Highly urgent liver transplantation: possible impact of donor-recipient ABO matching on the outcome after transplantation

Improving normothermic machine perfusion and blood transfusion through biocompatible blood silicification

The growing world population and increasing life expectancy are driving the need to improve the quality of blood transfusion, organ transplantation, and preservation. Here, to improve the ability of red blood cells (RBCs) for normothermic machine perfusion, a biocompatible blood silicification approach termed "shielding-augmenting RBC-in-nanoscale amorphous silica (SARNAS)" has been developed. The key to RBC surface engineering and structure augmentation is the precise control of the hydrolysis form of silicic acid to realize stabilization of RBC within conformal nanoscale silica-based exoskeletons. The formed silicified RBCs (Si-RBCs) maintain membrane/structural integrity, normal cellular functions (e.g., metabolism, oxygen-carrying capability), and enhance resistance to external stressors as well as tunable mechanical properties, resulting in nearly 100% RBC cryoprotection. In vivo experiments confirm their excellent biocompatibility. By shielding RBC surface antigens, the Si-RBCs provide universal blood compatibility, the ability for allogeneic mechanical perfusion, and more importantly, the possibility for cross-species transfusion. Being simple, reliable, and easily scalable, the SARNAS strategy holds great promise to revolutionize the use of engineered blood for future clinical applications.

Enhanced Role of Multi-Pair Donor Swaps in Response to Size Incompatibility: The First Two 5-Way and the First 6-Way Liver Paired Exchanges

A significant portion of liver transplantations in many countries is conducted via living-donor liver transplantation (LDLT). However, numerous potential donors are unable to donate to their intended recipients due to factors such as blood-type incompatibility or size incompatibility. Despite this, an incompatible donor for one recipient may still be a viable donor for another patient. In recent decades, several transplant centers have introduced liver paired exchange (LPE) programs, facilitating donor exchanges between patients and their incompatible donors, thereby enabling compatible transplants. Initially, LPE programs in Asia primarily involved ABO-i pairs, resulting in 2-way exchanges mainly between blood-type A and B recipients and donors. This practice has led to a modest 1-2% increase in LDLTs at some centers. Incorporating size incompatibility alongside blood-type incompatibility further enhances the efficacy and significance of multiple-pair LPEs. Launched in July 2022, a single-center LPE program established at Inönü University Liver Transplant Institute in Malatya, Türkiye, has conducted thirteen 2-way, nine 3-way, four 4-way, two 5-way, and one 6-way LPEs until February 2024. In 2023 alone, this program facilitated 64 LDLTs, constituting 27.7% of the total 231 LDLTs performed. This paper presents the world's first two 5-way LPEs and the first 6-way LPE.

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.

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.

Scandinavian Journal of Gastroenterology - the editors-in-chief

The SJG has enjoyed a sequence of active and dynamic editors-in-chief following the initial period with Professor Myren in charge. This paper gives a short overview of the subsequent editors including their clinical and scientific merits.

Patients with acute liver failure listed for superurgent liver transplantation in France: reevaluation of the Clichy-Villejuif criteria

In France, decisions regarding superurgent (SU) liver transplantation (LT) for patients with acute liver failure (ALF) are principally based on the Clichy-Villejuif (CV) criteria. The aims of the present study were to study the outcomes of patients registered for SU LT and the factors that were predictive of spontaneous improvement and to determine the usefulness of the CV criteria. All patients listed in France for SU LT between 1997 and 2010 who were 15 years old or older with ALF were included. In all, 808 patients were listed for SU transplantation: 22% with paracetamol-induced ALF and 78% with non-paracetamol-induced ALF. Of these 808 patients, 112 improved spontaneously, 587 underwent LT, and 109 died or left the waiting list because of a worsening condition. The 1-year survival rate according to an intention-to-treat analysis and the survival after LT were 66.3% [interquartile range (IQR), 62.7%-69.7%] and 74.2% (IQR, 70.5%-77.6%), respectively. The factors that were predictive of a spontaneous recovery with ALF-related paracetamol hepatotoxicity were as follows: hepatic encephalopathy grade 0, 1, or 2 [odds ratio (OR), 4.8; 95% confidence interval (CI), 1.99-11.6]; creatinine clearance≥60 mL/minute/1.73 m2 (OR, 4.77; 95% CI, 1.96-11.63), a bilirubin level<200 µmol/L (OR, 21.64; 95% CI, 1.76-265.7); and a factor V level>20% (OR, 5.79; 95% CI, 1.66-20.29). For ALF-related nonparacetamol hepatotoxicity, the factor that was predictive of a spontaneous recovery was a bilirubin level<200 µmol/L (OR, 10.38; 95% CI, 4.71-22.86). The sensitivity, specificity, and positive and negative predictive values for the CV criteria were 75%, 56%, 50%, and 79%, respectively, for ALF due to paracetamol and 69%, 50%, 64%, and 55%, respectively, for ALF not related to paracetamol. The performance of current criteria for SU transplantation could be improved if paracetamol-induced ALF and non-paracetamol-induced ALF were split and 2 other items were included in this model: the bilirubin level and creatinine clearance.

