Successful ABO-incompatible pediatric liver transplantation utilizing standard immunosuppression with selective postoperative plasmapheresis

Outcomes after ABO incompatible pediatric liver transplantation are comparable to ABO identical/compatible transplant

Background

ABO incompatible (ABOi) liver transplantation (LT) was initially associated with a higher incidence of vascular, biliary, and rejection complications and a lower survival than ABO compatible (ABOc) LT. Various protocols have been proposed to manage anti-isohemagglutinin antibodies and hyperacute rejection. We present our experience with a simplified protocol using only plasmapheresis.

Methods

A retrospective review of all patients who received an ABOi LT at our institution was performed. Comparisons were made based on era (early: 1997-2008, modern: 2009-2020) and severity of disease (status 1 vs. exception PELD at transplant). A pair-matched comparison was done to patients who received an ABOc LT. p < 0.05 was considered significant.

Results

17 patients received 18 ABOi LT (3 retransplants). Median age at transplant was 7.4 months (1.1-28.9). 66.7% patients were listed as status 1. Hepatic artery thrombosis (HAT) occurred in one patient (5.6%), there were 2 cases of portal vein thrombosis (PVT) (11.1%), and 2 biliary strictures (11.1%). Patient and graft survival improved in the ABOi modern era, although not significantly. In the pair-matched comparison, complications (HAT p = 0.29; PVT p = 0.37; biliary complications p = 0.15) and survival rates were similar. Patient and graft survivals were 100% in the non-status 1 ABOi patients compared to 67% (p = 0.11) and 58% (p = 0.081) respectively for patients who were transplanted as status 1.

Conclusion

ABO incompatible liver transplants in infants with a high PELD score have excellent outcomes. Indications for ABO incompatible transplants should be liberalized to prevent deaths on the waiting list or deterioration of children with high PELD scores.

ABO-incompatible Pediatric Liver Transplantation With Antibody and B-cell Depletion-free Immunosuppressive Protocol in High Consanguinity Communities

The success of orthotopic liver transplantation as a life-saving treatment has led to new indications and a greater competition for organ grafts. Pediatric patients with acute liver-related crises can benefit from orthotopic liver transplantation, but organ availability in the limited time can be a major obstacle. Crossing ABO blood group barriers could increase the organs available to such patients.

METHODS

From November 2010 to June 2015, 176 children aged 0.2-to18 y were transplanted in the King Faisal Specialist Hospital and Research Center. Out of those, 19 children were transplanted across blood group barriers (ABO incompatible). The underlying diseases were biliary atresia (n = 6); progressive familial intrahepatic cholestasis type 2 (n = 4); Crigler-Najjar syndrome (n = 3); hepatoblastoma (n = 2); and urea cycle disorder, Caroli disease, cryptogenic cirrhosis, and neonatal sclerosing cholangitis (n = 1 each). Immunosuppression consisted of basiliximab, mycophenolate, tacrolimus, and steroids. Pretransplant prophylactic plasmapheresis, high-dose immunoglobulins, and rituximab were not administered.

RESULTS

The grafts were from living donors (n = 17) and deceased donors (n = 2). Living donor morbidity was nil. The recipient median age was 21 mo (5-70 mo). After a median follow-up of 44 mo, 2 recipients (10%) died because of sepsis, 1 because of uncontrolled acute myeloid leukemia. The overall rejection rate was 7%, and no grafts were lost because of antibody-mediated rejection (AMR). HLA matching was 3.8 of 6 (A, B, DR), and there were 2 patients presented with acute cellular rejection, 1 patient with AMR, and 1 patient with biliary strictures.

CONCLUSIONS

ABO incompatible liver transplantation is a feasible and life-saving option even with antibody and B-cell depletion-free protocol without increasing the risks for AMR. We speculate that this excellent result is most likely because of presence of relatively low titer ABO isoagglutinins and the high HLA match compatibility caused by habit of longstanding interfamilial marriages as typical of Saudi Arabia.

Acute Antibody-mediated Rejection Coexisting With T Cell-mediated Rejection in Pediatric ABO-incompatible Transplantation

The management and outcome of ABO-incompatible (ABO-I) liver transplantation (LT) has been improving over the past few decades. Recently, the introduction of a pathological evaluation of acute antibody-mediated rejection (AMR) for liver allograft has provided a new recognition of allograft rejection in LT.

Methods

One hundred and one pediatric ABO-I LTs performed in our institute were retrospectively analyzed. We assessed the clinical manifestations, diagnosis, and treatment of acute AMR, focusing on the recipient age and pathological findings.

Results

Twelve cases (11.9%) of acute AMR related to ABO-I were observed. Nine cases developed mixed T cell-mediated rejection (TCMR)/AMR. These consisted of 6 patients in the younger age group for whom the preconditioning treatment was not indicated and 4 patients in the older age group to whom rituximab was administered as planned. Two patients in the older age group to whom preoperative rituximab was not administered as planned developed isolated AMR. Acute AMR in the older group required plasma exchange for treatment, regardless of the coexistence of TCMR. In contrast, those in the younger group were successfully treated by intravenous methylprednisolone pulse and intravenous immunoglobulin without plasma exchange, accounting for mild immune reaction.

Conclusions

Acute ABO-I AMR can develop simultaneously with TCMR, even in young patients with a compromised humoral immune response following ABO-I LT. Establishing the accurate diagnosis of AMR with a pathological examination, including component 4d staining, is crucial for optimizing treatment.

When Push Comes to Shove! Emergency ABO-Incompatible Pediatric Living Donor Liver Transplant for Acute Wilson's Disease

ABO-incompatible living donor liver transplantation (ABOi-LDLT) is on the rise as a viable option in countries with limited access to deceased donor grafts. While reported outcomes of ABOi-LT in children are similar to ABO- Compatible liver transplant (ABOc-LT), most children beyond 1-2 years of age will need desensitization to overcome the immunological barrier of incompatible blood groups. The current standard protocol for desensitization is Rituximab that targets B lymphocytes and is given 2-3 weeks prior to LT. However, this timeline may not be feasible in children requiring emergency LT for acute liver failure (ALF) or acute-on-chronic liver failure (ACLF). In this emergency situation of ABOi-LT, a safe multipronged approach may be an acceptable alternative solution. We report a child with acute Wilson's disease with rapidly deteriorating liver function who underwent a successful ABOi-LDLT using a rapid desensitization protocol.

Clinical outcomes after ABO-incompatible liver transplantation: A systematic review and meta-analysis

BACKGROUND

ABO-incompatible liver transplantation (ABOi-LT) is increasingly used to overcome donor shortage. Evidence about disadvantage and advantage in comparison with ABO-compatible liver transplantation (ABOc-LT) needs to be performed in the early and late periods. Herein, We compared the short-term and long-term outcomes between ABOi-LT and ABOc-LT cohorts.

