Posttransplant plasma cell hepatitis (de novo autoimmune hepatitis) is a variant of rejection and may lead to a negative outcome in patients with hepatitis C virus

An algorithm based on immunotherapy discontinuation and liver biopsy spares corticosteroids in two thirds of cases of severe checkpoint inhibitor-induced liver injury

BACKGROUND

There are few data on corticosteroids (CS)-sparing strategies for checkpoint inhibitor (ICI)-induced liver injury (ChILI).

AIM

We aimed to assess the performance of a 2-step algorithm for severe ChILI, based on ICI temporary discontinuation (step-1) and, if lack of biochemical improvement, CS based on the degree of necroinflammation at biopsy (step-2).

METHODS

Prospective study that included all subjects with grade 3/4 ChILI. Peripheral extended immunophenotyping was performed. Indication for CS: severe necroinflammation; mild or moderate necroinflammation with later biochemical worsening.

RESULTS

From 111 subjects with increased transaminases (January 2020 to August 2023), 44 were diagnosed with grade 3 (N = 35) or grade 4 (N = 9) ChILI. Main reason for exclusion was alternative diagnosis. Lung cancer (13) and melanoma (12) were the most common malignancies. ICI: 23(52.3%) anti-PD1, 8(18.2%) anti-PD-L1, 3(6.8%) anti-CTLA-4, 10(22.7%) combined ICI. Liver injury pattern: hepatocellular (23,52.3%) mixed (12,27.3%) and cholestatic (9,20.5%). 14(32%) presented bilirubin >1.2 mg/dL. Overall, 30(68.2%) patients did not require CS: 22(50.0%) due to ICI discontinuation (step-1) and 8/22 (36.4%) based on the degree of necroinflammation (step-2). Biopsy mainly impacted on grade 3 ChILI, sparing CS in 8 out of 15 (53.3%) non-improvement patients after ICI discontinuation. CD8+ HLA-DR expression (p = 0.028), central memory (p = 0.046) were lower in CS-free managed subjects, but effector-memory cells (p = 0.002) were higher. Time to transaminases normalisation was shorter in those CS-free managed (overall: p < 0.001, grade 3: p < 0.001). Considering our results, a strategy based on ICI discontinuation and biopsy for grade 3 ChILI is proposed.

CONCLUSIONS

An algorithm based on temporary immunotherapy discontinuation and biopsy allows CS avoidance in two thirds of cases of severe ChILI.

The significant IgG4 infiltrate in autoimmune hepatitis is associated with a greater ductular reaction and more advanced liver disease

BACKGROUND

Sclerosing cholangitis is the typical IgG4-related disease digestive involvement. However, the role of the IgG4 liver expression in autoimmune hepatitis remains unknown.

AIMS

to assess whether the expression of IgG4 plasma cells in patients with autoimmune hepatitis (AIH) was associated with different outcomes.

METHODS

Retrospective study including patients diagnosed with AIH by biopsy from January-2009 to June-2021. At least mild IgG4 expression (>10 IgG4+-plasma cells per field) was considered as significant.

RESULTS

85 patients with AIH were included. Overall, 58.8% were women, mean age 54 years. Nine (10.6%) presented cirrhosis at diagnosis. Fifteen (17.6%) had significant IgG4 liver expression. Patients with IgG4 infiltrate were older (p = 0.021), presented liver cirrhosis more frequently (33.3% vs. 5.7%, p = 0.007), greater IgG plasma values (p = 0.008) and atypical ANCAs (p = 0.086); ductular reaction was also more common (p = 0.009). Complete remission rate was similar regardless of the IgG4 infiltrate. Time to corticosteroids discontinuation was longer in subjects with IgG4 infiltrate (p = 0.068), but second-line therapy tended to be less frequent (p = 0.187).

CONCLUSION

Significant IgG4 liver infiltrate in patients with autoimmune hepatitis is associated with more advanced liver disease. The greater ductular reaction mediated by the IgG4 infiltrate may be the cause for this finding, though this finding should be prospectively assessed.

Morphologic and immunophenotypic evaluation of liver allograft biopsies with contemporaneous serum DSA measurements

BACKGROUND

Acute antibody mediated rejection is increasingly identified in liver allografts as a unique form of alloimmune injury associated with donor specific antibodies (DSA). This manifests pathologically as microvascular injury and C4d uptake. Despite the liver allograft's relative resistance to alloimmune injury, liver allografts are not impervious to cellular and antibody-mediated rejection.

METHODS

In this blinded control study, we evaluated CD163 immunohistochemistry and applied the Banff 2016 criteria for diagnosis of acute AMR on a group of indication allograft liver biopsies from DSA positive patients and compared them to indication biopsies from DSA negative controls.

RESULTS

Most DSA positive patients were females (75%, p = .027), and underwent transplantation for HCV infection. Significant histopathological predictors of serum DSA positivity were Banff H-score (p = .01), moderate to severe cholestasis (p = .03), and CD163 score > 2 (p = .029). Other morphologic features that showed a trend with DSA positivity include Banff portal C4d-score (p = .06), bile ductular reaction (p = .07), and central perivenulitis (p = .07). The odds of DSA sMFI ≥5000 was 12.5 times higher in those with a C4d score >1 than those with a C4d score ≤ 1 (p = .04). Incidence of definite for aAMR in the DSA positive cohort was 25% (n = 5), and 0% in the DSA negative cohort. A group of 5 DSA positive cases were not classifiable by the current scheme.

CONCLUSION

Sinusoidal CD163, Banff H-score, and diffuse C4d are predictors of serum DSA, and facilitate recognition of histopathological features associated with serum DSA and tissue-antibody interaction.

Regular protocol liver biopsy is useful to adjust immunosuppressant dose after adult liver transplantation

INTRODUCTION

Adjusting immunosuppression to minimal levels post-adult liver transplantation (LT) is critical; however, graft rejection has been reported in LT recipients with normal liver function evaluated by liver biopsy (LBx). Continual protocol liver biopsy (PLB) is performed regularly in LT recipients with normal liver function in some centers; however, its usefulness remains inadequately evaluated. This study aimed to assess retrospectively the usefulness of late PLB after adult LT.

METHODS

LBx evaluations of LT recipients with normal liver function and hepatitis B and C virus seronegativity were defined as PLB. The cases requiring immunosuppressive therapy for rejection findings based on Banff criteria were extracted from the PLBs, and pathological data collected before and after immunosuppressive dosage adjustment (based on modified histological activity index [HAI] score) were compared.

