Reply to: "Actin-specific smooth muscle antibodies bridge adult and juvenile autoimmune hepatitis diagnosis".

Autoimmune Liver Disease in Three Children with Sickle Cell Disease

Autoimmune hepatitis: review of histologic features included in the simplified criteria proposed by the international autoimmune hepatitis group and proposal for new histologic criteria

The revised score of the International Autoimmune Hepatitis Group (R-IAIHG) and the simplified criteria (SC) are used for diagnosis of autoimmune hepatitis (AIH). Our aim is to evaluate the performance of these classifications to differentiate AIH from other autoimmune liver diseases. The frequency of diagnosis of definite AIH was similar both by the R-IAIHG and the SC systems (41% versus 40%), whereas diagnosis of probable AIH was made more commonly by the R-IAIHG than the SC (59% versus 29%), and 23 patients that have been graded as definite (n = 7) or probable (n = 16) AIH by the R-IAIHG had non-diagnostic scores by the SC system. The scoring systems rendered concordant diagnosis of definite (n = 15) and probable (n = 13) AIH in 28/73 patients (38%). Discordant diagnoses of AIH were rendered in 45/73 patients (62%). The R-IAIHG exhibited a sensitivity of 95%, specificity of 90%, and positive predictive value (PPV) and negative predictive value (NPV) of 93% for both. On the other hand, the SC had a lower sensitivity (65%) but a higher specificity (100%), PPV of 100%, and NPV of 68%. In conclusion, both international scoring systems diagnosed the same number of cases as definite AIH. The R-IAIHG showed a higher sensitivity in diagnosing AIH, whereas the SC showed a higher specificity. SC are easier to apply at the bedside and exclude more patients that could have a different etiology.

