Accuracy of bile duct changes for the diagnosis of chronic liver allograft rejection: reliability of the 1999 Banff schema

Banff 2016 Global Assessment and Quantitative Scoring for T Cell-Mediated Liver Transplant Rejection are Interchangeable

Introduction. Histopathological assessment of liver biopsies is the current “gold standard” for diagnosing graft dysfunction after liver transplantation (LT), as graft dysfunction can have nonspecific clinical presentations and inconsistent patterns of liver biochemical dysfunction. Most commonly, post-LT, graft dysfunction within the first year, is due to acute T-cell mediated rejection (TCMR) which is characterised histologically by the degree of portal inflammation (PI), bile duct damage (BDD), and venous endothelial inflammation (VEI). This study aimed to establish the relationship between global assessment, which is the global grading of rejection using a “gestalt” approach, and the rejection activity index (RAI) of each component of TCMR as described in revised Banff 2016 guidelines. Methods. Liver biopsies (n = 90) taken from patients who underwent LT in 2015 and 2016 at the Australian National Liver Transplant Unit were identified from the electronic medical records. All biopsy slides were microscopically graded by at least two assessors independently using the revised 2016 Banff criteria. Data were analysed using IBM SPSS v21. A Fisher–Freeman–Halton test was performed to assess the correlation between the global assessment and the RAI scores for each TCMR biopsy. Results. Within the cohort, 60 (37%, n = 164) patients underwent at least 1 biopsy within 12 months after LT. The most common biopsy outcome (total n = 90) was acute TCMR (64, 71.1%). Global assessment of TCMR slides strongly positively correlated with PI ( $p$ value <0.001), BDD ( $p$ value <0.001), VEI ( $p$ value <0.001), and total RAI ( $p$ value <0.001). Liver biochemistry of patients with TCMR significantly improved within 4 to 6 weeks post-biopsy compared to the day of the biopsy. Conclusion. In acute TCMR, global assessment and total RAI are strongly correlated and can be used interchangeably to describe the severity of TCMR.

2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of Antibody-Mediated Rejection

The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.

Interleukin-2 receptor antagonists for pediatric liver transplant recipients: a systematic review and meta-analysis of controlled studies

IL-2RA are frequently used as induction therapy in liver transplant recipients to decrease the risk of AR while allowing the reduction of concomitant immunosuppression. The exact association with the use of IL-2RA, however, is uncertain. We performed a systematic literature search for relevant studies. Random effects models were used to assess the incidence of AR, steroid-resistant rejection, graft loss, patient death, and adverse drug reaction, with or without IL-2RA. Six studies (two randomized and four non-randomized) met the eligibility criteria. Acute rejection at six months or later favored the use of IL-2RA significantly (RR 0.38; 95% CI 0.22-0.66, p = 0.0005). Although not statistically significant, IL-2RA showed a substantial reduction of the risk of steroid-resistant rejection (RR 0.32; CI 0.19-1.03, p = 0.0594). Graft loss and patient death showed a reductive tendency through the use of IL-2RA. The use of IL-2RA is safe and is associated with a statistically significantly lower incidence of AR after transplantation and substantial reduction of steroid-resistant rejection, graft loss, and patient death.

What is the long-term outcome of the liver allograft?

With improved long-term survival following liver transplantation (LT), issues relating to the assessment of the liver allograft in long-term survivors are becoming increasingly relevant. Histological abnormalities are commonly present in late post-transplant biopsies, including protocol biopsies from patients who appear to be well with good graft function. Recurrent disease is the commonest recognised cause of abnormal graft histology, but may be modified by the effects of immunosuppression or interactions with other graft complications, resulting in complex or atypical changes. Other abnormalities seen in late post-transplant biopsies include rejection (which often has different appearances to those seen in the post-transplant period), de novo disease, "idiopathic" post-transplant hepatitis (IPTH) and nodular regenerative hyperplasia. In many cases graft dysfunction has more than one cause and liver biopsy may help to identify the predominant cause of graft damage. Problems exist with the terminology used to describe less well understood patterns of graft injury, but there is emerging evidence to suggest that late rejection, de novo autoimmune hepatitis and IPTH may all be part of an overlapping spectrum of immune-mediated injury occurring in the late post-transplant liver allograft. Careful clinico-pathological correlation is very important and the wording of the biopsy report should take into account therapeutic implications, particularly whether changes in immunosuppression may be indicated. This article will provide an overview of the main histological changes occurring in long-term survivors post-LT, focusing on areas where the assessment of late post-transplant biopsies is most relevant clinically.