METHODS

We performed a meta-analysis based on the observation studies which included outcomes at ≥1 year after ABOi-LT and ABOc-LT procedures, based on the MEDLINE (via Pubmed), the Cochrance Central Register of Controlled Trials (CENTRAL), and EMBASE (via Ovid) systems. Two researchers independently screened each study according to the pre-established inclusion and exclusion criteria to assess the quality of each study and extracted data from published studies. The primary outcome indicators were all-cause mortality and graft survival at 1, 3 and 5 years after transplantation. In the meta-analysis, we based on the value of heterogeneity using a fixed-effect and a random-effect. A fixed-effect model was used if the value of I2 was less than or equal 50%; and a random-effect model was used if the value of I2 was greater than 50%.

FINDINGS

Out of 335 identified records, 29 records with 10,783 patients with liver transplants; 2137 of them were ABOi-LTs and the remaining 8646 were ABOc-LTs. There was no significant difference at 1-year, 3-year, and 5-year in all-cause mortality, death-censored graft survival and complication incidence rate between ABO-incompatible living donor liver transplantation (ABOi-LDLT) group and ABO-compatible living donor liver transplantation (ABOc-LDLT) group. Compared with ABO-compatible deceased donor liver transplantation (ABOc-DDLT), ABO-incompatible deceased donor liver transplantation (ABOi-DDLT) had a higher 1-year all-cause mortality, and the value of totally pooled odds ratio (OR) was 1.89 (1.28,2.80). However, there was no significant difference at 3-year and 5-year all-cause mortality between ABOi-DDLT and ABOc-DDLT groups. ABOi-DDLT group had a lower 1-year and 5-year death-censored graft survival than ABOc-DDLT, as the value of totally pooled OR was 1.91 (1.41,2.60) and 1.52 (1.12,2.05), respectively. No significant difference was detected at 3-year death-censored graft survival between ABOi-DDLT and ABOc-DDLT groups. ABOi-DDLT group had a higher complication incidence rate than ABOc-DDLT, and the value of totally pooled OR was 2.26 (1.53,3.33). We found no obvious bias except for the complication of living donor liver transplantation (LDLT; P = 0.038).

IN CONCLUSION

The short-term and long-term outcomes were worse after ABOi-DDLT than ABOc-DDLT in the all-cause mortality, death-censored graft survival, and complication incidence rate. However, the same outcomes were essentially comparable between ABOi-LDLT vs. ABOc-LDLT cohorts. Considering the current shortage of liver donors, we believe that ABOi-LT from living donor and deceased donors can save lives under emergency situations.

ABO Incompatible Liver Transplantation in Children: A 20 Year Experience from Centres in the TransplantChild European Reference Network

An increasing number of AB0-incompatible (AB0i) liver transplantations (LT) are being undertaken internationally in recent years due to organ shortages and the need for urgent transplantation. The aim of our study was establish the value of ABOi LT from available retrospective results of AB0i pediatric liver transplantations performed in European reference centers now belonging to the TransplantChild, European Reference Network (ERN). Data from medical records were analyzed, including demographic data, diagnosis, urgency of transplantation, time on the waiting list, PELD/MELD score, desensitization procedures, immunosuppression, selected post-transplant complications, and patient and graft survival. A total of 142 patients (pts) with transplants between 1986 and 2018 in 8 European transplant centers were included in the study. The indications for liver transplantation were: cholestatic diseases in 62 pts, acute liver failure in 42 pts, and other conditions in the remaining 38 pts. Sixty-six patients received grafts from living donors, and seventy-six received grafts from deceased donors. Both patient and graft survival were significantly affected by deceased donor type, urgent transplantation, and the development of vascular complications. In the multivariate analysis, vascular complications had a negative impact on patient and graft survival, while a longer time from the first AB0i LT in the study showed better results, suggesting an international learning experience. In conclusion, we believe that AB0i LT in children is now a safe procedure that may be adopted more readily in children.

The management and outcomes of ABO-incompatible pediatric liver transplantation: Experience of a single Chinese center

BACKGROUND

To investigate the safety of using ABO incompatible (ABO-i) liver grafts in pediatric patients under our prophylactic strategies.

METHODS

A total number of 544 pediatric liver transplantations between January 2013 and December 2017 performed in Organ Transplant Center, Tianjin First Central Hospital were included in this study. The recipients were divided into 3 groups based on the compatibility of donor-recipient blood type matching (ABO-identical group, n = 352, ABO-compatible group, n = 121 and ABO-incompatible group, n = 71). Recipient characteristics, perioperative data, postoperative complications and recipient survival rate were compared. The recipient outcomes between living-related and non-living-related ABO-incompatible liver graft recipients were also compared.

RESULTS

The median follow-up time in three groups were 3.4 (1.8, 6.4) years, 3.2 (1.8, 6.1) years and 2.8 (1.8, 6.2) years, without statistical difference. The cumulative 1-year and 3-year graft survival rate were 94.3% and 94.0% in ABO-id group, 93.1% and 93.1% in ABO-c group and 97.1% and 97.1% in ABO-i group. The cumulative 1-year and 3-year recipient survival rate were 96.1% and 95.5% in ABO-id group, 94.8% and 94.8% in ABO-c group and 97.1% and 97.1% in ABO-i group, respectively. No significant difference was seen among three groups. The recipient characteristics and perioperative data were similar among three groups. The recipients in ABO-i group showed significantly lower incidence of portal vein stenosis. Apart from that, three groups shared equal incidence of other surgical complications and acute rejection. Among ABO-i liver graft recipients, the cumulative 1-year and 3-year recipient survival rate were 98.2% and 98.2% in living donor liver transplant (LDLT) recipients and 92.9% and 92.9% in deceased donor liver transplant (DDLT) recipients, without significant difference. The incidence of hepatic artery thrombosis was significantly higher in DDLT group compared with LDLT group, while the other complications were similar between two groups.

CONCLUSION

Our data revealed that the application of ABO-i liver grafts in pediatric liver transplantation under rational peri-operative management strategy is a safe measure to increase donor availability for pediatric patients in Chinese population.

LEVELS OF EVIDENCE

III.

Comparison of clinical outcomes between ABO-incompatible and ABO-compatible pediatric liver transplantation: a systematic literature review and meta-analysis

PURPOSE

ABO-incompatible (ABO-i) liver transplantation (LT) is a life-saving method for pediatric patients in emergency situations that has the potential to expand the pool of liver donors. However, the risks of ABO-i compared to ABO-compatible (ABO-c) LT are unclear. To address this clinical uncertainty, we conducted a systematic review and meta-analysis to compare clinical outcomes between ABO-i and ABO-c LT in pediatric patients.

METHODS

A systematic search for studies comparing outcomes between ABO-i and ABO-c LT was performed in the MEDLINE (PubMed), EMBASE, and Cochrane Library databases through May 2020. Outcomes evaluated included graft survival rate, patient survival rate, rejection, infection, biliary complications, and vascular complications. Quality of evidence was assessed using the Newcastle-Ottawa scale. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using RevMan 5.3.

