Antibodies against cytokeratin 8/18 in a patient with de novo autoimmune hepatitis after living-donor liver transplantation

The adaptive immune response to porous regenerated keratin as a bone graft substitute in an ovine model

Reconstituted keratin is a novel bone graft material when prepared as a rigid scaffold. Understanding the immunogenicity of this material is important to determine whether this substance is a viable surgical option. Previous studies have shown no innate immune system activation in response to reconstituted keratin implants. To examine antibody-mediated immune responses to reconstituted keratin implants, bone and blood samples were taken from twelve sheep with surgically created tibial defects containing such implants. RT-PCR was used to detect mRNA of the inflammatory marker SOCS 3 in local bony tissue, and a novel immunohistochemistry assay developed to detect antikeratin antibodies in serum. Two animals were sacrificed per time-point at weeks 1, 2, 4, 6, 8 and 12. Time points for serum analysis included baseline (pre-surgery) and all other time points; mRNA analysis examined samples from all time points. No upregulation in antikeratin antibodies or SOCS 3 mRNA was observed at any time point, indicating that reconstituted keratin implants do not trigger an adaptive immune response in vivo in an ovine model. These findings provide the platform for further development of keratin implants in other mammalian models to define its immunogenic profile and safety.

Autoantibodies against CYP-2C19: A Novel Serum Marker in Pediatric De Novo Autoimmune Hepatitis?

Diagnosis of de novo autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLT) is challenging especially in the absence of hyper-γ-globulinemia. Circulating autoantibodies are not sensitive nor specific in de novo AIH but when positive increase the diagnostic probability. We report the discovery of novel liver microsomal (LM) autoantibodies against CYP-2C19 in a 9-year-old boy with “de novo” AIH developed 7 years after OLT. Graft dysfunction presented with hypertransaminasemia (up to 400 IU/L), while serum γ-globulins remained within the normal range for age. Liver histology and response to high dose prednisone (2 mg/kg/day) with the addition of azathioprine therapy further supported the diagnosis of de novo AIH. Autoantibodies investigation by indirect immunofluorescence (IF) on rodent tissues showed a novel staining pattern involving the pericentral liver zone and sparing the renal tissue. Human but not rat liver proteins immunoblotting allowed us to characterize the novel LM antibodies and to identify CYP-2C19 as human antigen. The finding offers insights into the controversial discussion about autoimmunity versus alloreactivity with regard to the pathogenesis of de novo AIH. Correct information on human versus rat tissue antigens tested by methods other than IF for antibodies detection may have significant implications for the correct diagnosis and management of patients followed up after OLT.

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.

De novo autoimmune hepatitis after liver transplantation: A focus on glutathione S-transferase theta 1

De novo autoimmune hepatitis (DAIH) is a rare clinical condition with features that resemble those of autoimmune hepatitis (AIH) in patients undergoing liver transplantation (LT) for nonautoimmune liver disease. The diagnosis of this entity has been based on the presence of biochemical and histological patterns similar to those observed in the primary AIH, although several considerations must be taken into account. The impact of DAIH on graft survival is relevant, and early diagnosis and treatment is associated with a good longterm outcome. Although glutathione S-transferase theta 1 (GSTT1) alloimmune recognition has been shown to be involved in the pathogenesis of DAIH, further studies are necessary to fully determine its pathogenic mechanisms and risk factors. We review the pathophysiology, the most common histological patterns, the treatment strategies, and the longterm outcomes of DAIH after LT with a special focus on GSTT1. Liver Transplantation 23:75-85 2017 AASLD.

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.

ABO-compatible liver allograft antibody-mediated rejection: an update

PURPOSE OF REVIEW

Liver allograft antibody-mediated rejection (AMR) studies have lagged behind parallel efforts in kidney and heart because of a comparative inherent hepatic resistance to AMR. Three developments, however, have increased interest: first, solid phase antibody testing enabled more precise antibody characterization; second, increased expectations for long-term, morbidity-free survival; and third, immunosuppression minimization trials.