RESULTS

Among 548 LBx cases, 213 LBx in 110 recipients fulfilled the inclusion criteria for PLB. Immunosuppressive therapy after PLB was intensified in 14 LBx (6.6%) recipients (12.7%); of these, nine had late-onset acute rejection, three had isolated perivenular inflammation, one had plasma cell-rich rejection, and one had early chronic rejection. Follow-up LBx after immunosuppressive dose adjustment showed improvement in the modified HAI score grading in 10 of 14 cases (71.4%). No clinical background and blood examination data, including those from the post-LT period, immunosuppressant trough level, or examination for de novo DSA, predicted rejection in PLB. Complications of PLB were found in only three cases.

CONCLUSION

PLB is useful in the management of seemingly stable LT recipients, to discover subclinical rejection and allow for appropriate immunosuppressant dose adjustment.

Alloimmune versus autoimmune hepatitis following liver transplantation

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Prevalence and clinical significance of portal inflammation, portal plasma cells, interface hepatitis and biliary injury in liver biopsies from patients with non-alcoholic steatohepatitis

The significance of portal tract histological changes in non-alcoholic fatty liver disease (NAFLD) remains unclear. In 2019, CymaBay Therapeutics halted clinical trials of seladelpar (a PPARδ agonist) because initial end-of-treatment liver biopsies of patients with non-alcoholic steatohepatitis (NASH) showed concerning features of portal inflammation with plasma cells, interface hepatitis and focal bile duct abnormalities. Adjudication concluded that these findings were present in the initial, as well as the subsequent biopsies. Thus, this study's aim was to determine the prevalence and clinical significance of portal inflammation, portal plasma cells, interface hepatitis and features of bile duct damage in liver biopsies of adult patients with NAFLD. The pathology database was searched for cases of NAFLD, including steatosis alone and NASH, from January 2016 to October 2020. Liver biopsies were selected from age and sex matched adult patients with diagnoses of steatosis alone (n=10), NASH fibrosis stage 1 (n=10), stage 2 (n=10), stage 3 (n=10), and stage 4 (n=10). There were 24 males and 26 females with a mean age of 48 years (range 20-79). Exclusion criteria included age <18 years, daily alcohol intake >14 drinks per week, elevation of alkaline phosphatase level, comorbid chronic liver disease, or liver biopsy performed as part of a clinical trial for NASH. Control liver biopsies were selected from age and sex matched persons without significant steatosis and normal liver biochemical tests (n=10). Histological parameters were evaluated in 10 portal tracts or 10 septal areas in each liver biopsy. Portal inflammation and interface hepatitis were graded on a scale of 0-4. Portal plasma cells and bile duct damage were scored from 0-3. Ductular proliferation was assessed by CK7 immunostain and graded from 0-4. NASH biopsies with advanced fibrosis (stage 3 and 4) showed portal inflammatory infiltrates (score 2-3) with readily identifiable plasma cells (score 2), and mild to moderate interface hepatitis (score 2-3). All cases and controls showed focal, mild cholangiocyte changes, characterised by cytoplasmic vacuolation, segmental loss of nuclei, nuclear disarray and apoptosis. NASH patients with advanced fibrosis had frequent and diffuse cholangiocyte changes, along with focal lymphocytic cholangitis and moderate to marked ductular reaction (score 3-4). Histopathological features of advanced NASH frequently include increased portal inflammation with plasma cells, interface hepatitis, cholangiocyte injury and prominent ductular reaction.

Benign course of residual inflammation at end of treatment of liver transplant recipients after sofosbuvir based therapy

BACKGROUND

Persistent inflammation on histology after successful hepatitis C (HCV) treatment has been reported. However, data regarding the long-term impact in liver transplant recipients is limited, particularly after using direct-acting antiviral (DAA) therapies.

AIM

To evaluate the impact of successful treatment with DAAs on histological changes and occult HCV and to describe the clinical course of residual inflammation in liver transplant recipients.

METHODS

We conducted a case series of 13 chronic HCV infected liver transplant recipients successfully treated with DAAs between December 2013 and May 2014. All patients were treated for 24 wk and had non-detectable serum HCV RNA by the time of biopsy. Only patients with at least one liver biopsy at or after treatment were included. We examined liver biopsies for evidence of residual inflammation and the presence of intrahepatic HCV RNA.

RESULTS

Persistent inflammation was seen in 12/13 patients on end of treatment biopsy. Inflammation was still seen in the available five follow-up biopsies (range 38-48 wk after the end of treatment). Intrahepatic HCV RNA was undetectable in all biopsies. All patients had preserved graft function for a mean follow-up of 2.5 years, except one that developed chronic rejection.

CONCLUSION

After successful HCV treatment with DAAs, liver transplant recipients may have persistent inflammation on biopsy without evidence of intracellular RNA. The clinical outcome remained favorable in most patients. Further studies with a larger number and longer follow-up are needed to establish the implication of this finding on long-term graft function.

Differential IgG4-Producing Plasma Cell Infiltration in Non- and Post-Transplant Plasma Cell Hepatitis

Autoimmune hepatitis (AIH), post-transplant recurrent AIH (rAIH), and plasma cell-rich rejection (PCR) are clinical diagnoses with the shared histopathologic hallmark of plasma cell hepatitis (PCH). As these histologically and serologically indistinguishable diagnoses are differentiated by clinical context, it remains uncertain whether they represent distinct immunologic phenomena. Improved understanding of immunoglobulin subclass 4-producing plasma cells (IgG4-PC) has brought attention to IgG4 as an immunophenotypic biomarker. To date, degree and clinical significance of IgG4-PC infiltration in PCH remain elusive. This retrospective, single-center study assessed IgG4-PC infiltration in AIH, rAIH, and PCR via standardized immunohistochemistry analysis. Identified cases from 2005 to 2020 (n = 47) included AIH (treatment-naïve AIH (tnAIH): n = 15 and AIH-flare on treatment (fAIH); n = 10), rAIH (n = 8), and PCR (n = 14) were analyzed and correlated with clinical characteristics. IgG4-Positivity (# IgG4-PC/# pan-IgG-expressing cells) distribution was heterogenous and overlapping [tnAIH: 0.060 (IQR 0.040-0.079), fAIH: 0.000 (0.000-0.033), rAIH: 0.000 (0.000-0.035), PCR: 0.228 (0.039-0.558)]. IgG4-Positivity was inversely correlated with corticosteroid use (p < 0.001). IgG4-Positivity ≥0.500 was associated with rapid AST improvement (p = 0.03). The variable IgG4-Positivity of AIH, rAIH and PCR suggests diverse and overlapping immunopathologic mechanisms and that current diagnostic schemes inadequately capture PCH immunopathology. We propose incorporation of IgG4-Positivity to refine current PCH classification and treatment strategies.