Hepatocyte cytokeratin 7 expression in chronic allograft rejection

We examined hepatocyte cytokeratin 7 (CK7) expression in chronic allograft rejection (CR), a ductopenic condition in which this has not been systematically evaluated, in 20 patients with the clinicopathologic diagnosis of CR and age-, sex-, and native-disease-matched control subjects. We also studied baseline biopsy specimens from both groups. Three pathologists independently reviewed H&E- and CK7-stained sections, counting interlobular bile ducts (BDs) and portal tracts (PTs), noting the morphologic pattern of injury and scoring hepatocyte CK7 expression (0, none; 1+, rare; 2+, multifocal, predominantly periportal; 3+, extension into the lobule; 4+, diffuse). Mean BD/PT ratios and CK7 scores were calculated. The mean BD/PT ratio (0.58) and CK7 score (1.01) for the "CR, diagnostic" group were significantly different from all other group means (P < .05); no other comparisons were significant (P > .05). A CK7 score of 1 or more was observed in 9 (56%) of 16 CR specimens and in 3 (7%) of 41 remaining specimens. Hepatocyte CK7 expression is frequently noted in CR, and it would appear to reflect ductopenia. CK7 staining may be a useful diagnostic adjunct in evaluation of transplant liver biopsy specimens.

ELISA-based detection of C4d after liver transplantation--a helpful tool for differential diagnosis between acute rejection and HCV-recurrence?

Hepatitis-C is the most common indication for liver transplantation. Recurrence of HCV is universal leading to graft failure in up to 40% of all patients. The differentiation between acute rejection and recurrent hepatitis-C is crucial as rejection treatments are likely to aggravate HCV-recurrence. Histological examination of liver biopsy remains the gold standard for diagnosis of acute rejection but has failed in the past to distinguish between acute rejection and recurrent hepatitis-C. In a retrospective study we have recently reported that C4d as a marker of the activated complement cascade is detectable in a hepatic specimen in acute rejection after liver transplantation and may serve as a valuable tool in differential diagnosis between ACR and HCV-recurrence. We performed a prospective analysis by ELISA measurement of C4d concentration in cryo-preserved liver biopsies of LTX patients who had either experienced acute rejection, hepatitis-C recurrence or displayed no pathological alterations (controls). Opposed to our immunohistologically based findings in paraffinized tissue we were unable to detect significant differences of C4d concentration in ELISA of cryo-preserved liver tissue. Consequently the role and potential value of C4d as a diagnostic marker may not be determined using ELISA-based tissue evaluation.

Localization of apoptosis proteins and lymphocyte subsets in chronic rejection of human liver allograft

In chronic liver rejection lymphocyte mediated processes lead to chronic inflammation, necrosis and repair mechanisms. The aim of the present study was to investigate the expression of apoptosis related proteins (FAS/APO-1, FAS-L, Bcl-2, Bax, TNF-α, and INF-γ). ApopTag reaction and immunohistochemistry were performed on liver samples of chronically rejected allografts and compared with normal donor livers. In chronic rejection, apoptosis was detected in pericentral hepatocytes and in the biliary epithelium. Bcl-2 was strongly expressed on lymphocytes around the bile ducts, but not on the biliary epithelium itself. Bax, FAS, TNF-α and INF-γ were present in pericentral areas. T-cells showed up around bile ducts, whereas macrophages around pericentral areas. In pericentral areas apoptosis seems to be fostered through TNF-α and INF-γ and by the lack of Bcl-2. Based on these results both downregulation and upregulation of apoptotic proteins can be observed in chronic liver allograft rejection: FAS is upregulated in biliary epithelium and zone 2, protein levels of FASL remain unchanged, BAX is upregulated in zone 3, BCL2 is downregulated in both biliary epithelium and zone 1 and both TNFa and IFN are upregulated in zone 3. Our results suggest that the balance between pro- and antiapoptotic patterns was shifted to the proapoptotic side, mainly in the centrilobular area of the hepatic lobule, and in the bile ducts. According to these findings in chronic rejection the predictive sites of apoptosis are the biliary epithelium and the pericentral areas.