Diagnosing AIH in Children: Is the International AIH Group Scoring System Useful?Ebbeson RL, Schreiber RA. Clin Gastroenterol Hepatol 2004;2:935-940. Summary: In 1992, the International Autoimmune Hepatitis Group developed a scoring system for adults to differentiate autoimmune hepatitis from other causes of chronic liver disease (1). In the present study, Ebbeson and Schreiber investigated the possibility that a modification of this system could be applied to children both to diagnose autoimmune hepatitis and to distinguish them from children with biliary features or “overlap syndrome.” The authors retrospectively applied the International Autoimmune Hepatitis Group scoring system to 28 children with a diagnosis of chronic immune liver disease (21 with autoimmune hepatitis, 4 with isolated sclerosing cholangitis and 3 with overlap syndrome). A diagnosis of overlap syndrome was made when the patient had not only the clinical and histologic findings of autoimmune hepatitis but also findings of sclerosing cholangitis on cholangiography. The authors found that 18 of 21 patients with autoimmune hepatitis scored were identified as “definite” autoimmune hepatitis (>15 points) and the other three as “probable” (10 to 15 points). Four patients with primary sclerosing cholangitis were identified as “other” (<10 points) and three with overlap syndrome were identified as “definite” autoimmune hepatitis. It was noted that removing the two points allocated for <25 g daily alcohol intake did not alter the classification of the patients either before or after treatment in any way. The authors state that in growing children, gamma-glutamyl transaminase is a more specific marker of cholestatic liver disease than alkaline phosphatase, as the latter may reflect bone activity. When gamma-glutamyl transaminase was substituted for alkaline phosphatase in the item of the scoring system comparing the ratio of alkaline phosphatase to aspartate aminotransferase, five patients who scored “definite” for autoimmune hepatitis by the original system were reclassified as “probable” autoimmune hepatitis. Four of these five patients had incomplete response to treatment. Of the five reclassified as “probable” autoimmune hepatitis, two had sclerosing cholangitis confirmed by endoscopic retrograde cholangiopancreatography and a diagnosis of overlap syndrome, one had biliary changes on ultrasound and was awaiting cholangiography, one had inconclusive changes on endoscopic retrograde cholangiopancreatography because of incomplete filling of the biliary tree (follow-up liver biopsy showed biliary changes) and the last did not have cholangiographic studies performed (young age and complete response to treatment). Ebbeson and Schreiber concluded this paper by endorsing the modified International Autoimmune Hepatitis Group scoring system in the diagnosis of autoimmune hepatitis in children. Comments: The scoring system for autoimmune hepatitis studied in this paper was first proposed in 1992 by an international panel of experts (the International Autoimmune Hepatitis Group) (1). The need for clear diagnostic criteria for what was then known as chronic active hepatitis was heightened by the identification of the hepatitis C virus in 1989 (2). The scoring system was constructed on clinical and biochemical parameters characteristic of autoimmune hepatitis. In the original scoring system, points were assigned for “minimal” parameters of (i) female gender, (ii) hepatitic biochemical profile, (iii) hyperglobulinemia, (iv) increased autoantibody titers, (v) absence of viral hepatitis markers, (vi) family history of autoimmunity and (vii) absence of drug or alcohol ingestion. Additional parameters included (i) characteristic histology, (ii) genetic factors and (iii) response to immunosuppressive therapy. A pretreatment aggregate score of >15 was designated “definite” and scores between 10-15 “probable” autoimmune hepatitis. Post-treatment scores >17 were designated “definite” and scores of 12 to 17 “probable” autoimmune hepatitis, respectively (1). Several groups (2,3) have attempted to validate the International Autoimmune Hepatitis Group scoring system. In one pediatric study, when the original scoring system was applied retrospectively to 52 children with a diagnosis of untreated autoimmune hepatitis, 35 (67%) scored as definite autoimmune hepatitis and the remaining 17 as probable autoimmune hepatitis (4). While on treatment, 10 more patients fulfilled criteria for definite autoimmune hepatitis. As 86% of 52 children could be designated as definite autoimmune hepatitis and the remaining probable autoimmune hepatitis, the authors felt that the scoring system could be applied to the pediatric age group. The diagnostic criteria were reviewed and modified in 1999 (5). The principal changes related to the alkaline phosphatase:aspartate aminotransferase ratio, drug history, liver histology and response to treatment. To increase weighting against biliary disease, the negative