New protocol of immunosuppression for liver transplantation across ABO barrier: the use of Rituximab, hepatic arterial infusion, and preservation of spleen

Prior to ABOi liver transplant with PD-1 inhibitor in patients with hepatocellular carcinoma: A case report

BACKGROUND

Liver transplantation (LT) is a unique and effective method for treating end-stage liver diseases and acute liver failure, bringing hope to many patients with liver cancer. LT is currently widely used in the treatment of liver diseases. However, there have been no patients with liver cancer who have undergone ABO-incompatible (ABOi) LT after treatment with the programmed cell death protein 1 (PD-1) inhibitor reported in the literature.

CASE PRESENTATION

A patient with liver cancer who received sintilimab injection, an anti-PD1 therapy, before LT was admitted in the transplantation centre. This patient underwent ABOi LT. The perioperative treatment strategy of this patient was reported. A desensitisation protocol was conducted urgently for the patient before operation, and the immunosuppression programme of LT was adjusted. After operation, isoagglutinin titer and liver function indicators were strictly monitored. The patient recovered well after operation, and no sign of rejection reaction was observed.

CONCLUSION

We reported a patient with hepatocellular carcinoma (HCC) who received PD-1 inhibitor treatment before operation and successfully underwent ABOi LT. The present case report provides novel insights into the perioperative management of utilizing PD-1 inhibitors prior to ABOi LT in patients diagnosed with hepatocellular carcinoma (HCC).

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.

Current Status of ABO-incompatible Liver Transplantation

By 2014, strategies to prevent antibody-mediated rejection (AMR) after ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) were established in Japan and expanded primarily to Asia, where LDLT is now the predominant form of LT owing to the scarcity of brain-dead donors. A desensitization protocol consisting of rituximab (375 mg/m 2 ), plasma pheresis, tacrolimus, and mycophenolate mofetil before LDLT, followed by standard immunosuppression, is currently the best option in terms of safety and efficacy. Rituximab administration is now known not to increase the risk of hepatocellular carcinoma recurrence, and the feasibility of rituximab for LDLT for acute liver failure and the need for desensitization before LDLT in children older than 1 y have been documented. Strategies are needed to distinguish patients at high risk of AMR from those at low risk and to adjust immunosuppression to prevent both AMR and infection. Specific single-nucleotide polymorphisms in genes encoding Fcγ receptors affecting the cytotoxicity of rituximab on B cells could be useful for adjusting immunosuppression levels to decrease infectious complications. Immunological accommodation after ABO-I transplantation could be provided by immune factors in both the grafts and recipients.

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.

Is 0.6% Reasonable as the Minimum Requirement of the Graft-to-recipient Weight Ratio Regardless of Lobe Selection in Adult Living-donor Liver Transplantation?

BACKGROUND

Several studies reported favorable outcomes of small-for-size grafts with graft-to-recipient weight ratio (GRWR) <0.8% in living-donor liver transplantation (LDLT). However, their indications should be carefully determined because they must have been indicated for low-risk cases over larger grafts with 0.8% ≤ GRWR. Furthermore, evidence for minimum requirements of GRWR remains inconclusive. We investigated the safety of small-for-size grafts against larger grafts by adjusting for confounding risk factors, and minimum requirement of graft volume in adult LDLT.

METHODS

We enrolled 417 cases of primary adult-to-adult LDLT in our center between 2006 and 2019. The outcomes of small grafts (0.6% ≤ GRWR < 0.8%, n = 113) and large grafts (0.8% ≤ GRWR, n = 289) were mainly compared using a multivariate analysis and Kaplan-Meier estimates.

RESULTS

The multivariate analysis showed that small grafts were not a significant risk factor for overall graft survival (GS). In the Kaplan-Meier analysis, small grafts did not significantly affect overall GS regardless of lobe selection (versus large grafts). However, GRWR < 0.6% was associated with poor overall GS. Although there were no significant differences between the 2 groups, unadjusted Kaplan-Meier curves of small grafts were inferior to those of large grafts in subcohorts with ABO incompatibility, and donor age ≥50 years.

CONCLUSIONS

Similar outcomes were observed for small and large graft use regardless of lobe selection. 0.6% in GRWR was reasonable as the minimum requirement of graft volume in LDLT. However, small grafts should be indicated carefully for high-risk cases.

No diffuse intrahepatic biliary stricture after ABO-incompatible adult living donor liver transplantation using tailored rituximab-based desensitization protocol

Background

Rituximab (RTx) desensitization protocol offered good outcome in ABO-incompatible (ABOi) living donor liver transplantation (LDLT). However, diffuse intrahepatic biliary stricture (DIHBS) is still inevitable hurdle. We selectively added postoperative high dose intravenous immunoglobulin (IVIG) and/or simultaneous splenectomy if ABO isoagglutinin titer just before liver transplantation after plasma exchange (PE) was higher than 1/16. Herein, we reported the excellent outcome of ABOi LDLT without DIHBS using tailored desensitization protocol and compared it with that of ABO-compatible (ABOc) LDLT.

