Bortezomib: A New Promising Therapy for Early Antibody-Mediated Rejection After Liver Transplantation?

Successful Use of Bortezomib for Recurrent Progressive Familial Intrahepatic Cholestasis Type II After Liver Transplantation: A Pediatric Case with a 9-Year Follow-Up

Recurrence of progressive familial intrahepatic cholestasis (PFIC) type II poses challenges during postoperative liver transplant care. Posttransplant patients with PFIC type II risk developing recurrent cholestasis with normal gamma-glutamyl transferase activity, which mimics the original bile salt export pump (BSEP) protein deficiency and is related to a form of immunoglobulin G antibody (anti-BSEP)-mediated rejection. Bortezomib effectively induces apoptosis of actively antibody-producing plasma cells that may have a role in antibody-mediated rejection. In this case, we used bortezomib to treat PFIC type II recurrence after liver transplantation in a child.

Antibody-mediated rejection in xenotransplantation: Can it be prevented or reversed?

Antibody-mediated rejection (AMR) is the commonest cause of failure of a pig graft after transplantation into an immunosuppressed nonhuman primate (NHP). The incidence of AMR compared to acute cellular rejection is much higher in xenotransplantation (46% vs. 7%) than in allotransplantation (3% vs. 63%) in NHPs. Although AMR in an allograft can often be reversed, to our knowledge there is no report of its successful reversal in a pig xenograft. As there is less experience in preventing or reversing AMR in models of xenotransplantation, the results of studies in patients with allografts provide more information. These include (i) depletion or neutralization of serum anti-donor antibodies, (ii) inhibition of complement activation, (iii) therapies targeting B or plasma cells, and (iv) anti-inflammatory therapy. Depletion or neutralization of anti-pig antibody, for example, by plasmapheresis, is effective in depleting antibodies, but they recover within days. IgG-degrading enzymes do not deplete IgM. Despite the expression of human complement-regulatory proteins on the pig graft, inhibition of systemic complement activation may be necessary, particularly if AMR is to be reversed. Potential therapies include (i) inhibition of complement activation (e.g., by IVIg, C1 INH, or an anti-C5 antibody), but some complement inhibitors are not effective in NHPs, for example, eculizumab. Possible B cell-targeted therapies include (i) B cell depletion, (ii) plasma cell depletion, (iii) modulation of B cell activation, and (iv) enhancing the generation of regulatory B and/or T cells. Among anti-inflammatory agents, anti-IL6R mAb and TNF blockers are increasingly being tested in xenotransplantation models, but with no definitive evidence that they reverse AMR. Increasing attention should be directed toward testing combinations of the above therapies. We suggest that treatment with a systemic complement inhibitor is likely to be most effective, possibly combined with anti-inflammatory agents (if these are not already being administered). Ultimately, it may require further genetic engineering of the organ-source pig to resolve the problem entirely, for example, knockout or knockdown of SLA, and/or expression of PD-L1, HLA E, and/or HLA-G.

Curbing Proteastasis to Combat Antibody-Mediated Rejection Post Lung Transplant

Lung transplantation (LTx) has emerged as the treatment of choice for patients suffering from end-stage lung disease all over the past 35 years. Despite ameliorated early survival with a median survival of 6.5 years, its long-term outcomes are dissatisfactory. Although antibody-mediated rejection (AMR) remained “the Achilles heel of LTx,” yet we have not attained consensus on the optimal therapeutic approach. The aim of this review article is to address the upcoming role of proteasome inhibitor drugs in managing AMR post-LTx.

Quick preparation of ABO-incompatible living donor liver transplantation for acute liver failure

Acute liver failure is life-threatening and has to be treated by liver transplantation urgently. When deceased donors or ABO-compatible living donors are not available, ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) becomes the only choice. How to prepare ABO-I LDLT urgently is an unsolved issue. A quick preparation regimen was designed, which was consisted of bortezomib (3.5 mg) injection to deplete plasma cells and plasma exchange to achieve isoagglutinin titer ≤ 1: 64 just prior to liver transplantation and followed by rituximab (375 mg/m2 ) on post-operative day 1 to deplete B-cells. Eight patients received this quick preparation regimen to undergo ABO-I LDLT for acute liver failure from 2012 to 2019. They aged between 50 and 60 years. The median MELD score was 39 with a range from 35 to 48. It took 4.75 ± 1.58 days to prepare such an urgent ABO-I LDLT. All the patients had successful liver transplantations, but one patient died of antibody-mediated rejection at post-operative month 6. The 3-month, 6-month, and 1-year graft/patient survival were 100%, 87.5%, and 75%, respectively. In conclusion, this quick preparation regimen can reduce isoagglutinin titers quickly and make timely ABO-I LDLT feasible for acute liver failure.

Immunotherapy for Refractory Autoimmune Encephalitis

Autoimmune encephalitis (AE) is an immune-mediated disease involving the central nervous system, usually caused by antigen-antibody reactions. With the advent of autoantibody-associated diseases, AE has become a hot research frontier in neuroimmunology. The first-line conventional treatments of autoimmune encephalitis consist of steroids, intravenous immunoglobulin (IVIG), plasma exchange (PLEX), and second-line therapy includes rituximab. Despite considerable research and expanding clinical experience, current treatments are still ineffective for a significant number of patients. Although there is no clear consensus, clinical trial evidence limited, and the level of evidence for some of the drugs based on single reports, third-line therapy is a viable alternative for refractory encephalitis patients. With the current rapid research progress, a breakthrough in the treatment of AE is critical. This article aims to review the third-line therapy for refractory AE

Antibody-Mediated Rejection in Adult Liver Transplant Recipients: A Case Series and Literature Review

Antibody-mediated rejection is a rare complication following liver transplantation and there is a lack of a comprehensive treatment strategy to provide detailed information about the dose and duration of antibody-mediated rejection treatment. This study describes eight adult liver transplantation recipients who developed antibody-mediated rejection between 2002 and 2021 in our center, as well as a review of the literature on the reported cases of antibody-mediated rejection in liver transplantation recipients. Our center's medical records were reviewed retrospectively to extract the necessary data on patients' characteristics, management, and outcomes. Then, a comprehensive search using Embase, PubMed, Web of Science, Cochrane library, and Google Scholar databases was conducted without time limitation until June, 2021. Finally, a stepwise protocol was developed for managing acute, chronic, and recurrent antibody-mediated rejection in liver transplantation patients, based on our own experience, reported cases in the literature, and data from kidney transplantation. By review of the literature, 24 case studies containing 64 patients were identified and their management strategies and outcomes were evaluated. Although, various combinations of corticosteroids, plasma exchange, intravenous immunoglobulin, and biological agents are used in the treatment of acute antibody-mediated rejection in liver transplantation, treatment strategies should be classified according to the type, severity, and the timing of its onset. Given the importance of early treatment, rituximab and/or bortezomib should be started as soon as possible if no improvement in liver enzymes/bilirubin is observed during the initial treatment strategy using corticosteroids, plasma exchange and intravenous immunoglobulin. This article is protected by copyright. All rights reserved.