Living related liver transplantation: histopathologic analysis of graft dysfunction in 304 patients

Computed tomography findings in ABO-incompatible living donor liver transplantation recipients with biliary strictures

OBJECTIVES

To evaluate CT findings of biliary strictures in ABO-incompatible living donor liver transplantation (LDLT) recipients, with emphasis on associated 1-month post-transplantation CT findings, and evaluate clinical outcomes.

METHODS

Of 351 ABO-incompatible recipients, we retrospectively evaluated CT scans in 65 recipients with biliary stricture. The biliary strictures on CT scans were classified as type A (perihilar) and type B (diffuse). Precedent CT abnormality patterns and the presence of a periportal halo sign at 1-month post-transplantation were evaluated. For each patient, clinical outcomes were evaluated.

RESULTS

Of 65 ABO-incompatible recipients with biliary strictures, 36.9% had type B strictures. Compared with biliary strictures at diagnosis, similar CT abnormality patterns were observed for 84.4% in type A and 86.4% in type B strictures at 1-month post-transplantation. Complex periportal halo signs on the 1-month post-transplantation CT were more frequently noted for type B than type A strictures (86.4% vs. 3.1%, P < 0.001). Progressive clinical outcomes were more frequently observed for type B than type A strictures (79.2% vs. 26.8%, P < 0.001), with a significantly shorter graft survival time (46.4 months vs. 90.8 months, P < 0.001).

CONCLUSION

CT abnormality patterns and complex periportal halo signs on 1-month post-transplantation CT may be clinically useful for managing biliary strictures in ABO-incompatible LDLT recipients. Key Points • Of ABO-incompatible LDLT recipients, type B biliary stricture incidence was 6.8%. • Of type B strictures, 86.4% exhibited similar CT abnormality patterns at 1-month post-transplantation. • Complex periportal halo at 1 month was significantly associated with type B strictures. • Progressive clinical outcomes were more frequently observed in type B strictures.

Pathologic Analysis of Right-Lobe Graft Failure in Adult-to-Adult Live Donor Liver Transplantation

Live donor adult liver transplantation (LDALT) utilizing right-lobe grafts is now acceptable as an alternative to cadaveric orthotopic liver transplantation (OLT). However, some LDALTs fail and require urgent OLT or result in recipient death. Our aim was to determine the basis of LDALT failure. Liver specimens from 49 LDALT recipients were evaluated and the findings correlated with clinical outcome. Ten patients (20.4%) had either early (< 1 month) or late (> 1 month) graft failure. Eight early failures, 7 of which occurred among our first 25 cases, were due to extensive liver parenchymal necrosis as a result of hepatic artery thrombosis (n=3), portal vein thrombosis (n= 1), hyperperfusion syndrome (n= 1), complete graft thrombosis (n= 1) with Factor V Leiden on a regimen of therapeutic heparin (n=1), sepsis and concomitant graft dysfunction with venous outflow tract injury (n=I), and venous outflow tract thrombosis and parenchymal thermal injury with sepsis (n=1). Preoperative, intraoperative, or postoperative severe vessel wall injury was evident in 6/8 early failures. TWo patients had late graft failure, 1 from recurrent hepatitis C and 1 with sepsis/multisystem organ failure. There were no significant differences in graft size, rejection episodes, or operative or ischemic times between patients with and without graft failure. In conclusion, LDALT failed in 10/49 (20%) of our patients, with 8/10 occurring within 1 month post-LDALT owing to vascular/thrombotic complications experienced during the early phase of our institutional experience. Perioperative vessel wall injury appeared to be a major factor in predicting early graft loss.

