Autoimmune hepatitis/primary sclerosing cholangitis overlap syndrome in adults: report of three cases

Overlap syndromes are cases of liver diseases that share clinical, serological, histological and radiological criteria of autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC). No definitions have been fully established and therefore there is no solid evidence on the diagnosis and treatment. This article presents the cases of three adult patients with overlapping features of AIH and PSC. Orthotopic liver transplantation was considered the best therapeutic alternative due to advanced disease progression in one patient, while medical treatment was provided in the remaining two patients.     

自身免疫性肝病活检组织病理学特征分析109例

目的:分析比较自身免疫性肝炎(AIH)、原发性胆汁性肝硬化(PBC)、原发性硬化性胆管炎(PSC)及其重叠综合征的组织病理学变化,提高对自身免疫性肝病(AILD)的认识.方法:对27例AIH、67例PBC、4例PSC、1例AIH-PSC重叠综合征和10例AIH-PBC重叠综合征患者的肝穿组织病理资料进行回顾性分析.结果:AILD患者多发于中年女性(73.3%),肝组织病理变化以界面性肝炎为主(77.7%),在重度患者则出现重度界面性肝炎、桥样坏死等.PBC患者早期(Ⅰ、Ⅱ)占28.3%,而晚期(Ⅲ、Ⅳ)占71.7%,肝组织病理变化以小胆管减少甚至消失为主(62.6%).AIH-PBC重叠综合征患者并非罕见,他的肝组织病理学具有AIH和PBC的双重特征.结论:AILD是非病毒性肝病的重要组成部分,其诊断需综合临床表现、生化、免疫指标和组织学变化.     

Clinicopathological study of primary biliary cirrhosis with interface hepatitis compared to autoimmune hepatitis

AIM:To investigate histological and immunohistochemical differences in hepatitis between autoimmune hepatitis(AIH)and primary biliary cirrhosis(PBC)with AIH features.METHODS:Liver needle biopsies of 41 PBC with AIH features and 43 AIH patients were examined.The activity of periportal and lobular inflammation was scored0(none or minimal activity)to 4(severe),and the degree of hepatitic rosette formation and emperipolesis was semiquantatively scored 0-3.The infiltration of mononuclear cells positive for CD20,CD38,CD3,CD4,and CD8 and positive for immunoglobulins(IgG,IgM,and IgA)at the periportal areas(interface hepatitis)and in the hepatic lobules(lobular hepatitis)were semiquantitatively scored in immunostained liver sections(score 0-6).Serum aspartate aminotransferase(AST),immunoglobulins,and autoantibodies at the time of liver biopsy were correlated with the histological and immunohistochemical scores of individual lesions.RESULTS:Lobular hepatitis,hepatitic rosette formation,and emperipolesis were more extensive and frequent in AIH than in PBC.CD3+,CD4+,and CD8+cell infiltration scores were higher in the hepatic lobules and at the interface in AIH but were also found in PBC.The degree of mononuclear cell infiltration correlated well with the degree of interface and lobular hepatitis in PBC,but to a lesser degree in AIH.CD20+cells were mainly found in the portal tracts and,occasionally,at the interface in both diseases.Elevated AST correlated well with the hepatocyte necroinflammation and mononuclear cell infiltration,specifically CD38+cells in PBC.No correlation existed between autoantibodies and inflammatory cell infiltration in PBC or AIH.While most AIH cases were IgG-predominant at the interface,PBC cases were divided into IgM-predominant,IgM/IgGequal,and IgG-predominant types,with the latter sharing several features with AIH.CONCLUSION:These results suggest that the hepatocellular injuries associated with interface and lobular hepatitis in AIH and PBC with interface hepatitis may not be identical.     

Development of autoimmune hepatitis in primary biliary cirrhosis.

AIM/BACKGROUND: Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown aetiology. Up to 10% of patients with typical features of PBC will have additional features of autoimmune hepatitis (AIH). A subset, however, have no such features but go on to develop a 'sequential' AIH overlap syndrome. Objectives: Describe our experience with eight patients who developed AIH after the diagnosis of PBC was made. METHODS: We reviewed the charts of all PBC patients over a 9-year period (from 1996 to 2005). Only PBC patients with no features of AIH were included. RESULTS: There were 1476 patients with PBC. Of these, eight patients developed features of AIH overlap syndrome based on biochemical and histological parameters. Treatment included prednisone and azathioprine for 24 or more months. The majority of patients remained on ursodeoxycholic acid (UDCA) throughout treatment. Response to therapy was defined by improvement in enzymes, and was rapid for all patients. One patient was able to discontinue treatment with prednisone and azathioprine, while seven have continued on therapy to date. CONCLUSIONS: A 'sequential' overlap syndrome of AIH with PBC can occur. Treatment with prednisone and azathioprine may lead to a rapid improvement in aminotransferase levels.     