Recurrent Liver Allograft Injury in Patients With Donor-Derived Malignancy Treated With Immunosuppression Cessation and Retransplantation

OBJECTIVES

Donor-derived malignancy of the liver allograft is a rare but serious condition in the setting of necessary immunosuppression. Retransplantation after abrupt immunosuppression cessation has been performed with durable cancer-free survival.

METHODS

We present 2 cases of patients with donor-derived malignancy who were treated with complete immunosuppression cessation, which induced rapidly progressive liver allograft rejection and failure, with a need for subsequent retransplantation. We reviewed all serial liver biopsies and explants from both patients and performed C4d immunostaining.

RESULTS

Initial explants of both patients showed severe allograft rejection, with unusual features of sinusoidal obstruction syndrome and C4d positivity. Malignant tumors in the explants were necrotic, related to rejection of donor-derived cancer cells and tissue. Follow-up of both patients has shown long-term cancer-free survival but issues with recurrent allograft failure requiring a third transplant. The reasons for retransplantation in both cases were related to allograft failure from antibody-mediated rejection.

CONCLUSIONS

Clinicians should be aware of a potentially increased risk of rejection and recurrent allograft failure when strategizing treatment of donor-derived malignancy with immunosuppression cessation and retransplantation.

Antibody-mediated rejection of the liver allograft: An update and a clinico-pathological perspective

Antibody-mediated rejection after liver transplantation is an under-recognised cause of allograft injury. While definitions of acute and chronic antibody-mediated rejection have increased clinical awareness, timely identification and management of antibody-mediated rejection remain difficult because of complexities in diagnosis and histopathology, lack of treatment protocols, and unclear long-term outcomes. While recent cohort studies assessing the importance of donor-specific antibodies have aided in its diagnosis, literature on the treatment of antibody-mediated rejection in liver transplantation remain limited to case reports and small series. Further increasing the awareness and timely recognition of antibody-mediated rejection post-liver transplantation is crucial in order to stimulate future research and the development of protocols for its diagnosis and treatment. This review will summarise recent advances in the clinical diagnosis and treatment of antibody-mediated rejection in liver transplantation, as well as some of the histopathologic features (on liver biopsy tissue) of acute and chronic antibody-mediated rejection.

A two decade long study of disease progression of de novo and recurrent autoimmune hepatitis in the pediatric population

Recurrent autoimmune hepatitis (rAIH) occurs in patients who undergo liver transplantation (LT) for AIH and de novo AIH (dAIH) is seen in patients who are transplanted for etiologies other than AIH. Whether these are distinct diseases with a similar phenotype remains understudied. The aim of this study was to identify clinical and immunologic factors affecting outcome in patients with dAIH and rAIH. A retrospective review of 387 LT patients from 1997 to 2014 was carried out, and they were followed until 2018. Patients with rAIH or dAIH were identified based on the pre-transplant diagnosis of AIH (or not) and characteristic histology. Liver biopsies were stained with H&E, B-cell marker CD20, and plasma cell marker CD138. Out of 387 patients, 31 were transplanted for AIH, and 8/31 developed rAIH. Of the remaining 356 patients, eight developed dAIH. Compared to the dAIH group, rAIH occurred in older patients, had an earlier onset in the allograft, and had higher IgG and serum ALT levels. It was most commonly seen in African American (AA) patients (87%). rAIH patients had significantly higher CD20 and CD138 positivity in liver biopsies. In addition, they had increased rejection episodes prior to the onset of recurrence, increased graft loss, and mortality. rAIH is a more aggressive disease, and has a preponderance of B cells and plasma cells in the liver tissue as compared to dAIH. The concurrent association with increased graft loss and patient mortality in rAIH warrants further investigations into B cell-targeted therapies.

Recurrent Autoimmune Hepatitis and De Novo Autoimmune Hepatitis in the Liver Allograft

OBJECTIVES

Autoimmune hepatitis (AIH) is a form of severe hepatitis that can recur after orthotopic liver transplant (OLT). Presentation of AIH in patients with OLT who do not have a history of AIH is called de novo AIH (DNAIH). We evaluated the clinicopathologic characteristics of AIH and DNAIH.

METHODS

Clinicopathologic and outcome measures of 11 patients with recurrent AIH (RAIH) and 22 with DNAIH identified between 2000 and 2017 were compared.

RESULTS

Both cohorts showed female predominance. The mean clinical follow-up was 13 and 7.8 years in the in the RAIH and DNAIH groups, respectively (P = .1). Moderate portal inflammation was more common in patients with RAIH (64% vs 27%, P = .043). A trend was observed for more cases of DNAIH showing severe inflammation (36% vs 9%, P = .09) and submassive necrosis compared with RAIH (23% vs 0%, P = .086). A trend for more advanced fibrosis was also noted in the RAIH group (27% vs 5%, P = .059). Three patients with RAIH lost their grafts because of RAIH. Five-year disease-specific graft survival (GS) (P = .012) and overall GS (P = .015) were worse in patients with RAIH. Complement component 4d immunohistochemistry was positive in 2 patients with RAIH and 3 with DNAIH but showed no correlation with GS or other parameters.

CONCLUSIONS

RAIH seems to have a more aggressive clinical course than DNAIH and warrants closer clinical follow-up and aggressive treatment.

De Novo Donor Specific Antibody and Long-Term Outcome After Liver Transplantation: A Systematic Review and Meta-Analysis

Background

The impact of de novo anti-HLA donor-specific alloantibodies (DSA) which develop after long-term liver transplantation (LT) remains controversial and unclear. The aim of this study was to investigate the role of de novo DSAs on the outcome in LT.

Methods

We did a systematic review and meta-analysis of observational studies published until Dec 31, 2019, that reported de novo DSA outcome data (≥1 year of follow-up) after liver transplant. A literature search in the MEDLINE/PubMed, EMBASE, Cochrane Library, Scopus and Web of Science Core Collection databases was performed.

Results

Of 5,325 studies identified, 15 fulfilled our inclusion criteria. The studies which reported 2016 liver transplant recipients with de novo DSAs showed an increased complication risk, i.e. graft loss and chronic rejection (OR 3.61; 95% CI 1.94-6.71, P < 0.001; I2 58.19%), and allograft rejection alone (OR 6.43; 95% CI: 3.17-13.04; P < 0.001; I2 49.77%); they were compared to patients without de novo DSAs. The association between de novo DSAs and overall outcome failure was consistent across all subgroups and sensitivity analysis.

Conclusions

Our study suggested that de novo DSAs had a significant deleterious impact on the liver transplant risk of rejection. The routine detection of de novo DSAs may be beneficial as noninvasive biomarker-guided risk stratification.

