ABO blood type incompatible kidney transplantation without splenectomy prepared with plasma exchange and rituximab

Advancement in preoperative desensitization therapy for ABO incompatible kidney transplantation recipients

ABO incompatibility has long been considered an absolute contraindication for kidney transplantation. However, with the increasing number of patients with ESRD in recent years, ABO-incompatible kidney transplantation (ABOi-KT) has expanded the types of donors by crossing the blood group barrier through preoperative desensitization therapy. At present, the desensitization protocols consist of removal of preexisting ABO blood group antibody titers and prevention of ABO blood group antibody return. Studies have suggested similar patient and graft survival among ABOi-KT and ABOc-KT recipients. In this review, we will summarize the effective desensitization regimens of ABOi-KT, aiming to explore effective ways to improve the success rate and the long-term survival rate of ABOi-KT recipients.

Low-dose Rituximab and Thymoglobulin Induction With Steroid-free Maintenance Immunosuppression and Protocol Biopsies Improves Long-term Patient and Graft Survival After Kidney Transplantation: Survival and Safety Outcomes in More Than 1100 Patients From a Single Center

Background.

Steroid-free maintenance immunosuppression after kidney transplantation provides acceptable patient and graft survival and minimizes steroid-associated side effects among recipients with a low immunological risk. However, the long-term outcomes of such protocols, incorporating low-dose rituximab and thymoglobulin induction along with protocol biopsies, in non-European populations remains underreported.

Methods.

We retrospectively analyzed 1142 consecutive kidney transplantations conducted at our center from July 2005 to October 2017. Immunosuppression protocol included induction with thymoglobulin and low-dose preoperative rituximab. Maintenance immunosuppression consisted of tacrolimus and mycophenolate mofetil; prednisolone was discontinued on postoperative day 5. Protocol biopsies were carried out at 3 months and at 1, 5, and 10 years after transplantation—in addition to the indicated biopsies. The 12-year patient and graft survival and posttransplantation complications were studied.

Results.

The analysis of outcomes was conducted for 1111 transplant recipients. Patients (70.59%) remained steroid-free at 12 years after transplantation. The patient survival rates at 1, 5, and 12 years were 97.7%, 94.8%, and 92.4%, respectively. The corresponding graft survival rates were 97.2%, 90.9%, and 86.1%, respectively. Biopsy-proven acute rejection occurred in 12.7% of recipients, including 3.5% subclinical rejections. The cumulative incidence of graft loss was 6.56% at 12.3 years. The overall incidence of death was 5.3%.

Conclusions.

Steroid-free maintenance immunosuppression was associated with excellent long-term patient and graft survival rates and reduced incidence of prednisolone-related side effects, despite acceptable rejection rates. Low-dose rituximab with thymoglobulin induction with immediate steroid withdrawal and surveillance biopsies resulted in excellent long-term outcomes in our single-center experience.

Production of human blood group B antigen epitope conjugated protein in Escherichia coli and utilization of the adsorption blood group B antibody

Background

In the process of ABO-incompatible (ABOi) organ transplantation, removal of anti-A and/or B antibodies from blood plasma is a promising method to overcome hyperacute rejection and allograft loss caused by the immune response between anti-A and/or B antibodies and the A and/or B antigens in the recipient. Although there are commercial columns to do this work, the application is still limited because of the high production cost.

Results

In this study, the PglB glycosylation pathway from Campylobacter jejuni was exploited to produce glycoprotein conjugated with Escherichia coli O86:B7 O-antigen, which bears the blood group B antigen epitope to absorb blood group B antibody in blood. The titers of blood group B antibody were reduced to a safe level without changing the clotting function of plasma after glycoprotein absorption of B antibodies in the plasma.

Conclusions

We developed a feasible strategy for the specific adsorption/removal of blood group antibodies. This method will be useful in ABOi organ transplantation and universal blood transfusion.

Electronic supplementary material

The online version of this article (doi:10.1186/s12934-016-0538-z) contains supplementary material, which is available to authorized users.

Preconditioning Therapy in ABO-Incompatible Living Kidney Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

ABO-incompatible (ABOi) kidney transplantation is now an established form of renal replacement therapy, but the efficacy and safety of the different types of preconditioning therapies are unclear. We aimed to synthesize the totality of the published evidence about the effects of any form of preconditioning therapies in living donor ABOi kidney transplantation on graft and patient outcomes.

