ABO-incompatible Living Kidney Transplantation Research Articles

P.063: Comparison of preoperative desensitization strategies in ABO-incompatible living kidney transplantation and subsequent COVID-19 infection.

P.063: Comparison of preoperative desensitization strategies in ABO-incompatible living kidney transplantation and subsequent COVID-19 infection.

Comparison of estimated blood loss during living kidney transplantation according to the number of double-filtration plasmapheresis

BackgroundPlasmapheresis is an important preoperative desensitization treatment for ABO-incompatible living kidney transplantation. However, in cases with plasma exchange therapy (PET), it is necessary to consider the risks of perioperative bleeding and healthcare economic costs. This study investigated the association between intraoperative blood loss and the frequency of preoperative double-filtration plasmapheresis (DFPP) and explored the correlation between DFPP frequency and coagulation factors. Furthermore, the study examined the incidence of perioperative bleeding complications.MethodsWe enrolled 294 patients (205 men and 89 women) who underwent living kidney transplantation at our institution between January 2020 and March 2023, without PET or with only DFPP performed as PET. A single dose of rituximab (200 mg) was administered to ABO-incompatible living kidney transplant patients within 7 days before transplantation. In these patients, PET was performed until anti-blood group IgG and IgM antibody titers were reduced to 32 times or less.ResultsThe intraoperative blood loss increased in accordance with the DFPP sessions. The amount of bleeding significantly increased when DFPP was performed ≥ 2 sessions. Considering this, we initiated serum fibrinogen level measurements from the middle of the study and observed that serum fibrinogen levels decreased in correlation with the number of DFPP sessions. Fibrinogen levels dropped to critical levels (< 100 mg/dL) after three sessions of DFPP. Within the entire cohort, four patients (1.4%) underwent post-transplantation hematoma removal surgery, and among them, three had received DFPP before transplantation.ConclusionsThe number of DFPP procedures was associated with the amount of bleeding and serum fibrinogen levels during living kidney transplantation.

A Case Report of a Kidney Transplant Recipient With Organizing Pneumonia After Graft Loss

We present a case of a 68-year-old male patient who underwent ABO-incompatible living kidney transplantation from his wife because of immunoglobulin A nephropathy 13 years ago. Over time, the patient showed a gradual decline in graft function and required reinitiation of hemodialysis because of fluid overload, which led to his admission to our hospital. An arteriovenous fistula was created, and subsequently, hemodialysis therapy was started. Because he had chronic cytomegalovirus retinopathy and thrombotic microangiopathy due to immunosuppressive therapy at admission, mycophenolate mofetil and tacrolimus were discontinued during hemodialysis initiation. Only low-dose prednisolone was continued. One week later, the patient had a fever, and chest computed tomography revealed bilateral pneumonia, which was not improved by antibiotics. The patient was diagnosed with organized pneumonia. After ruling out opportunistic infection, including pneumocystis pneumonia, increased doses of prednisolone resulted in the remission of organizing pneumonia.

Feasibility of the automated column agglutination technique for titration of anti‐A/B antibodies in ABO‐incompatible living kidney transplantation

Quantitative measurement of anti-A/-B antibody titers is important during ABO-incompatible living kidney transplantation (ABOi-LKT). We conducted a multi-institutional study to measure the antibody titers using the automated column agglutination technique (auto-CAT) and tube test (TT) method in ABOi-LKT recipients. Statistical analysis was performed to evaluate the two methods. We examined 111 samples from 35 ABOi-LKT recipients at four institutions. The correlation coefficient of the two methods was >0.9; the concordance rate and clinically acceptable concordance rate for the IgG titers were 60.4% and 88.3%, respectively. Perioperative status did not influence the statistical significance. Parallel changes were observed in the IgG antibody titers measured using the auto-CAT or TT technique by desensitizing therapy in time-course monitoring. Auto-CAT is comparable with the TT technique and is feasible for IgG anti-A/B antibody titration in ABOi-LKT recipients.

Effect of rituximab dose on induction therapy in ABO-incompatible living kidney transplantation: A network meta-analysis.