RECENT FINDINGS

Two overlapping liver allograft AMR phenotypic expressions are beginning to emerge: acute and chronic AMR. Acute AMR usually occurs within the several weeks after transplantation and characterized clinically by donor-specific antibodies (DSA) persistence, allograft dysfunction, thrombocytopenia, and hypocomplementemia. Acute AMR appears histopathologically similar to acute AMR in other organs: diffuse microvascular endothelial cell hypertrophy, C4d deposits, neutrophilic, eosinophilic, and macrophag-mediated microvasculitis/capillaritis, along with liver-specific ductular reaction, centrilobular hepatocyte swelling, and hepatocanalicular cholestasis often combined with T-cell-mediated rejection (TCMR). Chronic AMR is less well defined, but strongly linked to serum class II DSA and associated with late-onset acute TCMR, fibrosis, chronic rejection, and decreased survival. Unlike acute AMR, chronic AMR is a slowly evolving insult with a number of potential manifestations, but most commonly appears as low-grade lymphoplasmacytic portal and perivenular inflammation accompanied by unusual fibrosis patterns and variable microvascular C4d deposition; capillaritis can be more difficult to identify than in acute AMR.

SUMMARY

More precise DSA characterization, increasing expectations for long-term survival, and immunosuppression weaning precipitated a re-emergence of liver allograft AMR interest. Pathophysiological similarities exist between heart, kidney, and liver allografts, but liver-specific considerations may prove critical to our ultimate understanding of all solid organ AMR.

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.

Tissue biopsy monitoring of operational tolerance in liver allograft recipients

PURPOSE OF REVIEW

Highly selected, long-surviving, liver allograft recipients with normal/near normal liver injury tests can be weaned from immunosuppression. Baseline biopsies document changes before weaning and can help stratify risk of rejection or dysfunction after weaning; biopsies after weaning are used to study mechanisms of operational tolerance and to monitor for subclinical events.

RECENT FINDINGS

Clinicopathological features associated with successful weaning include a lack of sensitization [negative donor-specific antibodies (DSA) and lack of tissue C4d deposits]; 'inexperienced' recipient immune system with limited potential for cross-reactivity (less immunological memory; infant recipients); noninflamed allograft in those with nonviral, nonimmunological original diseases; upregulation of liver genes associated with iron metabolism; allograft colonization with 'immunosuppressive' cells (Treg and γδ-1>γδ-2); and longer time on immunosuppression, which might signal slow clonal deletion or silencing. The differential diagnosis of histopathological findings detected before and after weaning includes emerging infections, typical and atypical cellular rejection, indolent antibody-mediated rejection, 'autoimmunity', and other causes of progressive fibrosis.

SUMMARY

Operationally tolerant liver allograft recipients can be successfully managed with very low, and sometimes no immunosuppression, but challenges exist. Newer approaches to tissue pathology and tissue, serum, and cross-platform analytics are needed to predict successful weaning and to monitor for subclinical events.

Is there a role for cyclophilin inhibitors in the management of primary biliary cirrhosis?

Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are poorly understood autoimmune liver diseases. Immunosuppression is used to treat AIH and ursodeoxycholic acid is used to slow the progression of PBC. Nevertheless, a proportion of patients with both disorders progress to liver failure. Following liver transplantation, up to a third of patients with PBC experience recurrent disease. Moreover a syndrome referred to as "de novo AIH" occurs in a proportion of patients regardless of maintenance immunosuppression, who have been transplanted for disorders unrelated to AIH. Of note, the use of cyclosporine A appears to protect against the development of recurrent PBC and de novo AIH even though it is a less potent immunosuppressive compared to tacrolimus. The reason why cyclosporine A is protective has not been determined. However, a virus resembling mouse mammary tumor virus (MMTV) has been characterized in patients with PBC and AIH. Accordingly, we hypothesized that the protective effect of cyclosporine A in liver transplant recipients may be mediated by the antiviral activity of this cyclophilin inhibitor. Treatment of the MMTV producing MM5MT cells with different antivirals and immunosuppressive agents showed that both cyclosporine A and the analogue NIM811 inhibited MMTV production from the producer cells. Herein, we discuss the evidence supporting the role of MMTV-like human betaretrovirus in the development of PBC and de novo AIH and speculate on the possibility that the agent may be associated with disease following transplantation. We also review the mechanisms of how both cyclosporine A and NIM811 may inhibit betaretrovirus production in vitro.

Incidence and risk factors associated with de novo autoimmune hepatitis after liver transplantation

BACKGROUND/AIMS

De novo autoimmune hepatitis (AIH) describes the development of hepatitis with autoimmune features in liver transplant (LT) patients without prior diagnosis of AIH. We aimed to evaluate the incidence and risk factors for de novo AIH.

METHODS

A cohort of 576 patients with LT for aetiologies other than AIH was evaluated.