[Quality and quantity in hepatopathology. Diagnostic and clinically relevant grading for non-tumourous liver diseases]

This article describes the grading and staging systems used in the clinical context for non-neoplastic liver diseases (chronic and autoimmune hepatitis, fatty liver and steatohepatitis, medicinal toxic liver damage, iron storage disease and gall duct diseases). Fibrotic parenchymal alterations can also be assessed as well as livers planned for transplantation, with respect to possible rejection reactions. The basis for the histopathological diagnostic procedure is the liver biopsy. The consistent and correct use of the histological scores is obligatory in the diagnostic assessment of non-neoplastic liver diseases. Different scores are available for the various liver diseases. These are qualitative and quantitative scores based on empiricism and the practical relevance has been effectively proven. Grading describes the inflammatory activity and staging the extent of fibrosis or structural disorders up to liver cirrhosis. In many instances staging is the histopathological criteria for the prognosis assessment and is, therefore, decisive for therapy indications and therapy initiation.

Subacute nonsuppurative cholangitis (cholangitis lenta) in pediatric liver transplant patients

BACKGROUND

Subacute nonsuppurative cholangitis (cholangitis lenta) is an uncommon yet important histological finding in liver biopsies from pediatric liver transplant recipients. The histopathological features include proliferation of bile ductules at the edges of portal tracts, inspissated bile within dilated bile ductules, absence of acute inflammation within ducts or ductules, and normal structure of interlobular bile ducts.

OBJECTIVE

To describe the histopathology and clinical outcomes of pediatric liver transplant recipients with subacute nonsuppurative cholangitis.

MATERIALS AND METHODS

This is a retrospective analysis involving review of medical records and analysis of liver-biopsy specimens by a pathologist blinded to clinical diagnosis. We identified 9 pediatric patients meeting the criteria for nonsuppurative cholangitis. These patients were compared with a control group of patients with biliary obstruction.

RESULTS

Liver histopathology clearly distinguishes subacute nonsuppurative cholangitis from biliary obstruction and other causes of posttransplant cholestasis. Clinical biochemistry cannot reliably distinguish between the 2, although statistically significant differences existed in levels of serum total and direct bilirubin, alanine aminotransferase, and alkaline phosphatase. The rate of proven bacterial or fungal infection in the study group was 100% in contrast to a rate of 54.5% in the control group (P < .05). Graft and patient survival were similarly poor.

CONCLUSIONS

: Finding subacute nonsuppurative cholangitis suggests the presence of severe local or systemic infection in liver-transplant recipients, and its recognition is important for clinical management.

C4d in acute rejection after liver transplantation--a valuable tool in differential diagnosis to hepatitis C recurrence

Hepatitis C is the most common indication for liver transplantation. Recurrence of HCV is universal leading to graft failure in up to 40% of all patients. The differentiation between acute rejection and recurrent hepatitis C is crucial as rejection treatments are likely to aggravate HCV recurrence. Histological examination of liver biopsy remains the gold standard for diagnosis of acute rejection but has failed in the past to distinguish between acute rejection and recurrent hepatitis C. We have recently reported that C4d as a marker of the activated complement cascade is detectable in hepatic specimen in acute rejection after liver transplantation. In this study, we investigate whether C4d may serve as a specific marker for differential diagnosis in hepatitis C reinfection cases. Immunohistochemical analysis of 97 patients was performed. A total of 67.7% of patients with acute cellular rejection displayed C4d-positive staining in liver biopsy whereas 11.8% of patients with hepatitis C reinfection tested positive for C4d. In the control group, 6.9% showed C4d positivity. For the first time we were able to clearly demonstrate that humoral components, represented by C4d deposition, play a role in acute cellular rejection after LTX. Consequently C4d may be helpful to distinguish between acute rejection and reinfection after LTX for HCV.

