ABO-incompatible liver transplantation with no immunological graft losses using total plasma exchange, splenectomy, and quadruple immunosuppression: evidence for accommodation

Risk factors for antibody-mediated rejection in ABO blood-type incompatible and donor-specific antibody-positive liver transplantation

Antibody-mediated rejection (AMR) is a refractory rejection after ABO blood-type incompatible (ABOi) or donor-specific antibody (DSA)-positive liver transplantation (LT). Pretransplant rituximab desensitization dramatically reduced posttransplant AMR development; however, risk factors for AMR in the rituximab era remain unclear in both ABOi living-donor LT (ABOi-LDLT) and preformed DSA-positive LT (pDSA-LT). Of our 596 adult LDLTs (≥18 y) after rituximab introduction (2004-2019), 136 were ABOi-LDLT (22.8%). After excluding retransplants (9), acute liver failure (7), and protocol deviations (16), 104 ABOi-LDLTs were finally enrolled. Of these, 19 recipients developed AMR, 18 of which occurred within 2 weeks after transplantation (95%). ABOi-AMR significantly worsened graft and recipient survival than those without ( p =0.02 and 0.04, respectively). Model for End-stage Liver Disease (MELD) ≤13 (OR: 5.15 [1.63-16.3], p =0.005) and pre-rituximab anti-ABO IgM-titer ≥128 (OR: 3.25 [1.05-10.0], p =0.03) were identified as independent risk factors for ABOi-AMR development. Recipients fulfilling both factors showed significantly worse survival rates than those who did not ( p =0.003). Of 352 adult LTs, after introducing the LABScreen Single Ag method (2009-2019), pDSA with mean fluorescence intensity (MFI) ≥500 was detected in 50 cases (14.2%). After excluding 10 ABOi-LDLTs, 40 pDSA-LTs were finally analyzed, of which 5 developed AMR. The combination of high-titer (sum-MFI ≥10,000) and multi-loci pDSAs was a significant risk factor for pDSA-AMR development ( p <0.001); however, it did not affect the 5-year recipient survival compared with those without ( p =0.56). In conclusion, preoperative MELD ≤13 and pre-rituximab anti-ABO IgM-titer ≥128 for ABOi-LDLT, and the combination of sum-MFI ≥10,000 and multi-loci pDSAs for pDSA-LT, are risk factors for AMR in the era of rituximab desensitization. Characteristically, ABOi-AMR significantly deteriorated graft and recipient survival, whereas pDSA-AMR did not.

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.

Evaluating the Potential for ABO-incompatible Islet Transplantation: Expression of ABH Antigens on Human Pancreata, Isolated Islets, and Embryonic Stem Cell-derived Islets

BACKGROUND

ABO-incompatible transplantation has improved accessibility of kidney, heart, and liver transplantation. Pancreatic islet transplantation continues to be ABO-matched, yet ABH antigen expression within isolated human islets or novel human embryonic stem cell (hESC)-derived islets remain uncharacterized.

METHODS

We evaluated ABH glycans within human pancreata, isolated islets, hESC-derived pancreatic progenitors, and the ensuing in vivo mature islets following kidney subcapsular transplantation in rats. Analyses include fluorescence immunohistochemistry and single-cell analysis using flow cytometry.

RESULTS

Within the pancreas, endocrine and ductal cells do not express ABH antigens. Conversely, pancreatic acinar tissues strongly express these antigens. Acinar tissues are present in a substantial portion of cells within islet preparations obtained for clinical transplantation. The hESC-derived pancreatic progenitors and their ensuing in vivo-matured islet-like clusters do not express ABH antigens.

CONCLUSIONS

Clinical pancreatic islet transplantation should remain ABO-matched because of contaminant acinar tissue within islet preparations that express ABH glycans. Alternatively, hESC-derived pancreatic progenitors and the resulting in vivo-matured hESC-derived islets do not express ABH antigens. These findings introduce the potential for ABO-incompatible cell replacement treatment and offer evidence to support scalability of hESC-derived cell therapies in type 1 diabetes.

ABO incompatible living donor liver transplant with antibody titer of 1:4: First case report from Pakistan

Introduction and importance

The most common reason for live liver donor rejection is ABO incompatibility. With breaching this incompatibility barrier, probably an additional 25%–35% of liver transplantation (LT) procedures would become possible. Also, ABOi-LT can be lifesaving in acute settings. Initially, ABOi-LT reported a poor prognosis secondary to antibody-mediated rejection (AMR) which is more common in ABOi allograft recipients. AMR may be avoided by desensitization. Various desensitization protocols are practiced globally, however, there is no consensus available on the optimal desensitization protocol for the ABOi-LT. The ABO-incompatible (ABOi) can expand the liver donor pool tremendously. We report the first case of ABO incompatible-liver transplantation (ABOi-LT) from Pakistan.

Case presentation

A 48 years old male, presented with decompensated liver diseaseand hepatocellular carcinoma secondary to HCV infection. LT was advised as the optimal modality of treatment. Due to the non-availability of a compatible donor, ABOi-LT was planned.His daughter agreed to donate.Pre-LT desensitization was started on the 23rd-day pre-LT with intravenous (I/V) rituximab 700 mg/body (375 mg/m²) along with I/V Bortezomib 2mg (1.3 mg/m²⁾. Bortezomib was repeated subcutaneously (S/C) on the 20th, 16th, and 13th days pre-LT. One week before LT oral Mycophenolate mofetil 500 mg and Tacrolimus 1 mg were started twice daily. Therapeutic plasmapheresis was done on the 5th, 3rd, and 1st-day pre-LT. Per-operatively, Basiliximab was administeredI/V with a dose of 0.8 gm/kg during the anhepatic phase. Anti-A & Anti-B titer level was determined on the 5th day before plasmapheresis and repeated on the 2nd and 1st-day pre-LT. Then post-LT plasmapheresis was done onthe 15th day and at 3 months. The CD 19 activity was determined one day before LT and on the 15th-day post-LT. His LT was performed uneventfully and was discharged on the 15th postoperative day (POD). However, on the 26th POD, he was diagnosed with left subclavian vein thrombosis which was treated successfully with anticoagulation therapy for 6 months. Till the last follow up patient is doing well.