RESULTS

A total of 12 studies involving 7461 patients were included in the review. Meta-analysis of these studies showed significantly lower 1 year, 3 year, and 5 year graft survival rates for ABO-i vs. ABO-c LT (1 year: OR = 0.46, 95% CI 0.35-0.59, P < 0.00001; 3 years: OR = 0.47, 95% CI 0.36-0.63, P < 0.00001; 5 year: OR = 0.48, 95% CI 0.37-0.63, P < 0.00001) as well as significantly lower 1 year, 3 year, 5 year, and 10 year patient survival rates for ABO-i vs. ABO-c (1 year: OR = 0.34, 95% CI 0.24-0.49, P < 0.00001; 3 years: OR = 0.24, 95% CI 0.14-0.40, P < 0.00001; 5 years: OR = 0.47, 95% CI 0.35-0.64, P < 0.00001; 10 years: OR = 0.59, 95% CI 0.38-0.90, P = 0.02). No significant differences were observed between the groups in incidence of cytomegalovirus infection, acute cellular rejection, acute rejection, biliary complications, or hepatic artery thrombosis.

CONCLUSIONS

Our systematic review and meta-analysis showed consistently lower patient survival and graft survival in pediatric ABO-i LT compared to ABO-c LT. However, ABO-i LT is still a life-saving emergency option for pediatric patients waiting for a suitable liver source.

ABO-Incompatible Living Donor Liver Transplantation with Reduced Rituximab Dose: A Retrospective Analysis of 65 Patients - Can We Fast-Track Liver Transplant Surgery and Improve Long-Term Survival?

BACKGROUND ABO-incompatible (ABO-i) living donor liver transplantation (LDLT) is a feasible alternative for donor liver allograft in emergency situations, especially in Asia, where deceased-donor organs remain scarce. The reported outcomes of ABO-i LDLT after optimal desensitization are comparable to those of ABO-compatible LDLT. In this retrospective study, we found improved outcomes after ABO-i LDLT with a low-dose rituximab in combination with double-filtration plasmapheresis (DFPP) and prophylactic antibiotic therapy. MATERIAL AND METHODS Between January 2006 and December 2018, a total of 65 recipients underwent ABO-i LDLT surgeries at our center. The study cohort consisted of 50 recipients (Era III) who underwent ABO-i LDLT using the recently updated desensitization protocol, which included rituximab 200 mg intravenous injection once a week prior to LDLT, 4 sessions of DFPP in all patients, and prophylactic antibiotics for 3 months. RESULTS The 3-year overall survival rate achieved in ABO-i LDLT patients was 72.7% (66.6% for Era I and 33.3% for Era II patients). In the study population, 11 patients developed complications due to infection. Five of these patients (10%) died due to overwhelming sepsis. Four patients (8%) were diagnosed with multiple strictures and diffusely scattered dilatation of intrahepatic bile ducts on computed tomography, without vascular complications. Three of them had evidence of antibody-mediated rejection (AMR). CONCLUSIONS Our experience shows that the ABO-i LDLT protocol of lowered rituximab combined with pre-transplant sessions of plasmapheresis and a quadruple immunosuppressive regimen can be effective in chronic liver failure patients with clinical urgency in the absence of an ABO-compatible donor. Fast-tracking the use of ABO-i LDLT is feasible in patients with an acute liver failure (ALF) and can safely increase the donor liver pool, with an acceptable outcome.

Deceased Donor Predictors for Pediatric Liver Allograft Utilization

BACKGROUND

The number of pediatric deceased organ donors has recently declined, and the nonutilization of pediatric liver allografts has limited the development of liver transplantation. We determined the utilization rate of pediatric livers and identified risk factors for graft discard.

METHODS

We used data from the Scientific Registry of Transplant Recipients database from January 1, 2000, to December 31, 2012. The trends of pediatric liver donors and utilization rates were analyzed. Donor risk factors that impacted the graft use of pediatric livers were measured. Logistic regression modelling was performed to evaluate graft utilization and risk factors.

RESULTS

A total of 11,934 eligible pediatric liver donors were identified during this period. A total of 1191 authorized liver grafts did not recover or recovered without transplantation. Factors including pediatric donors >1 year of age (odds ratio [OR] = 2.956, 95% confidence interval [CI] 2.494-3.503, P < .001), nonhead trauma (OR = 2.243, 95% CI 1.903-2.642, P < .001), lack of heartbeat (OR = 7.534, 95% CI 5.899-9.623, P < .001), hepatitis B surface antigen positivity (OR = 4.588, 95% CI 1.021-20.625, P = .047), anti-hepatitis C virus positivity (OR = 4.691, 95% CI 1.352-16.280, P = .015), total bilirubin >1 mg/dL (OR = 1.743, 95% CI 1.469-2.068, P < .001), and blood urea nitrogen >21 mg/dL (OR = 1.941, 95% CI 1.546-2.436, P < .001) were significantly related to graft nonutilization. Steroids or diuretics administered prerecovery were significantly related to graft utilization (OR = 0.684, 95% CI 0.581-0.806, P < .001; OR = 0.744, 95% CI 0.634-0.874, P < .001; respectively).

CONCLUSIONS

The pediatric liver allograft utilization rate and risk factors for nonutilization of grafts were determined.

ABO-incompatible deceased donor pediatric liver transplantation: Novel titer-based management protocol and outcomes

ABO-ILT have re-emerged as an alternate option for select patients awaiting transplant. However, treatment protocols for children undergoing deceased donor ABO-ILT are not standardized. We implemented a novel IS protocol for children undergoing deceased donor ABO-ILT based on pretransplant IH titers. Children with high pretransplant IH titers (≥1:32) underwent an enhanced IS protocol including plasmapheresis, rituximab, IVIG, and mycophenolate, while children with IH titers ≤1:16 received steroids and tacrolimus. We retrospectively assessed our outcomes of ABO-ILT with ABO-compatible recipients of similar age and diagnosis over a 2-year period. Ten children with median age of 8.9 months underwent ABO-ILT, 4 of 10 patients underwent enhanced IS due to high IH titers. Rates of complications (rejection, infections, biliary, and vascular) at both 1 year and up to 3 years post-transplant were comparable between the groups. Patients with ABO-ILT had good graft function with 100% survival at a median follow-up of 3.3 years. In conclusion, IS tailored to pretransplant IH titers in pediatric deceased donor ABO-ILT is feasible and can achieve outcomes similar to ABO-CLT at 1 and 3 years post-transplantation.

A simplified protocol using rituximab and immunoglobulin for ABO-incompatible low-titre living donor liver transplantation

BACKGROUND & AIMS

No consensus has been reached regarding optimal treatment strategies for ABO-incompatible (ABO-I) living donor liver transplantation (LDLT). We introduce a simplified protocol using rituximab and intravenous immunoglobulin (IVIG).