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.

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.

Acute liver failure and liver transplantation

Acute liver failure (ALF) is defined by the presence of coagulopathy (International Normalized Ratio ≥ 1.5) and hepatic encephalopathy due to severe liver damage in patients without pre-existing liver disease. Although the mortality due to ALF without liver transplantation is over 80%, the survival rates of patients have considerably improved with the advent of liver transplantation, up to 60% to 90% in the last two decades. Recent large studies in Western countries reported 1, 5, and 10-year patient survival rates after liver transplantation for ALF of approximately 80%, 70%, and 65%, respectively. Living donor liver transplantation (LDLT), which has mainly evolved in Asian countries where organ availability from deceased donors is extremely scarce, has also improved the survival rate of ALF patients in these regions. According to recent reports, the overall survival rate of adult ALF patients who underwent LDLT ranges from 60% to 90%. Although there is still controversy regarding the graft type, optimal graft volume, and ethical issues, LDLT has become an established treatment option for ALF in areas where the use of deceased donor organs is severely restricted.

Predicting survival after living and deceased donor liver transplantation in adult patients with acute liver failure

BACKGROUND

Post-transplant outcomes for acute liver failure (ALF) are unsatisfactory, and there are debates about the most suitable type of graft. Given the critical shortage of donor organs, accurate assessment of post-transplant outcome in ALF patients is crucial to avoid a futile liver transplantation (LT).

METHODS

A database of 160 consecutive adult ALF patients who underwent primary LT between 2000 and 2009 in a tertiary LT center was analyzed.

RESULTS

The most common causes of ALF were hepatitis B virus infection (30%) and herbal/folk medicine use (30%). Thirty-six (22.5%) and 124 (77.5%) patients underwent deceased-donor LT (DDLT) and adult-to-adult living-donor LT (LDLT), respectively. During a median follow-up period of 38 (range 1-132) months, the DDLT and LDLT groups showed similar patient (P = 0.99) and graft (P = 0.97) survival rates. The overall 1- and 3-year patient survival rates were 78.8 and 74.6%, respectively. Five predictors of patient survival were identified by bootstrapping and multivariate analysis: vasopressor requirement, estimated glomerular filtration rate, serum sodium concentration, recipient age, and donor age, at the time of transplant. By summing scores weighted in each of these predictor categories, we designed a prognostic scoring system (scores from -2 to 20) that estimated 1-year post-transplant mortality from 0 to 100% (c statistic 0.79).

CONCLUSIONS

Long-term outcomes after LDLT and DDLT were comparable in adult patients with ALF. A simple prognostic scoring system that includes 5 predictive variables at the time of LT may help estimate post-transplant survival in ALF patients, regardless of the type of transplant.

Liver transplantation for acute liver failure in Europe: outcomes over 20 years from the ELTR database

BACKGROUND & AIMS

Liver transplantation for acute liver failure (ALF) still has a high early mortality. We evaluated changes during 20 years, and identified risk factors for poor outcome.

METHODS

Donor, graft, and recipient variables from the European Liver Transplant Registry database (January 1988-June 2009), were analysed. Aetiologies and time periods were compared. Three and 12-month survival models were generated from separate training data sets, which were validated. A sub-analysis was performed for recipient older than 50 years.