Methods

Sixty-five cases (14.8%) of ABOi LDLTs were performed among 438 primary adult LDLTs in our center between March 2012 and June 2017. We performed 1-to-2 propensity score matching (PSM) to extract 60 cases of ABOi LDLTs and 120 cases of ABOc LDLTs.

Results

There were no significant differences in clinical characteristics between ABOi and ABOc recipients. There were no significant differences in complications and rejection. There was no DIHBS in both groups. The 1-, 3-, and 5-year overall survival rates were 98.3%, 86.7%, and 82.9% in ABOi group and 96.7%, 86.7%, and 85.4% in ABOc group, respectively (P=0.88). Most common cause of deaths of both groups was hepatocellular recurrence. The 1-, 3-, and 5-year biliary complication (anastomosis leakage or stricture) free survival rates were 81.4%, 69.5%, and 67.5% in ABOi group and 83.0%, 81.3%, and 80.0% in ABOc group, with no significant differences (P=0.11).

Conclusions

RTx-based tailored (optional IVIG + splenectomy) desensitization protocol for ABOi LDLT was feasible and acceptable.

Challenge to ABO blood type barrier in living donor liver transplantation

ABO incompatible living donor liver transplantation has the potential to expand the donor pool for patients with end stage liver diseases on the expense of challenges to overcome immunological barriers across blood type. There is a profound impact of age on incidence and severity of antibody mediated rejection (AMR). Even children older than 1 year have chances of AMR; children aged 8 years or older have risks of hepatic necrosis similar to adult liver recipients. The mechanism of AMR is based on circulatory disturbances secondary to inflammation and injury of the vascular endothelium caused by an antibody-antigen-complement reaction. The strategy to overcome ABO blood type barrier is based on both pre-transplant desensitization and adequate treatment of this phenomenon. Nowadays, rituximab is the standard means of desensitization but unfortunately an insufficient aid to treat AMR. Because of low incidence (less than 5% in the rituximab era), in practice of AMR only some case reports about the treatment of clinical AMR are available in the literature. Initial experiences revealed that the proteasome inhibitor, bortezomib might be a promising treatment based on its capacity to deplete plasma cell agents. Although ABO blood type barrier has been counteracted in 95% of patients by applying "rituximab-desensitization", many issues, such as prediction of high-risk patients of infection and AMR and secure treatment strategies for evoked AMR, remain to be resolved.

Prognostic index consisting of early post-transplant variables <2 weeks in adult living-donor liver transplantation

AIM

Six-month recipient mortality after adult-to-adult living-donor liver transplantation (LDLT) remains high. Early and accurate prediction of recipient outcome and continuous monitoring of recipient severity after surgery are both essential for guiding appropriate care. This study was designed to identify early post-transplant parameters associated with 6-month mortality, and thereby to construct a discriminatory prognostic index (PI).

METHODS

We retrospectively analyzed 400 consecutive primary adult-to-adult LDLTs in our center (2006-2017). Perioperative variables were comprehensively analyzed for their accuracy in predicting recipient mortality by comparing the area under the receiver operating characteristic (AUROC) of each factor.

RESULTS

The AUROCs of preoperative predictive factors, for example, Model for End-stage Liver Disease (MELD) score and donor age, were 0.56 and 0.64, respectively, whereas those of post-transplant platelet count (PLT), total bilirubin (T-BIL), and prothrombin time - international normalized ratio (INR) on postoperative day (POD)-7-14 were 0.71/0.84, 0.68/0.82, and 0.71/0.78, respectively. Logistic regression analysis provided a formula: PI_POD-14  = 3.39 + 0.12 × PLT_POD-14  - 0.09 × T-BIL_POD-14  - 1.23 × INR_POD-14 , indicating a high AUROC of 0.87. Recipient 6-month survival with PI_POD-14  < 2.38 (n = 173) was 71.7%, whereas that with PI_POD-14  ≥ 2.38 (n = 222) was 97.7% (P < 0.001). The AUROCs of PI_POD-7 were as high as 0.8 in the subgroups with younger donors (<50 years of age), right lobe grafts, ABO-identical/compatible combinations, or low MELD score (<20), indicating usefulness of PI to identify unexpectedly complicated cases within the first week.

CONCLUSIONS

A novel, post-transplant survival estimator, PI, accurately predicts recipient 6-month mortality within 1-2 weeks after adult LDLT. Daily monitoring of PI could facilitate early interventions including retransplantation in critically ill patients.

