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

The critical role of therapeutic plasma exchange in ABO-incompatible liver transplantation

BACKGROUND

The shortage of donor liver restricts liver transplantation (LT). Nowadays, donor liver with ABO blood group incompatibility between donor and recipient has become an option to expand the source of donor liver. Although it is now possible to perform ABO-incompatible (ABO-I) LT, antibody-mediated rejection (AMR) has been recognized as the primary cause of desperate outcomes after ABO-I LT. Anti-A/B antibody is the trigger of immune response to ABO-I LT graft injury. Therapeutic plasma exchange (TPE) can quickly reduce the titer of plasma antibodies and effectively inhibit humoral immunity.

DATA SOURCES

We searched PubMed and CNKI databases using search terms "therapeutic plasma exchange", "ABO-incompatible liver transplantation", "ABO-I LT", "liver transplantation", "LT", "antibody-mediated rejection", and "AMR". Additional publications were identified by a manual search of references from key articles. The relevant publications published before September 30, 2020 were included in this review.

RESULTS

Different centers have made different attempts on whether to use TPE, when to use TPE and how often to use TPE. However, the control standard of lectin revision level is always controversial, the target titer varies significantly from center to center, and the standard target titer has not yet been established. TPE has several schemes to reduce antibody titers, but there is a lack of clinical trials that provide standardized procedures.

CONCLUSIONS

TPE is essential for ABO-I LT. Hence, further research and clinical trials should be conducted to determine the best regimen for TPE to remove ABO antibodies and prevent AMR.

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.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Living Donor Liver Transplantation for Hepatocellular Carcinoma: An Asian Perspective

Despite advancements in early diagnosis and medico-surgical treatment, hepatocellular carcinoma (HCC) is still a major cancer that causes substantial mortality in Asian countries. Liver transplantation (LT) has been accepted worldwide as the most effective treatment modality for patients with HCC; however, with the high incidence of HCC and low organ donation rate, Asia has developed distinctive features of indications and strategies for the application of LT. Unlike Western countries, living donor liver transplantation (LDLT) accounts for most LT cases for HCC in Asian countries, and most major transplantation centers perform LDLT for HCC patients with extended criteria. This article reviewed the current practice and outcome of LDLT for HCC from an Asian perspective and summarized the strategies that the high-volume LT centers in Asia use to obtain satisfactory oncologic results.

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

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

Long-term Outcomes of ABO-incompatible Pediatric Living Donor Liver Transplantation

BACKGROUND

ABO-incompatible (ABOi) living donor liver transplantation (LDLT) has been performed to compensate for donor shortage. To date, few studies have reported detailed B-cell desensitization protocols and long-term outcomes of ABOi pediatric LDLT.

METHODS

Twenty-nine pediatric ABOi LDLT recipients were retrospectively analyzed. We compared the clinical outcomes between ABOi (n = 29) and non-ABOi (n = 131) pediatric LDLT recipients. Furthermore, we evaluated the safety and efficacy of our rituximab-based regimen for ABOi pediatric LDLT (2 ≤ age < 18; n = 10).

RESULTS

There were no significant differences in the incidence of infection, vascular complications, biliary complications, and acute cellular rejection between ABOi and non-ABOi groups. The cumulative graft survival rate at 1, 3, and 5 years for non-ABOi group were 92.1%, 87.0%, and 86.1%, and those for ABOi group were 82.8%, 82.8%, and 78.2%, respectively. Rituximab-based desensitization protocol could be performed safely, and reduced CD19+ lymphocyte counts effectively. Although rituximab-treated ABOi group showed comparable clinical outcomes and graft survival rate, 2 patients developed antibody-mediated rejection.

CONCLUSIONS

ABOi LDLT is a feasible option for pediatric end-stage liver disease patients. However, it should be noted that current desensitization protocol does not completely prevent the onset of antibody-mediated rejection in several cases.

Outcome of ABO-incompatible adult living-donor liver transplantation for patients with hepatocellular carcinoma

BACKGROUND & AIMS

Living-donor liver transplantation (LDLT) can simultaneously cure hepatocellular carcinoma (HCC) and underlying liver cirrhosis, improving long-term results in patients with HCC. ABO-incompatible LDLT could expand the living-donor pool, reduce waiting times for deceased-donor liver transplantation, and improve long-term survival for some patients with HCC.

