Concurrent de novo autoimmune hepatitis and recurrence of primary biliary cirrhosis post-liver transplantation

Plasma Cell Infiltrate in Liver Allograft Biopsy: Clinical and Histological Implications

Introduction:

The relevance of plasma cells in the allograft liver is of utmost importance and objective assessment of these infiltrates and correlation with other ancillary findings needs to be evaluated.

Materials and Methods:

Three hundred and sixty-eight graft liver biopsies received in the department from 2012 to 2022 and 115 allograft liver biopsies with histopathological diagnosis of rejection were selected. Based on plasma cells percentage in the portal tracts, the biopsies were divided into three groups: Group 1 showing not more than an occasional plasma cell, Group 2 showing <10% plasma cells, and Group 3 showing >10% plasma cells. Rejection activity index (RAI), portal/lobular inflammation, interface activity, subendothelial inflammation (portal and central vein), duct damage/loss, presence of cholestasis, apoptosis, perivenulitis, necrosis, rosette along with serial liver function tests (LFTs), and patient status at 1 year of follow-up were recorded and compared between the groups.

Results:

Plasma cell infiltrates were observed in 52.6% of the specimens, with the mean percentage of plasma cells in the infiltrates being 4.9. Increased plasma cell infiltrates were associated with higher RAI scores, marked duct damage, marked portal and central vein endotheliitis, marked portal inflammation, and presence of interface activity. Higher levels of transaminitis were recorded at the time of biopsy, but no significant association was observed in the fall of serial LFTs over a 2-week period with the presence of plasma cells.

Conclusion:

Identifying plasma cell infiltrates in liver allografts can serve as a clue toward increased severity of rejection in liver allograft biopsies. Further studies with emphasis on correlation with the clinical outcome and response to treatment are needed to validate its utility as an objective tool.

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.

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.

Liver transplantation and autoimmune liver diseases

Liver transplantation (LT) is an effective treatment for patients with end-stage autoimmune liver diseases such as primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis. Indications for LT for these diseases do not differ substantially from those used for other acute or chronic liver diseases. Despite the good outcomes reported, the recurrence of autoimmune liver disease is relatively common in the allograft. In addition, it has become apparent that autoimmunity and autoimmune liver disease can arise de novo after transplantation for nonautoimmune liver disorders. An awareness of the existence of recurrent autoimmune liver diseases and de novo autoimmune hepatitis after LT has important clinical implications because their management differs from the standard antirejection treatment and is similar to the management of classic autoimmune liver diseases in the native liver.

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 %.

De novo autoimmune hepatitis associated with PTH(1-34) and PTH(1-84) administration for severe osteoporosis in a liver transplant patient

De novo autoimmune hepatitis (AIH) is a rare graft dysfunction occurring in patients having undergone liver transplantation (LT) for causes other than AIH. We describe for the first time a case of de novo AIH associated with the administration of parathyroid hormone 1-34 [PTH(1-34)] and PTH(1-84) for severe osteoporosis. A 61-year-old woman was referred to our metabolic bone clinic due to severe osteoporosis, 3 years after LT for primary biliary cirrhosis. Initial treatment with PTH(1-34) led to asymptomatic hypertransaminasemia (two-fold the upper limit of normal), which normalized after drug discontinuation. A new flare of transaminases (three-fold the upper limit of normal) along with elevated alkaline phosphatase was observed after administration of PTH(1-84), which did not resolve after PTH(1-84) withdrawal. Subsequently, after exclusion of common causes of liver enzyme elevation, a liver biopsy was performed. Histological findings showed de novo AIH, which responded rapidly to treatment with methylprednisolone.

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.

Immune-mediated complications of the graft in interferon-treated hepatitis C positive liver transplant recipients

Hepatitis C virus (HCV) re-infection of the graft is universal and interferon based antiviral therapy remains at present the treatment of choice in HCV liver transplant recipients. Apart from the antiviral effects, interferon and ribavirin have both potent immunomodulatory properties resulting in a broad range of immune-related disorders including acute cellular rejection and chronic ductopenic rejection as well as de novo autoimmune hepatitis. Further complicating the picture, HCV infection per se is associated with a variety of autoimmune phenomena. We discuss here the immune-mediated complications and their relationship to chronic HCV and interferon based antiviral therapy.