Background:Rituximab is an induction immunosuppressant essential for ABO-incompatible kidney transplantation (ABOi KT). However, studies on its dosing, which differs among countries and transplant centers, are lacking. Therefore, we retrospectively investigated the effectiveness of the induction dose of rituximab against patient mortality, graft failure, and adverse events.Methods:We included the studies referring to at least 2 of eligible induction doses (200 mg, 200–500 mg, or 500 mg) of rituximab during ABOi KT and relevant outcomes such as patient survival, graft failure, and bacterial and viral infections. We performed direct and indirect network meta-analyses using Bayesian models and ranked different rituximab doses using generation mixed treatment comparison. Publications were retrieved using CENTRAL, MEDLINE, EMBASE, and Science Citation Index Expanded databases from 1970 to February 2020 and analyzed. The GRADE of network meta-analysis approach specified 4 levels of certainty for a given result: high, moderate, low, and very low.Results:Among the 4256 patients from 21 trials, glomerular filtration rate, graft loss, antibody-mediated rejection, T-cell mediated rejection, fungal infection, bacterial infection, and CMV infection did not differ among ABOi groups treated with different rituximab doses. The effect on mortality was significantly higher in rituximab 200 to 500 mg, and rituximab 500 mg groups (odds ratios [OR] 3.5, 95% CrI: 1.3–9.8, and OR 3.0, 95% CrI 1.1–9.8), but not in rituximab 20 mg group (OR 0.45, 95% CrI 0.036–2.5). The incidence of BK virus was significantly lower in the rituximab 200-mg group than in the other groups.Discussion:In ABO-incompatible kidney transplantation, low-dose rituximab is more efficacious than higher doses and reduces serious infection risks. Additional randomized controlled trials might be needed to confirm these findings due to small sample size.

ABO-incompatible living kidney transplantation.

ABO-incompatible living kidney transplantation is nowadays a routine procedure to expand living donor pool. The past decades have seen the evolution of desensitization protocol and immunosuppression regimen. Despite increased bleeding events, infectious complications, and rejection episodes reported in some studies, favorable graft and patient survival rate are now achieved, regardless of various protocols among transplant centers. Several issues such as the usage of rituximab and standardization of blood group antibody titration remain to be settled. The deposition of C4d is no longer the histopathologic hallmark of antibody-mediated rejection, which have inspired innovative strategies of peripheral molecular screening and the improvement of histological diagnosis of AMR (antibody-mediated rejection). The better understanding of the underlying mechanism might facilitate the distinction and therapeutic schemes of AMR.

Latest developments in living kidney donation.

Although the first successful kidney transplantation 65 years ago was performed with a living donor kidney, the number of living donor kidney transplantations has increased especially during the last 2 decades. The enlargement of living donor programs was made possible by new modes of living donation and by expansion of the living donor pool. At the same time, the long-term risks of kidney donation have been better delineated. In this review, the latest developments on these topics are summarized. While the results of ABO-incompatible living kidney transplantation are superior to those of deceased donor transplantation, recent meta-analyses show a reduced patient and graft survival as compared with ABO compatible transplantation as well as increased risk of severe infection and bleeding. Kidney paired donation programs can be extended by including compatible couples and by advanced donation, although the latter raises ethical concerns. Living donors appear to have a higher risk of end-stage renal disease and this is especially true for obese donors and probably also for black donors with an APOL1 high-risk genotype. The importance of psychosocial outcomes after living kidney donation is increasingly recognized. Living donor kidney transplantation remains the optimal treatment option for patients with end-stage renal disease. To increase the donor pool, a well developed paired kidney donation program and sufficient reimbursement of costs associated with donation are essential ingredients. Other ways of expanding the donor pool, such as ABO-incompatible transplantation, use of higher risk donors, providing donors with financial incentives and advanced donation are associated with medical, ethical and logistical complications. There should be a careful selection and follow-up of living kidney donors with attention for medical consequences as well as for psychosocial outcomes.