Clinical discussion

Desensitization is the removal of preformed anti-ABO antibodies and depleting serum B cells production. Antibody-mediated rejection irreversibly damages the graft and predisposes it to graft failure. The prognosis of ABOi-LT has dramatically improved since the introduction of desensitization protocols.

Conclusion

Antibody-mediated rejection may be avoided by desensitization. The intravascular infusion therapies and splenectomy can be omitted from the desensitization protocol. ABO-i LT can tremendously increase the liver donor pool.

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Antibody-mediated rejection could be avoided by desensitization.

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There is no consensus available on a standardized ABOi-LDLT desensitization protocol.

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We report the first case of ABOi-LDLT from Pakistan with an antibody titer of 1:4.

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We used bortezomib along with rituximab and plasmapheresis as a desensitization protocol.

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In our case, we managed to reduce the anti-body titer to as low as 1:4 before the transplant.

Protection of transplants against antibody-mediated injuries: from xenotransplantation to allogeneic transplantation, mechanisms and therapeutic insights

Long-term allograft survival in allotransplantation, especially in kidney and heart transplantation, is mainly limited by the occurrence of antibody-mediated rejection due to anti-Human Leukocyte Antigen antibodies. These types of rejection are difficult to handle and chronic endothelial damages are often irreversible. In the settings of ABO-incompatible transplantation and xenotransplantation, the presence of antibodies targeting graft antigens is not always associated with rejection. This resistance to antibodies toxicity seems to associate changes in endothelial cells phenotype and modification of the immune response. We describe here these mechanisms with a special focus on endothelial cells resistance to antibodies. Endothelial protection against anti-HLA antibodies has been described in vitro and in animal models, but do not seem to be a common feature in immunized allograft recipients. Complement regulation and anti-apoptotic molecules expression appear to be common features in all these settings. Lastly, pharmacological interventions that may promote endothelial cell protection against donor specific antibodies will be described.

Massive Polycystic Liver with a Poor Performance Status Successfully Treated by ABO-incompatible Adult Living-donor Liver Transplantation While Overcoming Complications

We encountered a 47-year-old woman with polycystic liver disease (PLD) and severe malnutrition successfully treated by living-donor liver transplantation (LDLT). Her PLD became symptomatic with abdominal distension and appetite loss. Transcatheter arterial embolization and percutaneous cyst drainage failed to improve her symptoms. ABO-incompatible LDLT from her husband was performed after rituximab administration and mycophenolate mofetil introduction. Although she showed severe postoperative complications, she ultimately regained the ability to walk and was discharged. Because advanced PLD cases are difficult to treat conservatively or with surgery, like fenestration and hepatectomy, liver transplantation should be considered before it becomes too late.

Excellent outcome following emergency deceased donor ABO-incompatible liver transplantation using rituximab and antigen specific immunoadsorption

BACKGROUND

The acceptance of ABO-incompatible (ABOi) liver grafts will expand the donor pool for a patient in urgent need for a liver transplantation (LT). Here we report our results with emergency ABOi DD (deceased donor) LT using rituximab and antigen specific immunoadsorption.

PATIENTS AND METHODS

2009 to 2019 we performed 20 ABOi DD LTs (adults n = 17, children n = 3) for patients in urgent need for a LT. Immunosuppression consisted of rituximab (n = 20) and basiliximab (n = 15) or anti-thymocyte globuline (n = 4), intravenous immunoglobulin (IVIG; n = 6), tacrolimus, prednisolone and mycophenolate mofetil. Fifteen patients were treated with IA (n = 14) or both IA and plasmapheresis (PP; n = 1) pre-transplant and 18 patients were treated with IA (n = 15) or both IA and PP (n = 3) post-transplant. The median pre-transplant MELD- score was 40 (range 18-40). Patient and graft survival and complications were compared to a 1:4 case matched control group of ABO-identical or compatible (ABOid/c) DDLT.

RESULTS

The 1-, 3- and 5-year patient and graft survival rates were 85, 85 and 78% for the ABOi recipients and not significantly different compared to ABOid/c controls. Only one ABOi patient developed antibody-mediated rejection.

CONCLUSION

Patient and graft survival after emergency ABOi DDLT using rituximab and immunoadorption was equal to ABOid/DDLT. ABOi DD LT was a successful approach to expand the donor pool for patients in urgent need for a liver graft.

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.

Is ABO-Incompatible Living Donor Liver Transplantation Really a Good Alternative for Pediatric Recipients?

BACKGROUND

ABO-incompatible (ABOi) living donor liver transplantation (LDLT) has been proposed to compensate for donor shortage. To date, few studies have reported detailed ABOi LDLT results in large series of pediatric patients. C4d complement deposition in graft capillaries has been reported to be associated with antibody-mediated rejection in solid organ transplantation.

METHODS

A retrospective case-control study was conducted, comparing clinical outcomes of each of 34 consecutive pediatric ABOi LDLT recipients with those of 2 non-ABOi pairs (n = 68), matched according to pre-transplant diagnostic criteria, age, and date of transplantation. In addition, we studied the C4d immunostaining pattern in 22 ABOi and in 36 non-ABOi recipients whose liver biopsy was performed within the first 4 post-transplant weeks for suspected acute rejection.

RESULTS

The incidence of biliary complications was higher in ABOi recipients (p < 0.05), as were the incidence of acute humoral rejection (p < 0.01) and the incidence of retransplantation (p < 0.05). All children who required retransplantation were older than 1 year at the time of ABOi LDLT. Positive C4d immunostaining was observed in 13/22 (59%) ABOi recipients versus 3/36 (8.3%) non-ABOi recipients (p < 0.0001).