RESULTS

De novo AIH was diagnosed in 17 patients (3%) with an overall incidence of 4.0 cases per 1000 patient-years. By univariate Cox analysis, patients who received cyclosporine A had lower risk (HR 0.24, 95% CI 0.07-0.80, P = 0.02), whereas patients who had female donors (HR 3.03, 95% CI 1.11-8.25, P = 0.03), donors ≥40-years (HR 6.95, 95% CI 1.93-25.03, P = 0.003), and those who received tacrolimus (HR 4.39, 95% CI 1.47-13.13, P = 0.008) and mycophenolate mofetil (HR 6.37, 95% CI 1.62-25.13, P = 0.008) had higher risk. Survival was similar in patients with de novo AIH compared with the LT population (mean survival time, 17 ± 1.5 vs. 16 ± 0.5 years, Log-rank test; P = 0.4).

CONCLUSIONS

The incidence of de novo AIH is low and does not impact on long-term survival. Recipients of female or older donor grafts, or recipients using tacrolimus, or mycophenolate mofetil as part of their immunosuppressive regimen have a higher risk of de novo AIH, whereas LT recipients maintained on cyclosporine A have a lower risk.

Diagnosis, pathogenesis, and treatment of autoimmune hepatitis after liver transplantation

Autoimmune hepatitis can recur or appear de novo after liver transplantation, and it can result in hepatic fibrosis, graft loss, and re-transplantation. The goals of this review are to describe the prevalence, manifestations, putative pathogenic mechanisms, outcomes, and management of these occurrences. Autoimmune hepatitis recurs in 8-12 % of transplanted patients at 1 year and 36-68 % at 5 years. Recurrence may be asymptomatic and detected only by surveillance liver test abnormalities or protocol liver tissue examination. Autoantibodies that characterized the original disease, hypergammaglobulinemia, increased serum immunoglobulin G level, and histological findings of interface hepatitis, lymphoplasmacytic infiltration, perivenular hepatocyte necrosis, pseudo-rosetting, and acidophil bodies typify recurrence. Premature corticosteroid withdrawal and pre-transplant severity of the original disease are possible risk factors. De novo autoimmune hepatitis occurs in 1-7 % of patients 0.1-9 years after transplantation, especially in children. The appearance of autoantibodies may herald its emergence, and antibodies to glutathione-S-transferase T1 have been predictive of the disease. Recurrent disease may reflect recruitment of residual memory T lymphocytes and host-specific genetic predispositions, whereas de novo disease may reflect an allo-antigenic immune response and molecular mimicries that override self-tolerance. Treatment should be appropriate for autoimmune hepatitis and not based on anti-rejection drugs. Corticosteroid therapy alone or combined with azathioprine is the essential treatment. The substitution of mycophenolate mofetil for azathioprine and switch of the calcineurin inhibitor or its replacement with rapamycin have also been used for refractory disease. Re-transplantation has been necessary in 8-23 %.

Autoimmune hepatitis after liver transplantation

Liver transplantation is an effective treatment for patients with end-stage acute and chronic autoimmune hepatitis. However, despite the good outcomes reported, disease recurrence is relatively common in the allograft. In addition, autoimmunity and autoimmune liver disease can arise de novo after transplantation for non-autoimmune liver disorders. Little is known about the mechanisms by which autoimmune diseases develop after liver transplantation, but genetic factors, molecular mimicry, impaired regulatory T-cell responses, and exposures to new alloantigens might be involved. Regardless of the pathogenic mechanisms, it is important to remain aware of the existence of recurrent and de novo autoimmune hepatitis after liver transplantation; these disorders are similar to classic autoimmune hepatitis and are therefore not treated with standard antirejection strategies.

Cytokeratins in hepatitis

Experimental and clinical evidence suggests that cytokeratins (CK), among other physiological functions, are expressed in hepatocytes and can be released in the bloodstream after acute or chronic inflammatory liver injury. Interest in CK in viral and nonviral hepatitis has been rapidly increasing during the last years, especially as they have been proposed as circulating biomarkers of hepatocyte necrosis and apoptosis. In the present review, we sought to summarize and discuss the alterations in circulating CK levels in different form viral and nonviral hepatitis, as well as their potential relation with liver histology. Understanding the mechanisms of hepatitis impact on CK and vice versa is a promising area of research that will positively enhance our understanding of the complexity of acute and chronic inflammatory liver injury.