Unexpected presentation and surgical salvage of transplant renal artery dissection caused by vascular clamping: a case report

BackgroundTransplant renal artery dissection is a rare and serious event that can cause allograft dysfunction and activation of the renin–mediated renovascular hypertension. Most cases are induced by percutaneous transluminal angioplasty, arteriosclerotic disease, or fibromuscular dysplasia. We observed a case of transplant renal artery dissection induced by unusual causes during kidney transplantation.Case presentationA 35-year-old woman, whose mother donated a kidney to her, underwent ABO-incompatible living kidney transplantation. The allograft had one renal artery and vein that were anastomosed to the internal iliac artery and external iliac vein, respectively. Although careful handling was performed in all procedures including vascular clamping, Doppler ultrasonography (US) immediately after reperfusion showed an increase in the systolic blood velocity and urine output was not observed. Arterial anastomotic stenosis was suspected, but upon exploration, a renal artery dissection was detected in the middle portion of the donor artery. The part of the transplant renal artery was resected, and cold reflux was started again. At the resected part of transplant renal artery, dissection was identified. After re-anastomosis, Doppler US revealed that the blood flow of the renal artery was adequate without an increase in the systolic blood velocity, and sufficient blood flow was observed throughout the allograft. Urine output was also observed as soon as blood flow returned, and serum creatinine level decreased to 0.95 mg/dL after surgery. The cause of injury might have been vascular clamping in order to drain the air and check bleeding at the anastomosis.ConclusionsOur case reaffirmed that careful handling is needed in all procedures, including donor nephrectomy, cannulation for transplant perfusion, vascular clamping, and anastomosis, even without any evidence of arteriosclerosis. Kidney transplant recipients commonly have atherosclerosis and hypertension, which are risk factors for arterial dissection. Early diagnosis and intervention can lead to the prevention of allograft dysfunction. Therefore, close monitoring of allograft blood flow by Doppler US during surgery should be considered.

Association between response to rituximab and antibody-mediated rejection in ABO-incompatible living kidney transplantation.

To examine the association of response to rituximab and the incidence of antibody-mediated rejection in preconditioning of rituximab and plasma exchange without post-transplant plasmapheresis in patients undergoing ABO-incompatible living kidney transplantation. A total of 115 patients who underwent ABO-incompatible living kidney transplantation at Tokyo Women's Medical University Hospital, Tokyo, Japan, were divided into two groups based on the response to rituximab: good response (n=75) or poor response (n=40). The rituximab good response and poor response patients were defined as patients whose CD19+ cells were non-detected (0%) and detected on the day of transplantation (2-5days, median 3days, after rituximab administration), respectively. Rituximab response and anti-A/B blood antibody titer after plasmapheresis were significant risk factors for antibody-mediated rejection (P=0.036, 0.045, respectively). The occurrence of antibody-mediated rejection was higher in the poor response group than in the good response group (22.5% vs 8.0%; P=0.028). The 14-day, 3-month and 1-year cumulative incidence of antibody-mediated rejection was 2.7%, 5.3% and 8.0% in the good response group, and 17.5%, 20.0% and 22.5% in the poor response group after ABO-incompatible living kidney transplantation. The patient survival was not significantly different between the two groups. However, graft survival 1month after transplantation was lower in the poor response group. There is no significant difference in graft function and in the incidence of complications, including infection, after transplantation between the two groups. Antibody-mediated rejection after ABO-incompatible living kidney transplantation was significantly associated with the response to rituximab in our preconditioning protocol.

Current protocols and outcomes of ABO-incompatible kidney transplantation based on a single-center experience.

ABO-incompatible living kidney transplantation (ABO-ILKT) is an effective option for increasing living kidney transplant opportunities. ABO-ILKT has been conducted in our institution since 1989 to widen the indication for living kidney transplantation. ABO-ILKT is considered to require extra treatment, and it has increased risks compared with ABO-compatible living kidney transplantation (ABO-CLKT). In the past two decades, some protocols have removed anti-blood-type antibodies to prevent the production of antibodies. Additionally, we have made considerable changes to our ABO-ILKT protocol as new immunosuppressive agents have been developed. Consequently, increased immunosuppression and immunological understanding have helped shape recent desensitization protocols. Herein, we review the history, therapeutic strategy, pathology, and future directions of ABO-ILKT. Our standard immunosuppressive regimen and desensitization protocol for ABO-ILKT recipients consist of low doses of tacrolimus (TAC), mycophenolate mofetil (MMF), and rituximab; several sessions of double filtration plasmapheresis; and basiliximab induction. We do not use thymoglobulin induction, intravenous immunoglobulin, or prophylactic post-transplant plasmapheresis. Recently, ABO-ILKT has been recognized as a useful alternative therapy for end-stage kidney disease with ABO-incompatibility, and its outcome is comparable to that of ABO-CLKT.