METHODS

Data were analysed on adult patients who underwent ABO-I LDLT of which protocol added rituximab (300 mg/m² ) before surgery and IVIG (0.8 g/kg) on post-operative days 1 and 4 to the conventional immunosuppressive regimen used in ABO-compatible (ABO-C) LDLT, without plasmapheresis, splenectomy or graft local infusion. The outcomes were compared with those of ABO-C LDLT by 1:2 propensity score-matched analysis.

RESULTS

Consecutive 43 ABO-I LDLT patients were identified between 2014 and 2016. Before desensitization, the median isoagglutinin titre was 1:8 (range, 1:2-1:64). The titre was reduced to 4 (range, 0-16) at the time of LDLT. None showed a rebound rise of isoagglutinin titres. No antibody-mediated rejection occurred. Biliary stricture was the most common complication with an incidence of 30.2%. A comparator group of 86 ABO-C LDLT patients were selected. There was no statistical difference in the overall complication rate including acute cellular rejection, biliary complications and infection between ABO-I and ABO-C groups. The 3-year cumulative patient survival rates in the ABO-I and ABO-C groups were 82.4% and 85.9% respectively (P = .115).

CONCLUSIONS

A simplified protocol using rituximab and IVIG for ABO-I LDLT was safe and effective in achieving sufficient desensitization and comparable outcomes in patients with the titre no higher than 1:64.

Outcomes after liver transplantation in accordance with ABO compatibility: A systematic review and meta-analysis

AIM

To evaluate the differences in outcomes between ABO-incompatible (ABO-I) liver transplantation (LT) and ABO-compatible (ABO-C) LT.

METHODS

A systematic review and meta-analysis were performed by searching eligible articles published before No-vember 28, 2016 on MEDLINE (PubMed), EMBASE, and Cochrane databases. The primary endpoints were graft survival, patient survival, and ABO-I-related complications.

RESULTS

Twenty-one retrospective observational studies with a total of 8247 patients were included in this meta-analysis. Pooled results of patient survival for ABO-I LT were comparable to those for ABO-C LT. However, ABO-I LT showed a poorer graft survival than ABO-C LT (1-year: OR = 0.66, 95%CI: 0.57-0.76, P < 0.001; 3-year: OR = 0.74, 95% CI 0.64-0.85, P < 0.001; 5-yearr: OR =0.75, 95%CI: 0.66-0.86, P < 0.001). Furthermore, ABO-I LT was associated with more incidences of antibody-mediated rejection (OR = 74.21, 95%CI: 16.32- 337.45, P < 0.001), chronic rejection (OR =2.28, 95%CI: 1.00-5.22, P = 0.05), cytomegalovirus infection (OR = 2.64, 95%CI: 1.63-4.29, P < 0.001), overall biliary complication (OR = 1.52, 95%CI: 1.01-2.28, P = 0.04), and hepatic artery complication (OR = 4.17, 95%CI: 2.26-7.67, P < 0.001) than ABO-C LT. In subgroup analyses, ABO-I LT and ABO-C LT showed a comparable graft survival in pediatric patients and those using rituximab, and ABO-I LT showed an increased acute cellular rejection in cases involving deceased donor grafts.

CONCLUSION

Although patient survival in ABO-I LT was comparable to that in ABO-C LT, ABO-I LT was inferior to ABO-C LT in graft survival and several complications. Graft survival of ABO-I LT could be comparable to that of ABO-C LT in pediatric patients and those using rituximab.

Changes in DNA Methylation of Glucocorticoid-Induced Tumor Necrosis Factor Receptor and Its Ligand in Liver Transplantation

Liver transplantation (LT) is the criterion standard of care in patients with end-stage liver disease and those with tumors of hepatic origin in the setting of liver dysfunction. Chronic immune rejection of the liver transplant can lead to bad prognosis for patients. Glucocorticoid-induced tumor necrosis factor receptor (GITR) play a key role in dominant immunologic self-tolerance maintained by CD25+/CD4+ regulatory T cells. Here, we investigated the DNA methylation variations of GITR and GITR ligand (GITRL) using pyrosequencing by analyzing blood DNA samples of patients after LT. Our results showed that the methylation level of certain CpGs, such as CpG_13, in GITRL was significantly reduced after LT. Furthermore, we found that the GITRL methylation statuses of cohorts with no chronic immune rejection were significantly lower compared with cohorts with chronic immune rejection after LT treatment. However, the methylation statuses of GITR were less varied. Using linear regression analysis, we further found that factors such as upper gastrointestinal hemorrhage, splenectomy, and creatinine might affect DNA methylation patterns in chronic immune rejection cohorts. These findings provide novel insights into the pivotal role of GITRL as a potential molecular biomarker for the triage of liver transplantation.

Pediatric Liver Transplantation Across the ABO Blood Group Barrier: Is It an Obstacle in the Modern Era?

BACKGROUND

The initial experience with ABO incompatible (ABOi) orthotopic liver transplantations (OLTs) was dismal. In the current study, we investigated whether ABOi pediatric OLTs could achieve acceptable patient outcomes. The option for ABOi transplantation is vital because critically ill children have limited access to donor liver allografts.

STUDY DESIGN

Kaplan-Meier and multivariate Cox analysis was performed on data collected from 13,179 pediatric OLT recipients in the United Network for Organ Sharing database, including 540 ABOi recipients. We also analyzed 18 pediatric recipients of ABOi OLTs at Texas Children's Hospital. Recipients were divided into 2 groups: transplanted between 1987 to 2002 (remote era) and 2002 to 2013 (modern era).

RESULTS

Analysis revealed 4 main points. First, there was a significant (p < 0.01) improvement in ABOi OLT survival in the modern era. Second, threshold analysis revealed superior outcomes (p < 0.01) for OLT recipients younger than 2 years of age. Third, survival outcomes for ABOi and ABO-identical OLTs were the same for recipients younger than 2 years: ABOi was 91.8% (1 year) and 88.4% (5 year), and ABO identical was 91.5% (1 year) and 86.7% (5 year) (p = 0.94). Lastly, we found identical OLT results when analyzing our own institutional experience. To date, there has been a 92.9% survival rate in the modern era compared with 75% in the remote era. All recipients younger than 2 years (n = 9) are still alive, compared with 78% of those older than 2 years.

CONCLUSIONS

This analysis revealed a significant improvement in the survival of ABOi liver transplant recipients in the modern era. Importantly, ABOi liver transplantation can be performed in recipients younger than 2 years of age with equivalent outcomes compared with ABO-identical recipients.

