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

Management of Biliary Complications in Liver Transplant Recipients

Biliary complications are often referred to as the Achilles' heel of liver transplantation (LT). The most common of these complications include strictures, and leaks. Prompt diagnosis and management is key for preservation of the transplanted organ. Unfortunately, a number of factors can lead to delays in diagnosis and make adequate treatment a challenge. Innovations in advanced endoscopic techniques have increased non-surgical options for these complications and in many cases is the preferred approach.

Cholangitis lenta: An underdiagnosed lesion associated with severe cholestasis following liver transplantation

BACKGROUND

Cholangitis lenta (CL) represents a specific histological lesion associated with severe cholestasis and related to sepsis. Despite being well known by pathologists, CL has been poorly studied in liver transplantation (LT).

METHODS

We performed a retrospective 12-year analysis of the incidence, risk factors, and outcome of CL in LT recipients. Biopsy samples performed within 3 months after LT underwent blinded rereading to identify recipients with CL.

RESULTS

Among 587 LT performed, 45 (7.7%) developed CL. Of these, 7 (15.6%) had no signs of clinical sepsis at the time of biopsy, but further investigations revealed positive cultures. Independent factors associated with CL were sepsis at the time of LT (OR = 3.62 [95%CI = 1.63-8.06]), donor age (OR = 1.05 [1.03-1.08]), and operative time (OR = 1.23 [95%CI = 1.02-1.48]). Cholangitis lenta was associated with increased severe morbidity (71.1% vs 33.0%, P < .001), 90-day mortality (24.4% vs 5.9%, P < .001) and decreased one-year graft (62.1% vs 89.4%, P < .001) and patient survival (55.6% vs 87.9%, P < .001).

CONCLUSION

Cholangitis lenta represents a possible lesion associated with cholestasis after LT, which strongly affects its outcome. In the event of an unexplained post-transplant cholestasis, the diagnosis of CL must be considered, even in the absence of clinically evident sepsis.

Therapy with boceprevir or telaprevir in HIV/hepatitis C virus co-infected patients to treat recurrence of hepatitis C virus infection after liver transplantation

OBJECTIVE

Severe hepatitis C virus (HCV) recurrence affects post-transplant survival in HIV/HCV co-infected patients. This article describes the results of triple anti-HCV therapy with boceprevir or telaprevir in seven HIV/HCV co-infected patients following liver transplantation.

METHODS

All patients had severe HCV recurrence [fibrosis stage ≥F2 or acute hepatitis ≥A2 (n = 5) or fibrosing cholestatic hepatitis (n = 2)] associated with genotype 1a (n = 4) or 1b (n = 3). Patients were treated with Peg-interferon/ribavirin and boceprevir (n = 2) or telaprevir (n = 5) immediately (n = 3) or after a 4-week lead-in phase (n = 4). Immunosuppression included either cyclosporine (n = 5) or tacrolimus (n = 2). Prior to introducing telaprevir, combined antiretroviral therapy was switched in one patient to prevent drug-drug interactions.

RESULTS

At 24 weeks after the end of treatment, sustained virological response was observed in 60% (3/5) of the patients treated with telaprevir; no responders were observed in the boceprevir group. Triple anti-HCV therapy was prematurely discontinued in six patients [treatment failure (n = 2), infection (n = 2), acute rejection (n = 1) and myocardial infarction (n = 1)]. Anaemia occurred in all patients, requiring erythropoietin, ribavirin dose reduction and red blood cell transfusions in five patients.Average cyclosporine doses were reduced by 50-84% after telaprevir initiation and by 33% after boceprevir initiation. Tacrolimus doses were reduced by 95% with telaprevir.

CONCLUSION

Our data suggest that in HIV/HCV co-infected patients, triple anti-HCV therapy with telaprevir greatly improved efficacy despite poor tolerability. Significant decreases in cyclosporine or tacrolimus doses are necessary prior to introduction of boceprevir or telaprevir. Close monitoring is essential to prevent drug-drug interactions among antiretroviral therapy, immunosuppressive agents and anti-HCV therapy.

Chemokines in chronic liver allograft dysfunction pathogenesis and potential therapeutic targets

Despite advances in immunosuppressive drugs, long-term success of liver transplantation is still limited by the development of chronic liver allograft dysfunction. Although the exact pathogenesis of chronic liver allograft dysfunction remains to be established, there is strong evidence that chemokines are involved in organ damage induced by inflammatory and immune responses after liver surgery. Chemokines are a group of low-molecular-weight molecules whose function includes angiogenesis, haematopoiesis, mitogenesis, organ fibrogenesis, tumour growth and metastasis, and participating in the development of the immune system and in inflammatory and immune responses. The purpose of this review is to collect all the research that has been done so far concerning chemokines and the pathogenesis of chronic liver allograft dysfunction and helpfully, to pave the way for designing therapeutic strategies and pharmaceutical agents to ameliorate chronic allograft dysfunction after liver transplantation.