RESULTS

Four thousand nine hundred and three patients were evaluated. One, 5- and 10-year patient, and graft survival rates were 74%, 68%, 63%, and 63%, 57%, 50%, respectively. Survival was better in 2004-2009 compared to previous quinquennia (p<0.001), despite donors >60 years increased from 1.8% to 21%. A higher incidence of suicide or non-adherence occurred in paracetamol-related ALF (p<0.001). Death or graft loss were independently associated with male recipients (adjusted OR 1.25), recipient >50 years (1.26), incompatible ABO matching (1.93), donors >60 years (1.21), and reduced size graft (1.54). For both 3- and 12-month models, incompatible ABO matching, non-viral aetiology, reduced size graft, and non-UW preservation fluid were associated with increased mortality/graft loss, whereas male recipients and age >50 years were associated only at 12 months. Both models had reasonable discriminative ability with good calibration at 3 months. Recipients >50 years, combined with donors >60 years resulted in 57% mortality/graft loss within the first year.

CONCLUSIONS

Survival after liver transplantation has improved despite increases in donor/recipient age. Recipients >50 years paired with donors >60 years had a very high mortality/graft loss within the first year.

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.

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.

Long-term outcomes of emergency liver transplantation for acute liver failure

Acute liver failure continues to be associated with a high mortality rate, and emergency liver transplantation is often the only life-saving treatment. The short-term outcomes are decidedly worse in comparison with those for nonurgent cases, whereas the long-term results have not been reported as extensively. We report our center's experience with urgent liver transplantation, long-term survival, and major complications. From 1994 to 2007, 60 patients had emergency liver transplantation for acute liver failure. The waiting list mortality rate was 6%. The mean waiting time was 2.7 days. Post-transplantation, the perioperative mortality rate was 15%, and complications included neurological problems (13%), biliary problems (10%), and hepatic artery thrombosis (5%). The 5- and 10-year patient survival rates were 76% and 69%, respectively, and the graft survival rates were 65% and 59%. Recipients of blood group-incompatible grafts had an 83% retransplantation rate. Univariate analysis by Cox regression analysis found that cerebral edema and extended criteria donor grafts were associated with worse long-term survival. Severe cerebral edema on a computed tomography scan pre-transplant was associated with either early mortality or permanent neurological deficits. The keys to long-term success and continued progress in urgent liver transplantation are the use of good-quality whole grafts and a short waiting list time, both of which depend on access to a sufficient pool of organ donors. Severe preoperative cerebral edema should be a relative contraindication to transplantation.

ABO-incompatible adult living donor liver transplantation for hepatocellular carcinoma

Living donor liver transplantation (LDLT) offers timely transplantation for patients with hepatocellular carcinoma (HCC). If ABO-incompatible LDLT is feasible, the need for pretransplantation treatment may be eliminated, which may reduce overall morbidity. In this article, we have described 8 adult HCC patients who successfully underwent LDLT from ABO-incompatible donors. Antirejection therapy included multiple preoperative plasmaphereses, splenectomy, and an immunosuppressive regimen with tacrolimus, methylprednisolone, and mycophenolate mofetil. The maintenance dose of immunosuppression did not differ from that of the ABO-identical cases. In addition, we also performed intrahepatic arterial infusion of prostaglandin E1. In 5 patients, we administered a single dose of rituximab, a chimeric CD20 monoclonal antibody. As a result of this treatment, 6/8 patients are still alive. Our experience has shown that it is possible to control antibody-mediated humoral rejection and other complications in adult ABO-incompatible LDLT.

ABO-incompatible liver transplantation: a pathological analysis of 2 cases

AIM: To observe the pathological features of ABO-incompatible liver transplantation, and to investigate the diagnostic criteria for humoral rejection of liver transplantation.

METHODS: The pathological changes and the deposition of all kinds of immunoglobulins and complements were observed in 2 cases of ABO-incompatible liver transplantation by immunohistochemical and HE staining.

RESULTS: Under light microscope, hepatocyte edema, spotty necrosis, infiltration of lymphacytes and mononuclear cells in portal region were observed in the transplanted livers of both cases. Immunohistochemistry showed mixture of CD3- and CD20-positive cells and different degrees of linear or granular depositions of IgG, IgM, IgA, C4c, C4d and C1q in the liver sinusoidal endothelial cells. One of the cases was diagnosed with light acute cellular rejection accompanied by light humoral rejection, and the other was diagnosed with light liver preservation and reperfusion injury accompanied by light humoral rejection.