Long-term outcome of liver transplantation for autoimmune hepatitis

BACKGROUND

Liver transplantation is the final therapeutic option for about 10% of patients with autoimmune hepatitis (AIH) who do not respond to medical therapy. The aim of this study was to evaluate the long-term outcome in serologically defined subgroups of AIH after transplantation.

METHODS

Pre- and post-transplantation data of 28 patients with AIH transplanted between 1987 and 1999 were retrospectively analyzed and compared with 24 patients, who underwent liver transplantation because of Wilson's disease and glycogen storage disease type 1.

RESULTS

Serological analyses identified patients with AIH type 1 (n = 13), type 2 (n = 5), and type 3 (n = 10). The 5-yr patient survival rate after liver transplantation was 78.2%, which was not significantly different from the control group. Six AIH patients and four control patients required re-transplantation because of initial non-function, chronic rejection or AIH recurrence. Patients transplanted for AIH (88%) had more episodes of acute rejection when compared with patients transplanted for genetic liver diseases (50%). Clinical and histological features of chronic rejection were present in four patients, which did not differ significantly from the controls. Recurrence of AIH was diagnosed in nine patients (32%) based upon the presence of autoantibodies, increased gamma-globulins, steroid dependency, and histological evidence of chronic hepatitis. These combined features were not found in any of the controls.

CONCLUSIONS

Our data do not suggest that AIH subtypes influence prognosis after liver transplantation. Despite a high frequency of acute cellular rejection episodes and disease recurrence, transplantation for AIH has a 5-yr survival rate, which does not differ from that observed in patients transplanted for genetic liver diseases.

Centrilobular necrosis after orthotopic liver transplantation: association with acute cellular rejection and impact on outcome

Several studies have linked centrilobular necrosis (CN) to acute cellular rejection (ACR) following liver transplantation. However, it may be difficult to establish the diagnosis of ACR when the classic portal features are absent. The aim of the present study was to identify specific features that would help to recognize ACR in biopsies with CN. One hundred and forty liver biopsies with CN were identified from 97 patients who underwent liver transplantation. The following histopathologic features were assessed: CN, steatosis, lobular inflammation, cholestasis, endothelialitis, and fibrosis. CN was graded semiquantitatively. A number of clinical and biochemical parameters were also recorded. Biopsies with CN were assessed for the presence or absence of ACR and divided into two groups accordingly. The associations of the biochemical, pathologic, and clinical features with ACR were assessed using a multivariate logistic regression model. The outcomes of patients with and without rejection were compared using the Cox proportional hazards regression model. Seventy-four biopsies (52.9%) showed evidence of ACR, and 52 patients (53.6%) had evidence of ACR at the first biopsy with CN. The multivariate analysis showed the presence of cholestasis, lobular inflammation, the ALT level, and time since liver transplantation to be independent predictors of the presence of ACR in biopsies with CN. Patients with ACR on their first biopsy with CN were significantly more likely to experience graft loss compared with patients without ACR. In conclusion, the presence of cholestasis and lobular inflammation on biopsies with CN appeared helpful in predicting its association with ACR.

CC chemokine receptor 5delta32 polymorphism-a risk factor for ischemic-type biliary lesions following orthotopic liver transplantation