CONCLUSIONS

ABOi LDLT is a feasible option for pediatric end-stage liver disease but carries increased risks for the recipient, especially for children older than 1 year, even with a specific preparation protocol. C4d immunostaining may be a hallmark of acute humoral rejection in ABOi liver transplantation.

Anaesthetic implications and transfusion practices in ABO incompatible living donor liver transplantation: Case series

ABO incompatible liver transplants (ABOi LT) are considered as a life-saving option when compatible donor grafts are unavailable. Fourteen adults (right lobe graft) and three children (left lateral segment/lobe) who underwent ABOi LT from living donors between 2011 and 20 period were analysed for transfusions and desensitisation protocols. All recipients received packed red blood cells (PRBC) of their own group. AB plasma that does not contain any antibody was transfused in eight patients and donor group plasma in others. None of the patients developed transfusion related complications. Plasmapheresis and rituximab/bortezumab desensitisation was practised in 11 patients, only rituximab in four, only plasmapheresis in one, and no treatment in a 1 year child. Rejection was manifest in three patients while nine patients developed infections and sepsis. A working knowledge of the blood and product transfusions in ABOi LT is crucial for the anaesthesiologist. Perioperative management and impact of desensitisation protocol are discussed.

Characteristics of Immunoglobulin M Type Antibodies of Different Origins from the Immunologic and Clinical Viewpoints and Their Application in Controlling Antibody-Mediated Allograft Rejection

Antibody-mediated allograft rejection (AMR) hinders patient prognosis after organ transplantation. Current studies concerning AMR have mainly focused on the diagnostic value of immunoglobulin G (IgG)-type donor-specific antihuman leukocyte antigen antibodies (DSAs), primarily because of their antigen specificity, whereas the clinical significance of immunoglobulin M (IgM)-type DSAs has not been thoroughly investigated in the context of organ transplantation because of their nonspecificity against antigens. Although consensus regarding the clinical significance and role of IgM antibodies is not clear, as discussed in this review, recent findings strongly suggest that they also have a huge potential in novel diagnostic as well as therapeutic application for the prevention of AMR. Most serum IgM antibodies are known to comprise natural antibodies with low affinity toward antigens, and this is derived from B-1 cells (innate B cells). However, some of the serum IgM-type antibodies reportedly also produced by B-2 cells (conventional B cells). The latter are known to have a high affinity for donor-specific antigens. In this review, we initially discuss how IgM-type antibodies of different origins participate in the pathology of various diseases, directly or through cell surface receptors, complement activation, or cytokine production. Then, we discuss the clinical applicability of B-1 and B-2 cell-derived IgM-type antibodies for controlling AMR with reference to the involvement of IgM antibodies in various pathological conditions.

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.

ABO-nonidentical liver transplantation from a deceased donor and clinical outcomes following antibody rebound: A case report

BACKGROUND

Although ABO-nonidentical and ABO-incompatible liver transplantation (LT) are other options for end-stage liver disease treatment, the development of antibodies against blood group antigens (anti-A/B antibodies) is still a challenge in managing and follow-up of the recipients.

CASE SUMMARY

A 56-year-old male with end-stage liver disease with rapid deterioration and poor prognosis was considered to receive a deceased ABO-nonidentical liver graft. All required tests were performed according to our pre-LT diagnostic protocol. The orthotopic LT procedure involving O+ donor and A1B+ recipient was performed. Our treatment strategy to overcome the antibody‐mediated rejection included a systemic triple immunosuppressive regimen: methylprednisolone, mycophenolate mofetil, and tacrolimus. The immunological desensitization consisted of the chimeric anti-CD20 monoclonal antibody rituximab and intravenous immunoglobulins. The patient was also on antibiotic treatment with amoxicillin/clavulanate, cefotaxime, and metronidazole. On the 10^th postoperative day, high titers of IgG anti-A and anti-B antibodies were found in the patient’s plasma. We performed a liver biopsy, which revealed histological evidence of antibody-mediated rejection, but the rejection was excluded according to the Banff classification. The therapy was continued until the titer decreased significantly on the 18^th postoperative day. Despite the antibiotic, antifungal, and antiviral treatment, the patient deteriorated and developed septic shock with anuria and pancytopenia. The conservative treatment was unsuccessful, which lead to the patient’s fatal outcome on the 42^nd postoperative day.

CONCLUSION

We present a patient who underwent ABO-nonidentical LT from a deceased donor. Even though we implemented the latest technological advancements and therapeutic approaches in the management of the patient and the initial results were promising, due to severe infectious complications, the outcome was fatal.

ABO-Incompatible Adult Living Donor Liver Transplantation in the Era of Rituximab: A Systematic Review and Meta-Analysis

Aim

The primary aim of this study is to compare the short- and long-term outcomes between ABO-incompatible (ABOi) adult living donor liver transplantation (ALDLT) with rituximab prophylaxis and ABO-compatible (ABOc) ALDLT.

Background

The strategy of ABOi liver transplantation (LT) was originated initially to increase the donor pool and to enable liver transplantation in emergency conditions. However, ABOi ALDLT remains a controversial approach in comparison to ABOc ALDLT.

Methods

PubMed, Embase, and the Cochrane Library study search were accomplished to recognize studies comparing ABOi and ABOc ALDLT. Meta-analyses were conducted based on the evaluation of heterogeneity using a fixed-effect model and a random-effect model to assess the short- and long-term outcomes following ABOi ALDLT with rituximab prophylaxis.

Results

Nine studies comprising a total of 3,922 patients (ABOi = 671 and ABOc = 3,251) were identified. There was no significant difference between ABOi and ABOc groups for 1-year, 3-year, and 5-year OS and graft survival, respectively. Moreover, 1-year and 3-year OS and DFS were similar between both groups for HCC patients. However, ABOi ALDLT had higher incidences of CMV infection, AMR, overall biliary complications, and biliary stricture than ABOc ALDLT and had other comparable postoperative complications.