METHODS

We searched MEDLINE, Embase, and Clinicaltrial.gov databases (inception through June 2015) to identify all studies that described the outcomes of adult living donor ABOi kidney transplantations using any form of preconditioning therapies. Two independent reviewers identified studies, extracted data, and assessed the risk of bias. Data were summarized using the random effects model, and heterogeneity was explored using subgroup analyses. We assessed confidence in the evidence using the Grading of Recommendations Assessment, Development, and Evaluation framework.

RESULTS

Eighty-three studies (54 case reports and case series, 25 cohort, 2 case-control, and 2 registry studies) involving 4810 ABOi transplant recipients were identified. Overall, confidence in the available evidence was low. During a mean follow-up time of 28 (standard deviation [SD], 26.6) months, the overall graft survival for recipients who received immunoadsorption or apheresis was 94.1% (95% confidence interval [95%CI], 88.2%-97.1%) and 88.0% (95% CI, 82.6%-91.8%), respectively. For those who received rituximab or underwent splenectomy, the overall graft survival was 94.5% (95% CI, 91.6%-96.5%) and 79.7% (95% CI, 72.9%-85.1%), respectively. Data on other longer-term outcomes, including malignancy, were sparse.

CONCLUSIONS

Rituximab or immunoadsorption appeared to be promising preconditioning strategies before ABOi kidney transplantation. However, the overall quality of evidence and the confidence in the observed treatment effects are low. The increased use of ABOi kidney transplantation needs to be matched with randomized trials of different types, dosing, and frequency of preconditioning therapies so that this scarce resource can be used most effectively and efficiently.

Current progress in ABO-incompatible kidney transplantation

ABO-incompatible kidney transplantation (ABOi KT) was introduced to expand the donor pool and minimize shortage of kidneys for transplantation. Because improved outcomes of ABOi KT were reported in Japan in the early 2000s, the number of ABOi KTs has been increasing worldwide. In addition, a better understanding of immune pathogenesis and subsequent aggressive immunosuppression has helped to make effective desensitization protocols. Current strategies of ABOi KT consist of pretransplant antibody removal using plasmapheresis or immunoadsorption to prevent hyperacute rejection and potent maintenance immunosuppression, such as tacrolimus and mycophenolate mofetil, to inhibit antibody-mediated rejection. Recent outcomes of ABOi KT are comparable with ABO-compatible KT. However, there are still many problems to be resolved. Very high anti-ABO antibody producers are difficult to desensitize. In addition, ABOi KT is associated with an increased risk of infection and possibly malignancy due to aggressive immunosuppression. Optimization of desensitization and patient-tailored immunosuppression protocols are needed to achieve better outcomes of ABOi KT. This review provides an overview of the history, immune mechanism, immunosuppressive protocol, outcomes, current obstacles, and future perspectives in ABOi KT.

An update on ABO-incompatible kidney transplantation

ABO-incompatible kidney transplantation is nowadays a well-established procedure to expand living donor transplantation to blood group incompatible donor/recipient constellations. In the last two decades, transplantation protocols evolved to more specific isohaemagglutinin elimination techniques and established competent antirejection protection protocols without the need of splenectomy. ABOi kidney transplantation associated accommodation despite isohaemagglutinin reappearance, C4d positivity of peritubular capillaries as well as the increased incidence of bleeding complications is currently under intense investigation. However, most recent data show excellent graft survival rates equivalent to ABO-compatible kidney transplantation outcome.

ABO incompatible renal transplants: Good or bad?