Impact of Donor Age on Recipient Survival in Adult-to-Adult Living-donor Liver Transplantation

OBJECTIVE

To investigate the influence of donor age on recipient outcome after living-donor partial liver transplantation (LDLT).

BACKGROUND

Donor age is a well-known prognostic factor in deceased donor liver transplantation; however, its role in LDLT remains unclear.

METHODS

We retrospectively analyzed 315 consecutive cases of primary adult-to-adult LDLT in our center between April 2006 and March 2014. Recipients were divided into 5 groups according to the donor age: D-20s (n = 60); D-30s (n = 72); D-40s (n = 57); D-50s (n = 94); and D-60s (n = 32). The recipient survival and the association with various clinical factors were investigated.

RESULTS

Recipient survival proportions were significantly higher in D-20s compared with all the other groups (P = 0.008, < 0.001, < 0.001, and = 0.006, vs D-30s, -40s, -50s, and -60s, respectively), whereas there was no association between recipient survival and their own age. There are 3 typical relationships between donors and recipients in adult-to-adult LDLT: from child-to-parent, between spouses/siblings, and from parent-to-child. The overall survival in child-to-parent was significantly higher than in spouses/siblings (P = 0.002) and in parent-to-child (P = 0.005), despite significantly higher recipient age in child-to-parent [59 (42-69) years, P < 0.001]. Contrastingly, parent-to-child exhibited the lowest survival, despite the youngest recipient age [26 (20-43) years, P < 0.001]. In addition, younger donor age exhibited significantly better recipient survival both in hepatitis C virus-related and in non-hepatitis C virus diseases. Univariate and multivariate analyses both demonstrated that donor age and graft-type (right-sided livers) are independent prognostic factors for recipient survival.

CONCLUSIONS

Donor age is an independent, strong prognostic factor in adult-to-adult LDLT.

Low Titers of Antidonor ABO Antibodies After ABO-Incompatible Living Donor Liver Transplantation: A Long-Term Follow-Up Study

Background

The ABO blood-type barrier in kidney and liver transplantation has been overcome by aggressive treatments such as B cell depletion using rituximab. However, the long-term effects of ABO-incompatible liver transplantation (ABO-I LTx) on immunological status have not previously been studied. Here, we assessed whether long-term immune hyporesponsiveness against ABO blood-group antigens was retained.

Methods

We recruited 81 patients, 75 patients who had survived ABO-I LTx without retransplantation and 6 patients who had survived after retransplantation using blood type-compatible grafts. The time between ABO-I LTx and outpatient visits for blood sampling for this study ranged from 1.1 to 16.8 years. We also evaluated patients' backgrounds and postoperative therapies.

Results

Overall, antidonor ABO antibody titers in the 75 patients without retransplantation decreased during long-term follow-up. In the subset of 40 patients with blood type O, anti-nondonor ABO antibody titers did not decrease and were significantly higher than antidonor ABO antibody titers. In addition, long-term antidonor ABO antibody titers were significantly lower in pediatric patients than in adult patients. In the 6 patients who were retransplanted with blood type–compatible grafts, antidonor ABO antibody immunoglobulin G titers remained low, but IgM titers increased slightly long after removal of the ABO-incompatible graft.

Conclusions

These findings suggest that donor-specific hyporesponsiveness remains after ABO-I LTx, particularly in pediatric patients. Long-term persistence of blood antigens may contribute to this donor-specific hyporesponsiveness.

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.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation (LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally, despite the decrease in the prevalence of hepatitis B virus (HBV) over the past two decades, the absolute number of HBsAg-positive people has increased, leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently, a large demand exists for LT. While the wait time for patients on the donor list is, to some degree, shorter due to the development of living donor liver transplantation (LDLT), there is still a shortage of liver grafts. Furthermore, recipients often suffer from emergent conditions, such as liver dysfunction or even hepatic encephalopathy, which can lead to a limited choice in grafts. To expand the pool of available liver grafts, one option is the use of organs that were previously considered "unusable" by many, which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however, there is still a lack of discussion on this topic, especially regarding the feasibility of using marginal grafts in LDLT. Therefore, the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.

Management of immunosuppressant agents following liver transplantation: Less is more

Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.

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.

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.

Impact of recipient age and preoperative fasting blood glucose level as the risk factors of living donor liver transplantation in cirrhotic patients in the recent comprehensive era with knowledge of indications: Recent status in a Japanese single center

AIM

Recently, knowledge for indications of living donor liver transplantation (LDLT) has been robustly accumulated in. For further improvement, risks should be reexamined in recent cases. In this study, we investigated preoperative risk factors in cirrhotic patients who underwent LDLT in recent era.