CONCLUSION: It may be regard as the evidence of humoral rejection in hepatic tissues that immunoglobulin G accompanied with C4d and other complements diffusely deposits in hepatic sinusoidal endothelial cells.

ABO blood group-related waiting list disparities in liver transplant candidates: effect of the MELD adoption

BACKGROUND

Blood group O candidates remain on the waiting list for a liver transplant for a longer time than candidates of other blood groups. Herein, we analyzed potential factors affecting waiting times in the period that preceded the introduction of the model for end-stage liver disease (MELD) and in MELD era, remarking possible corrections introduced by the adoption of the MELD.

METHODS

Our analysis was entirely based on data obtained from the "Organ Procurement and Transplantation Network", referring to the periods before and after the adoption of the MELD.

RESULTS

In the MELD era, taking into consideration all candidates, the cumulative probability of remaining on the waiting list significantly diminished whereas that of undergoing transplantation significantly increased when compared with the pre-MELD era. However, group O candidates maintained the lowest cumulative probability of undergoing liver transplant, in all MELD classes, and the highest percentage of list removal for death/too sick. What caused the highest disadvantage for group O, in both eras, was the use of group O organs for ABO-compatible transplants, even in the absence of urgency. In candidates receiving ABO-compatible organs a significantly lower graft survival rate was observed compared with candidates receiving ABO-identical organs, even when the analysis was adjusted for the MELD score.

CONCLUSIONS

The introduction of the MELD significantly reduced the waiting time for all candidates as also the shift of group O organs. Limiting ABO-compatible organs exclusively to urgent cases would have a positive effect not only in terms of individual justice, but also terms of in general utility, considering the effect of ABO-matching on graft survival.

ABO-incompatible liver transplantation for critically ill adult patients

ABO incompatible (ABO-In) liver transplant remains a controversial solution to acute liver failure in adults. Adult liver recipients with acute liver failure or severely decompensated end-stage disease, intubated and/or in the intensive care unit, were grouped as ABO-In (n = 14), ABO-compatible (n = 29, ABO-C) and ABO-identical (n = 65, ABO-Id). ABO-In received quadruple immunosuppression with antibody-depleting induction agents (except two), calcineurin inhibitors, antimetabolites and steroids. No significant difference of patient and graft survivals was observed among ABO-In, ABO-C and ABO-Id: graft survivals were 64%, 62% and 67%, respectively, in 1 year and 56%, 54% and 60%, respectively, in 5 years; patient survivals 86%, 69% and 67%, respectively, in 1 year and 77%, 61% and 62%, respectively, in 5 years. Three ABO-In grafts were lost (one hyper-acute rejection and two hepatic artery thrombosis). Surgical and infectious complications were similarly distributed between groups, except the hepatic artery thrombosis, more frequent in ABO-In (2, 14%) than ABO-I (1, 1.5%, P < 0.05). In contrast to previous studies, no significant difference of patient and graft survivals could be observed among all ABO-compatibility settings. Our results suggest that ABO-incompatible transplants should be viewed as an important therapeutic option in adult patients with acute liver failure awaiting an emergency procedure.

B-cell surface marker analysis for improvement of rituximab prophylaxis in ABO-incompatible adult living donor liver transplantation

Although the effectiveness of rituximab has been reported in ABO blood group (ABO)-incompatible (ABO-I) organ transplantation, the protocol is not yet established. We studied the impact of the timing of rituximab prophylaxis and the humoral immune response of patients undergoing ABO-I living donor liver transplantation (LDLT), focusing on clinicopathological findings and the B-cell subset. From July 2003 to December 2005, 30 adult patients were treated with hepatic artery infusion (HAI) protocol without splenectomy for ABO-I LDLT. A total of 17 patients were treated only with HAI (no prophylaxis), and the other 13 were treated with rituximab prophylaxis at various times prior to transplantation. For B-cell study of the spleen, another 4 patients undergoing ABO-I LDLT both with HAI after prophylaxis and eventual splenectomy, and 3 patients with ABO-compatible LDLT with splenectomy were enrolled. The mortality of the 30 patients with HAI, without splenectomy, and with/without rituximab prophylaxis was 33% and the main cause of death was sepsis. Peripheral blood B cells were completely depleted, anti-donor blood-type antibody titer was lower, and clinical and pathological antibody-mediated rejection was not observed in patients with prophylaxis earlier than 7 days before transplantation (early prophylaxis). Early rituximab prophylaxis significantly depleted B cells and memory B cells in the spleen but not in lymph nodes. On the other hand, B cells and memory B cells increased and memory B cells became dominant during antibody-mediated rejection. In conclusion, early prophylaxis with rituximab depletes B cells, including memory B cells, in the spleen and is associated with a trend toward lower humoral rejection rates and lower peak immunoglobulin (Ig)G titers in ABO-I LDLT patients.