Conclusion

Our meta-analysis included studies comparing ABOi and ABOc ALDLT after the introduction of rituximab in a desensitization protocol for ABOi ALDLT. The results of ABOi ALDLT were comparable with those of ABOc ALDLT. However, biliary complications, CMV infection, and AMR remain a concern in the era of rituximab.

ABO-Incompatible Liver Transplantation - A Review of the Historical Background and Results

ABO-incompatible liver transplantation (ABOi LT) using conventional immunosuppression has been considered a contraindication due to the high risk for antibody-mediated complications potentially resulting in graft loss. However, organ shortage has led to the development of anti-A/B antibody reducing immunosuppressive protocols which have made the outcome after living donor (LD) ABOi LT equivalent to that achieved with LD ABO-compatible (ABOc). The experience of deceased donor (DD) ABOi LT is however still limited. In this article, we discuss the historical background and the results after ABOi LT, in the setting of both LD and DD transplantation. We also discuss the remaining hurdles and future strategies in the breaching of the ABO barrier for LT.

Feasibility of Monotherapy by Rituximab Without Additional Desensitization in ABO-incompatible Living-Donor Liver Transplantation

BACKGROUND

Rituximab is a cornerstone in the regimens of desensitization for ABO-incompatible living-donor liver transplantation (ABO-i LDLT) that makes this modality an acceptable option for liver transplantation. Plasmapheresis (PP) to reduce anti-ABO antibody titer and local infusion (LI) therapy were practiced as the strategies for desensitization before the application of rituximab and were reported as additional treatments. The aim of this study was to clarify the feasibility of monotherapy by rituximab without any additional desensitization treatments in ABO-i LT.

METHODS

Forty patients receiving ABO-i LDLT with rituximab were enrolled in this retrospective study. The patients were divided into 2 groups: the rituximab with pretransplant PP and posttransplant LI (RPL) group (n = 20) and the rituximab monotherapy (RM) without any additional treatment group (n = 20). The groups were then compared in terms of the rates of patient survival, antibody-mediated rejection (AMR), and infection.

RESULTS

The 1-, 3-, and 5-year patient survival rates were 85%, 85%, and 85% in the RPL group and 89%, 80%, and 80% in the RM group, respectively. There was no significant difference in patient survival between the 2 groups. There were no episodes of AMR in either group. The RM group had a lower rate of fungal and viral infections than the RPL group.

CONCLUSIONS

Pretransplant rituximab without additional treatments yielded satisfactory outcomes comparable to that with additional treatments, such as PP and LI.

Application of Pediatric Donor Livers After Circulatory Death in Adult Liver Transplantation: A Single-Center Experience

OBJECTIVES

This study aimed to investigate the outcomes of adult liver transplant procedures using grafts from pediatric donors after circulatory death.

MATERIALS AND METHODS

We retrospectively analyzed the data of 19 pediatric-to-adult liver transplant procedures from July 2013 to May 2016 in our hospital. Nineteen adult liver transplant procedures were performed using livers from pediatric donors after circulatory death.

RESULTS

We performed 18 orthotopic and 1 piggyback liver transplant procedure. The median graft-to-recipient weight ratio was 1.26% (range, 0.86% to 2.46%). The median warm and cold ischemia times were 11 minutes (range, 8-20 min) and 638 minutes (range, 200-843 min), respectively. Complications after the operation included postoperative pulmonary infection (8 patients), fungal infection (1 patient), cytomegalovirus infection (1 patient), hepatic artery thrombosis and biliary stricture (1 patient), portal vein stenosis (1 patient), and graft failure (2 patients). For patients with graft failure, 1 patient received retransplant and 1 died. The patients were followed for 22.44 months (range, 9.63-44.07 mo) after transplant and showed normal liver function and good health. The 3-year survival rates of grafts and patients were 89.47% and 94.74%, respectively.

CONCLUSIONS

Appropriate evaluation of donors and recipients and accurate intraoperative and postoperative treatment can ensure successful application of livers from pediatric donors after circulatory death in adult recipients.

Acute Liver Failure

Acute liver failure (ALF) is a life-threatening condition of heterogeneous etiology. Outcomes are better with early recognition and prompt initiation of etiology-specific therapy, intensive care protocols, and liver transplantation (LT). Prognostic scoring systems include the King's College Criteria and Model for End-stage Liver Disease score. Cerebral edema and intracranial hypertension are reasons for high morbidity and mortality; hypertonic saline is suggested for patients with a high risk for developing intracranial hypertension, and when it does, mannitol is recommended as first-line therapy. Extracorporeal liver support system may serve as a bridge to LT and may increase LT-free survival in select cases.

Role of spleen in hepatic ischemia reperfusion injury: Splenic congestion during ischemia accelerates leukocyte infiltration within the liver after reperfusion

AIM

The precise mechanism by which prophylactic splenectomy reduces hepatic ischemia-reperfusion injury (IRI) are still unclear. In this study, we focused on the histological changes of spleen during hepatic IRI, and tested how splenectomy provided cytoprotective effects against hepatic IRI.

METHODS

Rats underwent 70% warm hepatic IRI with or without splenectomy prior to IRI. To determine whether splenic congestion by itself induces liver damage in the absence of hepatic IRI, we also undertook a splenic vein clamp model.

RESULTS

Liver injury and macrophage and neutrophil infiltration into the liver after reperfusion were significantly depressed in the animals with prophylactic splenectomy, compared to those without splenectomy. Histology of the spleens showed noted congestion during hepatic ischemia (hepatic hilar clamp), which promptly disappeared after declamping. At 6 and 24 h after reperfusion, the spleens showed remarkable recongestion and parenchymal damage, and the splenic venous level of interleukin-2, which is secreted by T cells and enhances macrophage recruitment, and its mRNA levels within the spleen were significantly elevated. In the splenic vein clamp model, the splenic vein clamp by itself produced a certain liver injury and macrophage infiltration within liver even without hepatic IRI.