METHODS

Seventy-four cirrhotic patients who underwent LDLT at our institution between 2003 and 2011 were included. Recipient and donor age and sex, existence of hepatocellular carcinoma (HCC), preoperative Model for End-Stage Liver Disease score, fasting blood glucose (FBG), triglyceride, total cholesterol, serum creatinine, hemoglobin A1c, graft : recipient weight ratio, ABO compatibility and choice of calcineurin inhibitor were analyzed. A proportional hazard model was applied and P < 0.05 was considered statistically significant.

RESULTS

In multivariate analysis, recipient age (hazard ratio = 1.188, P = 0.011) and FBG (hazard ratio = 1.009, P = 0.016) showed as significant independent factors. Theoretical mortalities were 9.2%, 21.9% and 51.7% in patients with normal FBG at 55, 60 and 65 years old, respectively, and 34.3% and 53.6% in patients with FBG of 150 and 200 mg/dL, respectively, at 60 years old.

CONCLUSION

Recipient age and FBG remain important risk factors for LDLT in cirrhotic patients even in the recent era. These factors should be considered for selecting liver transplant candidates in cirrhotic patients.

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.

Pathogenesis in ABO incompatible liver transplantation: a clinicohistological evaluation of four patients

The aim of this study was to clarify the pathogenesis of antibody-mediated rejection (AMR) of ABO-incompatible liver transplantation (ABO-I-LT). We investigated, within one month of surgery, the clinical courses of 10 patients who received ABO-I-LT. We encountered four cases of AMR, which were classified into two groups according to the stage of the AMR: early (within the first 14 postoperative days [PODs]) or late (after the 14th POD). There were three patients in the early stage, and one patient in the late stage. Three early-stage AMR patients had both hyperbilirubinemia and thrombocytopenia within one month after LDLT, but the one late-stage AMR patient had neither. On liver biopsy, hemorrhagic infiltration was seen more frequently in the early-stage AMR patients than in the patient with late-stage AMR. Plasma exchange combined with a large amount of gamma-globulin bolus infusion therapy was effective in the three early-stage patients, but the late-stage AMR was controlled by antibiotic treatment. This study showed that the early-stage AMR resulted from the antigen-antibody reaction of ABO-blood-group antigens, while the late-stage AMR may have been caused by an infection.

Management of ABO-incompatible living-donor liver transplantation: past and present trends

Based on the concept that the liver is a "privileged organ," which resists acute rejection, Thomas Starzl introduced liver transplantation across the ABO blood group. However, with improved survival after liver transplantation came reports of an increased incidence of acute rejection, biliary and vascular complications, and decreased survival after ABO-incompatible liver transplantation. As a result, ABO-incompatible liver transplantations are performed only in emergencies when ABO-compatible grafts are unavailable. In living-donor liver transplantation (LDLT), donors are restricted to family members; therefore, breaking ABO blood group barriers becomes inevitable. This inevitable situation has forced liver transplant surgeons to exploit many innovative techniques to overcome the challenges of ABO-incompatible liver transplantation. This review looks at the history and current practices of ABO-incompatible LDLT to provide insight so that the protocol can be improved further.

Living-donor liver transplantation for progressive familial intrahepatic cholestasis

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) results in liver cirrhosis during the disease course, although the etiology includes unknown mechanisms. Some PFIC patients require liver transplantation (LT).

METHODS

In this study, 11 patients with PFIC type 1 (PFIC1) and 3 patients with PFIC type 2 (PFIC2) who underwent living-donor LT (LDLT) were evaluated.

RESULTS

Digestive symptoms after LDLT were confirmed in 10 PFIC1 recipients (90.9%); 8 PFIC1 recipients showed steatosis after LDLT (72.7%), which began during the early postoperative period (71.5±55.1 days). Seven of the eight steatosis-positive PFIC1 recipients (87.5%) showed a steatosis degree of ≥80%, which was complicated with steatohepatitis and resulted in fibrosis. Cirrhotic findings persisted in six PFIC1 recipients even after LDLT (54.5%), and three PFIC1 recipients finally died. The survival rates of the PFIC1 recipients at 5, 10, and 15 years were 90.9%, 72.7%, and 54.5%, respectively. In contrast, the PFIC2 recipients showed good courses and outcomes without any steatosis after LDLT.

CONCLUSIONS

The clinical courses and outcomes after LDLT are still not sufficient in PFIC1 recipients owing to steatosis/steatohepatitis and subsequent fibrosis, in contrast to PFIC2 recipients. PFIC2 is good indication for LDLT. PFIC1 patients require LT during the disease course; therefore, we suggest that the therapeutic strategies for PFIC1 patients, including the timing of LDLT, under the donor limitation should be reconsidered. The establishment of more advanced treatments for PFIC1 patients is required to improve the long-term prognosis of these patients.