Recurrence of hepatitis B is associated with cumulative corticosteroid dose and chemotherapy against hepatocellular carcinoma recurrence after liver transplantation

The incidence of hepatitis B (HB) recurrence after a liver transplantation has been reduced by prophylaxis with hepatitis B immunoglobulin (HBIG) and lamivudine. However, the long-term incidence of recurrence is <10%, and the factors associated with HB recurrence are unclear. This study analyzed the factors associated with HB recurrence in 203 recipients who underwent liver transplantation for HB in 3 major centers in Korea over 4 years. Eighty-five patients (41.9%) had a hepatocellular carcinoma (HCC). Preoperative active virus replicators with the HBeAg(+) (46.8%) and/or hepatitis B virus DNA(+) (39.4%) were observed in 136 patients (67.0%). The HB prophylaxis consisted of either HBIG monotherapy (n = 95, HBIG group) or combination therapy with lamivudine (n = 108, combination group). HB recurrence was defined as the appearance of the HBsAg. The follow-up period was 28.3 +/- 13.1 months (mean +/- SD). HB recurred in 21 patients (10.3%) after transplantation. The time from transplantation to recurrence was 16.3 +/- 9.4 months. Pre-LT DNA positivity was more prevalent in HBIG group (55.8%) than in the combination group (39.8%) (P = 0.015). However, the incidence of HB recurrence was similar in the HBIG (6.3%) and combination group (13.8%), as well as between the active replicators (12.5%) and nonreplicators (4.1%) (P < 0.05). There was a far higher incidence of HB recurrence in patients receiving corticosteroid pulse therapy (21.0% vs. 7.9%), patients who experienced HCC recurrence (31.3% vs. 8.6%), and patients receiving chemotherapy to prevent HCC recurrence (25.0% vs. 4.4%) (P < 0.05). The cumulative corticosteroid dose was higher in patients who experienced recurrence of HB (P = 0.002). Multivariable analysis confirmed the effect of the cumulative corticosteroid dose and chemotherapy to be risk factors. Liver transplantation for HB is safe, with low recurrence rates if adequate prophylaxis is used. However, the cumulative corticosteroid dose and the chemotherapy used for HCC were risk factors for HB recurrence, so careful monitoring for HB recurrence is needed in these patients.

Pathophysiologic observations and histopathologic recognition of the portal hyperperfusion or small-for-size syndrome

In an attempt to more completely define the histopathologic features of the portal vein hyperperfusion or small-for-size syndrome (PHP/SFSS), we strictly identified 5 PHP/SFSS cases among 39 (5/39; 13%) adult living donor liver transplants (ALDLT) completed between 11/01 and 09/03. Living donor segments consisting of 3 right lobes, 1 left lobe, and 1 left lateral segment, with a mean allograft-to-recipient weight ratio (GRWR) of 1.0 +/- 0.3 (range 0.6 to 1.4), were transplanted without complications, initially, into 6 relatively healthy 25 to 63-year-old recipients. However, all recipients developed otherwise unexplained jaundice, coagulopathy, and ascites within 5 days after transplantation. Examination of sequential posttransplant biopsies and 3 failed allografts with clinicopathologic correlation was used in an attempt to reconstruct the sequence of events. Early findings included: (1) portal hyperperfusion resulting in portal vein and periportal sinusoidal endothelial denudation and focal hemorrhage into the portal tract connective tissue, which dissected into the periportal hepatic parenchyma when severe; and (2) poor hepatic arterial flow and vasospasm, which in severe cases, led to functional dearterialization, ischemic cholangitis, and parenchymal infarcts. Late sequelae in grafts surviving the initial events included small portal vein branch thrombosis with occasional luminal obliteration or recanalization, nodular regenerative hyperplasia, and biliary strictures. These findings suggest that portal hyperperfusion, venous pathology, and the arterial buffer response importantly contribute to early and late clinical and histopathologic manifestations of the small-for-size syndrome.

Correlation between acute rejection severity and CD8-positive T cells in living related liver transplantation