Outcomes after identical and compatible orthotopic liver transplantation for fulminant hepatic failure: a single center experience in UK

To analyze the outcomes between identical and compatible liver transplantation (OLT) for fulminant hepatic failure (FHF) from September 1984 to November 2005. The patients were divided in three groups; group 1 (identical), group 2 (compatible) and group 3 (incompatible), according to the donor-recipient blood type matching. We analyzed several outcomes regarding mortality, patient and graft survival, incidence of acute graft rejection during the first postoperative month (30 days), incidence of biliary complications and indications of re-transplantation. We also analyzed the relationship of Coomb's positive test with postoperative hemolysis to all the above mentioned factors. During the study period, 168 males and 112 females underwent their first OLT for FHF, with 37.1% overall mortality and 42.1% overall graft failure rate. The results between group 1 (203 patients) and group 2 (73 patients) were comparable. A statistically significant difference was recorded in 1 year and overall graft survival between group 1 and group 2 (P = 0.049 and log-rank = 0.035 respectively). Coomb's positive test did not influence the outcomes. OLT in FHF can be safely carried out whether the donor organs are identical or compatible. Hemolysis (Coomb's positive test) after identical or compatible OLT does not influence the outcomes.

Development of a Novel ELISA for Detection of Anti-A and Anti-B Antibodies in Recipients of ABO-Incompatible Living Donor Liver Grafts

The survival rate in ABO-incompatible (ABO-I) liver transplantation was much lower than that in ABO-compatible recipients for the early experiences. It is therefore essential to develop the precise and fast measurement of anti-A and anti-B antibodies (Abs) to prevent humoral rejection in ABO-I liver transplantation. Agglutination titer has been the standard method to measure these Abs, but the interpretation of the results is subject to bias. Here, we have developed an objective and quantitative enzyme-linked immunosorbent assay (ELISA) to measure anti-A and anti-B Abs. This test requires only a small amount (10 microl) of recipient's serum. We applied the newly developed ELISA to monitor living donor liver transplant recipients and investigated the correlation between ELISA and agglutination titer. The Spearman's correlation coefficient for Abs ranged from 0.461 to 0.812. Moreover, in one case of humoral rejection, the increase of Abs was detected by ELISA one day earlier than by the agglutination titer. In conclusion, our ELISA method proved useful to detect an increase of anti-A and anti-B Abs titers at an early stage, thereby contributing to a prompt treatment of humoral rejection due to ABO-I.

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

Transplanting blood group A, B, or O (ABO)-incompatible (ABO-I) liver grafts has resulted in lower patient and graft survival with an increased incidence of vascular and biliary complications and rejection. We report that, without modification of our standard immunosuppression protocol, crossing blood groups is an acceptable option for children requiring liver transplantation. In our study, ABO-I liver grafts -- regardless of recipient age -- have comparable long-term survival (mean follow-up of 3.25 yr) with ABO-compatible grafts without any difference in rejection, vascular or biliary complications. From January 1, 1999 to October 1, 2005, we studied 138 liver transplants in 121 children: 16 (13.2%) received an ABO incompatible liver allograft. One-year actuarial patient survival for ABO-matched grafts vs. ABO-I grafts was 93.0% and 100%, respectively, whereas graft survival was 83.4% and 92.3%. Additionally, 6 of 16 (37.5%) ABO-I transplanted children had 8 rejection episodes, whereas 47 patients (44.8%) had 121 rejection episodes in the ABO-compatible group. There were no vascular complications and 2 biliary strictures in the ABO-I group. Plasmapheresis was not used for pretransplantation desensitization and was only required in 1 posttransplantation recipient. No child was splenectomized. Six of the 16 children were older than 13 yr of age, suggesting the possibility of successfully expanding this technique to an older population. In conclusion, our outcomes may support the concept of using ABO-I grafts in a more elective setting associated with split and living donor liver transplants.