ABO incompatible kidney transplantation (ABOi-KT) was previously considered to be an absolute contraindication for patients with end-stage kidney disease (ESKD) due to hyperacute rejection related to blood type barrier. Since the first successful series of ABOi-KT was reported, ABOi-KT is performed increasingly all over the world. ABOi-KT has led to an expanded donor pool and reduced the number of patients with ESKD awaiting deceased kidney transplantation (KT). Intensified immunosuppression and immunological understanding has helped to shape current desensitization protocols. Consequently, in recent years, ABOi-KT outcome is comparable to ABO compatible KT (ABOc-KT). However, many questions still remain unanswered. In ABOi-KT, there is an additional residual immunological risk that may lead to allograft damage, despite using current diverse but usually intensified immunosuppressive protocols at the expense of increasing risk of infection and possibly malignancy. Notably, in ABOi-KT, desensitization and antibody reduction therapies have increased the cost of KT. Reassuringly, there has been an evolution in ABOi-KT leading to a simplification of protocols over the last decade. This review provides an overview of the history, outcome, protocol, advantages and disadvantages in ABOi-KT, and focuses on whether ABOi-KT should be recommended as a therapeutic option of KT in the future.

Tailored desensitization strategies in ABO blood group antibody incompatible renal transplantation

ABO blood group incompatible renal transplantation, using desensitization procedures, is an effective strategy. Efforts have been made to reduce desensitization: these are usually applied to all patients indiscriminately. The Guy's Hospital ABO blood group incompatible desensitization regimen uses a tiered approach, tailoring strategy according to initial antibody titres. Sixty-two ABO blood group incompatible living donor transplant recipients were compared with 167 recipients of blood group compatible living donor renal transplants. There were no statistically significant differences in allograft survival rates at 1 or 3 years post-transplant, rejection in the first year post-transplant or renal function in the first 3 years post-transplant. There was a higher rate of death in ABO blood group incompatible transplant recipients - this could be associated with differences in age and HLA mismatch between the two groups. Four ABO blood group incompatible patients experienced antibody-mediated rejection (no episode was associated with a rise in ABO blood group antibodies). Of the patients who received no desensitization, or rituximab alone, none has experienced antibody mediated rejection or experienced allograft loss. Tailoring the use of desensitization in ABO blood group incompatible renal transplantation according to initial ABO blood group antibody titres led to comparable results to blood group compatible transplantation.

Rituximab in renal transplantation

Rituximab is a chimeric anti-CD20 monoclonal antibody that leads to B cell depletion. It is not licensed for use in renal transplantation but is in widespread use in ABO blood group incompatible transplantation. It is an effective treatment for post-transplant lymphoproliferative disorder, and is also used in both HLA antibody incompatible renal transplantation and the treatment of acute rejection. Recent evidence suggests rituximab may prevent the development of chronic antibody mediated rejection. The mechanisms underlying its effects are likely to relate both to long-term effects on plasma cell development and to the impact on B cell modulation of T cell responses. Rituximab (in multiple doses or in combination with other monoclonal antibodies and/or other immunosuppressants) may lead to an increase in infectious complications, although the evidence is not clear. Rarely, the drug can cause a cytokine release syndrome, thrombocytopenia and neutropenia. It has been related to an increased risk of progressive multifocal leucoencephalopathy and, recently, deaths from cardiovascular causes. Trials examining the effects of rituximab in induction therapy for compatible renal transplantation and the treatment of chronic antibody mediated rejection are ongoing. These trials should aid greater understanding of the role of B-cells in the alloresponse to renal transplantation.

Infectious risks and optimal strength of maintenance immunosuppressants in rituximab-treated kidney transplantation

Background

Rituximab, an anti-CD20 antibody, effectively depletes B lymphocytes. It is not clear whether the use of conventional doses of mycophenolate mofetil (MMF), methylprednisolone and tacrolimus as maintenance immunosuppression in rituximab-treated kidney transplantation is associated with increased risk.

Methods

We retrospectively evaluated 67 patients who underwent HLA-sensitized or ABO-incompatible living donor kidney transplantation after one dose of rituximab (200 or 500 mg) (group 1). Eighty-seven kidney transplant recipients who did not require rituximab served as a control (group 2).