Ischemic-type biliary lesions are a major complication following orthotopic liver transplantation. They occur in up to 26% of liver transplant recipients. Among other factors, unknown immunologic factors have always been assumed to be partly responsible for these lesions. CC-chemokines and their receptors play a key role in postoperative immunomodulation after liver transplantation. The non-function CC-chemokine receptor 5delta32 polymorphism (CCR5delta32) has been shown to lead to a lower rate of acute rejection after kidney transplantation; in liver transplantation the role of CCR5delta32 is unclear. We investigated the influence of the CCR5delta32 after liver transplantation with special regard to ischemic-type biliary lesions. The CC-chemokine receptor-5 (CCR5) of 146 recipients was analyzed by polymerase chain reaction to detect CCR5delta32 in blood samples of patients after liver transplantation. One hundred twenty patients with wild-type CCR5 and 26 patients with CCR5delta32 (1 homozygote, 25 heterozygote) were identified. Ischemic-type biliary lesions occurred in 14 of 120 patients with wild-type CCR5 and in 8 of 26 patients with CCR5delta32 polymorphism (P = = 0.01). 5 year patient survival with CCR5delta32 and CCR5 was 70% and 85%, respectively (P =.0067). Our results show that the CCR5delta32 is a significant risk factor for the development of ischemic-type biliary lesions after liver transplantation and leads to a reduction in 5-year survival. In conclusion, the CCR5 status should be screened prospectively before liver transplantation.

All liver recipients benefit from the protocol 10-year liver biopsies

The value of late protocol biopsies after liver transplantation remains to be evaluated to highlight the therapeutic policies. The study population was composed of patients who survived with the initial graft and with an available 10-year protocol biopsy (n = 143). The long-term histologic outcome of the graft, particularly the rate of ductopenia in cases with chronic rejection (CR), and Metavir scoring of fibrosis in cases with viral chronic hepatitis (VCH), were assessed. Fibrosis progression (FP) rates were compared over 3 periods (0-5, 5-10, and 0-10 years). At 10 years, histologic abnormalities present in 80% of the patients were not identifiable from liver function tests (LFTs), which were strictly normal in 52% of the patients. Histologic CR occurred in 24% at 10 years, with a mean rate of ductopenia higher at 10 years than at 5 years (49% vs. 34%, P <.001). In cases of VCH, fibrosis worsened, with a median FP rate of 0.20 fibrosis units/year. During the first 5 years, FP was as follows; hepatitis B virus infection was greater than recurrent hepatitis C virus (HCV) infection, which was greater than acquired HCV infection (P =.029). In patients with HCV, FP was higher during the second 5-year period than during the first one (P =.042). In conclusion, given the high prevalence of histologic abnormalities and the lack of sensitivity and specificity of LFTs, late protocol biopsies clearly are justified to adjust treatments, not only in HCV-infected patients in whom FP was fast and not linear, but also in the whole population of recipients.

Hepatobiliary pathology

Insights provided by molecular biology, immunohistochemistry, and transmission electron microscopy have increased our understanding of the pathogenesis and histopathology of hepatitis C virus (HCV) infection, nonalcoholic steatohepatitis (NASH), and bile ductular proliferative reactions in a number of liver diseases. Human and chimpanzee liver infected with HCV showed viral-like particles (50 to 60 nm in diameter) as well as aggregates of short tubules that represent viral envelope material. Interactions of HCV core protein with apolipoproteins have a role in the pathogenesis of HCV-related steatosis. Pathologists should be aware of the spectrum of liver pathology described with the use of highly active antiretroviral therapy (HAART) agents for the human immunodeficiency virus infection, which includes microvesicular steatosis and more severe hepatic injury with confluent necrosis. Proliferation of bile ductular structures is influenced by specific molecules and proteins (eg, the mucin-associated trefoil proteins and estrogens). The interplay between Notch receptors and Jagged 1 protein, as expressed by many cells of the liver (including bile duct epithelium) varies in primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Cholangiocarcinoma does not appear to be a long-term complication of small duct PSC. The fatty liver diseases, both alcoholic and nonalcoholic, are characterized by production of reactive oxygen species that have detrimental effects such as opening mitochondrial permeability transition pores with resultant release of cytochrome c into the cytosol. Hepatocellular carcinoma is now a recognized late complication of NASH. The derivation of hepatic stem cells, the roles of HFE protein and other hepatic and intestinal transport proteins in hemochromatosis, and the histopathologic interpretive challenge of centrilobular lesions in posttransplant liver biopsies are among other recent studies considered in this review.