score for anti-mitochondrial antibody epositivity was increased from −2 to −4 and the score for histologic evidence of bile duct damage was increased from −1 to −3. Because interface hepatitis is particularly characteristic of autoimmune hepatitis, a score of −5 was allocated to those who did not have this feature. As classic autoimmune hepatitis does not always respond to treatment, it was decided to remove points for “no response,” “treatment failure” or “partial response.” It was also noted that because low titers of antibodies may be significant in children, the previous specification for autoantibody titers was not a significant factor in childhood scoring. In consideration of the importance of correct identification of autoantibodies both in diagnosis and in monitoring disease activity, a committee was formed to work towards standardization of methodology and data collection on the sensitivity and specificity of various assay systems (6). The overlap between sclerosing cholangitis and autoimmune hepatitis has been a matter of controversy, and several groups have used the scoring system to better delineate this group of patients. Boberg et al. used the original scoring system to evaluate 114 primary sclerosing cholangitis patients in Norway and reported that two primary sclerosing cholangitis patients (1.8%) fulfilled criteria for “definite” and 38 (33%) fulfilled criteria for “probable” autoimmune hepatitis (7). After the criteria were modified, the modified scoring system was applied to the same group of primary sclerosing cholangitis patients. Reanalysis showed that of the 38 (33.3%) originally classified as probable, only 10 (8.8%) remained in this category, giving an overall specificity of 89.5% for exclusion of autoimmune hepatitis in this group of primary sclerosing cholangitis patients (1). Chazouilleres and colleagues evaluated four groups (7-10) using the scoring system and reported that the modified system was more specific in diagnosing the overlap syndrome (11). In pediatrics, Gregorio et al. investigated whether sclerosing cholangitis with an autoimmune serology and autoimmune hepatitis are distinct entities (12). Overall, 25 (89%) patients with autoimmune hepatitis and 15 of 23 (65%) with autoimmune sclerosing cholangitis would have been diagnosed as definite autoimmune hepatitis post-treatment (P = 0.041) by using the scoring criteria (12). The difference in the adult studies and the pediatric study could be explained by the inclusion criteria. In the adult studies, any patient with cholangiographic changes of sclerosing cholangitis was included, whereas in the pediatric study only those with both autoantibodies and characteristic changes on cholangiography were included. The International Autoimmune Hepatitis Group scoring system is not used commonly in pediatric clinical practice. The study of Ebbeson and Schreiber may persuade some readers to do so in children with a complicated presentation. The studies discussed above demonstrate that the International Autoimmune Hepatitis Group scoring system can effectively separate autoimmune hepatitis from isolated sclerosing cholangitis while highlighting the difficulty in identifying those with overlap between autoimmune hepatitis and sclerosing cholangitis. The current study, though retrospective and with small sample size, is novel in that by substituting gamma-glutamyl transferase for alkaline phosphatase, Ebbeson and Schreiber have tried to identify the overlap group. The basis for making this change appears appropriate given that alkaline phosphatase is affected by bone activity especially in a growing child (13). In routine clinical practice, the majority of children with autoimmune hepatitis are likely to be assigned to the “definite” group. Those who are designated as ‘probable’™ are more likely to have biliary features and comprise the overlap group. Problems with sedation for imaging studies in small children and the technical expertise required to perform endoscopic retrograde cholangiopancreatography have limited the use of this diagnostic test. The scoring system may help limit biliary imaging studies to those with overlap features whose scores indicate “probable” autoimmune hepatitis. This group of children might benefit from addition of ursodeoxycholic acid to the immunosuppressive regimen. The usefulness of the International Autoimmune Hepatitis Group scoring system has also been recently illustrated by Bridoux-Henno et al. in diagnosing autoimmune hepatitis when the sole antibody present was anti-liver cytosol antibody (14). In conclusion, the international scoring system has a place in confirming the diagnosis of autoimmune hepatitis in cases with a complicated clinical presentation. The scoring system also provides a means of comparison between different centers in different parts of the world. Nanda Kerkar Assistant Professor Division of Pediatric Hepatology Recanati Miller Transplant Institute, Mount Sinai Medical Center New York, New York