CONCLUSION

Spleen plays an important role as an accelerator in hepatic IRI, because splenic congestion and parenchymal damage during ischemia-reperfusion promote splenic IL-2 excretion and macrophage infiltration within the liver, which in turn exacerbate hepatic injury.

ABO-Incompatible Living Donor Liver Transplantation in Focus of Antibody Rebound

BACKGROUND

Living donor liver transplantation (LDLT) is an option to expand the donor organ pool for patients with life-threatening diseases who cannot be supplied with a cadaver organ. Next to the donor risks, complications after ABO-incompatible LDLT (ABOi LDLT) in the recipient are subject to controversial discussion. Improvement in ABOi graft survival rates have been achieved with plasma treatment procedures (PTP) and immunosuppression but antibody-mediated rejection (AMR) and graft loss still occur.

METHODS

Since 2008, we have prepared 10 patients for ABOi LDLT. Seven of the 10 patients for transplantation had hepatocellular carcinoma (HCC).

RESULTS

All patients underwent PTP before and after ABOi LDLT as well as immunosuppression according to the treatment schedule. We did not use anti-CD20 monoclonal antibodies in the transplant setting. We transplanted 6 of 10 preconditioned patients. After 3 years, 5 of the 6 transplanted patients were still alive.

CONCLUSION

Even if B-cell depletion with anti-CD 20 treatment in the setting of ABOi LDLT is commonly accepted, our center successfully administered only quadruple drug immunosuppression combined with PTP. Especially patients with HCC had a high titer increment also pre-transplantation and were at high risk for arterial thrombosis and graft loss.

Splenectomy is not indicated in living donor liver transplantation

Simultaneous splenectomy (SPX) is preferentially performed in living donor liver transplantation (LDLT) to modulate portal flow; increase postoperative platelet count, especially among those with hepatitis C virus (HCV) infection; and modulate the immunologic status in ABO-incompatible cases. The negative effects of the procedure, however, are not well established. Records of 395 LDLTs performed at our institution, including 169 (42.8%) patients with simultaneous SPX and 226 (57.2%) patients with spleen preservation, were reviewed with special reference to the simultaneous SPX cases. The most common indication for SPX was HCV-related disease (n = 114), followed by low preoperative platelet count (n = 52), and other reasons (n = 3). Simultaneous splenectomy did not increase the platelet count in the early postoperative period, but the incidence of reoperation for postoperative hemorrhage was increased, mainly at the SPX site, within the first week. In addition, the operative time, intraoperative blood loss, and incidence of lethal infectious disease were significantly higher in the SPX group, whereas the incidence of small-for-size syndrome was comparable between groups. Finally, SPX was an independent predictor for both postoperative hemorrhage (odds ratio [OR] = 2.451; 95% confidence interval [CI] = 1.285-4.815; P = 0.006) and lethal infectious complication (OR = 3.748; 95% CI = 1.148-14.001; P = 0.03). In conclusion, on the basis of the present findings, we do not recommend simultaneous SPX in LDLT. Liver Transplantation 22 1526-1535 2016 AASLD.

Current techniques for AB0-incompatible living donor liver transplantation

For a long time, it was considered medical malpractice to neglect the blood group system during transplantation. Because there are far more patients waiting for organs than organs available, a variety of attempts have been made to transplant AB0-incompatible (AB0i) grafts. Improvements in AB0i graft survival rates have been achieved with immunosuppression regimens and plasma treatment procedures. Nevertheless, some grafts are rejected early after AB0i living donor liver transplantation (LDLT) due to antibody mediated rejection or later biliary complications that affect the quality of life. Therefore, the AB0i LDLT is an option only for emergency situations, and it requires careful planning. This review compares the treatment possibilities and their effect on the patients’ graft outcome from 2010 to the present. We compared 11 transplant center regimens and their outcomes. The best improvement, next to plasma treatment procedures, has been reached with the prophylactic use of rituximab more than one week before AB0i LDLT. Unfortunately, no standardized treatment protocols are available. Each center treats its patients with its own scheme. Nevertheless, the transplant results are homogeneous. Due to refined treatment strategies, AB0i LDLT is a feasible option today and almost free of severe complications.

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.

Adult Living Donor Liver Transplantation Across ABO-Incompatibility

The objective of this study was to evaluate the results of adult ABO-incompatible living donor liver transplantation (LDLT).ABO-incompatible LDLT is an aggressive treatment that crosses the blood-typing barrier for saving lives from liver diseases. Although graft and patient survival have been improved recently by various treatments, the results of adult ABO-incompatible LDLT require further evaluation.Two regimens were designed based on isoagglutinin IgG and IgM titers and the time course of immunological reactions at this institute. When isoagglutinin IgG and IgM titers were ≤64, liver transplantation was directly performed and rituximab (375 mg/m) was administrated on postoperative day 1 (regimen I). When isoagglutinin titers were >64, rituximab (375 mg/m) was administered preoperatively with or without plasmapheresis and boosted on postoperative day 1 (regimen II). Immunosuppression was achieved by administration of mycophenolate mofetil, tacrolimus, and steroids.Forty-six adult ABO-incompatible and 340 ABO-compatible LDLTs were performed from 2006 to 2013. The Model for End-Stage Liver Disease scores for ABO-incompatible recipients ranged from 7 to 40, with a median of 14. The graft-to-recipient weight ratio ranged from 0.61% to 1.61% with a median of 0.91%. The 1-, 3-, and 5-year survival rates were 81.7%, 75.7%, and 71.0%, respectively, for ABO-incompatible LDLT recipients, compared to 81.0%, 75.2%, and 71.5% for ABO-C recipients (P = 0.912). The biliary complication rate was higher in ABO-incompatible LDLT recipients than in the ABO-compatible recipients (50.0% vs 29.7%, P = 0.009).In the rituximab era, the blood type barrier can be crossed to achieve adult ABO-incompatible LDLT with survival rates comparable to those of ABO-compatible LDLT, but with more biliary complications.