The Banff schema is the most widely used standard grading system for liver allograft rejection. To investigate the relationship between the Banff rejection activity index (RAI) and the presence of lymphocyte subpopulations in allograft liver tissue, assuming these cells to probably play an important role in the mechanism of acute cellular rejection (ACR), we performed immunohistological examinations using liver tissues with various ACR severities after living related liver transplantation (LRLT). In total, 37 needle liver biopsy specimens with ACR in LRLT were examined using antibodies to CD4, CD8, and CD20. Formalin-fixed and paraffin-embedded liver tissues were used to maintain morphology. Immunohistological findings and RAI score according to the Banff schema were compared. In the results, mainly CD8-positive (CD8+), rather than CD4-positive (CD4+), cells were detected in the portal tract and were also found in bile duct epithelium and subendothelial areas of portal veins. The number of CD8+ cells increased according to ACR grade, whereas CD4+ cells tended to decrease. There were significant correlations between the presence of CD8+ cells (p = 0.0006) and CD4+ cells (p = 0.0003) and ACR severity. On the other hand, CD20-positive cells did not correlate with ACR severity (p = 0.472). The results indicate that CD8+ cells play important roles in ACR severity of LRLT, suggesting the number of CD8+ cells in liver tissue to be useful as a supplementary tool, in addition to RAI of the Banff schema, for objective evaluation of ACR severity.

Cadaveric full-size liver transplantation and the graft alternatives in adults: a comparative study from a single centre

BACKGROUND/AIMS

This study aims to compare the results of living donor (LDLT), cadaveric split (SLT) and domino (DO) liver transplantation which are currently available alternatives to the conventional cadaveric full-size liver transplantation (CAD).

METHODS

Immunologic, vascular and biliary complications (BC) were evaluated in 38 LDLT, 20 SLT, 17 DO and 38 CAD recipients.

RESULTS

The incidence of acute rejection (AR) was similar between groups, and between blood-related and blood-unrelated patients. AR was more severe in the SLT group according to the Banff scores (P=0.03, P<0.001, P<0.001). The evolution of AR was similar between the groups, in terms of development of chronic rejection. No venous complications occurred in the overall population. The rate of arterial thrombosis (10.5, 10, 0 and 3%, respectively) was statistically similar between groups. The rate of BC (26, 40, 12, and 8%, respectively) was higher in the partial grafts than in the whole grafts (P=0.006), but was not significantly different within each group. There was an association between the severity of preservation injury and occurrence of AR (P=0.01) and arterial thrombosis (P=0.016), but not BC. One- and 2-year graft and patient survival rates were similar between groups.

CONCLUSIONS

None of the graft types seemed to confer immunological advantage. BC remained problematic in the partial grafts, independently from ischemia time.

Marked Differences in acute cellular rejection rates between living-donor and deceased-donor liver transplant recipients

BACKGROUND

: Due to ongoing organ donor shortage, an increasing number of adult live-donor liver transplants (LDLT) are being performed. The aims of this study were to compare the incidence of ACR between recipients of live- and deceased-donor liver transplants, and to note any differences in ACR among related and unrelated living-donor recipients.

METHODS

: Sixty-four adults undergoing LDLT between 1998-2001 were closely matched with a deceased recipient. Statistical comparisons in ACR between the live- and deceased-donor groups were based on the differences between the ACR rates of each LDLT patient and the corresponding matched deceased recipient. Analyses were performed separately for pairs in which the living donor was not related to the recipient, was a nonsibling relative, or was a sibling.

RESULTS

: Live- and deceased-donor recipients underwent a similar number of liver biopsies. In all, 16/50 (32%) of the biopsied LDLT patients had ACR compared to 36/49 (73%) of the deceased-donor recipients. ACR rates of living donors and their deceased-donor matches did not differ significantly for the unrelated living donors, but did differ for the nonsibling related (P=0.03) and the sibling LDLT (P=0.03). The results were similar when comparing rates of high-degree ACR for unrelated, nonsibling related, and sibling pairs. High-degree ACR differences in the sibling LDLT group were significantly greater than in the nonsibling group (P=0.05).

CONCLUSIONS

: Rates of ACR and high-degree ACR are decreased in living-related liver transplant recipients. This difference is likely genetically related as ACR rates are lower in recipient-donor pairs of increasing genetic similarity.

Low Incidence of Acute Rejection after Living-Donor Liver Transplantation: Immunologic Analyses by Mixed Lymphocyte Reaction using a Carboxyfluorescein Diacetate Succinimidyl Ester Labeling Technique

BACKGROUND

To monitor antidonor alloreactivity for accurate diagnosis of acute rejection after living-donor liver transplantation (LDLT), we used a mixed lymphocyte reaction (MLR) assay using an intracellular fluorescent dye carboxyfluorescein diacetate succimidyl ester (CFSE)-labeling technique (CFSE-MLR) in 29 consecutive patients who underwent adult-to-adult LDLT.