Muromonab-CD3 therapy for refractory rejections after liver transplantation: a single-center experience during two decades in Japan

BACKGROUND/PURPOSE

Refractory rejections still occur in the liver transplantation (LT) field. The aim of this study was to investigate significant factors for the introduction of therapy with muromonab-CD3 (MCD3) after LT.

METHODS

A total of 1415 LT patients were retrospectively evaluated, and 11 of the recipients received MCD3 therapy because of steroid-resistant rejections. The clinical factors before LT and before MCD3 therapy were investigated.

RESULTS

The recipients were retrospectively divided into two groups based on responses to MCD3 therapy, including their clinical courses after MCD3 therapy and their outcomes. The MCD3 therapy had positive effects in LT recipients with the following four factors: low score of model for end-stage liver disease or pediatric end-stage liver disease; earlier time point of the first incidence of rejection; more frequent steroid pulse therapy (SPT) within 2 weeks after LT; and the expression of CD3 in the peripheral blood before MCD3 introduction.

CONCLUSION

Optimal induction of MCD3 triggered recovery from refractory rejections, especially in LT recipients in a stable condition, but not in those in a critical or compromised condition.

Does a positive lymphocyte cross-match contraindicate living-donor liver transplantation?

BACKGROUND

There is still no consensus on the importance of lymphocyte cross-matching (LCM) in the field of living-donor liver transplantation (LDLT).

METHODS

LCM examinations are routinely performed before LDLT, and the results of complement-dependent cytotoxicity were used in this study. A total of 1157 LDLT cases were evaluated. The recipients were divided into four groups based on the LCM and ABO compatibilities: (1) negative LCM and identical/compatible ABO; (2) negative LCM and incompatible ABO; (3) positive LCM and identical/compatible ABO; and (4) positive LCM and incompatible ABO. The diagnosis of antibody-mediated rejection (AMR) was made based on the clinical course, immunological assays and histopathological findings. C4d immunostaining was added if AMR was suspected.

RESULTS

The LCM-positive LDLT recipients showed significantly poorer outcomes than the LCM-negative recipients. Among the LCM-positive recipients, 44.1% of recipients eventually died and 85.2% of recipients revealed positive C4d findings. The survival rate of LCM-positive and ABO-incompatible group was 0.50. The survival days were compared with the LCM-negative and ABO-identical/compatible group, and the LCM-positive and ABO-identical/compatible group clearly showed early death after LDLT, although the ABO-incompatible groups did not show significant. The factors of age, disease, pre-transplant scores, LCM, ABO compatibility and graft-recipient weight ratio showed statistical significance in multivariate analysis for important factors of LDLT outcomes. However, the LCM and ABO compatibilities had no synergetic effects on the LDLT survival.

CONCLUSION

HLA antigens are more widely expressed than ABO antigens, and advanced immunological strategies must be established for LCM-positive LDLT as well as for ABO-incompatible LDLT.

A survival case of ABO-incompatible liver transplantation complicated with severe preoperative infection and subsequent overwhelming postsplenectomy infection

A 47-year-old Japanese man was transferred to our hospital because of acute-on-chronic hepatitis B virus infection. On admission, he was suffering from sepsis due to a catheter infection and respiratory failure caused by pulmonary edema and pneumonia, but, as a result of preoperative intensive care, we avoided septic shock. ABO-incompatible liver transplantation (ABO-I-LT) was performed. In accordance with our ABO-I-LT protocol, we administered, rituximab and performed plasma exchange, splenectomy as well as hepatic artery infusion. The patient was discharged 80 days after living donor transplantation (LDLT). However, 136 days after LDLT, he experienced recurrent respiratory failure due to severe pneumonia. At that time, the CD19(+) B-cell count in the peripheral blood flow remained below 1%. We suspected a mixed infection involving Streptococcus pneumonia, Pneumocystis carinii, and fungus. The cause of the complication was overwhelming postsplenectomy infection (OPSI). We started administration of sulfamethoxazole and trimethoprim, ciprofloxacin hydrochloride, and micafungin sodium therapy as well as gamma-globulin. Oxygenation improved gradually; the patient was discharged at 41 days after re-admission. Although this patient survived the OPSI, it was clear that some aspects of the ABO-I-LT protocol should also be altered.

