useful for the treatment of cAMR. Our previous study also showed that rituximab and IVIg combination therapy effectively delayed the progression of cAMR. We administered rituximab and IVIg combination therapy to 18 biopsy-proven cAMR patients and found that it significantly slowed the decline of the estimated glomerular filtration rate. However, this effect was limited in patients with heavy proteinuria, and dissipated in all patients by 1 year post-treatment. Recently, new drugs targeting the humoral immune system, such as bortezomib and eculizumab, have been tested for the treatment of cAMR. However, the studies still lack definitive data in terms of successful treatment of cAMR. We speculate that those therapies will compensate for the limitation of previous anti-humoral therapies for cAMR.

IVIG and Rituximab for Treatment of Chronic Antibody-Mediated Rejection in Pediatric Renal Transplantation: A Prospective Pilot Study with a 2 Year Follow-Up

Background: Chronic antibody-mediated rejection (AMR) is the major cause of late renal allograft loss. There is, however, no established treatment for this condition. Here we report an update of our prospective study on an antihumoral regimen consisting of high-dose intravenous immunoglobulin G (IVIG) and rituximab in paediatric renal transplant recipients. Methods: Twenty patients with chronic AMR were treated with four weekly doses of IVIG (1 g/kg body weight per dose), followed by a single dose of rituximab (375 mg/m2 body surface area) 1 week after the last IVIG infusion. Response to antihumoral therapy was defined as a reduction of the rate of loss of GFR by at least 30%. Calculated eGFR (Schwartz) were smoothed by LOESS procedure (SAS 9.2) to reduce bias due to outliers. At least one serum creatinine value per month and patient was available. Donor-specific HLA antibodies (HLA DSA) were quantified with Luminex-based bead array technology. Results: Loss of eGFR decreased significantly from 7.6 ml/min/1.73 m2 (range, -29.2 to 1.9) during the 6 months prior to antihumoral therapy to 2.1 ml/min/1.73 m2 (range, -15.0 to 7.6; P=0.006) during the 6 months after intervention. Fourteen patients (70%) responded: 9 of 9 patients (100%) without and 5 of 11 (45%) with transplant glomerulopathy (P=0.014). During 2 years of follow-up, the respective median loss of eGFR in each of the four 6-month periods remained significantly lower than that prior to intervention.[Fig. 1]No patients had pre-existing anti-HLA DSA. At the time of index biopsy de novo anti-HLA DSA were found in 16 of 20 (80%) patients. In 13 of 20 patients (65%) the immunodominant DSA was directed against HLA class II antigens. HLA class I DSA declined in response to antihumoral therapy by 54.4% (p=0.027) and HLA class II DSA by 47% (p=0.040) at 12 months after intervention. The percentage of C4d positivity in peritubular capillaries decreased from 40 ± 18.5% in the index biopsy to 11.6 ± 12.2% (P=0.002) in the follow-up biopsy. In four of nine biopsies (44%) C4d staining turned completely negative. Conclusions: Antihumoral treatment with IVIG and rituximab significantly reduces or stabilizes the progressive loss of transplant function in paediatric patients with chronic AMR over an observation period of 2 years, apparently by lowering circulating DSA and reducing intrarenal complement activation. This treatment protocol may represent a significant advance in the management of this common and often difficult-to-treat posttransplant complication.

Partial therapeutic response to Rituximab for the treatment of chronic alloantibody mediated rejection of kidney allografts

Background and ObjectivesChronic rejection leads to kidney allograft failure and develops in many kidney transplant recipients. One cause of chronic rejection, chronic antibody mediated rejection (CAMR), is attributed to alloantibodies. Maintenance immunosuppression including prednisone, mycophenolate mofetil (MMF) and calcineurin inhibitors may limit alloantibody production in some patients, but many maintain or develop alloantibody production, leading to CAMR. Therefore, no efficacious therapy to treat CAMR is presently available to prevent the progression of CAMR to kidney allograft failure. Design, Setting, Participants, and MeasurementsWe performed a retrospective review of 31 subjects with CAMR, of which 14 received Rituximab and 17 subjects did not. Response to Rituximab was defined as decline or stabilization of serum creatinine for at least one year. Data reviewed included demographic, clinical, allograft, post-transplant, and pathological variables. Pathological variables in the diagnostic allograft biopsy were scored according to Banff criteria. ResultsThe median survival time (MST) for allografts in the control group was 439days, and for the Rituximab treated group was 685days. The Rituximab group was dichotomous with 8 subjects showing a medial survival time of 1180days, and 6 subjects having a median survival time of 431days. The MST for the responders was statistically significant from the non-responders and controls. No pathological parameter distinguished any subset of subjects. ConclusionsThese data show that Rituximab followed by standard maintenance immunosuppression shows a therapeutic effect in the treatment of CAMR, which is confined to a subset of treated subjects, not identifiable a priori.