METHODS

For patients who developed moderate or severe disorders in liver function, CFSE-MLR was performed together with needle biopsy of the liver allografts immediately after liver dysfunction had occurred. CFSE-labeled peripheral blood mononuclear cells (PBMC) from recipients and irradiated autologous, donor, or third-party PBMC were cultured, and then proliferation and CD25 expression in each of the CD4+ and CD8+ T cell subsets were analyzed by flow cytometry.

RESULTS

Twelve (41.4%) of the 29 patients developed moderate or severe disorders in liver function within 6 months after LDLT. Eight of the 12 patients (overall incidence of 27.6%) suffering from liver function disorder were diagnosed on the basis of liver biopsy results as having mild or moderate acute rejection. However, only 4 of the 12 patients (overall incidence of 13.8%) showed remarkable proliferation of CD8+ T cells in association with CD25 expression on antidonor CFSE-MLR. The other eight patients were eventually diagnosed as having recurrence of original hepatitis, drug-induced hepatotoxicity, or congestion of the anterior segment of the liver allograft by further extensive examinations or in retrospect.

CONCLUSIONS

The results of CFSE-MLR assays, which could be used for rigorously monitoring rejection, provided evidence of low incidence of acute rejection after LDLT.

The Histologic Pattern of ???Biliary Tract Pathology??? Is Accurate for the Diagnosis of Biliary Complications

A histologic pattern comprising centrilobular cholestasis and portal changes including edema, predominantly neutrophil polymorph infiltration, cholangiolar proliferation, and cholangiolitis is well known to correspond to biliary obstruction. This pattern, referred as biliary tract pathology (BTP) in this text, remains unclear in terms of its clinical significance. We aimed to assess the incidence, timing, and diagnostic accuracy of BTP after liver transplantation. All 248 liver biopsies and clinical records, from 94 patients, including 30 living donor, 17 split, 15 domino, and 32 cadaveric full-size primary liver transplantation, were reviewed. BTP was diagnosed in 21% of biopsies from 31% of patients at a median of 28 days after transplantation (range, 5-763 days). When radiologic imaging of the biliary tree was taken as the gold standard, biopsy was found to have a sensitivity of 87% (95% confidence interval, 73%-100%) and a specificity of 87% (95% confidence interval, 80%-95%) for the diagnosis of biliary complications. An underlying clinical condition was found in 86% of cases, which included biliary complications (69%), arterial thrombosis (3%), sepsis (10%), and recurrent disease (3%). In 14% of cases, BTP remained unexplained. In conclusion, BTP after liver transplantation has clinical significance in most cases, with a particular emphasis for true biliary complications. This pattern must incite radiographic verification of the biliary tract.

Periportal edema and necrosis as diagnostic histological features of early humoral rejection in ABO-incompatible liver transplantation

Humoral rejection caused by antidonor blood group A/B antibodies is one of the most important obstacles for successful ABO-incompatible liver transplantation. However, no specific morphologic features of liver biopsies to distinguish humoral rejection from other conditions such as ischemia or sepsis have been satisfactorily documented. To histologically clarify the early changes in humoral rejection, we studied 41 cases of living donor ABO-incompatible liver transplantation whose allograft biopsies during the first episode of suspected acute rejection were available within the first postoperative month. Postoperative isohemagglutinin IgM titers were x64 or more in 21 patients (51%; high-titer group) and less than x64 in 20 cases (49%; low-titer group). In the high-titer group, elevation of postoperative titers x64 or more occurred within postoperative days 5.7 +/- 4.1 (range: 1-17). An increase in the incidence of cholangitis was observed in the high-titer group (90% vs. 30%, P <.0001), as well as poorer overall graft survival than in the low-titer group (38% vs. 70%, P <.05). Seven biopsies obtained from the high-titer group within 3 days after the onset of elevation of the antibody titers and one biopsy obtained at the peak of the antibody titers demonstrated periportal edema and necrosis, neither of which was found in the low-titer group. All grafts of these patients caused massive hepatocyte necrosis or severe biliary complications. In conclusion, a high morbidity rate of ABO-incompatible liver transplantation is associated with high postoperative levels of antibody titers. Periportal edema and necrosis observed during elevation of antibody titers can be regarded as histological indications of early changes in severe humoral rejection.