METHODS

We retrospectively reviewed the medical records of patients undergoing LDLT for HCC from November 2008 to December 2015 at a single institution in Korea. In total, 165 patients underwent ABO-incompatible and 753 patients underwent ABO-compatible LDLT for HCC. ABO-incompatible recipients underwent desensitization to overcome the ABO blood group barrier, including pretransplant plasma exchange and rituximab administration (300-375 mg/m² /body surface area).

RESULTS

We performed 1:1 propensity score matching and included 165 patients in each group. 82.4% of ABO-incompatible and 83.0% of -compatible LDLT groups had HCC within conventional Milan criteria, respectively, and 92.1% and 92.7% of patients in each group had a Child-Pugh score of A or B. ABO-incompatible and -compatible LDLT groups were followed up for 48.0 and 48.7 months, respectively, with both groups showing comparable recurrence-free survival rates (hazard ratio [HR] 1.14; 95% CI 0.68-1.90; p = 0.630) and overall patient-survival outcomes (HR 1.10; 95% CI 0.60-2.00; p = 0.763).

CONCLUSIONS

These findings suggested that ABO-incompatible liver transplantation is a feasible option for patients with HCC, especially for those with compensated cirrhosis with HCC within conventional Milan criteria.

LAY SUMMARY

Despite hypothetical immunological concerns that the desensitization protocol for breaking through the ABO blood group barrier might have a negative impact on the recurrence of hepatocellular carcinoma, our experience demonstrated no significant differences in the long-term overall survival and recurrence-free survival rates between patients receiving ABO-compatible or ABO-incompatible liver transplantation. In conclusion, results from our institution indicated that ABO-incompatible living-donor liver transplantation constitutes a potentially feasible option for patients with hepatocellular carcinoma, especially those with compensated cirrhosis with hepatocellular carcinoma within conventional Milan criteria.

Early and Late Factors Impacting Patient and Graft Outcome in Pediatric Liver Transplantation: Summary of an ESPGHAN Monothematic Conference

As pediatric liver transplantation comes of age, experts gathered to discuss current paradigms and define gaps in knowledge warranting research to further improve patient and graft outcomes. Identified areas ripe for collaborative research include understanding the molecular and cellular mechanisms of tolerance and the role of donor-specific antibodies, considering ways to expand donor pool, minimizing long-term side effects of immunosuppression, and fine-tuning surgical techniques to minimize biliary and vascular complications.

Simultaneous ABO-incompatible living-donor liver transplantation and splenectomy without plasma exchange in China: Two case reports

ABO-incompatible (ABO-i) living-donor liver transplantation (LDLT) is performed if an ABO-compatible graft cannot be obtained. However, a perfect desensitization protocol has not been established worldwide, especially for simultaneous ABO-i LDLT and splenectomy. We herein report two cases of ABO-i LDLT. To the best of our knowledge, this is the first case report of ABO-i LDLT in an adult patient in China. Splenectomy and T-cell-targeted immunosuppression (basiliximab) was used to overcome the blood group barrier in these recipients. The patients had good graft function without signs of antibody-mediated rejection throughout the 12-month follow-up. Thus, ABO-i LDLT with splenectomy is undoubtedly life-saving when an ABO-compatible graft cannot be obtained for patients in critical condition.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Single-Center Experience of ABO-Incompatible Living-Donor Liver Transplantation With a New Simplified Intravenous Immunoglobulin Protocol: A Propensity Score-Matching Analysis

The outcomes of patients who undergo ABO-incompatible (ABO-I) living-donor liver transplantation (LDLT) have markedly improved as strategies have become more innovative and advanced. Here, we describe 25 cases of ABO-I LDLT with a simplified protocol and compare the outcomes to those of ABO-compatible LDLT. We analyzed outcomes via a retrospective review of 182 adult LDLT cases including 25 ABO-I LDLTs from January 2011 to December 2014. Propensity scoring was used to compare the groups. The desensitization protocol included plasma exchange, rituximab, and intravenous immunoglobulin without local infusion therapy. The triple immunosuppression protocol consisted of tacrolimus and steroids with mycophenolate mofetil; a splenectomy was not routinely performed. The median age of recipients was 51 years (range, 35-66 years), and the median mean Model for End-Stage Liver Disease (MELD) score was 15 (range, 7-37). The initial ranges of isoagglutinin IgM and IgG titers were 1:1 to 1:256 and 1:4 to 1:2048, respectively. There were no significant differences in patient demographics or perioperative variables between the groups. Although significant rebound elevation in anti-ABO antibody during the postoperative period was observed in 3 cases, neither C4d staining nor clinical signs of antibody-mediated rejection was apparent in these cases. No diffuse intrahepatic biliary stricture was encountered in any ABO-I LDLT patient within a mean follow-up of 22.6 ± 17.2 months. Moreover, no significant difference in overall or graft survival was observed between the groups. ABO-I LDLT can be performed safely under this new simplified protocol and may be proposed when ABO-compatible donors are unavailable.