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.

De novo autoimmune hepatitis with centrilobular necrosis following liver transplantation for primary biliary cirrhosis: a case report

De novo autoimmune hepatitis (AIH) occurred in patients who underwent liver transplantation for a different etiology. This 55-year-old woman was transplanted due to PBC. One year after liver transplantation, she complained of fatigue. Liver function tests showed markedly elevated serum alanine transaminase (ALT) and globulin levels. She also tested positive for anti-nuclear antibodies (ANA). Liver biopsy showed lymphocytic and plasmacytic infiltration in the portal and periportal areas, with numerous areas of bridging centrilobular necrosis, indicating AIH. She had a pretreatment AIH score of 16 points, and a posttreatment score of 18 points according to the scoring system of the International AIH Group (IAHG). The patient was treated effectively with prednisone, but then suffered two further episodes of AIH as a result of decreasing the prednisone dose. Histological features on liver biopsy were similar to those on initial presentation. Treatment with prednisone and azathioprine resulted in a dramatically improved outcome. Her liver function and globulin levels rapidly returned to normal and have remained so thereafter.

Global proteome analysis of hepatitis B virus expressing human hepatoblastoma cell line HepG2

In countries where hepatitis B virus (HBV) is endemic, a high incidence of hepatocellular carcinoma (HCC) occur in HBV carriers and the prolonged replication and expression of HBV proteins in the liver is considered an important risk factor for progression to malignancy. However, the mechanism of pathogenesis of HBV-associated carcinoma remains elusive. In this study, the human hepatoblastoma HepG2 cell line harboring 1.2 x unit-length of the HBV genome was generated and subjected to a proteomic approach analyzing the global protein expression profiles of HepG2 cells with and without HBV replication and protein expression. By using fluorescence two-dimensional difference gel electrophoresis (2D-DIGE), followed by MALDI-TOF-MS and database searching, a total of 50 differentially expressed proteins were identified, including some cell cycle-related proteins. These cycle-related proteins may lead to accumulation of HepG2-HBV cells in the G2/M phase, and an increase in the proportion of HepG2 cells with tripolar or multipolar spindles. This study described the proteomic alterations in HepG2 cells HBV-harboring, which may provide new insights into the underlying molecular mechanisms involved in HBV replication and pathogenesis.

Toward unraveling the complexity of simple epithelial keratins in human disease

Simple epithelial keratins (SEKs) are found primarily in single-layered simple epithelia and include keratin 7 (K7), K8, K18-K20, and K23. Genetically engineered mice that lack SEKs or overexpress mutant SEKs have helped illuminate several keratin functions and served as important disease models. Insight into the contribution of SEKs to human disease has indicated that K8 and K18 are the major constituents of Mallory-Denk bodies, hepatic inclusions associated with several liver diseases, and are essential for inclusion formation. Furthermore, mutations in the genes encoding K8, K18, and K19 predispose individuals to a variety of liver diseases. Hence, as we discuss here, the SEK cytoskeleton is involved in the orchestration of several important cellular functions and contributes to the pathogenesis of human liver disease.

Risk factors for developing de novo autoimmune hepatitis associated with anti-glutathione S-transferase T1 antibodies after liver transplantation

De novo autoimmune hepatitis (de novo AIH) is a rare form of graft dysfunction that develops after liver transplantation (LT) in patients transplanted for conditions other than autoimmune disorders. Although characterized by biochemical, serological, and histological features of AIH, de novo AIH is sometimes associated with atypical serum autoantibodies, many of which are directed against glutathione S-transferase T1 (anti-GSTT1). GSTT1 donor/recipient genotype mismatch has been suggested as a necessary condition for the appearance of autoantibodies and de novo AIH. However, clinically evident disease is not observed in all patients with anti-GSTT1 antibodies. We examined the incidence of de novo AIH and its conditioning (risk) factors in patients with anti-GSTT1 antibodies. Anti-GSTT1 autoantibodies were detected in 29 of 419 [6.9%; 95% confidence interval (CI), 4.9-9.8] consecutive adult LT recipients with donor/recipient GSTT1 mismatch. Twenty of 27 assessable patients (74%) developed de novo AIH after a median follow-up of 26 months (95% CI, 19.2-32.8). The probability of de novo AIH was 11%, 44%, and 60% 12, 24, and 36 months after LT, respectively. No relationship emerged between de novo AIH and recipient gender, donor and recipient age, rejection episodes, immunosuppressive regime, allelic GSTT1 expression, human leukocyte antigen distribution, or cytomegalovirus infection. Multivariate analysis identified male donor [hazard ratio (HR), 3.3; 95% CI, 1.18-9.26; P = 0.018], nonalcoholic etiology (HR, 4.67; 95% CI, 1.64-13.3; P = 0.002), and high anti-GSTT1 titer (HR, 2.98; 95% CI, 1.04-8.57; P = 0.035) as independent predictors of de novo AIH. Most patients with anti-GSTT1 antibodies and donor/recipient GSTT1 mismatch developed clinically evident de novo AIH after LT. The risk of developing the disease was increased by male donor gender, nonalcoholic etiology of original liver disease, and a high anti-GSTT1 titer.