Outcomes of Pediatric ABO-incompatible Living Kidney Transplantations From 2002 to 2015: An Analysis of the Japanese Kidney Transplant Registry.

Extensive data have been accumulated for adults who have undergone ABO-incompatible (ABOi)-living kidney transplantation (LKT). In contrast, available published data on pediatric recipients who underwent ABOi-LKT from the early to middle 2000s is very limited. Thus, pediatric ABOi-LKT has remained relatively rare, and there is a lack of large, multicenter data. We analyzed data from the Japanese Kidney Transplant Registry to clarify the patient and graft outcomes of pediatric recipients who underwent ABOi-LKT from 2002 to 2015. A total of 102 ABOi and 788 ABO-compatible (ABOc) recipients were identified in this study. All recipients had received basiliximab and a triple immunosuppressive protocol comprising calcineurin inhibitors, mycophenolate mofetil, and steroids. The ABOi recipients also received preconditioning therapies including B-cell depletion by a splenectomy or rituximab treatment and therapeutic apheresis. Death rates for ABOi and ABOc recipients were 0.17 versus 0.17 deaths per 100 patient-years. Graft loss rates for ABOi and ABOc recipients were 1.58 versus 1.45 events per 100 patient-years. No particular causes of death or graft loss predominantly affected ABOi or ABOc recipients. The results of this registry analysis suggest that pediatric ABOi-LKT can be performed efficiently. Although further studies are clearly required to perform pediatric ABOi-LKT more safely and less invasively, ABOi-LKT is now an acceptable treatment for pediatric patients with end-stage renal disease.

A CASE OF ABO INCOMPATIBLE LIVING KIDNEY TRANSPLANTATION IN A PATIENT WITH SELECTIVE IgA DEFICIENCY

We report a case of ABO incompatible living kidney transplantation in a 45-year-old man with selective IgA deficiency. He has been on hemodialysis for 1 year due to chronic renal failure. Although the serum anti-IgA antibody was negative, he has experienced anaphylactic reaction to red blood cell product in the past. Before the transplantation, we performed double filtration plasmapheresis for two times, but didn't performed plasma exchange, considering the possibility of producing anti-IgA antibody and anaphylactic reaction. He underwent kidney transplantation from his mother without anaphylactic reaction, following to the recirculation of renal blood flow. He was discharged on the 29th postoperative day when the serum creatinine level was 1.2 mg/dL. The graft function was stable at 8 months after transplantation with no evidence of rejection and infection.

Calcineurin Inhibitor–Induced Pain Syndrome in ABO-Incompatible Living Kidney Transplantation: A Case Report

BackgroundCalcineurin-inhibitor–induced pain syndrome (CIPS) was used as a reference in the literature as reflex sympathetic dystrophy syndrome related to calcineurin inhibitors. Much of the literature describes CIPS that occurred after kidney and bone marrow transplantation. We describe a rare case of CIPS in induction immunosuppression before kidney transplantation, under administration of an anti-rheumatoid drug. MethodsA 53-year-old woman had pre-status of ABO-incompatible living kidney transplantation. The patient had rheumatoid arthritis, but that was well-controlled with salazosulfapyridine as an anti-rheumatoid drug. Fourteen days before transplantation, she received induction immunosuppressive therapy consisting of tacrolimus (TAC) and mycophenolate mofetil (MMF) and she stopped taking salazosulfapyridine. The third day after that treatment, she had a high fever, fatigue, and joint pains of the knees, elbows, and wrists. ResultsWhen the patient stopped taking TAC and MMF and started taking salazosulfapyridine again, she soon recovered. Next, we challenged same induction immunosuppression therapy with administration of salazosulfapyridine; however, the patient had the same symptom. We considered that the symptom was caused by TAC or MMF, and we did not challenge-test each drug. We found that taking only TAC caused the same symptom for the patient. Also, we challenged cyclosporine (CsA) with MMF and confirmed that she did not have the symptom. ConclusionsWe decided that drugs of the induction immunosuppression therapy were CsA, MMF, prednisolone, and basiliximab. The patient received induction therapy with plasmapheresis and rituximab in addition to the above-mentioned drugs, and we performed ABO-incompatible kidney transplantation for her. The post-surgical course was good, without acute rejection, and she had no pain.

ABO-Incompatible Living Kidney Transplants: Evolution of Outcomes and Immunosuppressive Management.