Comparison of acute kidney injury between ABO-compatible and ABO-incompatible living donor liver transplantation: A propensity matching analysis

The anti-CD20 monoclonal antibody rituximab has significantly decreased the prevalence of antibody-mediated rejection of ABO-incompatible (ABOi) living donor liver transplantation (LDLT). However, little is known about acute kidney injury (AKI) following ABOi LDLT. The aim of this study was to identify the incidence of AKI in ABOi LDLT and compare it with that of ABO-compatible (ABOc) LDLT. We retrospectively collected and analyzed the data of 1617 patients who underwent liver transplant surgery from November 2008 to December 2014. Risk factors for AKI were investigated using multivariate regression analysis. In 271 ABOi LDLTs, AKI occurred in 184 (67.9%) according to Kidney Disease: Improving Global Outcomes criteria. After propensity score matching, the incidence of AKI was significantly higher after ABOi LDLT than after ABOc LDLT (67.0% versus 48.2%; P < 0.001). Furthermore, the intensive care unit stay (P = 0.01) was significantly prolonged, but there were no significant differences in mortality (P = 0.74), graft failure (P = 0.32), and postoperative dialysis (P = 0.74) between the 2 groups. Hemoglobin level and operation time were independent risk factors for AKI following ABOi LDLT. In conclusion, the incidence of AKI is higher in ABOi LDLT than ABOc LDLT. However, the impact of AKI on postoperative outcomes was not marked in our study. Therefore, ABOi LDLT in selected patients is promising with apparent good graft and survival outcomes. Liver Transplantation 22 1656-1665 2016 AASLD.

Feasible usage of ABO incompatible grafts in living donor liver transplantation

BACKGROUND

The use of ABO incompatible (ABOi) graft in living donor liver transplantation (LDLT) has not been an established procedure worldwide.

METHODS

Four hundred and eight adult LDLTs, using ABOi (n=19) and non-ABOi (n=389) grafts, were performed as a single center experience.

RESULTS

In ABOi-LDLT group (n=19), median isoagglutinin titer before plasma exchange (PE) at LDLT and after LDLT (max) was ×256, ×32 and ×32, respectively. Rituximab was given at 21.8±6.1 days before LDLT and PE was performed 3.7±1.6 times. Although ABOi-LDLTs had increased rate of splenectomy (89.4% vs. 44.7%, P<0.001) and lower portal venous pressure (PVP) at the end of surgery (13.8±1.1 vs. 16.9±0.2 mmHg, P=0.003), other operative factors including graft ischemic time, operative time and blood loss were not different between the groups. Although ABOi-LDLTs had increased incidence of cytomegalovirus infection (52.6% vs. 22.9%, P=0.007), other post-transplant complications including bacterial sepsis and acute rejection were not different between the groups. The 5-year graft survival rate was 87.9% in ABOi-LDLTs and 80.3% in non-ABOi-LDLTs (P=0.373).

CONCLUSIONS

ABOi-LDLT could be safely performed, especially under rituximab-based protocol.

Liver transplantation with deceased ABO-incompatible donors is life-saving but associated with increased risk of rejection and post-transplant complications

ABO-incompatible (ABOi) liver transplantation (LT) with deceased donor organs is performed occasionally when no ABO-compatible (ABOc) graft is available. From 1996 to 2011, 61 ABOi LTs were performed in Oslo and Gothenburg. Median patient age was 51 years (range 13-75); 33 patients were transplanted on urgent indications, 13 had malignancy-related indications, and eight received ABOi grafts for urgent retransplantations. Median donor age was 55 years (range 10-86). Forty-four patients received standard triple immunosuppression with steroids, tacrolimus, and mycophenolate mofetil, and forty-four patients received induction with IL-2 antagonist or anti-CD20 antibody. Median follow-up time was 29 months (range 0-200). The 1-, 3-, 5-, and 10-year Kaplan-Meier estimates of patient survival (PS) and graft survival (GS) were 85/71%, 79/57%, 75/55%, and 59/51%, respectively, compared to 90/87%, 84/79%, 79/73%, and 65/60% for all other LT recipients in the same period. The 1-, 3-, 5-, and 10-year GS for A2 grafts were 81%, 67%, 62%, and 57%, respectively. In conclusion, ABOi LT performed with non-A2 grafts is associated with inferior graft survival and increased risk of rejection, vascular and biliary complications. ABOi LT with A2 grafts is associated with acceptable graft survival and can be used safely in urgent cases.