Hepatocyte growth factor prevents chronic allograft dysfunction in liver-transplanted rats

BACKGROUND

Hepatocyte growth factor (HGF) is a growth factor with multiple biologic properties, including mitogenic, morphogenic, anti-apoptotic, and antifibrogenic activities. Long-term administration of the deletion variant of HGF (dHGF) might contribute to the prevention of chronic liver allograft dysfunction, which is attributed to immunologic and nonimmunologic reactions.

METHODS

Low-dose tacrolimus was administered to rat-liver recipients after transplantation. Effects of dHGF on transplanted livers treated with low-dose tacrolimus were investigated.

RESULTS

Rats receiving liver transplants treated with only low-dose tacrolimus administration showed chronic allograft dysfunction. Treatment with dHGF prolonged the survival time of rats that received liver allografts and suppressed fibrosis of liver allograft. Treatment with dHGF also suppressed the expression levels of interleukin (IL)-1beta, caspase-1, and transforming growth factor (TGF)-beta mRNAs in liver allografts.

CONCLUSIONS

The findings indicate that dHGF may prevent chronic liver-allograft dysfunction and thus may become a novel treatment for chronic liver-allograft dysfunction.

Postoperative Management and Complications in Living-related Liver Transplantation

Living-related liver transplantation is widely accepted as a treatment for patients with end-stage liver disease, with survival rates of up to 80%. Liver transplant recipients are at risk for the same postoperative complications as any patient undergoing a major intraabdominal operation, in addition to several complications specific to this procedure. Maintenance immunosuppression relies principally on administration of tacrolimus and methylprednisolone. Nevertheless, approximately 36% of liver transplant recipients suffer acute rejection in the early posttransplant period and require bolus steroid therapy as a rescue agent. Vascular complications, including hepatic arterial thrombosis and portal vein thrombosis, are additional major problems. When they occur in the immediate postoperative period, they can produce fulminant hepatic necrosis requiring retransplantation, so intensive anticoagulation therapy is needed as prophylaxis against these vascular complications. If thrombosis of the hepatic artery or portal vein is diagnosed early in the postoperative course, emergency thrombectomy with reanastomosis should be attempted. Outflow obstruction by hepatic vein stenosis sometimes causes liver dysfunction, pleural effusion, and hepatosplenomegaly. Percutaneous transhepatic or transjugular approached hepatic vein dilatation is very useful in case of hepatic vein stenosis. Recipients are generally immunocompromised secondary to immunosuppressive therapy and their poor clinical condition and are at high risk for postoperative infection. Infection is a major cause of morbidity and the most common cause of death in liver transplant recipients. Antibiotic, antifungal, and antiviral agents are used empirically, and serologic examinations and bacterial investigations of blood, sputum, stool, urine, and discharge from drains should be performed as well as antibiotic sensitivity tests when necessary. Other complications related to the operation are intraabdominal bleeding, bile leakage, biliary anastomotic stenosis, and intestinal perforation. The postoperative course of liver transplant recipients with these complications depends on making an accurate diagnosis promptly and initiating appropriate management. Postoperative complications of living-related liver transplantation are protean, so it is very important to communicate with professionals in each specialized field to ensure optimal treatment.