Hepatobiliary pathology

PURPOSE OF REVIEW

Recent studies pertaining to the histopathology of the liver and biliary tract are reviewed.

RECENT FINDINGS

Several studies are reviewed which describe the histologic features and clinical behavior of 'plasma cell hepatitis' in the posttransplant setting. Cytokeratin 7, EMA, and CD68 were found to be useful immunohistochemical stains in fibrolamellar hepatocellular carcinoma and may aid in the distinction between this variant and classic hepatocellular carcinoma. Arginase-1, another immunohistochemical stain, was found to have improved sensitivity over HepPar-1 in the diagnosis of classic hepatocellular carcinoma. Metabolic syndrome is common in children with nonalcoholic fatty liver disease and may be an indicator of more severe disease activity and fibrosis. Histologic features were described that may aid in the distinction between the steroid-responsive IgG4-associated cholangitis and the steroid-nonresponsive primary sclerosing cholangitis. In addition, immunohistochemical stains for IgM and IgG may be helpful in distinguishing between autoimmune liver diseases, with primary biliary cirrhosis and its antimitochondrial-negative variant, autoimmune cholangitis, being the two autoimmune liver diseases with a predominance of IgM-positive plasma cells.

SUMMARY

Several informative studies pertaining to hepatobiliary pathology were published this year, with topics including posttransplant plasma cell hepatitis, familial hemophagocytic lymphohistiocytosis, pediatric nonalcoholic fatty liver disease, and the use of immunohistochemical stains specific for various immunoglobulin subtypes.

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.

Plasma cell hepatitis in hepatitis C virus patients post-liver transplantation: case-control study showing poor outcome and predictive features in the liver explant

Plasma cell hepatitis (PCH) is characterized by plasma cell infiltration seen in allografts of patients who underwent liver transplantation (LT) for conditions other than autoimmune hepatitis. We identified 40 PCH patients who underwent LT for hepatitis C virus (HCV) by searching our pathology database (1994-2006) for the keywords liver allograft, lymphoplasmacytic, and plasma cell(s). We selected 2 control patients who received LT for HCV for each PCH case. The control patients were matched according to date of LT and availability of biopsy material at the time interval to development of PCH in PCH patients. Explant and post-LT biopsy slides were blindly reviewed by 2 liver pathologists and the severity of the plasma cell infiltrate was scored. A score of 3 (plasma cells composing >30% of the infiltrate) defined PCH in allograft biopsies. Five random areas of dense inflammation were also examined in explant livers and the highest score was used. Poor outcome was defined as death or advanced fibrosis (stage >or= 4 of 6). We found that PCH patients were more likely to have worse outcomes than control patients (65% versus 40%, P < 0.01), including increased mortality (50% versus 30%, P < 0.05). Kaplan-Meier survival analysis showed significantly worse survival for PCH patients from 4 to 10 years post-LT (P < 0.05). Explants from 40% of PCH patients had a score of 3 compared to 18% of control patients (P < 0.01). We found that the development of PCH is associated with poor outcome in patients undergoing LT for HCV. The association of significant plasma cell infiltrates in native livers of HCV patients developing PCH suggests that some patients may have a predisposition to developing PCH.

Recurrence of primary biliary cirrhosis and development of autoimmune hepatitis after liver transplant: A blind histologic study

AIM

This long-term study aimed to evaluate recurrence and evolution of primary biliary cirrhosis (PBC) after orthotopic liver transplantation (OLT).

METHODS

We reviewed "blindly" allograft biopsy specimens of women who underwent transplantation for PBC (n = 84), and women who received a transplant for chronic hepatitis C virus infection (CHCV ) (n = 108). All needle liver biopsy specimens obtained more than 6 months post-OLT were examined, including 83 specimens from 44 PBC patients and 152 specimens from 58 CHCV patients.