De novo and recurrent liver disease

Decompensated cirrhosis due to nonalcoholic steatohepatitis (NASH), and autoimmune liver diseases (AILD) are the most common indications for liver transplantation (LT). AILD include autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). NASH and AILD share some peculiarities as they can recur in the new graft, compromising the quality of life, and graft and patient survival. De novo NASH or AIH connotes the development of these liver diseases in patients transplanted for other indications. The diagnosis of recurrent or de novo liver disease usually requires a liver biopsy aside from recurrent PSC, which can be diagnosed with compatible imaging studies and exclusion of other causes of biliary strictures. The treatment of recurrent NASH is lifestyle modifications aiming for weight loss. Recurrent and de novo AIH is usually treated with corticosteroids with or without azathioprine. Recurrent PBC should be treated with ursodeoxycholic acid. There are no proven treatment options for recurrent PSC. Patients with graft failure should be considered for repeat LT. Future investigations should use standardized diagnostic criteria for each disease, seek diagnostic biomarkers, and evaluate treatments that improve outcomes.

[Liver transplantation. Current aspects of pretransplantation diagnosis and rejection]

Liver transplantation is an established treatment option for patients with end-stage liver disease. The therapy management of these patients is interdisciplinary and requires pathologists to have both clinical and immunological knowledge. Continuous advances in treatment and increasing clinical experience are accompanied by the further development of pathological transplant diagnostics. This article presents and discusses the latest classification of T‑cell-mediated rejection (TCMR), antibody-mediated rejection (AMR), and aspects of pretransplant diagnostics.

Recurrent Idiopathic Liver Allograft Failure

OBJECTIVES

Many transplant programs have had patients who develop idiopathic recurrent liver allograft failure, necessitating serial transplants, and are deemed to have refractory or recurrent rejection. The frequency and the etiology of this immunologic dysfunction have not been well characterized.

METHODS

Herein, we illustrate the case of a patient who required three retransplants over a period of 20 years for recurrent liver allograft failure. By extensively compiling the patient's many liver biopsy specimens and explants over time, we demonstrate that antibody-mediated rejection (AMR) was a major contributing factor from the outset. We conducted a review of the Scientific Registry for Transplant Recipients database to estimate the potential frequency of AMR.

RESULTS

As illustrated by this case, AMR has varied histologic findings in the setting of elevated donor-specific antibody titers.

CONCLUSIONS

The cause of recurrent allograft failure in this patient was likely a combination of acute cellular rejection and AMR, manifestations of likely underlying immune dysregulation. Pathologists and transplant physicians should recognize the variable histologic presentations of AMR, which is imperative for its timely intervention. This case demonstrates how difficult the diagnosis of AMR can be to make, highlighting the need for strong clinical suspicion in patients having difficult-to-treat rejection and recurrent allograft failure.

Recurrent and De Novo Autoimmune Hepatitis

Clinical indications for liver transplantation (LT) in patients with autoimmune hepatitis (AIH) are identical to those of patients with other chronic liver diseases that end in acute or semiacute liver failure, decompensated cirrhosis, or hepatocellular carcinoma. Recurrent disease after LT has been reported in 10%-50% of patients with AIH, and the frequency of detection is influenced in part by the use of protocol or clinically indicated liver biopsy. De novo AIH connotes the development of AIH in patients transplanted for liver diseases other than AIH, and it has been reported in 5%-10% of pediatric and 1%-2% of adult recipients. Recurrent disease can negatively impact on graft and patient survival, and retransplantation has been required in 8%-23%. De novo AIH is within the spectrum of graft dysfunction that includes plasma cell-rich rejection, and it can also progress to cirrhosis and graft failure. Treatment for recurrent or de novo disease is based on the conventional regimens for AIH, and corticosteroid therapy alone or combined with azathioprine is standard. Better control of disease activity prior to LT has been associated with less recurrence, and maintenance corticosteroid treatment after LT can reduce its frequency. In conclusion, recurrent AIH is far more frequent than de novo AIH. Both may have negative impacts on graft and patient survival, and early detection and treatment are key objectives. Future investigations must codify the diagnostic criteria for each graft dysfunction, seek diagnostic biomarkers, and evaluate treatments that improve outcomes without increasing the risk of pre- and post-LT infections.

Immune-mediated graft dysfunction in liver transplant recipients with hepatitis C virus treated with direct-acting antiviral therapy

Interferon treatment of hepatitis C virus (HCV) infection after liver transplantation (LT) can result in immune-mediated graft dysfunction (IGD). The occurrence of, risk factors for, and outcomes of IGD with direct-acting antiviral (DAA) therapy have not been reported. We conducted a multicenter study of HCV+LT recipients who did or did not develop DAA-IGD (1 case: 2 controls-33 vs 66). Among all treated between 2014 and 2016, DAA-IGD occurred in 3.4% (33/978). IGD occurred only after treatment completion (76.0 [IQR, 47.0;176]). Among those treated, 48% had plasma cell hepatitis, 36% acute cellular rejection, 6% chronic rejection, and 9% combined findings. Median time to liver enzyme resolution was 77.5 days (IQR, 31.5;126). After diagnosis, hospitalizations, steroid-induced hyperglycemia, and infection occurred in a higher percentage of cases vs controls (33% vs 7.5%, 21% vs 1.5%, 9% vs 0%; all P < .05). Only one IGD patient died and none required retransplant. A multivariate regression analysis found that liver enzyme elevations during and soon after DAA therapy completion correlated with subsequent IGD. In conclusion, while DAA-IGD is uncommon, liver enzyme elevations during or after DAA therapy may be a sign of impending IGD. These indicators should guide clinicians to diagnose and treat IGD early before the more deleterious later clinical presentation.

Rethinking de novo immune hepatitis, an old concept for liver allograft rejection: Relevance of glutathione S-transferase T1 mismatch

Antibody-mediated rejection (AMR) in liver transplantation has long been underestimated. The concept of the liver as an organ susceptible to AMR has emerged in recent years, not only in the context of the major histocompatibility complex with the presence of HLA donor-specific antibodies, but also with antigens regarded as “minor”, whose role in AMR has been demonstrated. Among them, antibodies against glutathione S-transferase T1 have been found in 100% of patients with de novo autoimmune hepatitis (dnAIH) when studied. In its latest update, the Banff Working Group for liver allograft pathology proposed replacing the term dnAIH with plasma cell (PC)-rich rejection. Antibodies to glutathione S-transferase T1 (GSTT1) in null recipients of GSTT1 positive donors have been included as a contributory but nonessential feature of the diagnosis of PC-rich rejection. Also in this update, non-organ-specific anti-nuclear or smooth muscle autoantibodies are no longer included as diagnostic criteria. Although initially found in a proportion of patients with PC-rich rejection, the presence of autoantibodies is misleading since they are not disease-specific and appear in many different contexts as bystanders. The cellular types and proportions of the inflammatory infiltrates in diagnostic biopsies have been studied in detail very recently. PC-rich rejection biopsies present a characteristic cellular profile with a predominance of T lymphocytes and a high proportion of PCs, close to 30%, of which 16.48% are IgG4⁺. New data on the relevance of GSTT1-specific T lymphocytes to PC-rich rejection will be discussed in this review.