Clinical and pathological characteristics of the autoimmune hepatitis and primary biliary cirrhosis overlap syndrome

BACKGROUND AND AIMS: The defining of the autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) overlap syndrome as a separate clinicopathological entity has been controversial and temporally and geographically subjective. METHODS: From 1979 until 2000, 227 patients diagnosed with AIH, PBC or the overlap thereof were treated. Cases with genuine AIH/PBC overlap syndrome were sorted out using close clinical follow up and serial liver biopsies. RESULTS: Of the 227 patients, 19 (8.4%) were diagnosed with the AIH/PBC overlap syndrome. They all cleared a score >10 for the diagnosis of AIH, and tested positive for antimitochondrial antibodies during their courses. Long-term follow up with frequent histological examinations, however, established the diagnosis of AIH/PBC overlap syndrome in only two (0.8%) patients. The most powerful factor distinguishing AIH from PBC was acidophilic bodies in lobules that were detected significantly more frequently in patients with AIH than PBC or spurious overlap syndrome (39/46 [85%]vs 3/85 [4%], P < 0.001). It was more reliable than bile-duct lesions for the distinction of PBC from AIH. CONCLUSIONS: Although AIH/PBC overlap syndrome does exist, it is infrequent and needs to be diagnosed carefully using close clinical and histological follow up to enable timely and effective treatment.     

Transitions between variant forms of primary biliary cirrhosis during long-term follow-up

BackgroundConditions exhibiting features of two different autoimmune liver diseases are designated overlap syndromes. Variant forms display some, but not all, characteristics of a distinct autoimmune liver disease. We describe transitions over time between variant forms of PBC, i.e. AMA-negative PBC, autoimmune hepatitis (AIH)–PBC overlap and autoimmune cholangitis (AIC) in a large cohort of PBC patients in Sweden.MethodsWe retrieved all patients with variant forms of PBC in six university hospitals in Sweden, covering 60% of the Swedish population. The diagnosis of PBC and its variants was based on laboratory findings and compatible histological features. The revised autoimmune hepatitis scoring system proposed by the International Autoimmune Hepatitis Group was used to establish the diagnosis of AIH.ResultsIn a population of 800 patients with PBC, we identified 35 (5%) variant forms; 25 patients with AIH–PBC overlap, 8 with AIC and 2 with AMA-negative PBC at the time of our study. The initial diagnoses were PBC (3 patients), AIH (3), AIH–PBC overlap (16), AIC (8) and AMA-negative PBC with (1) or without (4) concomitant AIH. The median follow-up was 125 (41–360) months. Immunosuppression and ursodeoxycholic acid induced a complete or good regression of increased aminotransferases in about half of the patients who were given one or both of these treatments.ConclusionsVariant forms of PBC are seen in approximately 5% of PBC patients in Sweden. Transition between different forms may occur, emphasizing the value of repeat biopsies, but established overlapping AIH–PBC seems to be stable over time.     

Enhanced intrahepatic inducible nitric oxide synthase expression and nitrotyrosine accumulation in primary biliary cirrhosis and autoimmune hepatitis

BACKGROUND/AIMS: Nitrosative stress resulting from increased nitric oxide (NO) synthesis contributes to the pathogenesis of chronic inflammatory diseases, including chronic viral hepatitis. Our goal was to assess the expression of inducible nitric oxide synthase (iNOS) and the formation of nitrotyrosine (NTY), as a marker of nitrosative stress, in liver biopsies from primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) patients. METHODS: Intrahepatic expression of iNOS and NTY was measured immunohistochemically and compared to histological scores of the severity of liver disease. RESULTS: Hepatocellular iNOS expression was observed in liver sections from PBC patients (with a diffuse lobular distribution) and from AIH patients (marked staining in areas of pronounced inflammation and necrosis), but not in control liver sections, including non-autoimmune cholestatic liver disease. Liver samples from PBC and AIH patients, but not from controls, showed NTY accumulation in clusters of hepatocytes and Kupffer cells. Increased iNOS expression and NTY accumulation correlated with the histological severity of PBC or AIH, especially with the degree of inflammation. CONCLUSIONS: Patients with PBC and AIH showed an enhanced intrahepatic iNOS expression and NTY accumulation, related to the histological severity of liver disease, consistent with NO-mediated nitration of hepatocellular proteins contributing to liver damage in both diseases.     