Liver autoimmune serology: a consensus statement from the committee for autoimmune serology of the International Autoimmune Hepatitis Group

THU-192 - Pregnancy and birth outcomes in a Danish nationwide cohort of women with autoimmune hepatitis and matched population controls

Many patients with autoimmune hepatitis are women of fertile age. Some concerns of these patients are related to pregnancy. To conduct a nationwide study on risk of miscarriage, birth rate, and birth outcomes in women with autoimmune hepatitis. From Danish healthcare registries, 1994-2015, we identified 179 births in 103 women with autoimmune hepatitis, 70 of which were first-time singleton births, and 1623 births in 1051 age-matched women (population controls), 662 of which were first-time singleton births. We calculated the risk of miscarriage and the birth rate after autoimmune hepatitis diagnosis in women with autoimmune hepatitis and controls. We used logistic regression to compare the odds of adverse birth outcomes (preterm birth, small for gestational age, congenital malformations and stillbirth) between women with autoimmune hepatitis and controls, adjusting for maternal age and smoking habits. The risk of miscarriage was similar in women with autoimmune hepatitis and controls: risk ratio 1.17 (95% confidence interval 0.81-1.68). The first-time birth rate, including singleton and multiple births, per 1000 person-years in women with autoimmune hepatitis was 37 (95% confidence interval 29-46), in controls 32 (95% confidence interval 30-35). Age at first-births was similar in women with autoimmune hepatitis and controls. Women with autoimmune hepatitis had an increased risk of preterm birth (adjusted odds ratio 3.19, 95% confidence interval 1.53-6.64) and small for gestational age babies (adjusted odds ratio = 3.20, 95% confidence interval 0.33-31.29), but not of congenital malformations (adjusted odds ratio = 1.27, 95% confidence interval 0.48-3.34) or stillbirth. Birth outcomes did not differ in autoimmune hepatitis patients on or off immunosuppression, and with or without cirrhosis. In Danish women with autoimmune hepatitis, fertility was unaffected. They had an increased risk of preterm birth and small for gestational age children, but not of congenital malformations or stillbirth.

Family occurrence of autoimmune hepatitis: A Danish nationwide registry-based cohort study

Aim: Autoimmune hepatitis (AIH) is a chronic disease observed especially in women. The International Autoimmune Hepatitis Group recommends scoring systems for diagnosis using clinical and laboratory data. All scoring systems gave points to autoantibodies as anti-nuclear antibody (ANA) and anti-smooth muscle antibody (SMA) positivity. This study investigates the impact of the co-positivity of the ANA and SMA antibodies on the autoimmune hepatitis diagnosis. Material and Method: We monitored 78 autoimmune liver disease (autoimmune hepatitis, AIH) suspected patients with positive SMA antibody and then further tested for ANA between 2014 and2021. SMA test was screened at 1/40 and 1/100 titers and patients who were positive were taken to further dilution. The ANA test was screened at a titer of 1/40 and 1/160, a positive result was found to be repeated with advanced dilutions. All patients’ autoantibody scores of simplified AIH diagnostic system were calculated. Results: Seventy eight patients with positive SMA antibodies screened for ANA test with 1/40 and 1/160 titer, only 2 patients was found to be negative. The most frequently observed ANA pattern is cytoplasmic linear fibrils (68% ). The 95% ANA positive results was examined at a screening titer of 1/160. The 95% SMA positive results was found at a screening titer of 1/100. The autoantibody scores of 76 patients were +2, patient’s scores were +1. Conclusion: SMA antibody positivity is accompanied by a high rate of ANA antibody positivity but the co-positivity didn’t effect diagnostic score systems. On the other the co-positivity could be a sign of another associated autoimmune diseases.