Liver transplantation

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

Cytomegalovirus infection following renal transplantation in patients administered low-dose rituximab induction therapy

Anti-CD20 antibody (rituximab) is recently being used as a B cell-depleting agent in renal transplantation (RTx). However, the incidence of infectious complications associated with rituximab therapy remains uncertain. We evaluated the incidence of cytomegalovirus (CMV) infection associated with rituximab therapy in RTx. A total of 83 patients were enrolled. The immunosuppressive regimen consisted of tacrolimus or cyclosporin, mycophenolate mofetil, methylprednisolone and basiliximab. In 54 patients, only one dose of rituximab (200 or 500 mg/kg body weight) was given before RTx. A total of 25 of 43 (58.1%) recipients who were CMV seropositive prior to RTx and who received rituximab induction therapy developed CMV infection, compared to 18 of 24 (75%) CMV seropositive recipients who did not receive rituximab therapy (P = 0.1676). A total of 8 of 11 patients who were CMV seronegative prior to RTx and who received rituximab developed CMV infection. However, CMV seroconversion was seen in all 8 of these infected patients. Low-dose rituximab induction therapy in renal transplant recipients appears to have no influence on the incidence of CMV infection and CMV seroconversion. However, we have to consider anti-CMV prophylaxis therapy, because of high incidents of CMV infection, especially for CMV seronegative recipients who received rituximab.

"To B or not to B?" B-cells and graft rejection

There is increasing evidence that various maturational stages of B-cells infiltrate various solid organ transplants undergoing acute rejection. The presence of immature CD20 and mature CD138 plasma cells associate with more aggressive and steroid-recalcitrant graft rejection and portend poor graft outcomes. Though associative, the causal role of B-cells in graft rejection remains to be better understood. This review discusses the possible roles of B-cells in graft rejection, whether involved as antigen presenting, as indirect effector, or antibody producing cells.

Adult living-donor liver transplantation with ABO-incompatible grafts

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Six consecutive cases of successful adult ABO-incompatible living donor liver transplantation: a proposal for grading the severity of antibody-mediated rejection

BACKGROUND

The clinical symptoms, histological findings, and treatments for antibody-mediated rejection (AMR), which is the leading cause of graft loss in adult ABO-incompatible liver transplantation (ABO-I-LT), have rarely been discussed.

METHODS

We performed adult living donor ABO-I-LT on six patients. We used anti-CD20 monoclonal antibody combined with plasma exchange preoperatively and intraportal or hepatic-arterial infusion, consisting of prostaglandin E1, corticosteroids, and protease inhibitor postoperatively to prevent AMR. Splenectomy was performed in patients 1, 4, 5 and 6 but not in patients 2 and 3. Weekly liver biopsies were performed after ABO-I-LT. When severe AMR was diagnosed, we performed plasma exchange combined with gamma-globulin bolus infusion (PE+IVIG).

RESULTS

In patients 1-3, severe jaundice, rapid decreases in platelet counts, and severe coagulopathy were observed in the early postoperative period. Liver biopsies sampled after the onset of these clinical findings were characterized by severe periportal and lobular hemorrhagic and neutrophil infiltration, suggesting that severe AMR occurred. However, after the initiation of PE+IVIG, AMR was remedied in all three patients. In patients 4-6, severe AMR was not observed. Mild AMR characterized by mild portal hemorrhagic infiltration was observed in patient 4, and moderate AMR characterized by moderate periportal and lobular hemorrhagic infiltration was observed in patient 6. Patients 4-6 did not require PE+IVIG and their clinical course was uneventful.

CONCLUSION

Given the experience of these six patients, we consider that AMR may be graded based on liver biopsy findings including hemorrhagic infiltration and neutrophil infiltration, as well as clinical findings. All six patients are currently doing well.

Whole-liver graft without the retrohepatic inferior vena cava for sequential (domino) living donor liver transplantation

Grafts used in Domino liver transplantation (LT) obtained from living donor liver transplantation (LDLT) for familial amyloid polyneuropathy (FAP) patients have been mainly used as reduced grafts. Because of small-for-size problems seen in LDLT, using whole liver grafts could improve post-LT outcome. Eight consecutive Domino LDLT using whole livers without retrohepatic inferior vena cava (IVC) from FAP patients were retrospectively analyzed. The graft weight/recipient's body weight ratio (GWRW) in the domino recipients ranged from 1.28% to 2.4% (mean: 1.52). Multiple vascular reconstructions in the whole-liver domino LT resulted in longer than usual warm ischemia time (mean: 64 min); however immediate post-operative recovery of hepatic function was uneventful. At 8-40 months after the transplant, all the FAP patients are well and all of the domino recipients are alive. Domino LT using a whole FAP liver from a LDLT for a FAP patient presents satisfactory results, even though the transplant procedure is technically complicated.