Use of "O" blood group liver donors for nonidentical recipients: does this represent a double penalty for "O" blood group candidates?

Candidates for liver transplantation with AB blood group remain on the waiting list for shorter times than candidates with O blood group. To investigate the reasons of this phenomenon, we analyzed data concerning deceased donors, liver transplant candidates, and liver first transplants performed in the United States during the period 2003 to 2004. The percentage of deceased donors with blood group O was higher than that of candidates on the waiting list with the identical blood group (P < .05). On the other hand, for blood groups A, B, and AB an opposite situation was observed: the percentages of deceased donors were significantly lower compared to those candidates with the identical blood group (A blood group, P < .05; B and AB blood groups, P < .001). When the number of grafts from deceased donors was compared with the number of those effectively transplanted, a negative difference for O blood group recipients was found (ie, transplanted livers < harvested livers) and a positive one for AB blood group (transplanted livers > harvested livers) were found. Since disease progression and causes of acute liver failure, including primary nonfunction and hepatic artery thrombosis leading to retransplantation were similar among the various blood groups, we concluded that the shorter waiting time for AB patients in the pre-MELD era was due to the use of compatible livers to the detriment of group O recipients.

Urgent Lung Transplantation in Spain

BACKGROUND

Lung donors are scarce and lung transplantation resources are limited. Because urgent lung transplantation (ULT) is assumed to yield poor results, its use is controversial. We assessed the outcome of patients who received ULT seeking to determine effectiveness and risk factors.

PATIENTS AND METHOD

We collected data from every ULT performed in Spain during 5 years (1998-2002). The survival of patients was studied using Kaplan-Meier, Cox regression, and chi-square statistical analyses. We compared outcomes and perioperative mortality (over 30 days) for ULT procedures, analyzing the influence of certain variables (age, type of transplant, diagnosis, indication, and time on waiting list).

RESULTS

Among 109 patients proposed for the procedure, 73 ULT were performed during the period. The most frequent indications were pulmonary fibrosis (19 cases) and cystic fibrosis (19 cases), showing the worst and the better survival rates, respectively. The bad prognosis, determined mainly by per operative mortality rate (35.62%), was significantly affected by age (worse for patients older than 40 years) and type of LT (single worse than double; P < .05). A longer time waiting for ULT also showed a worse prognosis (P < .005).

CONCLUSIONS

Long-term survival after ULT shows that the procedure is effective and efficient for a select group of patients, despite the high per operative risk. ULT should be reserved for younger patients. It also requires performance in a short period (just a few days), initially rejecting a single lung transplant, provided that the patient is adequately monitored.

ABO-incompatible liver transplantation: a new therapeutic option for patients with acute liver failure in Chile

Different ways have been suggested to expand donor numbers for liver transplantation. Transplantation using ABO-incompatible hepatic grafts has recently been a controversial issue due to the high risk of hyperacute rejection mediated by preformed anti-ABO antibodies. We report three patients with acute liver failure who were transplanted with ABO-incompatible livers: A to O in two patients and A to B in one case. We used pre- and posttransplant total plasma exchange, splenectomy, and triple immunosuppression. All three patients are alive; one graft was lost, probably secondary to thrombotic microangiopathy with low isohemagglutinin titers of 1:8. One patient developed acute cellular rejection that was reversed with a bolus of methylprednisolone. No antibody-mediated rejection occurred. Financial and infectious considerations have to be considered. In our series, the final liver transplantation cost was higher than average for acute liver failure. Plasmapheresis has the highest cost of all the additional procedures. ABO-incompatible liver transplantation, because of the splenectomy it requires, has been associated with more infections due to encapsulated organisms. However, with splenectomy in our three patients, none had infections due to these bacteria. In our country, we do not consider ABO-incompatible liver transplantation as a first-line option, except for highly selected patients.