Idiopathic post-transplantation hepatitis following living donor liver transplantation, and significance of autoantibody titre for outcome

Idiopathic post-transplantation hepatitis (IPTH) is a common histology occurring late after liver transplantation. Its natural history and the effect of treatment have not been determined. This study is a matched case-control study that evaluates predictors, outcome and response to treatment for IPTH. Patients were divided by autoantibodies into high-titre (> or = 1:160) and low-titre (<1:160) groups, so as to evaluate clinicopathological differences between the two groups. IPTH was identified in 42 of 944 recipients (4.4%) with tacrolimus-based immunosuppression. They comprised 10 males and 32 females, having median age 6.0 (0-50) years. IPTH presented at a median duration of 5.2 (0.7-10.8) years after transplantation. Particular risk of IPTH was associated with acute rejection, late-onset acute rejection occurring later than 6 month post-transplant, and autoantibody positivity. IPTH was associated with dependence on steroids and frequent adverse outcomes: retransplantation in five (12%); relapse in four (9.5%); and progression of fibrosis in eight (19%). The high-titre group and low-titre group did not differ in their clinicopathological features, response to treatment or outcome. To prevent the development of IPTH, appropriate adjustment of immunosuppression and close follow-up is necessary for patients who suffer repeated episodes of rejection.

De novo autoimmunity after organ transplantation: targets and possible pathways

The development of autoantibodies to different tissue-specific antigens in patients without existing history of autoimmune diseases suggests that autoimmunity may develop de novo after organ transplantation. In addition to allo-specific immune responses, tissue-specific autoimmunity also appears contribute to the host anti-graft response, and thus may affect long-term graft function. As graft failure caused by chronic rejection is a major challenge in clinical transplantation, understanding de novo autoreactivity after transplantation has important ramifications. This review investigates this emerging concept by discussing target antigens and possible pathways.

Total and caspase-cleaved cytokeratin 18 in chronic cholecystitis: a prospective study

BACKGROUND

Cell death mode has been studied in cancer, autoimmune, and neurodegenerative diseases. In this study, apoptosis and necrosis are investigated for the first time in patients with chronic calculous cholecystitis.

METHODS AND MATERIALS

Thirty five (35) patients (27 women and 8 men, aged 55.65 +/- 13.48 years) with symptomatic chronic calculous cholecystitis underwent laparoscopic cholecystectomy. The early specific apoptotic tendency (caspase-cleaved cytokeratin 18) was studied in these patients with M30 Apoptosense ELISA and the total cytokerarin 18 (both derived from apoptosis and necrosis) with M65 ELISA. The ratio M30/M65 (caspase-cleaved to total cytokeratin 18) was also computed. According to the histopathological examination, the patients were divided in two groups: group A included patients with chronic inactive cholecystitis (n = 10), and group B those with chronic active cholecystitis (n = 25).

RESULTS

The concentrations of caspase-cleaved cytokerarin 18 (CK18), and especially those of total CK18, were higher in bile samples than in serum samples. In group B, there were significant differences between serum and bile samples regarding both caspase-cleaved CK18 and total CK18. Cells staining positive for caspase-cleaved CK18 were present in the epithelial cells of the mucosa of the gallbladder.