Results

Cytomegalovirus infection (16.4 vs. 5.7%, p = 0.031) and pneumonia (9.0 vs. 1.1%, p = 0.043) occurred more often in group 1, and 2 patients of group 1 died of infection. The doses of methylprednisolone and tacrolimus levels of the two groups were not different. MMF dose was reduced when serious infection occurred. The doses of MMF (in grams/day) at the following times postoperatively were lower in group 1 than in group 2: 1 month: 1.26 ± 0.42 vs. 1.40 ± 0.39, p = 0.033; 3 months: 1.14 ± 0.51 vs. 1.36 ± 0.39, p = 0.011; 6 months: 1.07 ± 0.50 vs. 1.30 ± 0.42, p = 0.012; 1 year: 0.88 ± 0.52 vs. 1.19 ± 0.44, p = 0.009; 2 years: 0.69 ± 0.55 vs. 1.25 ± 0.49, p = 0.059, but the reduction of MMF doses did not increase the incidence of acute rejection in group 1 (4.5% in group 1 vs. 9.2% in group 2, p = 0.351). If patients who died with functioning graft were excluded, graft survival was 98.5% in group 1 and 100% in group 2.

Conclusions

Serious infectious complications were increased in rituximab-treated kidney transplant recipients and it might be adequate to reduce the MMF dose from the early postoperative period.

Splenectomy does not offer immunological benefits in ABO-incompatible liver transplantation with a preoperative rituximab

BACKGROUND

Preformed anti-ABO antibodies are primarily responsible for antibody-mediated rejection (AMR) after ABO-incompatible (ABO-I) liver transplantation (LT) resulting in lethal hepatic necrosis and biliary complications. Splenectomy, an integral part of protocol for ABO-I LT, decreases anti-ABO antibodies. With the preoperative rituximab prophylaxis, role of the splenectomy for ABO-I LT is now under debate. We investigated the necessity of splenectomy by retrospective analyses of the short-term anti-ABO antibody response and long-term outcomes of ABO-I LT.

METHODS

Thirty-seven ABO-I LTs performed from May 2006 through July 2009, at Kyoto University Hospital, Kyoto, Japan, were retrospectively analyzed. Twenty-seven patients who underwent splenectomy (splenectomy group) received 329.6 ± 35.8 mg rituximab 17.7 ± 11.9 days before living donor LT. Ten patients without splenectomy (nonsplenectomy group) received 320.0 ± 10.3 mg rituximab 26.6 ± 21.3 days before transplantation. All patients received a posttransplant hepatic artery infusion with prostaglandin E1 and methylprednisolone. Perioperative anti-ABO immunoglobulin M and immunoglobulin G antibody titers, rejections, biliary complications, infections, and survival results were compared.

RESULTS

Preoperative rituximab with plasma exchange effectively reduced anti-ABO antibodies in both patient groups at the time of LT. There was no statistically significant difference observed in anti-ABO immunoglobulin M and immunoglobulin G antibody titers between the "splenectomy" and "nonsplenectomy" groups during the initial 8 weeks. The clinical outcomes, including AMR, biliary complications, infections, and survival, were similar in both the groups.

CONCLUSIONS

Preoperative rituximab effectively decreased the anti-ABO antibodies sufficiently to prevent the AMR irrespective of splenectomy. Splenectomy does not offer any immunological benefit in ABO-I LT with preoperative rituximab.

The low dose of rituximab in ABO-incompatible kidney transplantation without a splenectomy: a single-center experience

PURPOSE

A new protocol for ABO-incompatible (ABO-i) kidney transplantation including rituximab was introduced in January 2005 in our institute. This study reviewed the results and evaluated the use of low-dose rituximab in ABO-i kidney transplantation.

MATERIAL AND METHODS

Seventy-four de novo ABO-i kidney transplantations were performed at Tokyo Women's Medical University between January 2005 and August 2010. The immunosuppressive protocol was consisting of tacrolimus, mycophenolate mofetil, and methylprednisolone. All the patients received induction therapy with basiliximab. The pre-conditioning protocol included double-filtration plasmapheresis and a single dose of rituximab. A dose of 500 mg/body rituximab was initially employed and yielded excellent results (Group I, n = 24). Afterward, the dose of rituximab was reduced to 200 mg/body in January 2007 (Group II, n = 50).

RESULTS

Seventy-four de novo ABO-i recipients were treated with this protocol, and all patients underwent kidney transplantation successfully. Effective elimination of the peripheral blood CD19 cells was observed in both groups. However, the peripheral blood CD19 levels were still low in both groups at 24 months after treatment.

CONCLUSION

The patients in Group II showed excellent results similar to Group I. These results suggest that the low dose of rituximab (200 mg/body) is the sufficient dose in ABO-i kidney transplantation.