ABO-incompatible liver transplantation for critically ill adult patients

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

Current trends in live liver donation

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

The role of apheresis therapy for ABO incompatible living donor liver transplantation: the Kyoto University experience

Liver transplantation is a radical surgical therapy for end-stage liver disease. Although in Japan organ transplantation from brain-dead donors (BDD) has been allowed since October 1997, to date, only 29 liver grafts from BDD have been obtained. Thus, most of the liver transplantations carried out use living-donor liver transplantation (LDLT), and BDD liver transplantation is only used in rare cases. In order to carry out LDLT more safely, apheresis (plasmapheresis: PE) plays a major role in our country because of the prevalence of LDLT wherein later re-transplantation is difficult. Thus, because of a limited donor supply and because the needs of patients with end-stage liver disease is critical, use of grafts from ABO-incompatible (ABO-I) donors might be the only available option. From June 1990 to November 2005, 1100 patients underwent 1151 LDLT cases at Kyoto University Hospital. Additionally, 159 LDLT cases (13.8%) received ABO-I living-donor liver grafts. The role of apheresis in ABO-I LDLT is the reduction of antibody titers such as anti-A or anti-B antibody. We carry out preoperative PE as a general rule for ABO-I cases, and the recipient's antibody level against the donor's blood type is decreased to one eighth of the baseline value before LDLT. Until now, baseline immunosuppressive agents included steroids, tacrolimus and cyclophosphamide. At first, splenectomy was carried out during surgery to suppress antibody production, and intraportal (PV) infusion therapy was carried out to control local disseminated intravascular coagulation (DIC) occurring in ABO-I grafts. At that time, three drugs-methylprednisolone, prostaglandin E1 (PGE1), and gabexate mesylate (FOY) were infused continuously for 3 weeks after LDLT. At present, instead of PV infusion therapy, hepatic artery infusion therapy without splenectomy is adopted because of portal thrombosis, and two drugs- methylprednisolone and PGE1- are infused continuously for 3 weeks following LDLT. Recently, we introduced anti-CD20 monoclonal antibody (Rituximab) instead of splenectomy for B cell deletion before ABO-I LDLT. In the present article, we describe the role of apheresis around ABO-I LDLT based on our recent experiences.

Outcomes of adult-to-adult living donor liver transplantation: a single institution's experience with 335 consecutive cases

OBJECTIVE

To determine outcomes for both donors and recipients of adult-to-adult living donor liver transplantation (AALDLT) and independent factors impacting those outcomes.

SUMMARY BACKGROUND DATA

Deceased donors for organ transplantation remain extremely rare, making living donor liver transplantation (LDLT) practically the sole therapeutic modality for patients with end-stage liver disease in Japan.

METHODS

Retrospective analysis of initial LDLT for 335 consecutive adult (>or=18 years) patients performed between November 1994 and December 2003.

RESULTS

: Of the 335 recipients, 275 received right-liver grafts and the remaining 60 recipients received non-right-liver grafts. Three of the 335 liver grafts were domino-splitting livers. Sixty of the 332 donors other than the domino-donors showed major postoperative complications. Multivariate analysis indicated that accumulation of case experience significantly and advantageously affected the surgical outcomes of these living liver donors, and right-liver donation and prolonged donor operation time were shown to be independent risk factors of major complications in the donors. Post-transplant patient and graft survival estimates were 73.1% and 72.5% at 1 year, 67.7% and 66.3% at 4 years, and 64.7% and 61.9% at 7 years, respectively. Obvious pretransplant encephalopathy, a higher (>or=31) modified Model for End-stage Liver Disease score (including points for persistent ascites and low serum sodium) and higher donor age (>or=50 years) were indicated as independent factors predictive of graft failure (graft loss or death) in the multivariate analysis.

CONCLUSIONS

Graft type and degree of experience exerted a significant impact on the surgical outcomes of AALDLT donors but did not significantly affect the survival outcomes of AALDLT recipients. Better pretransplant conditions and younger age (<50 years) among the living donors appeared to be advantageous in terms of gaining better survival outcomes of patients undergoing AALDLT.

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

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

Successful liver transplantation across the ABO incompatibility barrier in 6 cases of biliary atresia

BACKGROUND

The problem of ABO-incompatible liver transplantation still remains unsolved in older children. In this article, we report on our experience of 6 successful ABO-incompatible liver transplantations in patients with biliary atresia.

MATERIAL AND METHODS

Six patients (ABO incompatibility type A-->O:1 case, B-->O:2 cases, A-->B:3 cases) were enrolled in this study; 3 patients were aged approximately 1 year and the other 3 ranged in age from 9 to 24 years at the time of transplantation. Each patient received perioperative plasma exchange, until the anti-donor blood-type antibody titers became less than 1:16, and also systemic multidrug immunosuppressive therapy (cyclophosphamide, prednisolone, and tacrolimus). We applied the protocol of intraportal infusion therapy (local administration of prostaglandin E(1), steroid, and gabexate mesilate via a portal vein catheter), splenectomy, and rituximab administration for the older group.