ABO-incompatible living kidney transplantation (ABO-ILKT) has steadily become more widespread. However, the optimal immunosuppressive regimen for ABO-ILKT remains uncertain. We aimed to determine the longitudinal changes in the outcomes from ABO-ILKT compared with those from ABO-compatible living kidney transplantation (ABO-CLKT) over the last 25 years. Of 1195 patients who underwent living kidney transplantations (LKT) at our institute between 1989 and 2013, 1032-including 247 ABO-ILKT and 785 ABO-CLKT cases-were evaluated for graft survival, patient survival, infectious adverse events, and renal function. The patients were divided into four groups according to the transplantation era and ABO-compatibility. In the past decade, ABO-ILKT and ABO-CLKT recipients yielded almost equivalent outcomes with respect to the 9-year graft survival rates, which were 86.9% and 92.0%, respectively (hazard ratio [HR] 1.38, 95% confidence interval [CI] 0.59-3.22, p = 0.455). The graft survival rate for ABO-ILKT conducted between 2005 and 2013 was better than that for ABO-ILKT conducted between 1998 and 2004 (HR 0.30, 95% CI 0.13-0.72, p = 0.007). ABO-ILKT recipients showed substantial improvements in the graft survival rate over time. Graft survival was almost identical over the past decade, regardless of ABO-incompatibility. Currently, ABO-ILKT is an acceptable treatment for patients with end-stage renal disease.

Excellent Long-Term Outcome of ABO-Incompatible Living Donor Kidney Transplantation; a Single Center Experience for Over 20 Years

Background: Although kidney transplantation is the most reassuring treatment for patients with end-stage renal disease (ESRD), shortage of organ donation in Japan is crucial. This issue has forced widening of indications for kidney transplantation. Therefore, ABO-incompatible living kidney transplantation (ABO-ILKT) has been a popular alternative to deceased kidney transplantation. In this retrospective single center study, we analyzed the long-term graft survival of ABO-incompatible living donor kidney transplant for over 20 years by comparing with ABO-compatible living kidney transplantation (ABO-CLKT) as control. Methods: In all, 1020 patients with ESRD underwent living donor kidney transplantation at our institute between 1989 and 2011. 238 cases were ABO-ILKT and 782 cases were ABO-CLKT. The mean age of ABO-ILKT group was 42.1 years (range 17 to 75), with 146 males and 92 females. Plasmapheresis and immunoadsorption were carried out to remove the anti-AB antibodies before the kidney transplantation. In the induction phase, most of the recipients received CNI (tacrolimus or cyclosporine)-based immunosuppression including methylprednisolone and mycophenolate mofetil. After 2002, all patients received basiliximab perioperatively. Between 1986 and 2004, splenectomy was performed at the time of ABO-ILKT. Thereafter, alternative to splenectomy, rituxamab was administered prior to ABO-ILKT. Log-rank testing was performed to determine differences in survival data. Results: Patient survival of ABO-ILKT at 1, 5, 10, 15, and 20 years post-transplant were 97.8, 97.2, 92.0, 87.4, and 87.4%, respectively. Graft survival of ABO-ILKT at 1, 5, 10, 15, and 20 years post-transplant were 90.4, 86.9, 69.6, 55.6, and 48.4%, respectively. Whereas, Graft survival of ABO-CLKT at 1, 5, 10, 15, and 20 years post-transplant were 97.4, 88.2, 75.5, 64.7, and 58.1%, respectively. Patient survival had no significant difference from that of ABO-CLKT (p=0.741). Although graft survival of ABO-ILKT at 20 years post-transplant had approximately 10% reduction from that of ABO-CLKT, there was no statistical difference between ABO-ILKT and ABO-CLKT (p=0.08). Conclusion: Despite receiving intensified desensitization protocol compared to ABO-CLKT, ABO-ILKT is a acceptable treatment for patients with ESRD in terms of patient survival and graft survival.