The Role of Liver Sinusoidal Endothelial Cells in Induction of Carbohydrate Reactive B Cells Tolerance Through the Programmed Death 1/Programmed Death Ligand 1 Pathway

BACKGROUND

A spontaneous tolerance of B cells responding to blood group antigens frequently develops in ABO-incompatible pediatric liver transplantation (LT). Liver sinusoidal endothelial cells (LSECs), which exclusively express blood group antigens in the liver, possess a capacity to induce alloantigen-specific tolerance. In this study, we elucidated the role of LSECs in the tolerance induction of blood group antigen-reactive B cells after ABO-incompatible LT using mice that lack galactose-α(1,3)galactose (Gal) epitopes resembling blood group carbohydrate antigens.

METHODS

Using adoptive transfer of LSECs from wild type (WT) C57BL/6J mice to congenic α1,3-galactosyltransferase gene knockout (GalT) mice, we established orthotropic GalT → GalT LSEC chimera mice. Anti-Gal Ab (antibody) production was evaluated after immunization of GalT → GalT LSEC chimera mice with Gal rabbit RBC.

RESULTS

Adoptive transfer of LSECs isolated from WT GalT mice via the portal vein resulted in persistent engraftment of Gal LSECs in congenic GalT mouse livers. Only when GalT mice were splenectomized before LSEC inoculation, the GalT → GalT LSEC chimera lost the ability to produce anti-Gal Abs. The administration of blocking monoclonal Abs (mAbs) against programmed death ligand 1 to the splenectomized GalT → GalT LSEC chimera resulted in the recovery of anti-Gal Ab production.

CONCLUSIONS

These findings suggest that LSECs take a part in tolerization of immature but not mature B cells specifically for Gal. Furthermore, the programmed death 1/programmed death ligand 1 pathway likely plays a crucial role in the mechanisms underlying spontaneous tolerization of B cells responding to ABO-blood group antigens in LT.

Successful ABO-incompatible living-related intestinal transplantation: a 2-year follow-up

ABO-incompatible intestinal transplantation has rarely been performed due to poor patient outcomes. Herein we present a case of successful ABO-incompatible intestinal transplantation with a 2-year follow-up. A 16-year-old female with a history of extensive bowel resection received an ABO-incompatible living donor bowel graft from her father (blood type AB graft into a type A recipient). Posttransplant immunosuppression consisted of an initial anti-CD20, plasmapheresis/intravenous immunoglobulin before transplantation, followed by an anti-thymocyte globulin (ATG) induction and splenectomy, and maintenance with tacrolimus and prednisone. Her postoperative course was remarkable for a single episode of rejection on day 14 which responded promptly to treatment with methyprednisolone and ATG. Three months after transplantation, the patient developed an abdominal abscess requiring open surgical drainage. No viral infections were encountered. Posttransplant anti-B antibody titers and anti-B7 donor-specific antibody levels remained low. At a 2-year follow-up, the patient showed a progressive weight gain of 5.0 kg. This case illustrates that ABO-incompatible living-related bowel transplantation is immunologically feasible and is associated with good outcomes for the recipient. The management of blood type antibodies and the use of adequate immunosuppression in the early period of the procedure may be the keys to the success of future cases.

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.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Cascade plasmapheresis (CP) as a preconditioning regime in ABO-incompatible live related donor liver transplants (ABOi-LDLT)

Background

ABO-incompatible live donor liver transplant (ABOi-LDLT) is being widely done to bridge the gap of demand and supply of organs. Different desensitization regimes are being used to reduce titer of blood group antibodies for successful transplant and accommodation of graft. The authors used cascade plasmapheresis (CP) to bring down titer of naturally occurring blood group antibody to 16 or lower.

Material and methods

Four recipients of ABOi-LDLT were of blood groups O, O, B, and B while donors were of blood groups B, A, AB, and AB, respectively. Desensitization protocol included immunosuppressive drugs and plasmapheresis. CP consisted of separating patient’s plasma as the first step and passing it through pore size based filter column as the second step. The first step was performed using disposable kit (PL1, Fresenius Kabi, Germany) with minor modification on apheresis equipment COM.TEC (Fresenius Kabi, Germany). Pore size based filter column used was 2A column (Evaflux, Kawasumi Laboratories, Japan). Blood group antibody titer (immunoglobulin G (IgG)) was done by column agglutination technology (Ortho-Clinical Diagnostics).

Results

Cases 1, 2, 3, and 4 with pre-CP titer of 1,024, 512, 32, and 64 required four, three, one, and one CP procedures, respectively. No signs of antibody-mediated rejection were exhibited on histopathological evaluation by any of the patients. Successful organ engraftment occurred as documented by post-operative liver function tests and liver biopsy.

Conclusion

Cascade plasmapheresis offers a cost-effective and efficient way to decrease blood group antibody titer and helps in successful transplant.

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.

Use of ABO-incompatible grafts in living donor liver transplantation--first report from India

ABO incompatibility is the commonest reason for rejection of donors in living donor liver transplantation (LDLT). The donor pool could be expanded by 25 % to 35 % if the ABO barrier is overcome. In the absence of pre-conditioning, transplantation across the blood groups is fraught with the almost universal risk of antibody-mediated rejection (AMR) that rapidly leads to graft loss. However, AMR can be prevented by removal of preformed antibodies and reducing their production by B cells. We describe our initial experience of three cases of ABO-incompatible (ABO-i) LDLT: a 42-year-old male, an 8-month-old male and a 28-month-old female, all of blood group O+ who received blood group B + right lobe, B + left lateral segment, and A + left lateral segment liver grafts, respectively. Pre-LDLT conditioning included administration of anti-CD20 antibody (Rituximab(®)) to the adult 4 weeks prior, and four to seven sessions of double-filtration plasmapheresis to all, to remove preformed antibodies and achieve anti-donor blood group antibody (ADA) titers of ≤ 1:16 IgG and ≤ 1:8 IgM, respectively. In addition, cases 1 and 3 received mycophenolate mofetil for 7 days prior to LDLT. After LDLT, all three patients achieved normal graft function over 8-17 days with no evidence of AMR and without the need for further plasmapheresis. Postoperative complications included portal vein thrombosis (one successfully re-explored), CMV (one), Pseudomonas and Klebsiella sepsis (one each), and abdominal collection (one treated with percutaneous drainage). All are currently well with normal graft function and low ADA titers at 8, 16, and 19 months after ABO-i LDLT.