The impact of rituximab in ABO-incompatible pediatric living donor liver transplantation: the experience of a single center

Previous studies have demonstrated the safety of ABO-incompatible pediatric LDLT using preoperative plasmapheresis and rituximab; however, no reports have described the timing and dosage of rituximab administration for pediatric LDLT. This study aimed to describe a safe and effective dosage and timing of rituximab for patients undergoing pediatric ABO-incompatible LDLT based on the experience of our single center. A total of 192 LDLTs in 187 patients were examined. These cases included 29 ABO-incompatible LDLTs in 28 patients. Rituximab was used beginning in January 2004 in recipients older than two yr of age (first period: 375 mg/m(2) in two cases; second period: 50 mg/m(2) in two cases; and 200 mg/m(2) in eight cases). Two patients who received 375 mg/m(2) rituximab died of Pneumocystis carinii pneumonia and hemophagocytic syndrome. One patient who received 50 mg/m(2) rituximab required retransplantation as a consequence of antibody-mediated complications. All eight patients administered 200 mg/m(2) survived, and the mean CD20(+) lymphocyte count was 0.1% at the time of LDLT. In the preoperative management of patients undergoing pediatric ABO-incompatible LDLT, the administration of 200 mg/m(2) rituximab three wk prior to LDLT was safe and effective.

ABO-incompatible liver transplantation for severe hepatitis B patients

Effect of ABO-incompatible liver transplantation on patients with severe hepatitis B (SHB) remains unclear. Herein, we summarized 22 cases with SHB in whom were performed emergency liver transplantation from ABO-incompatible donors. The immunosuppressive protocol consisted basiliximab, tacrolimus, steroids and mycophenolate mofetil. The mean MELD score was 35.2 ± 7.1. Major complications included rejection, infections, biliary complications, hepatic artery thrombosis or stenosis and portal vein thrombosis. Patient survival rates were 40.9%, 78.9% and 82.3% in 1 year, 29.2%, 66.8% and 72.9% in 3 years, and 21.9%, 60.1% and 62.5% in 5 years for ABO-incompatible, ABO-compatible and ABO-identical groups. Graft survival rates were 39%, 78.9% and 82.3% in 1 year, 27.8%, 66.4% and 71.1% in 3 years, and 20.9%, 57.9% and 61.0% in 5 years for incompatible, compatible and identical ABO graft-recipient match. The 1-, 3-, 5-year graft and patient survival rates of ABO-incompatible were distinctly lower than that of ABO-compatible group (P < 0.05). Our results suggested that ABO-incompatible liver transplantation might be a life-saving procedure for patients with SHB as a promising alternative operation when ABO-compatible donors are not available and at least bridges the second opportunity for liver retransplantation.

A modified protocol with rituximab and intravenous immunoglobulin in emergent ABO-incompatible liver transplantation for acute liver failure

BACKGROUND

The established procedure for ABO-incompatible liver transplantation (ABO-I LT) was too complicated to be used in case of emergency. We developed a protocol consisting of rituximab and intravenous immunoglobulin (IVIG) for ABO-I LT in patients with acute liver failure (ALF).

METHODS

The data from 101 patients who had undergone liver transplantation (LT) for ALF were retrospectively analyzed. The patients were divided into two groups: ABO-compatible liver transplantation group (ABO-C LT, n=66) and ABO-I LT group (n=35). All the patients in the ABO-I LT group received a single dose of rituximab (375 mg/m2) and IVIG (0.4 g/kg per day) at the beginning of the operation. IVIG was administered for 10 consecutive days after LT. Plasma exchange, splenectomy and graft local infusion were omitted in the protocol. Quadruple immunosuppressive therapy including basiliximab, corticosteroids, tacrolimus and mycophenolatemofetil was used to reinforce immunosuppression.

RESULTS

The 3-year cumulative patient survival rates in the ABO-I LT and ABO-C LT groups were 83.1% and 86.3%, respectively (P>0.05), and the graft survival rates were 80.0% and 86.3%, respectively (P>0.05). Two patients (5.7%) suffered from antibody-mediated rejection in the ABO-I LT group. Other complications such as acute cellular rejection, biliary complication and infection displayed no significant differences between the two groups.

CONCLUSIONS

The simplified treatment consisting of rituximab and IVIG prevented antibody-mediated rejection for LT of blood-type incompatible patients. With this treatment, the patients did not need plasma exchange, splenectomy and graft local infusion. This treatment was safe and efficient for LT of the patients with ALF.

Neonatal haemochromatosis with reversible pituitary involvement

Neonatal haemochromatosis is a rare alloimmune gestational disease with a high mortality. The hallmark of neonatal haemochromatosis is severe neonatal liver failure associated with extrahepatic siderosis. Thus far, no pituitary dysfunction has been reported to result from the tissue damage associated with extrahepatic siderosis. The present report describes a neonate with neonatal haemochromatosis and secondary hypothyroidism associated with pituitary iron deposition. Both the conditions were successfully treated by ABO-incompatible liver transplantation. Pituitary gland dysfunction is another possible extrahepatic manifestation of neonatal haemochromatosis, and it is reversible after liver transplantation.

Pediatric therapeutic apheresis: rationale and indications for plasmapheresis, cytapheresis, extracorporeal photopheresis, and LDL apheresis

Apheresis refers to the removal of a component of the blood and is performed using a group of medical technologies in which peripheral blood is processed by an instrument that separates the various components. The selected component is isolated while the remainder is returned to the patient. The rationale behind therapeutic apheresis is to remove the pathogenic components from the circulation. Apheresis is also used for peripheral hematopoietic progenitor cell collection. The procedure can be safely performed in most children with modifications to account for smaller pediatric blood volumes.

Matching donor to recipient in liver transplantation: Relevance in clinical practice

Achieving optimum outcomes after liver transplantation requires an understanding of the interaction between donor, graft and recipient factors. Within the cohort of patients waiting for a transplant, better matching of the donor organ to the recipient will improve transplant outcomes and benefit the overall waiting list by minimizing graft failure and need for re-transplantation. A PubMed search was conducted to identify published literature investigating the effects of donor factors such as age, gender, ethnicity, viral serology; graft factors such as size and quality, recipient factors such as age, size, gender and transplant factors such as major or minor blood group incompatibility and immunological factors. We also report technical and therapeutic modifications that can be used to manage donor-recipient mismatch identified from literature and the authors’ clinical experience. Multiple donor and recipient factors impact graft survival after liver transplantation. Appropriate matching based on donor-organ-recipient variables, modification of surgical technique and innovative peri-transplant strategies can increase the donor pool by utilizing grafts from marginal donors that are traditionally turned down.

ABO-incompatible liver transplantation in acute liver failure: a single Portuguese center study

INTRODUCTION

ABO-incompatible liver transplantation (ABOi LT) is considered to be a rescue option in emergency transplantation. Herein, we have reported our experience with ABOi LT including long-term survival and major complications in these situations.