FK778 and FK506 Combination Therapy to Control Acute Rejection after Rat Liver Allotransplantation

BACKGROUND

In organ transplantation, several immunosuppressants are currently used to control graft rejection. Clinically, no single immunosuppressive agent can completely prevent posttransplantation immunoreaction; thus, combination therapy is usually performed. Novel agents with more powerful immunosuppressive activity and less toxicity need to be developed.

METHODS

Lewis rat livers were orthotopically transplanted into Brown-Norway recipients. FK778 was administered orally from day 0 to day 6 to prevent acute rejection and from day 7 to day 13 to rescue ongoing rejection. To assess the combined effects, recipients were treated with intramuscular injection of FK506 and oral administration of FK778 from day 0 to day 6. Blood chemistry and histopathologic findings were measured to determine the patient's general condition and the graft condition. Allospecific antibodies were measured using enzyme-linked immunosorbent assays. The FK778 trough concentration was examined by using high-performance liquid chromatography.

RESULTS

The acute immune response was suppressed by FK778 alone in a dose-dependent manner. The optimal FK778 dosage was determined to be 20 mg/kg per day, because adverse effects (weight loss and intestinal bleeding) occurred at 30 mg/kg per day. FK778 treatment from day 7 to day 13 rescued liver grafts from ongoing rejection. The intramuscular FK506 (0.125 mg/kg per day) injection and the oral FK778 (20 mg/kg per day) gavages suppressed acute liver graft rejection effectively and maintained better graft condition compared with monotherapy. CONCLUSIONS.: FK778 treatment effectively prevented acute rejection and rescued ongoing rejection after liver transplantation. The optimal dosage was determined to be 20 mg/kg per day. Combination therapy with FK506 was more beneficial than FK778 monotherapy.

Antibody-Mediated Rejection after Adult ABO-Incompatible Liver Transplantation Remedied by Gamma-Globulin Bolus Infusion Combined with Plasmapheresis

Adult ABO-incompatible liver transplantation has been known to be associated with markedly desperate outcomes. Antibody-mediated rejection (AMR) has been recognized as one of the primary causes of these desperate outcomes, but its clinical features and significance have not been well understood. Recently, some clinicians have succeeded in improving the outcome of adult ABO-incompatible liver transplantation. However, in some transplant patients undergoing these treatments, AMR has still led to graft losses. We recently encountered two patients suffering from AMR after adult ABO-incompatible liver transplantation and remedied their conditions with various therapeutic modalities including direct hepatic infusion therapy and gamma-globulin bolus infusion therapy combined with plasmapheresis. In this article, we describe the clinical features of these patients and the therapeutic strategies we applied. Furthermore, we show the histologic course of the recovery from AMR in the second patient, from whom we were able to extract serial liver biopsies.

Early death from paracetamol (acetaminophen) induced fulminant hepatic failure without cerebral oedema

BACKGROUND

Paracetamol overdose is a frequent cause of fulminant hepatic failure. In fatal cases the most frequent causes of death are cerebral oedema in the early phase or sepsis and multiorgan failure later. However some patients do not fit this pattern.

AIM

To review cause of death in paracetamol induced fulminant hepatic failure.

METHODS

We reviewed all fatal cases of paracetamol induced fulminant hepatic failure in our liver unit between 1995 and 2000.

RESULTS

Twenty one patients died without liver transplantation and post mortem examinations were performed on all. Significant cerebral oedema was present in 13 patients and absent in eight. The patients without cerebral oedema were significantly older (55.4+/-5.3 versus 36.3+/-3 years: P=0.0034), had a lower arterial pH on admission (pH 7.0+/-0.03 versus 7.3+/-0.05: P=0.0008), a shorter interval between overdose and death (3.75+/-0.7 versus 7.6+/-1.3 days: P=0.043) and a shorter interval between admission and death (1.9+/-0.6 versus 5.7+/-1.0 days: P=0.0097) than patients with cerebral oedema. The cause of death in the sub-group of patients without cerebral oedema was predominantly cardiovascular collapse with rapidly progressive resistant hypotension and/or cardiac arrest. No source of sepsis was identified in 7/8 patients without cerebral oedema.

CONCLUSIONS

In this series the most frequent causes of death were cerebral oedema or cardiovascular collapse. Patients without cerebral oedema appear to form a distinct subgroup associated with early mortality and may require specific management strategies.