Relationship between the histological appearance of the portal vein and development of ischemic-type biliary lesions after liver transplantation

Ischemic-type biliary lesions (ITBLs) are a major cause of morbidity after liver transplantation (LT). Their assumed underlying pathophysiological mechanism is ischemia/reperfusion injury of the biliary tree, in which the portal circulation has been proposed recently to have a role. The aim of this study was to investigate whether early histological changes, particularly in the portal vein, predispose patients to ITBLs. A case-control study of 22 LT recipients was performed through a retrospective assessment of more than 30 histological parameters in 44 intraoperative liver biopsy samples taken after cold ischemia (time 0) and portal reperfusion (time 1). Eleven grafts developed ITBLs requiring retransplantation (the ITBL group), and 11 matched controls had normally functioning grafts 11 years after LT on average (the non-ITBL group). Additionally, 11 liver biopsy samples from hemihepatectomies performed for metastases of colorectal cancer (CRC) were assessed similarly. Analyses showed no significant histological differences at time 0 between the ITBL and non-ITBL groups. However, the time 1 biopsy samples from the ITBL group showed smaller portal vein branches (PVBs) significantly more often than the samples from the non-ITBL group, which also showed persisting paraportal collateral vessels. Larger PVBs and paraportal collateral vessels were also found in the CRC group. A morphometric analysis confirmed these findings and showed that PVB measurements were significantly lower for the ITBL group at time 1 versus the ITBL group at time 0 and the non-ITBL and CRC groups (they were largest in the CRC group). Thus, the PVB dimensions decreased in the ITBL group in comparison with the time 0 biopsy samples, and they were significantly smaller at time 1 in comparison with the dimensions for the non-ITBL and CRC groups. In conclusion, a smaller PVB lumen size in postreperfusion biopsy samples from liver grafts, suggesting a relatively decreased portal blood flow, is associated with a higher incidence of ITBLs. These findings support recent clinical studies suggesting a possible pathophysiological role of portal blood flow in the oxygenation of the biliary tree after LT.

Fibrosing cholestatic hepatitis in HIV/HCV co-infected transplant patients-usefulness of early markers after liver transplantation

We characterized fibrosing cholestatic hepatitis (FCH) in a large cohort of HIV/HCV co-infected patients. Between 1999 and 2008, 59 HIV infected patients were transplanted for end-stage liver disease due to HCV. Eleven patients (19%) developed FCH within a mean period of 7 months [2-27] after liver transplantation (LT). At Week 1 post-LT, the mean HCV viral load was higher in the FCH group: 6.13 log(10) IU/mL ± 1.30 versus 4.9 log(10) IU/mL ± 1.78 in the non-FCH group, p = 0.05. At the onset of acute hepatitis after LT, activity was moderate to severe in 8/11 HIV+/HCV+ patients with FCH (73%) versus 13/28 (46%) HIV+/HCV+ non-FCH (p = 0.007) patients. A complete virological response to anti-HCV therapy was observed in 2/11 (18%) patients. Survival differed significantly between the two groups (at 3 years, 67% in non-FCH patients versus 15% in FCH patients, p = 0.004). An early diagnosis of FCH may be suggested by the presence of marked disease activity when acute hepatitis is diagnosed and when a high viral load is present. The initiation of anti-HCV therapy should be considered at this point.

Endoscopic management of biliary strictures after liver transplantation

Bile duct strictures remain a major source of morbidity after orthotopic liver transplantation (OLT). Biliary strictures are classified as anastomotic or non-anastomotic strictures according to location and are defined by distinct clinical behaviors. Anastomotic strictures are localized and short. The outcome of endoscopic treatment for anastomotic strictures is excellent. Non-anastomotic strictures often result from ischemic and immunological events, occur earlier and are usually multiple and longer. They are characterized by a far less favorable response to endoscopic management, higher recurrence rates, graft loss and need for retransplantation. Living donor OLT patients present a unique set of challenges arising from technical factors, and stricture risk for both recipients and donors. Endoscopic treatment of living donor OLT patients is less promising. Current endoscopic strategies for biliary strictures after OLT include repeated balloon dilations and placement of multiple side-by-side plastic stents. Lifelong surveillance is required in all types of strictures. Despite improvements in incidence and long term outcomes with endoscopic management, and a reduced need for surgical treatment, the impact of strictures on patients after OLT is significant. Future considerations include new endoscopic technologies and improved stents, which could potentially allow for a decreased number of interventions, increased intervals before retreatment, and decreased reliance on percutaneous and surgical modalities. This review focuses on the role of endoscopy in biliary strictures, one of the most common biliary complications after OLT.