RESULTS

Granulomatous destructive cholangitis was found in five biopsies from four PBC patients (P = 0.0048). Non-necrotizing epithelioid cell granulomas were present in four biopsies from four PBC patients, and in two biopsies from one CHCV patient. Piecemeal necrosis (P = 0.0002), lobular necroinflammatory activity (P < 0.0001), steatosis (P < 0.0001) and fibrosis (P < 0.0001) were more prevalent in CHCV patients than PBC patients. Four PBC patients developed histologic evidence of autoimmune hepatitis (AIH), at a mean time of 3.66 years post-OLT. One of these patients had histologic features of AIH/PBC overlap syndrome. All four patients developed bridging fibrosis (n = 2) or cirrhosis (n = 2). No other PBC patient had evidence of cirrhosis after OLT.

CONCLUSIONS

Histologic findings indicative of recurrent PBC were present in 15.9% of the PBC patients undergoing biopsy in this series. However, this group of patients did not suffer significant bile duct loss or fibrosis, as compared to the control group, suggesting that recurrent PBC is a mild or slowly progressive disease. Histologic evidence of AIH was observed in allograft biopsies of some PBC patients.

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

De novo autoimmune hepatitis has been described in both pediatric and adult liver transplantation (LT) recipients. Studies of small numbers of patients have proposed it to be an alloimmune hepatitis or form of chronic rejection. We have recently noted an increasing number of patients with post-LT recurrent hepatitis C virus (HCV) developing this, with an apparent negative impact on outcome and survival. We term this entity posttransplant plasma cell hepatitis (PCH). A search of our institution's pathology database was performed with the terms "plasma cell(s)," "lymphoplasmacytic infiltrate," and "liver allograft." A histological scoring system was devised to more reliably diagnose PCH in the setting of recurrent HCV. Thirty-eight patients were identified, and their clinical data were analyzed. Sixty percent had a negative outcome as defined by the development of cirrhosis, need for retransplantation, or death. Eighty-two percent had recent lowering of immunosuppression or subtherapeutic calcineurin inhibitor levels; 58% developed PCH within 2 years post-LT. Histologic resolution of PCH was associated with good outcome (P < 0.001). Patients not receiving treatment had a negative outcome (P = 0.007) as did patients receiving corticosteroids as therapy (P = 0.02). Persistence (P = 0.007) or recurrence of PCH was associated with negative outcome. In conclusion, PCH is a histologic variant of rejection. On liver biopsy, PCH can at times be difficult to diagnose, and the use of a standardized scoring system is recommended to differentiate it from other forms of allograft dysfunction. Treatment by optimization of immunosuppression without the use of corticosteroids appears effective. The development of PCH in the setting of recurrent HCV is a negative prognostic factor for patient outcome and allograft failure.

De novo autoimmune hepatitis following living-donor liver transplantation for primary biliary cirrhosis

Since first being described in 1998, de novo autoimmune hepatitis (AIH) after liver transplantation has been reported in several cases suffering from non-autoimmune liver diseases and primary biliary cirrhosis (PBC). Glutathione S-transferase (GST) T1 genotype mismatches between donor and recipient have also been suggested to constitute a risk factor for de novo AIH. Here, we report a 33-yr-old woman who presented complaining of marked fatigue and jaundice four yr after living-donor liver transplantation for PBC. On examination, transaminase levels were highly elevated and ANA and antimitochondrial antibody M2 were positive. Histological findings showed zonal necrosis with lymphoplasmacytic infiltration closely resembling AIH. She had pretreatment AIH score of 16 and 19 points after relapse of de novo AIH. Two color fluorescence in situ hybridization with X and Y chromosome-specific probes clearly revealed that the hepatocytes were of donor origin and lymphocytes were of patient origin. The GSTT1 genotype of the patient and the donor were the same null type, suggesting that mechanisms other than GSTT1 mismatches may exist in de novo AIH development. In conclusion, recipient immune cells attacked the allogeneic transplanted liver of the patient via de novo AIH, although the exact participation of autoimmune mechanisms is unclear.

Long-term clinical outcome of living-donor liver transplantation for primary biliary cirrhosis

AIM

We described the recurrence of primary biliary cirrhosis (PBC) after living donor liver transplantation (LDLT) (Liver Transplantation, 7, 2001: 588). However, since the follow-up period in that study was insufficiently long (median 35.5 months), we performed a long-term study to further characterize recurrence of PBC after LDLT.