Acute, Chronic, and Humoral Rejection: Pathologic Features Under Current Immunosuppressive Regimes

Under current immunosuppressive regimes, T-cell-mediated acute and chronic rejection remain common and important posttransplant complications. The definition of humoral (antibody-mediated) rejection has been greatly expanded in recent years. The histopathologic assessment of allograft biopsies continues to serve an important role in the diagnosis of rejection and to facilitate patient management. The diagnosis of both acute and chronic antibody-mediated rejection requires integration of the results of donor-specific antibody testing and C4d immunostaining, as well as exclusion of other potential etiologies of allograft dysfunction. Chronic antibody-mediated rejection should also be included in the differential diagnosis for unexplained allograft fibrosis.

Identification of the cellular components involved in de novo immune hepatitis: a quantitative immunohistochemical analysis

Background

Diagnosis of de novo immune hepatitis (dnIH) after liver transplantation relies on biopsy findings, with an abundance of plasma cells (PCs) in the inflammatory infiltrates a hallmark of the disease. Very little is known about what other types of immune cells exist in the infiltrates mainly located in the portal areas of the liver tissue.

Methods

We analyzed the composition of T cells, B cells, PCs, and macrophages in the liver biopsies of 12 patients with dnIH, 9 of them obtained at the time of diagnosis. For comparison, biopsies from 9 patients with chronic rejection (CR) were included in the study. The results were analyzed by a computer-assisted stereology quantification method.

Results

The major components of the infiltrates in the portal areas were CD3⁺ T lymphocytes in both groups, with 36.6% in the dnIH group versus 49.4% in the CR group. CD20⁺ B lymphocytes represented 14.9% in the dnIH group and 29.1% in the CR group. Macrophage levels were very similar in the dnIH and CR group (19.7% versus 16.8%, respectively). PCs were much less represented in CR biopsies than those from the dnIH group (mean value of 4.7% versus 28.8%).

Conclusion

In conclusion, the determination of a characteristic cellular profile could be an important tool for a more reliable diagnosis of dnIH, in support of the histological evaluation made by the pathologist, which in most cases is challenging. Recognition of this condition is crucial because it leads to graft failure if left untreated.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1440-8) contains supplementary material, which is available to authorized users.

Impact of Antibodies That React With Liver Tissue and Donor-Specific Anti-HLA Antibodies in Pediatric Idiopathic Posttransplantation Hepatitis

Background

The cause of late graft dysfunction has not been elucidated. Although an antibody-mediated reaction is suspected as a potential mechanism, the target antigens have not been clarified.

Methods

To clarify the etiology of idiopathic posttransplantation hepatitis (IPTH), we simultaneously examined the presence of antibodies that react with liver tissue (ARLT) by means of indirect immunofluorescence staining, as well as the presence of donor-specific anti-human leukocyte antigen antibodies (HLA-DSA). A subanalysis of the IPTH group was also performed. Within the IPTH group, the correlation between ARLT titer and clinical data were analyzed.

Results

In the sera of patients with IPTH (30 patients), ARLT were found at a significantly higher frequency than in patients without IPTH (42 patients; P < 0.001). Moreover, the ARLT titer appeared to be correlated with the severity of hepatitis or hepatic injury. In contrast, the frequency of HLA-DSA was significantly lower in patients with IPTH than in patients without IPTH (P = 0.001).

Conclusion

Our findings indicate that ARLT, and not HLA-DSA, profoundly influence the etiology of IPTH.

The authors show that antibodies that react with liver tissue and not donor-specific anti-human leukocyte antigen antibodies, profoundly influence the etiology of idiopathic posttransplantation hepatitis in children providing a rationale for therapy.

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.

De novo autoimmune hepatitis in liver transplant: State-of-the-art review

In the two past decades, a number of communications, case-control studies, and retrospective reports have appeared in the literature with concerns about the development of a complex set of clinical, laboratory and histological characteristics of a liver graft dysfunction that is compatible with autoimmune hepatitis. The de novo prefix was added to distinguish this entity from a pre-transplant primary autoimmune hepatitis, but the globally accepted criteria for the diagnosis of autoimmune hepatitis have been adopted in the diagnostic algorithm. Indeed, de novo autoimmune hepatitis is characterized by the typical liver necro-inflammation that is rich in plasma cells, the presence of interface hepatitis and the consequent laboratory findings of elevations in liver enzymes, increases in serum gamma globulin and the appearance of non-organ specific auto-antibodies. Still, the overall features of de novo autoimmune hepatitis appear not to be attributable to a univocal patho-physiological pathway because they can develop in the patients who have undergone liver transplantation due to different etiologies. Specifically, in subjects with hepatitis C virus recurrence, an interferon-containing antiviral treatment has been indicated as a potential inception of immune system derangement. Herein, we attempt to review the currently available knowledge about de novo liver autoimmunity and its clinical management.

Telaprevir versus simeprevir for the treatment of recurrent hepatitis C after living donor liver transplantation

AIM

Our aim was to evaluate the clinical outcomes of telaprevir (TVR)- or simeprevir (SMV)-based triple therapy for recurrent hepatitis C after living donor liver transplantation.

METHODS

Twenty-six patients received antiviral therapy, consisting of either TVR (n = 12) or SMV (n = 14) in combination with pegylated interferon and ribavirin, plus cyclosporin.

RESULTS

More patients had a dose reduction of the direct-acting agent (36.3% vs 0.0%, P = 0.02) or required blood transfusion for anemia (58.3% vs 7.1%, P < 0.01) in the TVR group. The cyclosporin trough/dose ratio increased significantly from week 0 to week 4 in the TVR group (1.6 ± 0.4 to 5.1 ± 2.0, P < 0.01), but not in the SMV group (1.2 ± 0.3 to 1.3 ± 0.2, P = 0.68). The 24-week cumulative viral clearance rate was 91.7% and 85.7% in the TVR and in SMV groups, respectively. The early viral response and sustained viral response rates were 91.7% and 83.3%, respectively, in the TVR group, compared with 85.7% and 64.3%, respectively, in the SMV group. Interferon-mediated graft dysfunction occurred in four and five patients in the TVR and SMV groups, respectively; two patients were treated by oral steroids, five by steroid pulse and two by thymoglobulin, resulting in viral breakthrough in one case.