Fourteen successful consecutive cases of ABO-incompatible living donor liver transplantation: new simplified intravenous immunoglobulin protocol without local infusion therapy

Since various innovative strategies including local infusion therapy and rituximab have been introduced, the survivals and outcomes of recipients in ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) have remarkably improved. Thus, ABO-I LDLT can be a feasible therapeutic option for the patient with end-stage liver disease if an ABO-compatible donor is not available. Although most ABO-I protocols are based on rituximab, plasma exchange, and local infusion therapy, treatment strategies have been changing according to a center's preference or their results. Nonetheless, the consensus of the ABO-I LDLT protocol remains undetermined. Herein, we present our experience with new simple ABO-I LDLT protocol and the excellent results for 14 patients from January 2011 to May 2013. All patients were administrated a single dose of rituximab over 7 days before transplantation followed by plasma exchange to lower anti-ABO antibody titer ≤32. The basic immunosuppression protocol consisted of tacrolimus and steroids with mycophenolate mofetil starting 3 days before transplantation. Splenectomy was not performed routinely and local infusion therapy was not applied at the postoperative period. Instead, the patients received intravenous immunoglobulin (IVIG) after LDLT on days 1, 3, and 5. Neither antibody-mediated rejection nor biliary stricture were encountered in the patients, with a mean follow-up of 16.27 ± 9.4 months. This new simplified ABO-I LDLT protocol seems to prevent antibody-mediated rejection and could be considered as the safe and effective modality to overcome the ABO blood-type barrier in LDLT.

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.

Kinetics of B, T, NK lymphocytes and isoagglutinin titers in ABO incompatible living donor liver transplantation using rituximab and basiliximab

BACKGROUND

The kinetics of isoagglutinin titers and lymphocyte subpopulations including B, T, and natural killer (NK) cells after ABO incompatible (ABO-I) living donor liver transplantation (LDLT) have not been evaluated.

METHODS

From January 2012 to July 2013, consecutive ABO-I LDLT patients were enrolled at the National Cancer Center. Our desensitizing protocol included rituximab, plasma exchanges, basiliximab, and intravenous immune globulin without splenectomy.

RESULTS

Twenty patients (14 males, 6 females) underwent ABO-I LDLT due to HCC (n=15) or liver cirrhosis (n=5). There was no hyperacute and antibody-mediated rejection. The isoagglutinin titers were effectively lowered less than 1:16 before operation. CD 19+ B cells were rapidly eliminated after rituximab and suppressed during 6months postoperatively. CD3+ and CD4+ T cells were elevated higher than CD8+ T cells. CD4/CD8 ratio was increased during first 1month postoperatively and decreased thereafter. CD16+CD56+ NK cells were lowered and restored after 4months of LDLT. Among 15 patients with HCC, 5 patients (33.3%) experienced early tumor recurrence (1/8 within Milan and 4/7 beyond Milan).

CONCLUSIONS

Our protocol showed effective results in preventing antibody-mediated rejection and suppressing B lymphocytes. Application to advanced hepatocellular carcinoma should be considered due to decreased natural immunity after ABO-I LDLT.

Challenges in living donor liver transplantation

Living donor liver transplantation is a procedure that has waned in its application over the past decade but remains a beneficial procedure for properly selected candidates. This review discusses some of the newer, relevant studies in the field, focusing on outcomes with hepatocellular carcinoma, ABO-incompatible transplant, and issues in donor complications and safety.

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.

Antibody-mediated rejection in liver transplantation: current controversies and future directions

Interest in the role of donor-specific human leukocyte antibodies in liver transplantation has been rekindled recently. Emerging evidence suggests that these antibodies may cause injury to the liver allograft. Here we review the clinical literature, highlight controversial results, and propose a path forward for the definition and better understanding of antibody-mediated injury to the liver.