PATIENTS

From 1991 to 2006, 15 patients with end-stage PBC underwent LDLT at Tokyo Women's Medical University. Of these patients, we studied 8 PBC patients (age 29 to 51 years, all females) who survived LDLT for more than 5 years. The follow-up period for these patients ranged form 68 to 120 months. Immunosuppression was maintained with tacrolimus and prednisone. Laboratory examinations performed in every patient and donor before LDLT included routine biochemical studies, antimitochondrial antibody (AMA) by immunofluorescence (IF), anti-M2 by enzyme-linked immunosorbent assay as well as antinuclear antibody (ANA) by IF, and immunoglobulin. After LDLT, the same laboratory examinations were performed in patients every 6 months. Liver biopsy was performed when patients exhibited clinical or biochemical signs of graft dysfunction. In addition, protocol biopsy was performed every 1 to 2 years after LDLT.

RESULTS

At the time of LDLT, all patients had end-stage cholestatic liver failure. Seven patients were positive for AMAand anti-M2 while 1 patient was negative for these markers but strongly positive for ANA. Donors were blood relatives in 6 cases, and 2 donors who were not blood relatives still exhibited multiple HLA matches with the recipients. At the end of the study in May 2006, all patients were doing well. On laboratory examination, mild abnormal liver function test results were found in 4 patients: 3 were probably due to recurrence of PBC, 1 resulted from nonalcoholic steatohepatitis. Comparison of the AMA titer between before LDLT and the most recent follow-up visit showed an increase in three patients, a decrease in two patients and no change in three patients. In contrast, the ANA titer increased in five patients. Histologically, strong evidence of recurrent PBC was found in 4 patients, and findings compatible with PBC were present in 2 additional patients.

CONCLUSIONS

Although the number of our patients is small, our findings confirm that PBC can recur at high frequency after LDLT. However, this complication has not developed to advanced stages and has not caused appreciable symptoms in our patients, all of whom have a good quality of life.

De novo autoimmune hepatitis following liver transplantation for primary biliary cirrhosis

De novo autoimmune hepatitis (AIH) is a rare disorder first described in 1998. It appears in patients with liver transplants for non-AIH etiology. The few cases in the literature make it a little known entity due to mechanisms that are unclear. We present the case of a woman with a liver transplant whose graft developed de novo AIH. Diagnosed with primary biliary cirrhosis, the patient underwent liver transplantation for refractory pruritus. Sixteen months after transplantation, we detected alterations in the hepatic profile with hypertransaminasemia and elevated alkaline phosphatase, together with elevated antinuclear antibodies. IgG levels were normal. Histological findings indicated AIH. The patient responded rapidly to treatment with prednisolone and azathioprine. De novo AIH in patients transplanted for PBC may cause graft dysfunction. This report also analyzes the case with respect to the other four reported cases, discussing etiologic hypotheses.

Progressive histological damage in liver allografts following pediatric liver transplantation

The long-term histological outcome after pediatric liver transplantation (OLT) is not yet fully understood. De novo autoimmune hepatitis, consisting of histological chronic hepatitis associated with autoantibody formation and allograft dysfunction, is increasingly recognized as an important complication of liver transplantation, particularly in the pediatric population. In this study, 158 asymptomatic children with 5-year graft survival underwent protocol liver biopsies (113, 135, and 64 at 1, 5, and 10 years after OLT, respectively). Histological changes we re correlated with dinical,biochemical, and serological findings. All patients received cydosporine A as primary immunosuppression with withdrawal of corticosteroids at 3 months post OLT. Normal or near-normal histology was reported in 77 of 113 (68%), 61 of 135 (45%), and 20 of 64 (31%) at 1, 5, and 10 years, respectively. The commonest histological abnormality was chronic hepatitis (CH), the incidence of which increased with time [25/113 (22%), 58/135 (43%), and 41/64 (64%) at 1, 5, and 10 years, respectively) (P < .0001)]. The incidence of fibrosis associatedwith CH increasedwith time [13/25 (52%), 47/58 (81%), and 37/41 (91%) at 1, 5, and 10 years, respectively) (P < .0001)]. The severity of fibrosis associated with CH also increased with time, such that by 10 years 15% had progressed to cirrhosis. Aspartate aminotransfemse (AST) levels were slightly elevated in children with CH (median levels 52 IU/L, 63 IU/L, and 48 IU/L at 1, 5, and 10 years, respectively), but this did not reach statistical significance compared with those with normal histology. On multivariate analysis, the only factor predictive of chronic hepatitis was autoantibody positivity (present in 13% and 10% of children with normal biopsies at 5 and 10 years, respectively, and 72% and 80% of those with CH at 5 and 10 years, respectively) (P < .0001). Four children with CH and autoantibodies, who also had raised immunoglobulin G (IgG) levels and AST greater than 1.5 x normal fulfilled the diagnostic criteria for de novo autoimmune hepatitis (AIH). Another two were found to be hepatitis C positive. No definite cause for CH could be identified in the other cases. In condusion, chronic hepatitis is a common finding in children after liver transplantation and is associated with a high risk of developing progressive fibrosis, leading to cirrhosis. Standard liver biochemical tests cannot be relied on either in the diagnosis or in the monitoring of progress of chronic allograft hepatitis. In contrast, the presence ofautoantibodies is strongly associated with the presence of CH. The cause of chronic hepatitis in transplanted allografts is uncertain but may be immune mediated, representing a hepatitic form of chronic rejection.