Overlap syndromes

In hepatology, the term overlap syndrome describes variant forms of the major hepatobiliary autoimmune diseases, autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC). Patients with overlap syndromes present with both hepatitic and cholestatic biochemical and histological features of AIH, PBC, and/or PSC, and usually show a progressive course toward liver cirrhosis and liver failure without adequate treatment. AIH-PBC overlap syndromes have been reported in almost 10% of adults with AIH or PBC, whereas AIH-PSC overlap syndromes were found in 6 to 8% of children, adolescents, and young adults with AIH or PSC. A minority of patients may also show transition from stable PBC to AIH, AIH to PBC, or AIH to PSC, as documented by single case reports and small case series. Single cases of AIH and autoimmune cholangitis (antimitochondrial antibody-negative PBC) overlap have also been reported. Empiric medical treatment of AIH-PBC and AIH-PSC overlap syndromes includes anticholestatic therapy with ursodeoxycholic acid and immunosuppressive therapy with corticosteroids and azathioprine. In end-stage disease, liver transplantation is the treatment of choice.     

Overlap syndromes among autoimmune liver diseases

The three major immune disorders of the liver are autoimmune hepatitis（AIH）,primary biliary cirrhosis（PBC） and primary sclerosing cholangitis（PSC）.Variant forms of these diseases are generally called overlap syndromes,although there has been no standardised definition.Patients with overlap syndromes present with both hepatitic and cholestatic serum liver tests and have histological features of AIH and PBC or PSC.The AIH-PBC overlap syndrome is the most common form,affecting almost 10% of adults with AIH or PBC.Single cases of AIH and autoimmune cholangitis（AMA-negative PBC） overlap syndrome have also been reported.The AIH-PSC overlap syndrome is predominantly found in children,adolescents and young adults with AIH or PSC.Interestingly,transitions from one autoimmune to another have also been reported in a minority of patients,especially transitions from PBC to AIH-PBC overlap syndrome.Overlap syndromes show a progressive course towards liver cirrhosis and liver failure without treatment.Therapy for overlap syndromes is empiric,since controlled trials are not available in these rare disorders.Anticholestatic therapy with ursodeoxycholic acid is usually combined with immunosuppressive therapy with corticosteroids and/or azathioprine in both AIH-PBC and AIH-PSC overlap syndromes.In end-stage disease,liver transplantation is the treatment of choice.     

Overlap syndromes from pediatrics to adulthood

Abstract   Overlap syndromes are autoimmune conditions with mixed immunological, clinical and histological features. The most frequent overlaps are between primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH), and between AIH and sclerosing cholangitis (SC). True AIH/PBC overlap syndrome is rare and characterized by elevation of transaminases and immunoglobulin G (IgG), positive anti-smooth muscle antibodies and a liver biopsy showing interface hepatitis as well as changes typical of PBC. These patients respond to immunosuppressive treatment that must be given promptly, to avoid progression to liver failure. The so-called 'autoimmune cholangitis' defines a small group of patients with cholestatic and histological features of PBC but negative for anti-mitochondrial antibody (AMA) and positive for PBC-specific anti-nuclear antibody (ANA). The positivity for ANA in these patients is a consequence of the AMA negativity, since AMA masks ANA on immunofluorescence. These patients' clinical course and response to treatment resemble that of classical PBC. AIH/ASC overlap syndrome is characterised by elevated levels of IgG and circulating autoantibodies, including ANA, SMA and atypical perinuclear anti-neutrophil cytoplasmic antibody, in association with cholangiographic changes typical of SC. This condition affects in particular children and young adults and may represent the early stage of adult primary SC. The parenchymal liver inflammation responds satisfactorily to immunosuppression, while the bile duct damage may progress despite treatment.     

Overlap of primary biliary cirrhosis and autoimmune hepatitis: Characteristics,therapy, and long term outcomes