De novo minimal change disease after ABO‐incompatible kidney transplantation

We report the clinical and pathological findings of a case of de novo minimal change disease (MCD) after ABO-incompatible living kidney transplantation. A 62-yr-old man with end-stage renal disease associated with type I diabetes received ABO-incompatible kidney transplantation from his 58-yr-old wife. Although allograft function was excellent immediately after surgery, massive proteinuria (35 g/d) appeared on post-transplantation day 5. After the allograft biopsy taken on post-transplantation day 6, he was treated with 12 cycles of plasma exchange, but the nephrotic-range proteinuria showed no remission. The biopsy specimen showed no significant pathological findings on light microscopy, but electron microscopy showed diffuse effacement of podocyte foot processes. Based on the diagnosis of de novo MCD, the patient received intravenous methylprednisolone pulse therapy, followed by high-dose steroid maintenance therapy. The steroid therapy induced complete remission of nephrotic syndrome and stable allograft function immediately, which was also maintained at one yr after the transplantation.

Kidney Transplantation of Living Unrelated Donor-Recipient Combinations

IntroductionAccording to the Japanese renal transplant registry in 2009, there were 1123 living kidney transplantations (LKT), including 35% from spouses (husband/wife). Up to the present in Japan, biologically living unrelated donors (LURD) are most frequently spouses. This study summarized our experience with LURD, especially spousal, kidney transplantation. Patients and methodsWe performed 112 cases of LKT between April 2003 and March 2011, including 44 (39%) from spouses and two from other LURD. The other 66 cases received kidneys from living related donors (LRD). We divided the patients into two groups: 44 patients (group 1) received kidneys from spouses (LURD) and 66 (group 2) from LRD. During the induction phase, tacrolimus or cyclosporine, mycophenolate mofetil, and methylprednisolone were prescribed for immunosuppression. Basiliximab was administered on postoperative days 0 and 4. In ABO-incompatible LKT, plasmapheresis was performed to remove anti-AB antibodies prior to LKT; splenectomy or rituximab administration, at the time of or before LKT. ResultsAmong group 1, one patient died with a functioning graft and one lost her graft. Among group 2, one patient died with a functioning graft and one lost his graft. The incidences of an acute rejection episode were 31.8% and 24.2% in groups 1 and 2, respectively. There were three cases of antibody-mediated rejection in group 1. No patient experienced a lethal infectious complication. ConclusionsOur results demonstrated that spousal LKT (LURD) was equivalent to LKT from LRD. In response to the shortage of deceased donors, LKT between married couples and from ABO-incompatible donors will spread in Japan.

Mechanism of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation: Which Anti-A/Anti-B Antibodies are Responsible, Natural or de Novo?

Mechanism of Acute Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation: Which Anti-A/Anti-B Antibodies are Responsible, Natural or de Novo?

ＡＢＯ不適合生体腎移植を予定した多発性嚢胞腎症例に対し経皮的腎動脈塞栓術による腎縮小が有用であった１例

28-year-old female received dialysis treatment due to chronic renal failure caused by polycystic kidney disease. Later, she underwent a laparoscopic splenectomy and ABO incompatible living kidney transplantation successfully following bilateral renal contraction therapy with renal transcatheter arterial embolization (renal TAE). A unilateral or bilateral native nephrectomy of a massively enlarged kidney performed at the time of renal transplantation is a common treatment in polycystic kidney patients scheduled for transplantation. On the other hand, when treated with renal TAE, such patients can avoid a laparotomy, which provides several advantages when undergoing peritoneal dialysis in the future or a laparoscopic splenectomy prior to ABO incompatible kidney transplantation. Furthermore, we consider that bilateral renal TAE is necessary for polycystic kidney patients prior to renal transplantation for a variety of reasons, including problems associated with contrast nephropathy if renal TAE for left kidney is remained after renal transplantation.

Specific issues in living donor kidney transplantation: ABO – incompatibility

Abstract Pre-emptive living kidney transplantation is the best choice of therapy to treat patients with advanced renal insufficiency. Unfortunately in up to one third of all cases kidney donation was refused due to blood group incompatibility. Limitations in donor availability for kidney transplantation therefore require that ABO-incompatible transplantation is safely established. This has changed when a new protocol was introduced in Stockholm, Sweden, in 2001. Almost 400 ABO-incompatible transplantations have since been performed in more than 20 centers with this protocol in Europe. ABO-incompatible living kidney transplantation can now be offered to our patients with advanced kidney disease as a safe procedure. To get more insight into the role ABO-incompatible organ transplantation might play in the near future transplantation centers currently involved in these processes should share their data to answer the unresolved issues we are concerned.