Biliary complications after liver transplantation: A review

After liver transplantation, the prevalence of complications related to the biliary system is 6-35%. In recent years, the diagnosis and treatment of biliary problems has changed markedly. The two standard methods of biliary reconstruction in liver transplant recipients are the duct-to-duct choledochocholedochostomy and the Roux-en-Y-hepaticojejunostomy. Biliary leakage occurs in approximately 5-7% of transplant cases. Leakage from the site of anastomosis, the T-tube exit site and donor or recipient remnant cystic duct is well described. Symptomatic bile leakage should be treated by stenting of the duct by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTCD). Biliary strictures can occur at the site of the anastomosis (anastomotic stricture; AS) or at other locations in the biliary tree (non-anastomotic strictures; NAS). AS occur in 5-10% of cases and are due to fibrotic healing. Treatment by ERCP or PTCD with dilatation and progressive stenting is successful in the majority of cases. NAS can occur in the context of a hepatic artery thrombosis, or with an open hepatic artery (ischaemic type biliary lesions or ITBL). The incidence is 5-10%. NAS has been associated with various types of injury, e.g. macrovascular, microvascular, immunological and cytotoxic injury by bile salts. Treatment can be attempted with multiple sessions of dilatation and stenting of stenotic areas by ERCP or PTCD. In cases of localized diseased and good graft function, biliary reconstructive surgery is useful. However, a significant number of patients will need a re-transplant. When biliary strictures or ischaemia of the graft are present, stones, casts and sludge can develop.

Seeking beyond rejection: an update on the differential diagnosis and a practical approach to liver allograft biopsy interpretation

Pathologic evaluation of liver allograft biopsies plays an integral role in the management of patients after liver transplantation. This review summarizes the clinical context and classical histology of different types of allograft rejection and also the common entities that enter the differential diagnosis of allograft rejection, and provides practical approaches to liver allograft biopsy interpretation. In addition, some of the new developments in the field of liver transplant pathology are updated. The purpose of this review is to provide guidance for pathologists interpreting liver allograft biopsies, particularly those interested in developing expertise in the field of liver transplant pathology.

Pediatric liver transplantation

In previous decades, pediatric liver transplantation has become a state-of-the-art operation with excellent success and limited mortality. Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, immunosuppression, and identification and treatment of postoperative complications. The utilization of split-liver grafts and living-related donors has provided more organs for pediatric patients. Newer immunosuppression regimens, including induction therapy, have had a significant impact on graft and patient survival. Future developments of pediatric liver transplantation will deal with long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible. This review describes the state-of-the-art in pediatric liver transplantation.

Biliary strictures following liver transplantation: past, present and preventive strategies

Biliary complications are still the major source of morbidity for liver transplant recipients. The reported incidence of biliary strictures is 5%-15% after deceased donor liver transplantation and 28%-32% after right-lobe live donor surgery. Presentation is usually within the first year, but the incidence is known to increase with longer follow-up. The anastomotic variant is due to technical factors, whereas the nonanastomotic form is due to immunological and ischemic events, which later may lead to graft loss. Endoscopic management of anastomotic strictures achieves a success rate of 70%-100%; it drops to 50%-75% for nonanastomotic strictures with a higher recurrence rate. Results of endoscopic maneuvers are disappointing for biliary strictures after live donor liver transplantation, and the success rate is 60%-75% for anastomotic strictures and 25%-33% for the nonanastomotic variant. Preventive strategies in the cadaveric donor include the standardization of the type of anastomosis and maintenance of a vascularized ductal stump. In right-lobe live donor livers, donor liver duct harvesting also involves a major risk. The concept of high hilar intrahepatic Glissonian dissection, dissecting the artery and the duct as one unit, use of microsurgical techniques for smaller ducts, use of ductoplasty, and flexibility in the performance of double ductal anastomosis are the critical components of the preventive strategies in the recipient. In the case of live donors, judicious use of intraoperative cholangiograms, minimal dissection of the hilar plate, and perpendicular transection of the duct constitute the underlying principals for obtaining a vascularized duct.