RESULTS

Both the patient and graft survival rates remain at 100%, with the follow-up period of the patients ranging from 12 and 123 months. Acute cellular rejection occurred in 2 cases, and both were steroid sensitive. There was no incidence of humoral rejection. Although all cases developed viral infection, all recovered uneventfully with the administration of antiviral agents.

CONCLUSION

ABO-incompatible liver transplantation can be performed with a low risk of humoral rejection or late biliary complications using this combined antirejection strategy, even in older children.

The emerging role of rituximab in organ transplantation

Long-term acceptance of solid organ allografts remains a challenge. While many acute rejection episodes can be treated, new mechanisms of allograft damage are now being defined especially in kidney transplantation. Unexpected clusters of CD20(+) cells have been discovered in renal biopsies performed for clinical rejection. C4d deposition is now routinely seen in refractory rejection. Despite the rapid introduction of new immunosuppressive agents in transplantation, the search for an efficacious anti-B-cell agent remains. With novel mechanisms of allograft damage now being defined, it is important to consider how an anti-B-cell agent might fit into an immunosuppressive regimen. Rituximab is a high-affinity CD20 specific antibody that depletes the B-cell compartment by inducing cellular apoptosis. Thus, it is a rational choice for therapy in transplantation to abrogate B-cell mediated events. In this review, we will discuss the mechanisms of action of rituximab, and its use in for a variety of indications in solid organ transplantation. There are emerging case reports that show that rituximab may be an effective agent to treat antibody-mediated rejection, and post-transplant lymphoproliferative disorder. Rituximab has been frequently cited as an important adjunct therapy in desensitization protocols for highly sensitized transplant recipients as well as recipients of ABO incompatible transplants. Rituximab demonstrates promise in this regard and warrants additional consideration in prospective clinical trials.

Long-term outcomes of 600 living donor liver transplants for pediatric patients at a single center

This report concerns the long-term outcome of living donor liver transplantation (LDLT) for pediatric patients at a single center. Between June 1990 and December 2003, a total of 600 LDLTs, including 568 primary transplantations and 32 retransplantations, were performed for pediatric patients, who were immunosuppressed with FK506 and low-dose corticosteroids. Patient survival at 1, 5, and 10 years were 84.6%, 82.4%, and 77.2%, respectively, and the corresponding findings for graft survivals were 84.1%, 80.9%, and 74.5%. Multivariate analysis demonstrated that fulminant hepatic failure (FHF), a graft vs. body weight (GBWR) ratio of <0.8, and ABO-incompatible transplants were independently associated with both patient and graft survival. The retransplantation rate was 6%, and 55 patients (9.7%) have been completely weaned off immunosuppressants. Long-term patient and graft survival after pediatric LDLT for a large cohort of children at our hospital were found to be as good as those for cadaveric liver transplantation, although this series includes 13% liver transplantations with ABO-incompatible donors, which are obviously inferior in patient and graft survival. To obtain better outcomes for patients with FHF and for patients with ABO-incompatible transplants, immunosuppressive therapy needs to be improved.

Acute humoral rejection and C4d immunostaining in ABO blood type-incompatible liver transplantation

Complement C4d deposition in graft capillaries has been reported to be associated with antibody-mediated rejection in kidney and other solid organ transplantation. The correlation of C4d deposits and humoral rejection in liver transplants, however, is not well understood. We investigated the C4d immunostaining pattern in 34 patients whose liver biopsy was taken within the first 3 postoperative weeks for suspected acute rejection after ABO blood type-incompatible liver transplantation. The staining pattern was classified as positive (portal stromal staining), indeterminate (endothelial staining only), and negative (no staining). Positive C4d immunostaining was seen in 17 (50%) patients and was significantly associated with high (x64 or more) postoperative antidonor A/B antibody (immunoglobulin M (IgM)) titers (88 vs. 35%, P = 0.002) and poorer overall survival rate (41 vs. 88%, P = 0.007). Ten of 11 (91%) cases with histological acute humoral rejection (periportal edema and necrosis (PEN) or portal hemorrhagic edema) were positive for C4d, all of which showed high postoperative antibody titers. The other histologies associated with C4d positivity was purulent cholangitis (n = 4), coagulative hepatocyte necrosis (n = 1), acute cellular rejection (n = 1), and hepatocanalicular cholestasis (n = 1). Full clinical recovery was observed in only 6 of 17 (35%) C4d-positive patients, and tended to be associated with a lower rejection activity index (RAI). In conclusion, our study indicates that C4d deposits in the portal stroma can be a hallmark of acute humoral rejection in ABO-incompatible liver transplantation, and allograft damage can be reversible in a minority of cases.