Background: Autoimmune hepatitis (AIH) is a hepatocyte injury characterized by a dis-regulated immune system, inflammation of the liver with interface hepatitis, serum antibodies and elevated gamma-globulins. Currently, it exists 2 mainly types on autoimmune hepatitis, based on the presentation of their autoantibodies: type 1 and 2. Type 1 is the one of interest in this review. Autoimmune hepatitis type 1 is an indolent inflammatory disease mediated by abnormal autoimmune reaction, commonly seeing in women (4:1), with no preference of age, however typically present in 4th and 6th decade’s individuals, and a good response to immunosuppressive therapy. Autoimmune hepatitis is known to present not specific symptoms which can go from inexistent to fulminant or exacerbate presentation. The incidence of autoimmune hepatitis in western country is 1/5000 - 1/10,000. Although the detection rate of AIH increasing, especially in China, autoimmune hepatitis diagnosis and treatment remain challenging. Most AIH case do not present pathognomonic biomarkers, however the diagnostic has to considerate other features, which had been codified into validated diagnosis scoring systems. Regarding the treatment, based on prior literature autoimmune hepatitis is mostly sensitive to prednisone or azathioprine, however the use of other immunosuppressive agent or event their combination had offer distinct advantages. Autoimmune hepatitis presents a great life threatening disorder especially because of the delay in the early stage on the disease, the not specific presentations, and the large overlap syndrome associate with it. A deep knowledge in its identification, specific diagnostic criteria, and its therapeutic strategy is much needed. Conclusion: Autoimmune hepatitis is a systemic disease that is difficult to recognize because of its variable clinical presentation and histological features that are not strictly specific. Several new autoantibodies as well as recently simplified diagnostic criteria may allow the primary care physician to progress in the diagnostic process. This is all the more important as undiagnosed and therefore untreated autoimmune hepatitis has a poor prognosis and immunosuppressive treatment leads to remission in a large majority of cases.

Introduction Immunoserologic investigation is of clinical use in the discrimination of liver disease of autoimmune aetiology from alternate causes. We sought to investigate the diagnostic utility of immune serology in patients investigated for liver disease. Method We analysed the immunoprofile of patients investigated for liver disease at a tertiary centre between 2001 and 2017. We compared Results for patients clinically coded with a diagnosis of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), or primary sclerosing cholangitis (PSC) against those without, amongst patients investigated by our liver services. Overlap features (o/l) were included if clinically documented. Results We evaluated Results from 2874 patients. Patients with AIH (n=556; incl. o/l (19.3%)) were predominantly female (3 F: 1 M), with a bimodal age distribution at presentation (≈18, 62 years). Antinuclear (ANA) and smooth muscle antibodies (SMA) were both sensitive (92.3%, 86.6% respectively) for a diagnosis of AIH, but poorly specific (23.6%, 27.2%). Amongst patients with T1AIH, 39 patients had antibodies to soluble liver antigen (SLA). Of these, 36 (92%) had concordance to Ro-52 antibodies. 2.3% of patients with AIH had T2AIH, defined by antibodies to liver-kidney microsome-1 (LKM); of the 13 patients, 4 had SMA and 8 have ANA reactivity. Patients with PBC (n=527; incl. o/l (18.3%)) were primarily female (9 F: 1 M), and in their 6th decade (mean=56 years). Anti-mitochondrial antibody (AMA) testing was both sensitive (70.6%) and specific (91.2%). In patients who were AMA negative at testing, anti-glycoprotein 210 (gp210) (sens 40.7%, spec 95%) and anti-SP100 (sens 40.3%, spec 96.3%) proved useful diagnostic adjuncts. Patients with PSC (n=291; incl. o/l (10.1%)) were predominantly male (3 M: 2 F) with a bimodal age distribution at presentation (≈25, 58 years). Perinuclear anti neutrophil cytoplasmic antibody was seemingly specific for PSC (93.9%), as compared to non-autoimmune liver patients, and found in 23.3% of patients. To differentiate between PSC and AIH, anti-SLA, -LC1, -Ro-52, ds-DNA and f-actin all had a PPV >95% for AIH;>85% in patients who were negative for SMA. Similarly, to distinguish PBC from PSC, AMA, anti Ro-52, -gp210 and -SP100 all have a PPV >90% for PBC; this was also true for anti-Ro52 and -SP100 in patients who were AMA-negative. Conclusion The optimal use of immunoserology requires careful evaluation of test parameters in the population served by a liver disease programme.