CONCLUSION

SMV-based triple therapy was associated with fewer adverse events and drug interactions with cyclosporin, and possibly less antiviral properties to TVR. Interferon-mediated graft dysfunction is a significant clinical problem that warrants particular caution following living donor liver transplantation.

Impact of fibrosis progression on clinical outcome in patients treated for post-transplant hepatitis C recurrence

BACKGROUND & AIMS

Patients who achieve sustained virological response (SVR) following the treatment of post-liver transplant (LT) recurrence of hepatitis C virus (HCV) infection have improved outcomes. The full impact of eradication of HCV on allograft histology is, however, not clearly known.

METHODS

We studied allograft histology in protocol-based paired liver biopsies in consecutive LT recipients who underwent post-LT treatment of recurrence of HCV.

RESULTS

A total of 116 patients were treated with interferon-based therapy for recurrent HCV. Paired pre-treatment baseline biopsies and post-treatment biopsies were available in 83.2% of patients. SVR was achieved in 37.9% of patients. Among the patients who achieved SVR, 20.5% had progression of fibrosis on post-treatment biopsies vs. 65.5% of patients with non-response/relapse (P < 0.001). The impact of virological response on fibrosis progression was sustained and a similar outcome was observed in the subset of patients who had 4-5 year post-treatment biopsies available. In the SVR group, 12.8% progressed to fibrosis stage ≥3 on post-treatment biopsies vs. 37.9% in the non-response/relapse group (P = 0.001). The 5-year survival in patients with progression of fibrosis 86% vs. 98% among patients who had improvement/stable fibrosis [P = 0.003; HR 3.8 (1.2-11.8)]. A small subset of patients who achieve SVR unfortunately still experience progression of fibrosis, most commonly associated with plasma cell hepatitis.

CONCLUSIONS

In post-transplant patients treated for HCV, SVR is associated with improved graft survival and also with sustained and significant improvement in histological outcome. Importantly, progression of fibrosis still occurred in a small subset of patients who achieved SVR.

Infiltrative (sinusoidal) and hepatitic patterns of injury in acute cellular rejection in liver allograft with clinical implications

Acute cellular rejection post liver transplant occurs most commonly but not exclusively in the first year. In this study, we report two patterns: sinusoidal infiltrative and hepatitic, which are not considered in the Banff system. We describe their presentation, response to Solu-Medrol, and compare these to the typical moderate-severe acute cellular rejection. Patients transplanted from 2007 to 2012 at University Health Network, who had biopsy-proven rejection in the first year, were studied. Baseline transaminases and bilirubin, time of acute cellular rejection, follow-up, and treatment responses were analyzed. A total of 407 biopsies were received, of which 77 had diagnosis of acute cellular rejection with rejection activity index 5 or above; 49 from viral hepatitis patients were excluded. Twenty-eight were included; 15/28 (54%) had typical acute cellular rejection (tACR) using Banff criteria. Six (21%) had hepatitic acute cellular rejection overlapping with typical features of acute cellular rejection; seven (25%) had infiltrative acute cellular rejection (iACR) overlapping with typical features. The iACR occurred later than the tACR (124 versus 50 days; P = 0.032) and had a higher rise in baseline aspartate aminotransferase (ΔAST) compared with tACR (289 U/l versus 109 U/l; P=0.046). Only one out of seven patients with iACR (14 versus 40% in tACR) failed Solu-Medrol boluses and required thymoglobulin. Patients with hepatitic acute cellular rejection (hACR) had similar ΔAST (P = 0.12) but higher bilirubinemia than typical acute cellular rejection (tACR) (160 μmol/l versus 35 mol/l; P = 0.039) and required thymoglobulin in four out of six (67% versus 40%) instances. Patients with iACR had higher ΔAST than tACR but better Solu-Medrol response compared with both tACR and hACR. hACR is different from plasma cell-rich late-occurring cellular rejection in its pattern but similar in its poor Solu-Medrol response.

Immunological dysfunction during or after antiviral therapy for recurrent hepatitis C reduces graft survival

INTRODUCTION

Pegylated interferon and ribavirin (PEGIFN/RBV) therapy for recurrent hepatitis C after liver transplantation (LT) is associated with a lower sustained virological response (SVR) rate as well as more frequent side effects compared to non-transplant patients. We aimed to determine the incidence and clinical characteristics of LT recipients with recurrent hepatitis C who developed immunological dysfunction (ID) during or after PEG-IFN/RBV therapy and to assess its impact on patient and graft survival.

METHODS

Seventy-four deceased donor LT recipients with histological recurrence of hepatitis C were treated with PEG-IFN/RBV from 1/00 to 12/08. ID was defined as biopsy-proven rejection or moderate plasma cell hepatitis. Patients were followed up until death, re-LT or 30 September 2011.

RESULTS

Twelve patients (16 %) had ID, 8 (10.7 %) had cholestasis without ID, while 54 had no ID/cholestasis during or after discontinuation of PEG-IFN/RBV therapy. Biopsy-proven acute cellular rejection prior to (hazard ratio = 4.87, p = 0.009) and type of immunosuppression at the time of initiation of PEG-IFN/RBV were the only independent predictors of ID. Patients who were on tacrolimus at the time of initiation of PEG-IFN/RBV had a significantly lower risk of ID compared to those who were on cyclosporine (HR 0.254, p = 0.023). Patients with ID had a trend toward a lower SVR rate (25 vs. 54 %, p = 0.18) and a significantly higher rate of graft failure (33 vs. 4 %, p = 0.004) compared to patients with no ID/cholestasis.

CONCLUSIONS

ID is common during or after PEG-IFN/RBV therapy for recurrent hepatitis C and frequently associated with decreased graft survival, trending toward low rates of SVR. Careful monitoring of liver biochemistries during or after PEG-IFN/RBV therapy with a low threshold to biopsy patients and particularly those receiving cyclosporine-based immunosuppression may improve outcomes in these patients.

Utility of the low-accelerating-dose regimen in 182 liver recipients with recurrent hepatitis C virus

AIM

To describe our experience using a low-accelerating-dose regimen (LADR) with pegylated interferon alpha-2a and ribavirin in treatment of hepatitis C virus (HCV) recurrence.

METHODS

From 2003, a protocolized LADR strategy was employed to treat liver transplant (LT) recipients with recurrent HCV at our institution. Medical records of 182 adult patients with recurrent HCV treated with LADR between 1/2003 and 1/2011 were reviewed. Histopathology from all post-LT liver biopsies were reviewed in a blinded fashion. Paired recipient and donor IL28B status were assessed. A novel technique was employed to ascertain recipient and donor IL28B (rs12979860) Gt data using DNA extracted from archival FFPE tissue from explanted native livers and donor gallbladders respectively. The primary endpoint was SVR; secondary endpoints examined include (1) patient and graft survival; (2) effect of anti-viral therapy on liver histology (fibrosis and inflammation); (3) incidence of on-treatment development of ACR, CDR, or PCH; (4) association of recipient and donor IL28B genotype with SVR; and (5) incidence of anti-viral therapy-associated adverse events (anemia, leukopenia, thrombocytopenia, depression) and hepatic decompensation.