Autoantibodies in autoimmune liver disease

Autoantibodies indicate an immune reactive state, but in liver disease they lack pathogenicity and disease specificity. Antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, antimitochondrial antibodies, and perinuclear antineutrophil cytoplasmic antibodies constitute the standard serological repertoire that should be assessed in all liver diseases of undetermined cause. Antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, actin, liver cytosol type 1, nuclear antigens specific to primary biliary cirrhosis, and pore complex antigens constitute an investigational repertoire that promises to have prognostic and diagnostic value. These autoantibodies may emerge as predictors of treatment response and outcome. Antibodies to histones, doubled-stranded DNA, chromatin, and lactoferrin constitute a supplemental repertoire, and they support the immune nature of the liver disease. Final diagnoses and treatment strategies do not depend solely on serological markers. Autoantibodies are floating variables, and their behavior does not correlate closely with disease activity. There are no minimum levels of significant seropositivity, especially in children. Over-interpretation is the major pitfall in the clinical application of the serological results. New autoantibodies will emerge as the search for target antigens and key pathogenic pathways continues.

Post-liver transplantation de novo hepatitis with overlap features

The development of de novo autoimmune liver disease after liver transplantation (LT) has been described in both children and adults. Reported herein is a case that is best characterized as post-LT de novo hepatitis with features of autoimmune hepatitis (AIH)-primary biliary cirrhosis (PBC) overlap. A 56-year-old man underwent LT for decompensated liver disease secondary to non-alcoholic steatohepatitis. His liver function tests became markedly abnormal 8 months after LT. Sequential liver transplant biopsy findings were confusing and shared findings seen with both AIH and PBC. Although standard autoimmune serological tests were negative, a dramatic biochemical response was observed to a regimen consisting of prednisone, mycophenolate mofetil, and ursodeoxycholic acid added to maintainance tacrolimus. The donor was histocompatibility leukocyte antigen, DR4, positive, a haplotype associated with the development of AIH-PBC overlap syndrome. In conclusion the authors believe that this may be a case of post-LT de novo overlap syndrome of AIH-PBC, a novel 'autoimmune-type' response.