Reassessement of the histological features of autoimmune hepatitis.

De novo autoimmune hepatitis after liver transplantation

See article on page 95 Autoimmune diseases aggregate in the one patient and/or family members: such clustering was an early defining marker for an autoimmune disease. 1 Examples are provided by the clustering of autoimmune thyroiditis with gastritis and insulitis (diabetes), Sjögren's disease with rheumatoid arthritis, primary biliary cirrhosis (PBC) with the CREST syndrome, and autoimmune hepatitis (AIH) with haemolytic blood diseases, thyroiditis, ulcerative colitis and others. 2 These clustered diseases are independent entities, but there is an underlying pathogenetic determinant in common: this is a defect in the establishment and maintenance of self tolerance, that is, autoimmunity and/or an aberrant inflammatory response. The independent existence within a cluster of two or even more autoimmune or inflammatory diseases poses less of a problem than when there is coexpression of two usually distinct disease entities within a single organ, in which case the term 'overlap' is used. One early example was the overlap of Hashimoto's thyroiditis and thyrotoxicosis, dubbed 'Hashitoxicosis'. In the case of the liver, several such coexistences or overlaps are recognized, and there is much uncertainty as to how they should be defined, named and classified. As background, Table 1 summarizes features of the known or suspected autoimmune diseases of the liver. Historically, in 1969, there was a viewpoint that chronic active hepatitis (the predecessor of autoimmune hepatitis of today) and PBC could be linked in the unified concept of autoimmune liver disease. 4 An early study revealed that in 11% of cases of chronic active hepatitis (CAH) there was a positive test for antimitochondrial antibody (AMA) together with clinical and histological features of both CAH and PBC, 5 and MacSween, in a personal experience covering both diseases, noted that histopathologIcal differentiation was difficult in some 15% of cases. 6 The concept of 'overlap' or 'mixed form' disease, with features of both CAH and PBC, was formally introduced in 1977 by Klöppel et al.7 In 1980, the CAH–PBC overlap syndrome was given a serological basis, together with yet another descriptive term of chronic cholestatic hepatitis by Berg et al. who reported 17 cases of which all were positive for auto-antibodies usually associated with CAH, and also for the AMA typical of PBC, together with a new antimitochondrial reactant designated M4. 8 In 1992, Davis et al. reported on the CAH–PBC overlap syndrome, citing 11 cases that were clinically typical, although not studied for the auto-antibodies characteristic of AIH: their cases were seropositive for anti-M2 but an anti-M4 type of reactivity was not demonstrable. The report of the International Autoimmune Hepatitis Group (IAIHG), 10 convened in Brighton in 1992 to generate diagnostic criteria for AIH, stated that the overlap of AIH and PBC was well recognized, but such cases comprised only a 'small proportion' of the total case-load in most centres and, hence, elected to defer preparation of diagnostic criteria. Intrafamilial occurrence of single or multiple autoimmune diseases is well recognized. Among the liver diseases, this applies more to PBC 11 than to AIH despite the weaker human leucocyte antigen (HLA) associations in PBC than AIH. Hence, it is surprising that reports are so scarce on the intrafamilial overlap of AIH with PBC. There is one published example, that of two elderly sisters of whom one had PBC and the other had AIH with concurrent myxoedema, with various tissue auto-antibodies being demonstrable among the relatives. 12 The perceived frequency of overlap may well depend on the standpoint of the observer, whether from a primary interest in AIH or PBC. From an AIH standpoint, Kenny et al. described 187 Mayo Clinic patients with severe, chronic, active (presumably autoimmune) hepatitis among whom they identified 37 (20%) with a positive test for AMA. 13 These 37 patients also had higher serum levels of alkaline phosphatase (ALP) and an increased frequency in liver biopsies of stainable hepatic copper (features suggestive of PBC), but 91% of the 37 cases could be allocated to a CAH category; only four (2.1%) of the 37 had titres of AMA > 1/40, and only two (1.1%) had histological features typical of PBC. From a PBC standpoint, Chazouillères et al. assessed clinical features and response to therapy in 12 patients (10 females, two males, median age 50 years), selected from 130 consecutive patients with a primary diagnosis of PBC, and for whom diagnostic criteria for both diseases were fulfilled. 14 For 11, there were histological features of both diseases at the time of clinical presentation and, for one, an initial presentation of 'pure' PBC was followed by a typical flare of AIH. The authors concluded that the frequency of the AIH–PBC overlap syndrome among patients with PBC was 9%, there was usually a coexistence ab initio of both diseases, and that treatment should be directed to both diseases (i.e. a combination of ursodeoxycholic acid (UDCA) and a corticosteroid drug). In a further Mayo Clinic study, Czaja analysed overlap or 'variant' syndromes based on 223 patients with primary diagnoses of AIH (162), PBC (37) or primary sclerosing cholangitis (PSC; 26). 15 Of the 162 cases with AIH, there were eight (5%) with coexisting PBC as judged simply by a positive test for AMA, and of 37 with PBC there were seven (19%) with coexisting AIH as judged by the IAIHG scoring system. 10 Detailed histological or immunoserological comparisons for overlap cases in the various groups were not given in any of the studies cited above. The second report from the IAIHG, prepared in 1999, discussed the overlap of AIH with various cholestatic syndromes, and concluded that 'all of these disparate disorders (if, indeed, they are distinct) are still in need of a universally agreed definition and classification', and suggested that advice be obtained from an international working party. 