ABO-incompatible living donor liver transplantation is suitable in patients without ABO-matched donor

BACKGROUND & AIMS

ABO-incompatible liver transplantation is usually contraindicated because of the risk of antibody-mediated humoral rejection of the graft. We describe 22 successful cases of patients who had living donor liver transplantation (LDLT) from ABO-incompatible donors.

METHODS

The immunosuppressive protocol consisted of rituximab and plasmapheresis prior to LDLT. Plasmapheresis was planned for up to 2 weeks after LDLT aiming at maintaining levels of anti-ABO titers below 1:32.

RESULTS

The median age of recipients was 54 years and the median MELD score was 13. The initial range of isoagglutinin IgM and IgG titers were 1:8-1:1024 and 1:2-1:1024, respectively. Preoperative isoagglutinin IgM and IgG titers were achieved less than or equal to 1:8 by performing therapeutic plasma exchange (TPE). While the median number of TPE was 4 (range, 2-18) in all patients, it was 4 (range, 2-8) in the initial low titer group (<1:256) and 8 (range, 6-18) in the high titer group (≥ 1:256). There were no statistically significant differences for liver function tests in the first 2 weeks after transplantation between the groups having high MELD score (≥ 20) vs. low MELD score (<20), local graft infusion vs. systemic infusion, or high initial isoagglutinin titer (≥ 1:256) vs. low initial isoagglutinin titer (<1:256). Patient and graft survival was 100% and there was no acute humoral rejection in recipients at a mean follow-up of 10months (range, 3-21).

CONCLUSIONS

ABO-incompatible LDLT can be safely performed when rituximab and TPE are used, and may be proposed when ABO-compatible donors are not available.

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.

The effects of intraoperative cryoprecipitate transfusion on acute renal failure following orthotropic liver transplantation

Purpose

The definition of risk factors associated with acute renal failure (ARF) following orthotropic liver transplantation (OLT) is still controversial. Cryoprecipitate, which can supply fibrinogen and other coagulation factors, is widely used in OLT. However, the effects of intraoperative cryoprecipitate transfusion on ARF following OLT remain unclear.

Methods

In a series of 389 adult patients who received grafts from deceased donors and underwent their first OLT, the clinical correlation between intraoperative cryoprecipitate transfusion and ARF following OLT was retrospectively studied after adjusting for potential confounders. The distribution of ARF and the causes of death within the first year after OLT were also compared separately in patients with and without cryoprecipitate transfusion.

Results

The incidence of ARF in patients with cryoprecipitate transfusion was significantly higher than in patients without cryoprecipitate transfusion (15.9 vs. 7.8 %, p = 0.012). A nonlinear relationship between intraoperative cryoprecipitate transfusion and ARF following OLT was observed. The risk of ARF increased with the cryoprecipitate transfusion level up to the turning point (16 U) (adjusted OR 1.1, 95 % CI 1.1–1.2; p < 0.001). When the cryoprecipitate level exceeded 16 U, the level of cryoprecipitate transfusion was not associated with the risk of ARF (OR 0.95, 95 % CI 0.85–1.1; p = 0.319). Deaths within the first year after the operation occurred more frequently in cases with cryoprecipitate transfusion (22.9 vs. 14.2 %, p = 0.029).

Conclusions

These findings suggested that intraoperative cryoprecipitate transfusion is associated with ARF following OLT. Cryoprecipitate transfusion during OLT should be performed carefully until more convincing evidence has been found.

Over-expression of heme oxygenase-1 does not protect porcine endothelial cells from human xenoantibodies and complement-mediated lysis

Accommodated organs can survive in the presence of anti-organ antibodies and complement. Heme oxygenase-1 (HO-1) is essential to ensure accommodation in concordant xenotransplant models. However, whether induction of HO-1 over-expression could protect porcine endothelial cells (PECs) against human xenoantibodies and complement-mediated lysis and induce an in vitro accommodation is still unknown. The SV40-immortalized porcine aorta-derived endothelial cell line (iPEC) was pre-incubated with 20, 50, or 80 μmol/L of cobalt-protoporphyrins IX (CoPPIX) for 24 h, and the HO-1 expression in iPECs was analyzed by using Western blotting. CoPPIX-treated or untreated iPECs were incubated with normal human AB sera, and complement-dependent cytotoxicity (CDC) was measured by both flow cytometry and lactate dehydrogenase (LDH) release assay. In vitro treatment with CoPPIX significantly increased the expression of HO-1 in iPECs in a dose-dependent manner. Over-expression of HO-1 was successfully achieved by incubation of iPECs with either 50 or 80 μmol/L of CoPPIX. However, HO-1 over-expression did not show any protective effects on iPECs against normal human sera-mediated cell lysis. In conclusion, induction of HO-1 over-expression alone is not enough to protect PECs from human xenoantibodies and complement-mediated humoral injury. Additionally, use of other protective strategies is needed to achieve accommodation in pig-to-primate xenotransplantation.