FasL expression in hepatic antigen-presenting cells and phagocytosis of apoptotic T cells by FasL+ Kupffer cells are indicators of rejection activity in human liver allografts

Fas-Fas ligand (FasL) interaction and apoptosis are important in the mechanism of allograft rejection. However, the interaction between donor and recipient cells, specifically focusing on antigen-presenting cells (APCs), under various conditions is poorly understood in human liver allografts. FasL expression on APCs, its association with apoptosis, and the origin of apoptotic lymphocytes in human liver allografts were assessed by immunohistochemistry and in situ hybridization. We found increased expression of FasL on Kupffer cells (KCs) and endothelium in acute cellular rejection (n = 20) and to lesser extent in chronic rejection (n = 6) and septic cholangitis (n = 5) compared with stable grafts and normal controls. In addition, the graft specificity of infiltrating T cells was confirmed by polymerase chain reaction examination of T-cell receptor-gamma loci. T-cell apoptosis occurred at a higher rate in acute cellular rejection than in chronic rejection or septic cholangitis. The number of apoptotic bodies derived from recipient lymphocytes correlated with the severity of rejection and was reversed by treatment. FasL(+) KCs phagocytosed CD4(+) interferon-gamma(+) T cells, rather than CD4(+) interleukin-4(+) T cells, suggesting a role of KCs in regulating CD4(+) T-cell subset differentiation. In conclusion, our data suggest that FasL expression on APCs and phagocytosis of apoptotic T cells by FasL(+) KCs are indicators of rejection activity in human liver allografts.

Biliary complications after deceased-donor orthotopic liver transplantation

A wide range of potential biliary complications can occur after orthotopic liver transplantation (OLT). The most common biliary complications are bile leaks, anastomotic and intrahepatic strictures, stones, and ampullary dyfunction, which may occur in up to 20%-40% of OLT recipients. Leaks predominate in the early posttransplant period; stricture formation typically develops gradually over time. However, with the advent of new techniques, such as split-liver, reduced-size, and living-donor liver transplantation, the spectrum of biliary complications has changed. Risk factors for biliary complications comprise technical failure; T-tube or stent-related complications; hepatic artery thrombosis; bleeding; ischemia/reperfusion injury; and other immunological, nonimmunological, and infectious complications. Noninvasive diagnostic methods have been established and treatment modalities have been modified towards a primarily nonoperative, endoscopy-based strategy. Besides, the management of biliary complications after OLT requires a multidisciplinary approach, in which interventional and endoscopic treatment options have to be weighed up against surgical treatment options. The etiology and spectrum of bile duct complications, their diagnosis, and their treatment will be reviewed in this article.

Liver biopsy interpretation for causes of late liver allograft dysfunction

Evaluation of needle biopsies and extensive clinicopathological correlation play an important role in the determination of liver allograft dysfunction occurring more than 1 year after transplantation. Interpretation of these biopsies can be quite difficult because of the high incidence of recurrent diseases that show histopathological, clinical, and serological features that overlap with each other and with rejection. Also, more than one insult can contribute to allograft injury. In an attempt to enable centers to compare and pool results, improve therapy, and better understand pathophysiological disease mechanisms, the Banff Working Group on Liver Allograft Pathology herein proposes a set of consensus criteria for the most common and problematic causes of late liver allograft dysfunction, including late-onset acute and chronic rejection, recurrent and new-onset viral and autoimmune hepatitis, biliary strictures, and recurrent primary biliary cirrhosis and primary sclerosing cholangitis. A discussion of differential diagnosis is also presented.

Hepatobiliary pathology

PURPOSE OF REVIEW

Publications concerning liver histopathology in fatty liver disease and chronic hepatitis C, iron and copper overload, and liver transplantation from the past year have been surveyed to highlight useful concepts and diagnostic information.

RECENT FINDINGS

Two microscopic forms of pediatric nonalcoholic steatohepatitis have been described: type 1 in which hepatocyte ballooning and/or pericellular fibrosis accompany the steatosis; and type 2 which has portal tract inflammation and/or fibrosis as the salient accompanying feature. In chronic hepatitis C, the ductular reaction appears to be a major factor associated with fibrosis. In patients transplanted for hepatitis C virus-related cirrhosis, immunostaining of post-transplant liver biopsies for alpha-smooth muscle actin (i.e. in activated hepatic stellate cells) may identify those individuals at risk for severe recurrence. Clinicopathological papers on several forms of non-HFE hemochromatosis were published and Wilson's disease was described in individuals of 60 years or more in age. Cholestasis in childhood was expertly reviewed and histopathologic precursor lesions of hepatocellular carcinoma were also examined in a comprehensive article.

SUMMARY

Recent publications with impact on liver biopsy interpretation include a morphologic classification of nonalcoholic steatohepatitis in childhood, the differential diagnosis of childhood cholestasis and pathogenetic factors involved in fibrogenesis in chronic hepatitis C.