PATIENT AND METHODS

ABOi LT was performed in cases of severe hepatic failure with imminent death. The standard immunosuppression consisted of basiliximab, corticosteroids, tacrolimus, and mycophenolate mofetil. Pretransplantation patients with anti-ABO titers above 16 underwent plasmapheresis. If the titer was above 128, intravenous immunoglobulin (IVIG) was added at the end of plasmapheresis. The therapeutic approach was based on the clinical situation, hepatic function, and titer evolution. A rapid increase in titer required five consecutive plasmapheresis sessions followed by administration of IVIG, and at the end of the fifth session, rituximab.

RESULTS

From January 2009 to July 2012, 10 patients, including 4 men and 6 women of mean age 47.8 years (range, 29 to 64 years), underwent ABOi LT. At a mean follow-up of 19.6 months (range, 2 days to 39 months), 5 patients are alive including 4 with their original grafts. One patient was retransplanted at 9 months. Major complications were infections, which were responsible for 3 deaths due to multiorgan septic failure (2 during the first month); rejection episodes (4 biopsy-proven of humoral rejections in 3 patients and 1 cellular rejection) and biliary.

CONCLUSION

The use of ABOi LT as a life-saving procedure is justifiable in emergencies when no other donor is available. With careful recipient selection close monitoring of hemagglutinins and specific immunosuppression we have obtained acceptable outcomes.

Emergency ABO-incompatible liver transplant secondary to fulminant hepatic failure: outcome, role of TPE and review of the literature

The increasing demand for solid organ transplants has brought to light the need to utilize organs in critical situations despite ABO-incompatibility. However, these transplantations are complicated by pre-existing ABO antibodies which may be potentially dangerous and makes the transplantation prone to failure due to rejection with resulting necrosis or intrahepatic biliary complications. We report the clinical outcome of an emergency ABO-incompatible liver transplant (due to fulminant hepatic failure with sudden and rapidly deteriorating mental status) using a modified therapeutic plasma exchange (TPE) protocol. The recipient was O-positive with an initial anti-B titer of 64 and the cadaveric organ was from a B-positive donor. The patient underwent initial TPE during the peri-operative period, followed by a series of postoperative daily TPE, and later a third series of TPE for presumptive antibody-mediated rejection. The latter two were performed in conjunction with the use of IVIg and rituximab. The recipient's anti-B titer was reduced and maintained at 8 or less 8 months post-op. However, an elevation of transaminases 3 months post-transplant triggered a biopsy which was consistent with cellular rejection and with weak C4d positive staining suggestive of antibody mediated rejection. Additional plasma exchange procedures were performed. The patient improved rapidly after modification of her immunosuppression regimen and treatment with plasma exchange. This case illustrates that prompt and aggressive plasma exchange, in conjunction with immunosuppression, is a viable approach to prevent and treat antibody mediated transplant rejection in emergency ABO-incompatible liver transplant.

Segmental ABO-incompatible liver graft from a donor after cardiac death in neonatal acute liver failure

Segmental liver grafts from DCD in pediatric LT have been safely used even in acute liver failure situations. Furthermore, despite the risk of antibody-mediated acute rejection, some studies have also demonstrated the safety of ABO incompatible LT in infants. The use of such grafts can be beneficial by reducing the time on the transplant waiting list but they are more susceptible to initial dysfunction and there is a lack of enthusiasm to consider their use especially for an emergency LT as a life-saving procedure. In this short article, we describe the use and successful outcome in a neonate with fulminant acute liver failure secondary to neonatal hemochromatosis who received an ABO-incompatible reduced-size DCD graft.

ABO-incompatible pediatric liver transplantation in very small recipients: Birmingham's experience

Liver transplantation (LT) for very small recipients is challenging but in experienced centres, good results can be achieved. Despite the risk of antibody-mediated acute rejection, some studies have demonstrated the safety of ABO incompatible liver transplantation (ILT) in children and particularly in infants. The aim of our study was to describe the outcome of liver transplantation in infants <5 kg and the safety of using ILT in this group. All LT performed between 1991 and 2010 in children <5 kg were reviewed. Twenty-nine patients were included, five of whom had an ILT. Acute liver failure was encountered in 20 cases. The recipient age and weight at transplantation were respectively 63 days (range: 14-268 days) and 4 kg (range: 2.4-5 kg). The graft-to-recipient ratio was 6.1% (range 2.3-9%). An aortic conduit and delayed abdominal closure were used respectively in 76% and 81% of the procedures. The ABO compatible liver transplantation (CLT) and ILT groups were similar regarding recipient's demographics, graft types or technical transplantation data. The one- and five-yr patient and graft survival were respectively 62%, 62% and 62%, 57.9% with a median follow-up of 95 months. Vascular complications occurred in six cases (21.4%) and biliary complications were encountered in five patients (17%). Acute and chronic rejection developed respectively in 37% and 26% of the recipients. The five patients undergoing ILT are all alive without graft lost after a median follow-up of 34 months (range 7-55 months). When compared with the CLT group, no significant differences were found regarding patient or graft survival, vascular or biliary complications and rejection rates. In our experience, ILT in small infants has short and long term outcomes comparable to ABO-compatible grafts and excellent results can be achieved with a standard immunosuppressive protocol. To avoid mortality on the waiting list for neonatal recipients, ABO-incompatible liver grafts can be used safely.

Recipient outcomes after ABO-incompatible liver transplantation: a systematic review and meta-analysis

Background

ABO-incompatible live transplantation (ILT) is not occasionally performed due to a relative high risk of graft failure. Knowledge of both graft and patient survival rate after ILT is essential for donor selection and therapeutic strategy. We systematically reviewed studies containing outcomes after ILT compared to that after ABO-compatible liver transplantation (CLT).

Methodology/Principal Findings

We carried out a comprehensive search strategy on MEDLINE (1966–July 2010), EMBASE (1980–July 2010), Biosis Preview (1969–July 2010), Science Citation Index (1981–July 2010), Cochrane Database of Systematic Reviews (Cochrane Library, issue 7, 2010) and the National Institute of Health (July 2010). Two reviewers independently assessed the quality of each study and abstracted outcome data. Fourteen eligible studies were included which came from various medical centers all over the world. Meta-analysis results showed that no significantly statistical difference was found in pediatric graft survival rate, pediatric and adult patient survival rate between ILT and CLT group. In adult subgroup, the graft survival rate after ILT was significantly lower than that after CLT. The value of totally pooled OR was 0.64 (0.55, 0.74), 0.92 (0.62, 1.38) for graft survival rate and patient survival rate respectively. The whole complication incidence (including acute rejection and biliary complication) after ILT was higher than that after CLT, as the value of totally pooled OR was 3.02 (1.33, 6.85). Similarly, in acute rejection subgroup, the value of OR was 2.02 (1.01, 4.02). However, it was 4.08 (0.90, 18.51) in biliary complication subgroup.

Conclusions/Significance

In our view, pediatric ILT has not been a contraindication anymore due to a similar graft and patient survival rate between ILT and CLT group. Though adult graft survival rate is not so satisfactory, ILT is undoubtedly life-saving under exigent condition. Most studies included in our analysis are observational researches. Larger scale of researches and Randomized-Control Studies are still needed.