Strategic breakthrough in adult ABO-incompatible living donor liver transplantation: preliminary results of consecutive seven cases

ABO-incompatibility is a major obstacle to expanding exiguous donor pools in adult liver transplantation, especially in countries where grafts from deceased donors are uncommon. We present our preliminary results of ABO-incompatible (ABO-I) adult living donor liver transplantation (LDLT) using a new, simple protocol. Seven consecutive cases of ABO-I LDLT were managed by the same protocol including pre-operative administration of a single dose of rituximab (375 mg/m(2) ) followed by three to five sessions of plasma exchange before LDLT without portal infusion therapy. The triple immunosuppression protocol consisted of tacrolimus, mycophenolate mofetil and steroids, with mycophenolate mofetil starting seven d before LDLT. Splenectomy was performed for all cases. All patients are alive (100% survival) with a mean follow-up of 852 d (715-990 d). Neither antibody-mediated nor hyperacute rejection were encountered. There was only one episode of mild acute cellular rejection, for which steroid augmentation was effective. The median preformed isoagglutinin antibody titer before plasma exchange was 256, while the median antibody titer immediately before LDLT was 16. In conclusion, adult ABO-I LDLT results were excellent - comparable or even superior to those of ABO-compatible LDLT. ABO-I adult LDLT has now become a more applicable modality without the need for an appropriate donor.

Selective capture of anti-A antibodies from human blood using a novel integrated bead and hollow fiber module

Anti-A/B antibody removal from blood in the peritransplantation period facilitates ABO-incompatible transplantation and significantly increases the donor pool. We have been developing an anti-A/B immunoadsorption device (BSAF), compatible with whole blood perfusion. The BSAF is based on integrated microfiltration hollow fibers with antibody capturing beads uniformly distributed within the fiber interstitial space. In this study we fabricated BSAF prototypes, appropriately scaled down from a conceptual clinical scale device. We then, for the first time, measured the time course of anti-A capture from blood samples recirculating through the scaled down BSAF devices. We observed a significant reduction in IgM (96% ± 5%, n = 5, p < 0.001), and IgG (81% ± 18%, n = 5, p < 0.05) anti-A antibody titers within 2 h. We did not observe a significant change between the initial and final values of hematocrit, total plasma protein concentration, plasma free hemoglobin concentration, and anti-B antibody titer over five experiments. In conclusion we showed that the BSAF modules selectively removed anti-A antibodies from blood in a simple one step process, without requiring a separate plasmapheresis unit.

Glycemic management in living donor liver transplantation for patients with glycogen storage disease type 1b

GSD type 1b is an autosomal recessive inborn error of carbohydrate metabolism caused by defects of the G6Pase translocase (G6PT). Patients with GSD1b have severe hypoglycemia with several clinical manifestations of hepatomegaly, obesity, a doll-like face, and neutropenia. LT has been indicated for severe glucose intolerance. This study retrospectively reviewed glycemic management of eight children with a diagnosis of GSD1b who underwent liver transplantation (LDLT). Between November 2005 and September 2011, 172 children underwent LDLT, of which eight (4.7%) were indicated for GSD1b. Glucose-rich solution was placed in all children when preoperative fasting started to prevent preoperative hypoglycemia. During the reperfusion of graft, the glucose administration could significantly be reduced to maintain the proper blood glucose level, while the dosage of glucose administration prior to reperfusion of graft was significantly higher in the patients with GSD1b in comparison with patients with BA. The current series also showed significantly high incidence of infectious complications in the patients with GSD1b owing to persistent neutropenia after LDLT. All patients are doing well with an excellent quality of life owing to the stabilization of glucose intolerance. This current study clearly documented drastic change in glycemic management in LDLT. Cautious perioperative management to prevent hypoglycemia and infection is crucial for successful LT.

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.

Ischemia-Reperfusion Injury and Ischemic-Type Biliary Lesions following Liver Transplantation

Ischemia-reperfusion (I-R) injury after liver transplantation (LT) induces intra- and/or extrahepatic nonanastomotic ischemic-type biliary lesions (ITBLs). Subsequent bile duct stricture is a significant cause of morbidity and even mortality in patients who underwent LT. Although the pathogenesis of ITBLs is multifactorial, there are three main interconnected mechanisms responsible for their formation: cold and warm I-R injury, injury induced by cytotoxic bile salts, and immunological-mediated injury. Cold and warm ischemic insult can induce direct injury to the cholangiocytes and/or damage to the arterioles of the peribiliary vascular plexus, which in turn leads to apoptosis and necrosis of the cholangiocytes. Liver grafts from suboptimal or extended-criteria donors are more susceptible to cold and warm I-R injury and develop more easily ITBLs than normal livers. This paper, focusing on liver I-R injury, reviews the risk factors and mechanisms leading to ITBLs following LT.

Kinetics of anti-blood type isoagglutinin titers and B lymphocytes in ABO-incompatible living donor liver transplantation with rituximab and plasma exchange

BACKGROUND

A novel immunosuppression protocol using rituximab and plasma exchange treatment was developed for ABO-incompatible living donor liver transplantation (ABO-I LDLT). The aim of this study was to investigate the kinetics of anti-blood type isoagglutinin titers and the number of blood B lymphocytes in ABO-I LDLT with the new protocol and their impact on the outcomes after ABO-I LDLT.

METHODS

Fifteen patients underwent ABO-I LDLT plus splenectomy with the new protocol between November 2005 and December 2010, and their data were retrospectively analyzed.

RESULTS

CD19-positive lymphocytes in the blood rapidly disappeared after rituximab treatment and began to recover approximately 6 months later. Anti-blood type isoagglutinin titers were lowered by pretransplant plasma exchange (2(3)∼2(12)→2(1)∼2(8)). Although the anti-donor blood type isoagglutinin titers remained consistently low after transplantation in comparison to the pretreatment levels, they persisted long after LDLT, whereas posttransplant biopsy specimens showed sustained A/B antigens on the graft livers. ABO-I hepatitis C virus-positive patients were prone to acceleration of hepatitis C viremia and cytomegalovirus antigenemia in comparison to the control patients.

CONCLUSIONS

Although the new protocol for ABO-I LDLT yielded great success with 100% graft survival, the acceptable anti-blood type isoagglutinin titers just before LDLT, and its application to hepatitis C-positive patients must be determined.

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.