RESULTS

The overall SVR rate was 38% (29% Gt1, 67% Gt2, 86% Gt3 and 58% Gt4). HCV Gt (P < 0.0001), donor age (P = 0.003), cytomegalovirus mismatch (P = 0.001), baseline serum bilirubin (P = 0.002), and baseline viral load (P = 0.04) were independent predictors for SVR. SVR rates were significantly higher in the recipient-CC/donor-non CC pairs (P = 0.007). Neither baseline fibrosis nor change in fibrosis stage after anti-viral therapy were associated with SVR. Fibrosis progressed in 72% of patients despite SVR. Median graft survival was 91 mo. Five-year patient survival was superior in patients who achieved SVR (97% vs 82%, P = 0.001). Pre-treatment ALP ≥ 150 U/L (P = 0.01), total bilirubin ≥ 1.5 mg/dL (P = 0.001) and creatinine ≥ 2 mg/dL (P = 0.001) were independently associated with patient survival. Only 13% of patients achieving SVR died during the follow-up period. Treatment discontinuation and treatment-related mortality occurred in 35% and 2.2% of patients, respectively. EPO, G-CSF and blood transfusion were needed in 89%, 40% and 23% of patients, respectively. Overall hospitalization rate for treatment-related serious adverse events was 21%. Forty-six (25%) of the patients were deceased; among those who died, 25 (54%) were due to liver-related complications, and 4 deaths (9%) occurred while receiving therapy (2 patients experienced hepatic decompensation and 2 sepsis).

CONCLUSION

LADR strategy remains relevant in managing post-LT recurrent HCV where access to DAAs is limited. SVR is associated with improved survival, but fibrosis progression still occurs.

Plasma cell hepatitis induced by the termination of antiviral therapy for recurrent hepatitis C after living donor liver transplantation

Plasma cell hepatitis (PCH) is an idiopathic disorder characterized by plasma cell infiltration in the allografts of patients who have undergone liver transplantation. Although an increasing number of cases of PCH have been reported in liver transplant recipients with hepatitis C recurrence treated with interferon, it is unclear whether PCH is induced by interferon itself. Here, we describe the cases of two patients who developed PCH just after the termination of antiviral therapy for recurrent hepatitis C after living donor liver transplantation. Liver dysfunction appeared at 1 month in one patient and 2 months in the other patient after pegylated interferon plus ribavirin therapy, and liver histology showed interface hepatitis with plasma cell-rich lymphoid aggregates. Both patients recovered after steroid therapy and achieved sustained virological response. These cases suggest that PCH could be induced by the alteration of the immune condition resulting from the termination of antiviral therapy. PCH should be considered when the transaminase levels increase after antiviral therapy, and it should be carefully distinguished from hepatitis C relapse.

Management of Hepatitis C Before and After Liver Transplantation in the Era of Rapidly Evolving Therapeutic Advances

Management of hepatitis C (HCV) in liver transplantation (LT) population presents unique challenges. Suboptimal graft survival in HCV+ LT recipients is attributable to universal HCV recurrence following LT. Although eradication of HCV prior to LT is ideal for the prevention of HCV recurrence it is often limited by adverse events, particularly in patients with advanced cirrhosis. Antiviral therapy in LT candidates needs careful monitoring, and prophylaxis with HCV antibodies is ineffective. Early antiviral therapy after LT has been investigated, but no clear benefit has been demonstrated. Protocol liver biopsy is generally recommended in HCV+ LT recipients, and antiviral therapy can be considered in those with severe/progressive HCV recurrence. Sustained virological response (SVR) can be achieved in approximately 30% of LT recipients with pegylated interferon/ribavirin (PEG-IFN/RBV) with survival benefit, but adverse effects are common. Favorable patient characteristics for response to therapy include non-1 genotype, previously untreated, low baseline HCV-RNA, and donor IL28B genotype CC. Direct acting antiviral (DAA)-based triple therapy is associated with higher rates of SVR, but with similar or slightly higher rates of side effects, and immunosuppressive regimens need to be closely monitored and adjusted during the treatment period. Notably, the safety and efficacy of HCV treatment are very likely to improve with newer generation DAA. The benefit of immunosuppressive strategy on the natural history HCV recurrence has not been well elucidated. Based upon available evidence, cyclosporine A (CSA), mycophenolate mofetil (MMF), and sirolimus appear to have a neutral or small beneficial impact on HCV recurrence. Donor interleukin 28 B (IL28B) polymorphisms appear to impact the course and treatment outcomes in recurrent HCV. Retransplantation should be considered for patients with reasonable survival probability.

Histopathological evaluation of recurrent hepatitis C after liver transplantation: A review

Although the morphological features of hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) have been well established in the last decades, the differential diagnosis still represents a challenge for the pathologist, especially early recurrent hepatitis C vs mild acute cellular rejection. The present review focuses on the role of the pathologist and the pathology laboratory in the management of recipients with recurrent hepatitis C, the usefulness of early and late post-OLT liver biopsies, and the potential role of ancillary techniques (immunohistochemistry and reverse transcription-polymerase chain reaction, RT-PCR). The English literature on the topic is reviewed, focusing on the histopathology, the immunohistochemistry and the use of RT-PCR on HCV-positive post-OLT biopsies. The different histopathological illustrations of early and chronic recurrent hepatitis C are presented, with special focus on the main differential diagnoses and those features with prognostic relevance (cholestasis above all). The usefulness of ancillary techniques are discussed, especially HCV RNA quantitation by RT-PCR. Finally, the usefulness of long-term protocol biopsies is addressed: their usefulness for the study of allograft disease progression is clear, but their meaning in the long term is still debated. The significance of plasma cell infiltrate in HCV-positive allografts, the prognostic weight of graft steatosis, and the impact of donor age in recurrent hepatitis C also represent additional open issues.

Histologic findings predictive of a diagnosis of de novo autoimmune hepatitis after liver transplantation in adults

BACKGROUND

Autoimmune hepatitis (AIH) after liver transplantation has been defined histologically as a "hepatitic" pattern of injury, characterized by lymphoplasmacytic inflammation with necroinflammatory activity (NIA), comparable with findings seen in native livers. This definition, however, is difficult to apply in practice because specific histologic criteria are not clearly delineated. This study aimed to determine which histologic features correlated best with clinical and serologic features of dAIH.