De novo cholangiocarcinoma after liver transplantation in a pediatric patient

To date, no child has been reported to develop de novo CCA after liver transplantation although patients with transplants have a significantly higher risk of malignancy than the general population. CCA is extremely rare in the pediatric age group, seen mostly in patients with a history of choledochal cysts, Caroli's disease, or PSC. We report the first case of pediatric de novo CCA in the liver allograft 12 yr after liver transplantation.

Successful long-term outcome of ABO-incompatible liver transplantation using antigen-specific immunoadsorption columns

ABO-incompatible (ABO-I) liver transplantation has been performed essentially in patients with acute liver failure awaiting an urgent liver transplantation. Early results with ABO-I liver transplantation were disappointing with a very low graft survival rate (20-50%). The main risk is the occurrence of severe humoral and cellular rejection, vascular thrombosis, and biliary complications. In order to avoid humoral rejection and improve graft survival, total plasma exchange in combination with an intense immunosuppressive regimen has been proposed to decrease hemagglutinin titers in ABO-I liver grafts. In some centers, this regimen was associated with splenectomy, phototherapy, and portal or arterial intrahepatic infusion therapy; however, as these patients are at high risk of sepsis, a selective approach using antigen-specific immunoadsorption with immunoadsorbent columns has been successfully proposed for ABO-I living donor kidney transplantation. Few cases have been reported following liver transplantation. We report our recent experience with three adult patients (two patients with acute liver failure, and one with severe cirrhosis and hepatic encephalopathy) transplanted in an emergency situation with an ABO-I liver graft and managed with the use of GlycoSorb ABO immunoadsorbent columns and a quadruple immunosuppressive regimen with preservation of the spleen. Eight sessions were performed in the three patients. Antigen-specific immunoadsorption greatly lowered the anti-A hemagglutinin titers. None of the three patients developed acute humoral or cellular rejection. Two patients are alive at 1.5 and 3 years follow-up with a normally functioning graft. The third patient died with a functioning graft, one month after the transplantation, from septic complications.

Liver retransplantation in children: the Atlanta experience

Liver retransplantation is routinely offered at our institution. Previous reports document that patient and graft survival is significantly less after pediatric rLT compared to primary LT. This has engendered intense debate regarding optimal allocation of organs. Here, we examine our program's approach to pediatric hepatic retransplantation related to patient factors affecting outcomes. Between 1997 and 2009, 272 LTs were performed in 234 patients (mean survival 1994 +/- 1367 days) at our center. Thirty-four patients required rLT including 10 who received their primary transplant elsewhere and four who required two retransplantations. Patient survival did not differ significantly between rLT and LT at one and three yr (p = 0.56). Graft survival between rLT and LT was also similar (p = 0.606) at one and three yr. No significant difference in graft or patient survival was noted between: Patients retransplanted <30 days after LT vs. those >30 days (p = 0.152); patients transplanted with technical variants vs. whole grafts (p = 0.966); technical variants utilized for LT vs. rLT (p = 0.713); rLT recipient age (< or >5 yr; p = 0.298); or ABOI for rLT and LT (p = 0.650). Retransplantation should be offered to optimize pediatric recipient survival after LT and offers similar survival as primary transplant.

Pediatric liver transplantation for acute liver failure at a single center: a 10-yr experience

Children transplanted for ALF urgently require an optimal graft and have lower post-transplant survival compared with children transplanted for chronic liver disease. Over 10 yr, 33 consecutive children transplanted for ALF were followed. Demographics, encephalopathy, intubation, dialysis, laboratory values, graft type ABOI, XL (GRWR > 5%), DDSLT, LDLT and WLT were evaluated. Complications and survival were determined. ALF accounted for 33/201 (16.4%) of transplants during this period. Twelve of 33 received ABOI, five XL grafts, 18 DDSLT, and three LDLT. Waiting time pretransplant was 2.1 days. One- and three-yr patient survival in the ALF group was 93.4% and 88.9%, and graft survivals were 86.4% and 77.7%. Median follow-up was 1452 days. ABOI one- and three yr patient and graft survival in the ALF was 91.6% and 78.6%. No difference in graft or patient survival was noted in the ALF and chronic liver disease group or the ABOI and the ABO compatible group. A combination of ABO incompatible donor livers, XL grafts, DDSLT, LDLT and WLT led to a short wait time and subsequent graft and patient survival comparable to patients with non-acute disease.

Liver transplantation

Liver transplantation has become a lifesaving procedure for patients who have chronic end-stage liver disease and acute liver failure. The satisfactory outcome of liver transplantation has led to insufficient supplies of deceased donor organs, particularly in East Asia. Hence, East Asian surgeons are concentrating on developing and performing living-donor liver transplantation (LDLT). This review article describes an update on the present status of liver transplantation, mainly in adults, and highlights some recent developments on indications for transplantation, patient selection, donor and recipient operation between LDLT and deceased-donor liver transplantation (DDLT), immunosuppression, and long-term management of liver transplant recipients. Currently, the same indication criteria that exist for DDLT are applied to LDLT, with technical refinements for LDLT. In highly experienced centers, LDLT for high-scoring (>30 points) Model of End-Stage Liver Disease (MELD) patients and acute-on-chronic liver-failure patients yields comparably good outcomes to DDLT, because timely liver transplantation with good-quality grafting is possible. With increasing numbers of liver transplantations and long-term survivors, specialized attention should be paid to complications that develop in the long term, such as chronic renal failure, hypertension, diabetes mellitus, dyslipidemia, obesity, bone or neurological complications, and development of de novo tumors, which are highly related to the immunosuppressive treatment.

ABO-incompatible deceased donor liver transplantation in the United States: a national registry analysis

In the United States, ABO-incompatible liver transplantation (ILT) is limited to emergent situations when ABO-compatible liver transplantation (CLT) is unavailable. We analyzed the United Network for Organ Sharing database of ILT performed from 1990-2006 to assess ILT outcomes for infant (0-1 years; N = 156), pediatric (2-17 years; N = 170), and adult (> 17 years; N = 667) patients. Since 2000, the number of ILT has decreased annually, and there has been decreased use of blood type B donors and increased use of blood type A donors. Furthermore, ILT graft survival has improved for all age groups in recent years, beyond the improved graft survival attributable to era effect based on comparison to respective age group CLT. On matched control analysis, graft survival was significantly worse for adult ILT as compared to adult CLT. However, infant and pediatric ILTs did not have worse graft survival versus age-matched CLT. Adjusted analyses identified age-specific characteristics impacting ILT graft loss. For infants, transplant after 2000 and donor age < 9 years were associated with reduced risk of ILT graft loss. For pediatric patients, female recipient sex and donor age > 50 years were associated with increased risk of ILT graft loss. For adults, life support, repeat transplant, split grafts, and hepatocellular carcinoma were associated with increased risk of ILT graft loss. The current study identifies important trends in ILT in the United States in the modern immunosuppression era, as well as specific recipient, donor, and graft characteristics impacting ILT graft survival that could be utilized to guide ILT organ allocation in exigent circumstances. Liver Transpl 15:883-893, 2009. (c) 2009 AASLD.