16 Meanwhile overlaps could be dealt with either by nominating the independent occurrence of two diseases, given that criteria for both are fulfilled, or by defining criteria for each overlap syndrome as such. The latter seems preferable, given a likely shared immunopathological basis for both conditions, and the known tendency for escalation among autoimmune diseases. More detailed serological investigation should help. Apart from the conventional auto-antibodies described above, diagnostic pointers may be provided by the perinuclear type of anti-neutrophil cytoplasmic antibody (pANCA) which occurs frequently in AIH 16,17 but seldom in PBC, and perhaps also by other AIH-related auto-antibodies (e.g. to soluble liver antigen (anti-SLA), or to liver cytosol antigen type 1 (anti-LC1). 18 The entity known as autoimmune cholangitis/cholangiopathy (AIC) has itself been thought to represent an overlap disease. This was first described in 1987 as a chronic obstructive intrahepatic inflammatory cholangitis in which the biochemical features were those of PBC, but the serological features differed in that the test for AMA was negative and that for antinuclear antibody (ANA) was positive, and there was a response to corticosteroid drugs. 19 This entity subsequently attracted a number of case studies and commentaries, recently summarized and reviewed in a conjoint study on 24 cases of AIC from Japanese colleagues and this laboratory. 20 This study compared clinical, biochemical, histological and serological features of AIC with those of AIH and PBC. The results refuted the idea that AIC is a cholangiopathic variant of AIH and indicated that so-called AMA-negative PBC 21 may be too simplistic, yet were consistent with the current viewpoint that AIC aligns closely with PBC, clinically and histologically. 20 Also, in AIC, the expressions of ANA by immunofluorescence and immunoblot are those that occur in the 50% of ANA-positive cases of PBC, namely auto-antibodies to centromere, the Sp-100 antigen, and anti-nuclear pore proteins including gp210, its aminoterminal fragment and/or p62 nucleoporin. 20 Studies by immunoblot on our 24 cases of AIC disclosed that, whereas AMA was negative by immunofluorescence, there was often serological reactivity demonstrable by immunoblot with components of the M2 autoantigen family, the E2 subunits of the 2-oxo-acid dehydrogenase complex (2-OADC) enzymes: this is in accord with positivity by immunoblot in cases of AMA-negative PBC. 22 Thus, we concluded that AIC is part of PBC but, by reason of the distinctive serological features, it should be regarded as a nosological entity, at least until the actual pathogenesis of PBC itself is revealed. 20 The above having been said, might AIC in fact coexist with AIH? Some reports indicate this to be the case. Ben-Ari et al. recorded the shared histological features of periportal and introlobular inflammation and bile duct damage, and biochemical remission with prednisolone, 23 and Czaja stated that 11 of 162 cases (17%) of AIH had features of AIC. 15 Li and co-authors, in this issue of the Journal, report the case of a 42-year-old Chinese female who expressed 'characteristic features of both diseases'. 24 The biochemical features included highly raised serum levels of ALP and γ-glutamyl transpeptidase, increased serum cholesterol and normal immunoglobulin (Ig)G but an increased IgM: all are more suggestive of PBC or AIC than of AIH. Serologically, AMA was negative but immunoblot to confirm non-reactivity to 2-OADC-E2 enzymes was not performed. The test for smooth muscle antibody (SMA) was negative and ANA was positive, but the specificity of the ANA was that of anticentromere, which is one of the particular trio of ANA reactivities (see above) that mark ANA-positive cases of PBC. Histologically, there was an AIH-PBC overlap, but the presence of periductular granulomas points more particularly to PBC. There was an initial response to prednisolone, and prednisolone dependence, in addition to benefit from UDCA. Thus, the case of Li et al.24 shows sufficient features to justify being styled an overlap, but the bias seems much more towards AIC than AIH. Autoimmune hepatitis–primary sclerosing cholangitis is an interesting overlap because PSC can be questioned as a 'qualified' autoimmune disease. Taking data from a recent review, 25 the sex bias is towards men (70%); the usual accompanying disease, ulcerative colitis, which coexists in some 75% of cases, is itself questionable as an autoimmune expression; the characteristic histopathology with biliary periductular 'onion-skin' fibrosis is not typical for an autoimmune process; there is neither a disease-specific nor tissue-specific auto-antigen; there is a muted, if any, response to corticosteroids or immunosuppressive drugs; and, finally, the miscellaneous immune aberrations that are described 25,26 cannot be readily assembled into a concept of autoimmune pathogenesis. The evidence for autoimmunity that does exist for PSC comprises a high frequency of pANCA 27 and an association with HLA alleles that includes the autoimmune haplotype HLA B8,DR3, and DRw52a. 28 Thus, PSC may well be viewed as immunologically mediated but is, like its partner disease ulcerative colitis, the outcome of an aberrant immune response directed primarily to intestinal luminal antigens, presumably of bacterial origin. The frequency of overlap of AIH and PSC is hard to estimate. Roberts et al. from the Mayo Clinic reported eight patients (four males, four females) fulfilling criteria for both diseases, with five developing PSC after the clinical onset of AIH, seven having an accompanying ulcerative colitis and all giving a poorer response to corticosteroid therapy. 29 The analysis of overlaps by Czaja included 26 cases of PSC, with a positive IAIHG score for AIH in as many as 14 (54%) of the cases; 15 this may reflect the recognized low specificity of the scoring system in the setting of cholestatic syndromes. 16 Boberg et al. reported on 114 adults with PSC among whom criteria for AIH were met by 40, two definite and 38 probable; 30 however, using a revised scoring system, only 10 of the 38 retained a score for probable AIH. 16 Although cases with the primary diagnosis of AIH seldom show concordant features of PSC, an obstructive pattern of tests of liver function may develop in the later stages of AIH. McNair et al., in 1998, commented on the scarcity of overlap between AIH and PSC in their report of five examples, claiming that of cases reported in the literature, only 11 were sufficiently well documented for comparison with their five cases. 