Autoimmune overlapping syndromes

The overlap syndrome raises several questions. First could these patients have two coincident autoimmune diseases? Such possibility cannot be discarded in particular in the setting of consecutive occurrence of the two conditions (eg, PBC followed by AIH) and this is consistent with the fact that autoimmune diseases are associated with one another in about 5% to 10% of cases. Furthermore, it is presumed that they share similar genetic susceptibility. A second possibility could be that overlap syndrome represents the middle of a continuous spectrum of two autoimmune liver diseases. The systematic study of the relationships between elementary histologic lesions and biochemistries in "pure" PBC patients pleads strongly for such a hypothesis. Pure PBC is characterized by 2 different groups of elementary lesions that are not interrelated: first, florid bile duct lesions and bile duct paucity and second, lymphocytic piecemeal necrosis and lobular necro-inflammatory changes. Furthermore, the first set of lesions is selectively associated with biochemical cholestasis and IgM levels, whereas the second set of lesions is selectively associated with serum transaminase activities and IgG levels. These observations are consistent with the assumption that two main mechanisms are involved in the progression of liver injury in PBC. The first is bile duct destruction leading to chronic cholestasis and fibrosis of biliary pattern. The second is lymphocytic piecemeal necrosis of hepatocytes, which tends to lead to cirrhosis, the pattern of which resembles cirrhosis following various forms of chronic active hepatitis. The author has therefore speculated that the picture of pure PBC results always forms the clinical and biochemical expression of the two main histologic lesions, and combination of these processes might explain why the spectrum of PBC varies from typical PBC to AIH or PBC overlap. A third hypothesis is that an exaggerated hepatitic response in PBC is associated with the HLA haplotype commonly seen in AIH, eg, B8, DR3, DR4. Further studies are obviously needed to confirm such an attractive hypothesis. Other possible explanation for the concurrent occurrence of features of both conditions in the same individual includes the selective modulation of HLA class 1, class 2 expression and Rantes by cholestasis itself and in particular bile acids. It is conceivable that the degree of interface and lobular inflammation in PBC and PSC may be modulated by chemokines, their receptors, and the parenchymal concentrations of individual bile acids that are all, at least in part, genetically determined.

Autoimmune hepatitis after liver transplantation and other lessons of self-intolerance

Autoimmune hepatitis has been described as recurrent or de novo disease after transplantation. The legitimacy of these diagnoses and the bases for their occurrence are unknown. To better understand these aspects of allograft dysfunction, the purported pathogenic mechanisms of classical autoimmune hepatitis were reviewed and extrapolated to recurrent and de novo disease after transplantation. Loss of self-tolerance may relate to defects in the negative selection of autoreactive immunocytes and the clonal expansion of promiscuous lymphocytes that are cross-reactive to homologous antigens (molecular mimicry). Repopulation of the allograft with recipient antigen-presenting cells and the presence of primed promiscuous cytotoxic T cells within the recipient are likely factors for recurrent disease. Targets may be the same peptides that triggered the original disease, donor-derived class II antigens of the major histocompatibility complex, or homologous antigens associated with unidentified hepatotrophic viruses. De novo disease is probably due to similar mechanisms, but its predilection for children suggests that thymic dysfunction associated with cyclosporine treatment may be a factor. Corticosteroid therapy is effective in each condition. In conclusion, recurrent and de novo autoimmune hepatitis after transplantation are examples of self-intolerance. The mechanisms that perturb immunologic homeostasis in this human model of the classical disease must be studied more rigorously.

Diagnostic issues in liver transplantation pathology

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

Response to steroids in de novo autoimmune hepatitis after liver transplantation

Graft dysfunction associated with autoimmune phenomena has been recently described in liver transplant recipients without previous autoimmune disease. However, the natural history, diagnostic criteria, and definitive therapeutic approach of de novo autoimmune hepatitis (de novo AIH) are poorly understood. We report 12 cases of de novo AIH 27.9 +/- 24.5 months after liver transplantation: the outcome of 7 patients treated with steroids is compared with a group of 5 nontreated patients. Nontreated patients lost the graft after 5.8 +/- 2.6 months from de novo AIH onset. All treated patients were alive after 48.4 +/- 14 (29-65) months from de novo AIH onset, and none of them lost the graft. However, 5 patients relapsed in relation to steroid tapering. All patients presented an atypical antiliver/kidney cytosolic autoantibody, associated to classical autoantibodies in 10 cases. Histological study showed several degrees of lobular necrosis and inflammatory infiltrate. HLA antigen frequencies and matching were compared with 2 control groups (16 orthotopic liver transplantation [LTX] patients without de novo AIH and 929 healthy blood donors); de novo AIH patients showed a higher prevalence of HLA-DR3 (54.5% vs. 25.9%, P =.04) than healthy controls, which was not observed in LTX patients without de novo AIH. In conclusion, this new disease should be included in the differential diagnosis of unexplained graft dysfunction. In addition, treatment with steroids results in a dramatically improved outcome. However, maintenance therapy is usually required.