METHODS

Index liver biopsies from patients with autoimmune-like hepatitis transplanted for non-AIH in two centers (n=35 and 20) were reviewed. Histologic features were correlated with the clinical diagnosis of AIH based on a retrospective review of clinical and serologic data, including therapeutic response.

RESULTS

A clinical diagnosis of AIH was retrospectively assigned to 24 of 35 (68%) and 18 of 20 (90%) patients, respectively (P=0.10). In multivariate analysis, centrilobular NIA and centrilobular plasma cell (PC) ratio of 30% to 50% were independently discriminating for a clinical diagnosis of AIH (P=0.04 and 0.05, respectively). The best level of predictability (99.6%) was mathematically achieved when severe centrilobular NIA and centrilobular PC ratio of 30% to 50% were both present.

CONCLUSION

A histologic pattern of centrilobular injury including increased NIA and increased PC infiltration correlates with measurements of autoimmunity in liver recipients. It could be used to segregate cases for further study and introduced into the AIH scoring systems when applied in the context of liver transplantation.

"Plasma cell hepatitis" in liver allografts: identification and characterization of an IgG4-rich cohort

Plasma cell hepatitis (PCH), also known as "de novo autoimmune" hepatitis, is an increasingly recognized, but suboptimally named and poorly understood, category of late allograft dysfunction strongly resembling autoimmune hepatitis (AIH): They share plasma-cell-rich necro-inflammatory activity on biopsy, autoantibodies and steroid responsiveness, but overlap with rejection is problematic. A retrospective study of clinical, serological, histopathological and IgG4 immunohistological features of PCH (n = 20) in liver allograft recipients, native liver AIH (n = 19) and plasma-cell-rich renal allograft rejection (n = 20) showed: (1) high frequency (44%) of HLA-DR15; (2) less female predominance (p = 0.03) and (3) n = 9/20 PCH recipients showed >25 IgG4+ plasma cells/high-power field (IgG4+ PCH) versus AIH (n = 1/19, p = 0.008) or plasma-cell-rich kidney rejection (n = 2/20, p = 0.03). The IgG4+ PCH (n = 9) subgroup showed lower alanine transaminase (ALT) (p < 0.01) and aspartate transaminase (AST) (p < 0.05) at index biopsy but (a) higher plasma cell number/percentage, (b) more aggressive-appearing portal/periportal and perivenular necro-inflammatory activity and (c) more severe portal/periportal fibrosis than IgG4- PCH (n = 11). Significant demographic, histopathologic and plasma cell phenotype differences between PCH and AIH suggest distinct pathogenic mechanisms for at least the IgG4+ PCH subgroup likely representing an overlap between allo- and auto-immunity. IgG4+ PCH was associated with fibrosis, but also highly responsive to increased immunosuppression.

Immunoglobulin G4-associated de novo autoimmune hepatitis after liver transplantation for chronic hepatitis B- and C-related cirrhosis and hepatocellular carcinoma: a case report with literature review

Immunoglobulin G4 (IgG4)-associated autoimmune hepatitis (AIH) was recognized as a new disease entity; however, IgG4-associated de novo AIH after the liver transplantation had not been reported yet. Herein we have described a 56-year-old man who developed IgG4 de novo AIH as 1 year-post liver transplantation after receiving pegylated interferon alpha-2a and ribavirin therapy for hepatitis C virus recurrence. The histopathologic evidence showed an aggressive lymphoplasmacytic interface hepatitis with centrilobular necrosis (plasma cells > 30%) and IgG4-positive plasma cells (>10 per high power field). Serum IgG (9220 mg/dL) and IgG4 (3289 mg/dL) were also elevated. Improvement of liver function tests (LFTs) by prednisone and azathioprine therapy are manifested as normalized alanine aminotransferase and IgG levels. IgG4 relates to more severe histological activity; however, it is believed to be a good prognostic predictor of a response to prednisone plus azathioprine therapy especially with early diagnosis and timely management.

Treatment of hepatitis C in compensated cirrhotic patients is equally effective before and after liver transplantation

AIM: To investigate differences in tolerability and response to treatment in compensated cirrhotic patients affected by hepatitis C virus (HCV) infection before and after liver transplantation.

METHODS: Forty-three HCV non-liver transplanted (LT) cirrhotics (mean age 55 ± 8 years, 65.1% male, Child-Pugh-A, genotype 1-4: 65.1%, 2-3: 34.9%) and 17 LT recipients with recurrent HCV-related cirrhosis (mean age 57 ± 9 years, 88.2% male, Child-Pugh-A, genotype 1-4: 76.5%, 2-3: 23.5%) were included in the analysis from retrospective series. All patients received recombinant or pegylated interferon plus ribavirin at a standard dose and duration. Adverse events were recorded and classified according to the Common Terminology Criteria for Adverse Events. The mean duration of follow-up was of 4.3 ± 1.8 years after the end of the treatment.

RESULTS: An early virological response (EVR) was achieved in 30/43 (69.8%) non-LT and in 8/17 (47.1%) LT cirrhotics, a sustained virological response (SVR) in 18/43 (41.9%) and 5/17 (29.4 %), respectively. No statistical difference was observed in EVR and SVR rates between the two groups. Among HCV non-LT cirrhotics, 6/43 (13.9%) discontinued the treatment prematurely, 11.6% of them receiving ≤ 80% of treatment; 8/17 (47%) LT cirrhotics withdrew the treatment, 35.2% of them receiving ≤ 80% of treatment. If compared with LT-ones (P = 0.015), an higher risk of treatment discontinuation could affect LT cirrhotics, who undergo more frequently ≤ 80% of treatment (P = 0.05). None of the non-LT cirrhotics died after the end of the treatment. With no regards to the achievement of SVR, LT cirrhotic patients showed a reduced survival in respect to non-LT ones (87% at 1 year, 76% at 3 and 5 years after the end of treatment).

CONCLUSION: HCV antiviral treatment is equally effective in compensated cirrhotics both before and after LT, which patients show a higher risk of premature treatment withdrawal and a reduced survival, independently of the achievement of SVR.

Liver Transplant Pathology: Review of Challenging Diagnostic Situations

Histopathologic assessment of allograft liver biopsies has an important role in managing patients who have undergone liver transplantation. In this review, several topics are discussed that create diagnostic problems in transplant pathology, with emphasis on pathologic features and differential diagnosis. The topics discussed are acute cellular rejection, late acute rejection (centrizonal/parenchymal rejection), chronic rejection, plasma cell hepatitis, idiopathic posttransplant chronic hepatitis, fibrosing cholestatic hepatitis, selected viral infections (cytomegalovirus, Epstein-Barr virus, and hepatitis E), and acute antibody-mediated rejection.