31 Of these five, four were male (a PSC bias), four had a marked elevation of ALP (a PSC bias), all had hyperglobulinaemia (an AIH bias), and two had ulcerative colitis. Immunoserological tests (performed in the hospital laboratory) revealed that ANA was positive in two (titres 1:2560 and 1:320, pattern not specified), SMA in four (an AIH bias) and pANCA in all five. Radiography showed strictured ducts with beading (a PSC bias); histology showed changes of pericholangitis in three cases; and there was a response to prednisolone in all cases (an AIH bias). While the frequency of overlap of AIH and PSC is low in adults, this may not pertain in children, according to the description by Wilschanski et al.32 although this overlap was not emphasized in the report by Gregorio et al. on 47 cases of AIH in children. 33 Roberts commented on the difficulties in distinguishing between the two conditions on clinical, histological or even serological data and called for further studies to elucidate whether the overlap represented a single disease process with combined features of AIH and PSC, or the concurrence of two 'mechanistically distinct' but clinically similar entities. 34 There can be apparent overlaps between AIH and other diseases within the immunoinflammatory spectrum of histological CAH. First, in reference to chronic viral hepatitis, an autoimmune overlay appears to be much more frequent in infection with hepatitis C than hepatitis B. In fact, in chronic hepatitis C infection, there are various immune aberrations including the mixed cryoglobulinaemia syndrome which is due to deposition of immune complexes that include components of HCV, as well as autoimmune serological expressions similar to those seen in either type 1, or type 2, AIH. These are probably provoked by virus infection in the liver. 35 Wilsonian CAH may resemble the necroinflammatory features of AIH histologically 36 but, according to the literature review of Milkiewicz et al. (submitted for publication, 1999), autoimmune serological expressions are rare. Similarly, CAH in alcoholic patients is more a histological than a serological diagnosis. 37 Perhaps in these various examples, autoimmunization is consequential to hepatocellular damage from a primary cause but serves as an additional pathogenetic component. There may be insights to be gained from immune-mediated liver diseases that do not overlap. One example is type 2 AIH, for which reports of overlap with other diseases are lacking, even with the type 1 variant. Another claimed example of non-overlap among inflammatory liver diseases is PBC and PSC. 26 There remain substantial gaps in knowledge on how autoimmune diseases are initiated and sustained: a provisional outline is presented in Table 2. Consideration of overlap syndromes has conceptional connotations for at least three areas. First, for nosologists, overlap syndromes pose uncertainty whether there should be separate nomination of the two diseases contributing to the overlap, or whether the overlap should be defined as a single entity. If the latter were the case, nomenclature groups will need to develop appropriate criteria, equivalent to those established or in de facto use for AIH, PBC and PSC. A recognized handicap is that a defining serological marker (or markers) for the common type 1 AIH, equivalent to the anti-CY-P450-2D6 that characterizes type 2 AIH, is still not yet available. For the most-discussed of the overlaps, AIH and PBC, it seems that PBC is the more dominant of the partners onto which features of AIH become added, as judged from observations that this overlap is more frequent from the PBC perspective than the AIH perspective. 13,14 Second, for therapists, medication appropriate to each partner of the overlap should be prescribed. This applies particularly to AIH–PBC and AIH–PSC overlaps, and to AIC, in which a combination of immunosuppression (prednisolone, azathioprine) and UDCA would be logical, and preliminary indications of benefit are already available. 24,38 Third, for theorists, the study of overlaps may be informative for an understanding of the general pathogenesis of autoimmune liver diseases (see Table 2). The recognized genetic elements in autoimmune disease are estimated to comprise 30–60% of the overall risk and, of this, genes of the major histocompatibility complex (AIH) are the main contributor. These HLA alleles, and genes that influence the specificity of B and T cell antigen receptors, determine the direction of responses to specific auto-antigenic molecules and, thus, confer disease individuality. Other immune-response genes will have a general influence, either by effects on tolerogenesis overall, or on apoptosis, on the balance of cytokines produced by T helper -l or -2 cells, or on expression of other inflammatory mediators. The combined effects of such general immune response genes would explain autoimmune escalation in which there is cumulative organ or tissue involvement to produce a complex multisystem disease phenotype. The process of epitope-spreading is described as either intramolecular, which implies spread to different epitopes on the one auto-antigen, or intermolecular, which implies spread to different auto-antigens in the one cell or tissue. 39 This process would be facilitated by a permissive genotype and an inflammatory milieu and ambient cytokines, and also could contribute to disease overlaps and diversification and serological responses to multiple auto-antigens. In the context of genetics, Lohse et al. suggest, as indicated above, that the PBC–AIH overlap syndrome is, in fact, primarily PBC with hepatic expressions conferred by HLA susceptibility alleles B8, DR3 or DR4. 40 In conclusion, overlap syndromes, are a reality among the hepatic autoimmune diseases. These are a nuisance for nosologists, but careful study of clinical, laboratory and particularly the serological features of these syndromes and their outcome, should provide interesting insights for autoimmunity. Moreover, their recognition should prompt the use of novel combined therapies. A clarion call can, therefore, be made for increased international collaborations among hepatologists, including exchanges of histological material, serum samples and DNA for immunogenetic analysis, as no single clinic would have sufficient cases or access to sufficient technological resources, to provide a solution to these 'double disease' occurrences. The outcome would be an overlap of benefits for both hepatology and clinical immunology.

Clinical features of antinuclear antibodies‐negative type 1 autoimmune hepatitis