IVIG and rituximab for treatment of chronic antibody-mediated rejection: a prospective study in paediatric renal transplantation with a 2-year follow-up

Chronic antibody-mediated rejection (AMR) is the major cause of late renal allograft loss. There is, however, no established treatment for this condition. We report the results of a prospective pilot study on an antihumoral therapy (AHT) consisting of high-dose intravenous immunoglobulin G (IVIG) and rituximab in 20 paediatric renal transplant recipients. Donor-specific HLA antibodies (HLA DSA) were quantified by Luminex-based bead array technology. Loss of eGFR decreased significantly from 7.6 ml/min/1.73 m² during 6 months prior to AHT to 2.1 ml/min/1.73 m² (P = 0.0013) during 6 months after AHT. Fourteen patients (70%) responded: nine of nine patients (100%) without and five of 11 (45%) with transplant glomerulopathy (P = 0.014). C4d positivity in PTC decreased from 40 ± 18.5% in the index biopsy to 11.6 ± 12.2% (P = 0.002) in the follow-up biopsy. In four of nine biopsies (44%) C4d staining turned negative. During 2 years of follow-up, the median loss of eGFR in each of the four 6-month periods remained significantly lower compared with prior to AHT. Class I DSA declined in response to AHT by 61% (p = 0.044), class II DSA by 63% (p = 0.033) 12 months after intervention. AHT with IVIG and rituximab significantly reduces or stabilizes the progressive loss of transplant function in paediatric patients with chronic AMR over an observation period of 2 years, apparently by lowering circulating DSA and reducing intrarenal complement activation.

Current and future challenges in therapy for antibody-mediated rejection

Antibody-mediated rejection (AMR) continues to present a challenge for the survival of the cardiac allograft. AMR appears to be on the rise, likely secondary to changing trends in clinical practice, including selection of patients for transplantation on mechanical circulatory support and development of more effective combinations of immunosuppressive drugs against acute cellular rejection. Most current strategies are aimed at treating acute AMR, but the treatment of chronic AMR is still not well defined. Clinically, AMR can often be more severe than cellular rejection and more difficult to treat, often not responding to typical protocols of increased immunosuppression. Complex steps involved in the antibody response allows for several potential targets for therapeutic intervention, including suppression of T and B cells, elimination of circulating antibodies, and inhibition of residual antibodies. Existing evidence suggests a multiregimen approach is the best option. Sustenance of accommodation and induction of tolerance could be viewed as viable options if adequate immune surveillance can be achieved in this setting. This review discusses the challenges in treating AMR and provides a critical analysis of current and possible future therapies.

Antibody-mediated rejection: treatment alternatives and outcomes

Over the past 10 years, thanks to the development of sensitive methods of antibody detection and markers of antibody injury such as C4d staining, the role of anti-human leukocyte antigen (HLA) and non-HLA alloantibodies as effectors of acute and chronic immune allograft injury has been revisited. Antibody-mediated rejection (AMR) defines all allograft rejection caused by antibodies directed against donor-specific HLA molecules, blood group antigen (ABO)-isoagglutinins, or endothelial cell antigens. Antibody-mediated rejection can be a recalcitrant process, resistant to therapy and carries an ominous prognosis to the graft. In concordance with these views, treatment protocols for AMR use permutations of a multiple-prong approach that include (1) the suppression of the T-cell dependent antibody response, (2) the removal of donor reactive antibody, (3) the blockade of the residual alloantibody, and (4) the depletion of naive and memory B-cells. Although all published protocols report a variable rate of success, a major weakness of all current protocols is the lack of effective anti-plasma cell agents. In comparison to acute AMR, the treatment for chronic AMR (CAMR) is not well characterized. Although in acute AMR large titers of pre-existent alloantibodies result in massive activation of the complement system and lytic injury of the graft endothelium, thereby requiring aggressive and fast removal of the offending agents, in CAMR, complement activation results in sublytic endothelial cell injury and activation. Although this type of injury results in chronic graft failure, its slow progression likely renders it amenable of suppression by heightening of maintenance immunosuppression and anti-idiotypic blockade of the circulating alloantibody without the need of plasma exchange. In this review, we will discuss the rationale behind the design of treatment protocols for acute AMR and CAMR as well as their reported results and complications.

Successful Treatment of Chronic Antibody-Mediated Rejection With IVIG and Rituximab in Pediatric Renal Transplant Recipients

Chronic antibody-mediated rejection (CAMR) of renal allografts has recently been recognized as a defined nosologic entity. The outcome of CAMR is poor; there is no established treatment protocol for this condition. We therefore initiated a pilot study on treatment of CAMR with an antihumoral regimen consisting of high-dose intravenous immunoglobulin (IVIG) and the chimeric anti-CD20 antibody rituximab. Six pediatric renal transplant recipients with CAMR received four weekly doses of IVIG (1 g/kg body weight per dose), followed by a single dose of rituximab (375 mg/m2 body surface area) 1 week after the last IVIG infusion. Renal allograft biopsies were evaluated using the Banff '05 classification. Human leukocyte antigen-specific antibodies were detected by panel-reactive lymphocytotoxicity and solid phase ELISA assays. Median glomerular filtration rate during 6 months before intervention dropped by 25 (range, 11-26) mL/min/1.73 m2 (P<0.05) and increased in response to antihumoral therapy by 21 (-14 to +30) 6 months (P<0.05) and by 19 (-14 to +23) mL/min/1.73 m2 12 months (P=0.063) after start of treatment. Glomerular filtration rate improved or stabilized in 4 patients; the two nonresponders had the highest degree of transplant glomerulopathy, the highest degree of C4d deposition in peritubular capillaries and pronounced interstitial inflammation. The treatment regimen was well tolerated. This pilot study demonstrates that CAMR in pediatric renal transplant recipients can be treated successfully and safely with a combination of IVIG and rituximab. This observation should encourage more extensive studies to evaluate this new treatment strategy.