Long-term outcome of ABO-incompatible living-donor liver transplantation: a single-center experience

PURPOSE

We report the long-term outcome of ABO-incompatible living donor liver transplantation (LDLT) performed in our hospital.

METHODS

We started the LDLT program in 1991 and from that year up to now (2008) 11 patients have received an ABO-incompatible graft.

RESULTS

Nine out of the 11 cases have survived from 3.7 years to 13.9 years (mean 7.3 years) and they are in good conditions at present. Seven patients were subjected to preoperative apheresis. Eight patients experienced acute rejection and of them, 6 experienced steroid-resistant rejection that was treated with deoxyspergualin and apheresis. One patient who suffered rapidly progressing rejection died due to liver failure. Three patients who were administered rituximab did not suffer severe rejection nor adverse effects. During the long-term follow up 5 recipients had major complications such as postoperative lymphoproliferative disease, post-transplantation diabetes mellitus, portal vein occlusion and biliary stenosis. But those complications were controlled under stable conditions.

CONCLUSIONS

We concluded that long-term survival can be expected after ABO-incompatible LDLT provided perioperative complications such as humoral rejection are overcome.

Impact of preexisting circulating effector T cells on the outcome of ABO-incompatible adult LDLT

Our aim was to clarify the significance of phenotype of circulating CD8 T(+) cells on the outcome of ABO-incompatible (ABO-I) living donor liver transplantation (LDLT). Twenty-six recipients undergoing ABO-I LDLT and 92 undergoing ABO-compatible (ABO-C) LDLT were classified into three groups according to preoperative proportion of CD8 T(+) cells: naive-dominant (group I), effector memory-dominant (group II), and effector-dominant (group III) recipients. The clinical courses were analyzed. The results showed that in ABO-C groups I and II and in ABO-I group I, effector cells remained above the pretransplant levels after tacrolimus administration. However, in ABO-C group III and ABO-I groups II and III, effector cells were down-regulated for a prolonged period, along with markedly decreased perforin expression and frequent life-threatening complications. ABO-I group II and group III recipients had higher infection rates. It was concluded that recipients with preexisting high effector CD8 T(+) cells are unfavorable candidates for ABO-I LDLT.

Liver transplantation: Yesterday, today and tomorrow

With the advances in technical skills, management of postoperative complications and improvements in immunosuppressive drugs, liver transplantation is the standard treatment for many patients with chronic liver disease. Today, shortage of donor organs seems to be the major limiting factor for the application of liver transplantation. This review focuses on five issues that are challenging to clinical practice of liver transplantation and relevant to gastroenterologists. These include living donor liver transplantation, recurrent viral hepatitis, non-heart-beating donors, hepatocellular carcinoma, and ABO incompatible liver transplantation. Living donor and non-heart beating donor transplantations were initiated as a solution to increase the donor organ pool and it is expected that there will be an increase in the number of these donors. Recurrent hepatitis C and hepatocellular carcinoma following liver transplantation are among major problems and ongoing research in these diseases may lead to better outcomes in these recipients.

Adult living-donor liver transplantation with ABO-incompatible grafts

BACKGROUND

Liver transplantation using ABO-incompatible grafts is rarely performed because the reported outcome is poorer than with compatible grafts. We report our positive experience with adult-to-adult living-donor liver transplant (LDLT) using ABO-incompatible grafts.

METHODS

The immunosuppressive protocol consisted of plasmapheresis/intravenous immunoglobulin infusion before LDLT followed by thymoglobulin induction and splenectomy, maintenance with tacrolimus/cyclosporine (FK/CSA), mycophenolate mofetil, and a rapid steroid taper. Plasmapheresis was planned for up to 3 months after LDLT aiming at maintaining the anti-ABO titers level below 1:16. Liver biopsies were routinely stained for humoral rejection with complement 4d (C4d) and for biliary damage with cytokeratin 7.

RESULTS

Between January 2003 and September 2004, five patients, mean age 59 years, received an ABO-incompatible LDLT. Patient and graft survival was 80% at mean follow-up of 43 months (range, 34-54) for the four surviving patients. One patient died 4 months after LDLT. Humoral rejection occurred in one patient whereas acute cellular rejection was diagnosed in four patients.

CONCLUSIONS

ABO-incompatible LDLT can be performed with patient and graft survival similar to compatible LDLT. Minimization of immunosuppression is possible, and chronic biliary damage is not the norm. Better tools than complement 4d staining must be researched to diagnose the features of immunologic damage to the graft. If these results will be confirmed in a greater number of patients, ABO-incompatible LDLT may be proposed when ABO-compatible donors are not available or when the ABO-incompatible donor is the better candidate.

Current status of liver transplantation across ABO blood-type barrier

Outcomes of ABO-blood type incompatible liver transplantation have recently improved owing to various treatments. The typical clinical manifestations of antibody mediated rejection (AMR) are hepatic necrosis and intrahepatic biliary complication (IHBC). The prognosis of AMR is poor. AMR is the result of circulatory disturbance which is caused by injury to the endothelium due to an antibody-antigen-complement reaction. Diffuse C4d staining in the portal capillaries and periportal areas in severe AMR. Since natural antibodies against A/B carbohydrate determinants are likely to develop as a result of exposure to environmental bacteria that express similar determinants, the B-1 lineage has been speculated to be the major population of B-cell types responding to A/B determinants. Calcineurin inhibitors block B-1 cell differentiation. Rituximab can be used to deplete both cells that are producing IgM antibodies and those that have already differentiated into B-1 cells. Mycophenolate mofetil is required to inhibit the production of IgG subclass of antibodies. The outcome is now similar to that of blood-type-matched transplantation. However, there are still issues to be solved in order to further improve the outcome via a decrease of infection.

Current trends in live liver donation

The introduction of living donor liver transplantation (LDLT) has been one of the most remarkable steps in the field of liver transplantation (LT), able to significantly expand the scarce donor pool in countries in which the growing demands of organs are not met by the shortage of available cadaveric grafts. Although the benefits of this procedure are enormous, the physical and psychological sacrifice of the donors is immense, and the expectations for a good outcome for themselves, as well as for the recipients, are high. We report a current overview of the latest trends in live liver donation in its different aspects (i.e. donor's selection, evaluation, operation, morbidity, mortality, ethics and psychology). This review is based on our center's personal experience with almost 200 LDLTs and a detailed analysis of the international literature of the last 7 years about this topic. Knowing in detail how to approach to the different aspects of living liver donation may be helpful in further improve donor's safety and even recipient's outcome.