Marked hyperbilirubinemia caused by acute cellular rejection combined with preservation injury in an infant undergoing living-related liver transplantation

Acute cellular rejection (ACR) and preservation injury (PI) are major complications occurring early after liver transplantation (LTx) and sometimes lead to severe graft dysfunction. We herein report an infant who developed marked hyperbilirubinemia as a result of combined ACR and PI in addition to ischemic damage from bleeding, but recovered without re-LTx. In a 1-yr-old-girl undergoing living-related LTx, liver biopsy (LBx) on post-operative day 7 showed ballooning of the hepatocytes, i.e. microvesicular steatosis (30%) and occasional centrolobular necrosis, consistent with mild-to-moderate PI and ACR with a rejection activity index (RAI) of 2.0. Because drainage of an intra-abdominal abscess was performed and a systemic infection was considered severe, the tacrolimus level was decreased and steroids were discontinued. The total bilirubin level started to rise, thereafter, reaching a maximum of 47.6 mg/dL at 1 month after LTx. LBx showed an RAI of 6.0 and steatosis of 10%. With good response to an increase of tacrolimus level and administration of steroid, the total bilirubin level gradually decreased, finally reaching the normal range in 3 months, and LBx showed no steatosis or finding of ACR. From this experience, ACR, if combined with mild-to-moderate PI or other ischemic damage, may lead to severe clinical manifestations after LTx, which, however, could remit with conservative therapy and without re-LTx.

Diagnostic issues in liver transplantation pathology

Liver biopsy is used to determine the pathogenesis of liver dysfunction after liver transplantation. One or more causative factors may be identified on biopsy. The pathologist must be familiar with the histopathology of acute rejection to differentiate it from other potential complications, including biliary obstruction, intercurrent cytomegalovirus hepatitis, or recurrent disease. Consensus documents from the Banff international panel provide useful guidelines for the appropriate grading of acute and chronic rejection.

Living-donor liver transplantation in children

With evolution of surgical technique, advances in immunosuppression, and better understanding of pre- and post-operative care, the 1-yr survival rate after liver transplantation in children has reached 85-90%. As a result, a greater number of patients have been listed for transplantation and waiting times have lengthened. Innovative techniques such as reduced-size, split, and living-donor liver transplantation are being applied more often to decrease long waiting times and reduce associated morbidity and mortality. In this review, living donor liver transplantation in pediatrics is described. Special issues, such as donor and recipient selection, surgical procedures in donors and recipients, and ethical issues, are discussed.

Adult-to-adult live donor liver transplantation: a short-term clinicopathologic study

With the success of pediatric live donor liver transplantation (LDLT) and the continued shortage of cadaveric donors, adult-to-adult LDLT has been performed at some centers, including ours. We performed a detailed histologic review of all liver specimens obtained from 9 adult recipients at and after LDLT and correlated these findings with the patients' course and outcome. Five patients had histologic evidence of biliary tract pathology; 3 of 5 required surgical or radiologic intervention. The other 2 had clinically insignificant biliary disease. Diffuse hepatocytic hemorrhagic necrosis secondary to massive portal blood flow after portal venous revascularization resulted in graft failure and retransplantation in a single patient with severe preoperative portal hypertension. Two perioperative deaths were caused by sepsis and multiorgan failure (day 25) and generalized thrombosis related to factor V Leiden (day 6). The preoperative diagnosis, presence of portal vein thrombosis in the native liver, postoperative cholangiopathy, and subcapsular hemorrhagic necrosis in donor liver wedge biopsies did not affect the short-term outcome. In conclusion, biliary tract pathology is common after adult-to-adult LDLT but does not negatively affect graft or patient survival. Infrequent but catastrophic vascular complications related to portal hemodynamics or thrombosis can result in graft loss and/or patient death.

Liver transplantation. Living donor, hepatocyte, and xenotransplantation

Liver transplantation is now accepted as effective therapy in the treatment of acute and chronic hepatic failure. Improvements in surgical techniques and immune suppression have led to 5-year survival rates that exceed 70% in most centers. The success of transplantation has led to a dramatic increase in the number of candidates to over 14,000 places on the national waiting list. While the number of patients in need of transplantation increases, there has been little growth in the supply of available cadaveric organs, resulting in an organ shortage crisis. With waiting times often exceeding 1 to 2 years, the waiting list mortality now exceeds 10% in most regions. Several novel approaches have been developed to address the growing disparity between the limited supply and excessive demand for suitable organs.