CONCLUSION

CK18 is expressed in the gallbladder epithelial cells. The concentrations of both caspase-cleaved CK18 and total CK18 were higher in bile samples than in serum samples. The levels of total CK18, as well as caspase-cleaved CK18, do not seem to differ between active and inactive chronic cholecystitis.

c-Jun NH2-terminal kinase 2 inhibits gamma interferon production during Anaplasma phagocytophilum infection

Gamma interferon (IFN-gamma) plays a critical role in the early eradication of Anaplasma phagocytophilum. However, the mechanisms that regulate IFN-gamma production upon infection remain poorly understood. Here we show that c-Jun NH2-terminal kinase 2 (JNK2) inhibits IFN-gamma production during A. phagocytophilum infection. jnk2-null mice were more refractory to infection with A. phagocytophilum and produced increased levels of IFN-gamma after challenge with the pathogen. The resistance of jnk2-null mice to A. phagocytophilum infection was due to elevated levels of IFN-gamma secreted by conventional and natural killer (NK) T cells. The administration of alpha-galactosylceramide, a strong NK T-cell agonist, increased IFN-gamma release and protected mice from A. phagocytophilum, further demonstrating the inhibitory effect of JNK2 on IFN-gamma production. Collectively, these findings provide strong evidence that JNK2 is an important regulatory protein for IFN-gamma secretion upon challenge with A. phagocytophilum.

Autoimmune liver disease and rheumatic manifestations

PURPOSE OF REVIEW

To review studies that clarify the rheumatic manifestations of autoimmune hepatitis, elucidate shared pathogenic pathways, and encourage innovative site-specific therapies.

RECENT FINDINGS

Autoimmune hepatitis has clinical manifestations, serological markers, pathogenic mechanisms, genetic predispositions, and therapies similar to the rheumatic diseases. The rheumatic manifestations may mask the underlying liver disease and vice versa. Variations in clinical phenotype and outcome for the autoimmune liver diseases may reflect host-specific and region-specific factors, and defects in counter-regulatory suppressor functions by regulatory T cells may facilitate cell-mediated cytotoxicity and autoreactivity. Mixed syndromes with hallmark features of one disease in another probably reflect a genetic predisposition for immune expression that is shared among the diseases. Mycophenolate mofetil, budesonide, rapamycin, and 6-thioguanine are promising treatments, and de-novo autoimmune hepatitis after liver transplantation suggests that the calcineurin inhibitors may have paradoxical effects on self-tolerance.

SUMMARY

Clinical phenotypes of autoimmune hepatitis commonly include rheumatic manifestations that can mask the liver disease. Defects in counter-regulatory functions enhance cell-mediated cytotoxicity, and pharmacological interventions that promise site-specific actions affecting immunocyte differentiation and proliferation are feasible.

Autoimmune liver disease

PURPOSE OF REVIEW

To review studies that improve the diagnosis and treatment of autoimmune hepatitis and presage new drug and molecular site-specific interventions.

RECENT FINDINGS

Autoimmune hepatitis can present as acute or chronic hepatitis and as allograft dysfunction after liver transplantation. Elderly patients have an indolent but aggressive disease that responds well to corticosteroid therapy, and human leukocyte antigen DR4 characterizes this population. Geographic and ethnic factors influence clinical phenotype and behavior, and defects in T-regulatory cells may enhance cell-mediated cytotoxicity. Treatment response is the best index of prognosis, and normalization of serum aminotransferase abnormalities prevents disease progression. Mycophenolate mofetil, budesonide, rapamycin, and 6-thioguanine have been effective in small clinical experiences. De-novo autoimmune hepatitis can occur in adults and children after liver transplantation, and rapamycin may be an effective treatment.

SUMMARY

Autoimmune hepatitis has a global distribution and diverse clinical manifestations. Phenotypes are affected by regional and ethnic factors which may provide clues to the etiologic agents. Defects in counter-regulatory functions enhance cell-mediated cytotoxicity, and interventions that promise site-specific actions affecting immunocyte differentiation and proliferation are now feasible. Autoimmune hepatitis must be considered in all patients with acute and chronic hepatitis and in all cases of allograft dysfunction after liver transplantation.

Chronic allograft dysfunction: diagnosis and management. Is it always progressive?

1. There are many causes of graft dysfunction post-liver transplant, but recurrent disease remains the most common cause. 2. Viral hepatitis, nonalcoholic and alcoholic steatohepatitis, and autoimmune diseases are the most common causes of recurrent disease. 3. Graft hepatitis occurs frequently and in many cases will not progress. 4. Cirrhosis in the absence of any identifiable cause develops in a minority. 5. Treatment is of the underlying cause but some, such as recurrent and de novo autoimmune hepatitis and recurrent primary sclerosing cholangitis may not respond well, and regraft may be required.