Background: Coexistence of primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) is referred to as PBC‐AIH overlap. Pathogenesis of PBC‐AIH is not well understood and its diagnosis is challenging. We previously reported the clinical characteristics of 10 patients diagnosed with PBC‐AIH overlap. Aims: The aim of the study was extend the earlier series and evaluate the diagnostic criteria, biological characteristics, potential therapy, and long‐term outcomes of patients with PBC‐AIH overlap. Methods and Results: We retrospectively analyzed clinical, biochemical, and histological characteristics of 144 patients diagnosed with PBC and 73 diagnosed with AIH. We identified 16 cases of PBC‐AIH overlap, according to criteria established by Chazouillères et al. and other studies. PBC preceded AIH in 6 patients and both diseases occurred simultaneously in the remaining 10 patients. PBC‐AIH overlap has clinical, biochemical, and histological characteristics of both PBC and AIH. Thirteen patients treated with both ursodeoxycholic acid (UDCA) and immunosuppressive therapy responded well, with normal alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels. The remaining three patients treated with either prednisolone (PSL) or UDCA alone developed cirrhosis, varices, ascites, encephalopathy, or died of liver‐related causes at the 5, 12, and 14‐year follow up. Conclusions: PBC‐AIH overlap is not a rare entity; it was observed in 11% of PBC patients in this study. Further studies will be required to investigate whether PBC‐AIH overlap is distinct from the two individual diseases in terms of long‐term outcomes and therapeutic implications.     

Development of autoimmune hepatitis in patients with typical primary biliary cirrhosis

Primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap syndrome is a clinical entity characterized by the occurrence of both conditions at the same time in the same patient. In addition to PBC-AIH overlap syndrome, transitions from one autoimmune disease to another have been reported, but no systematic series have been published. We report a series of 12 patients with consecutive occurrence of PBC and AIH (i.e., PBC followed by AIH). Among 282 PBC patients, 39 were identified who fulfilled criteria for probable or definitive AIH. AIH developed in 12 patients (4.3%). The baseline characteristics of the patients were similar to those of patients with classical PBC. Time elapsed between the diagnosis of PBC and the diagnosis of AIH varied from 6 months to 13 years. Patients with multiple flares of hepatitis at the time of diagnosis of AIH had cirrhosis on liver biopsy. Ten patients were given prednisone +/- azathioprine; short-term as well as sustained remissions were obtained in 8 of these, while two had multiple relapses and eventually died 8 and 7 years after diagnosis of AIH. In conclusion, the development of superimposed AIH could not be predicted from baseline characteristics and initial response to UDCA therapy. If not detected early, superimposed AIH can result in rapid progression toward cirrhosis and liver failure in PBC patients.     

Clinical significance of autoantibodies to p53 protein in patients with autoimmune liver diseases

BACKGROUND:Autoantibodies to p53 (anti-p53) are rarely present in the sera of patients with autoimmune diseases or the sera of patients with malignancies.OBJECTIVE:To examine the prevalence of anti-p53 in patients with autoimmune liver disease including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), AIH/PBC overlap syndrome (AIH/PBC OS) and primary sclerosing cholangitis (PSC), and to determine the clinical significance of anti-p53 in autoimmune liver diseases.METHODS:Forty patients with AIH, 41 patients with PBC, eight patients with AIH/PBC OS and five patients with PSC were enrolled. Anti-p53 and antibodies to double-stranded DNA (anti-ds-DNA) were analyzed using commercially available ELISA kits. Demographic, laboratory and histological data were compared between the AIH groups seropositive and seronegative for anti-p53.RESULTS:Six of 40 (15.0%) patients with AIH and four of eight (50.0%) patients with AIH/PBC OS were positive for anti-p53. One of 41 (2.4%) patients with PBC was also positive for anti-p53, but all five patients with PSC were negative, indicating a significantly higher prevalence of anti-p53 in patients with AIH or AIH/PBC OS compared with patients with PBC. None of the AIH patients positive for anti-p53 progressed to hepatic failure or relapsed after immunosuppressive treatment. Titres of anti-ds-DNA in patients with AIH and AIH/PBC OS significantly correlated with titres of anti-p53 (r=0.511; P=0.0213).CONCLUSION:The emergence of anti-p53 is likely to be useful for discriminating AIH or AIH/PBC OS from PBC and helpful for predicting favourable prognoses in patients with AIH. DNA damage may trigger the production of anti-p53 in patients with AIH or AIH/PBC OS.     

Evolución de cirrosis biliar primaria a síndrome de solapamiento con hepatitis autoinmune en paciente con hepatitis B crónica

We describe the case of a female patient with a previous diagnosis of primary biliary cirrhosis (PBC) and chronic hepatitis B in inactive phase who developed increased transaminase levels with no evidence of hepatitis B virus reactivation while receiving ursodeoxycholic acid treatment. A liver biopsy showed changes compatible with overlapping autoimmune hepatitis (AIH). Budesonide treatment achieved normalization of transaminase levels. We provide a review of PBC and AIH overlap syndrome and discuss the particular features of this case that led us to this diagnosis, as well as the treatment provided.     

Rapid-onset primary biliary cirrhosis resembling drug-induced liver injury

A 54-year-old woman was admitted to our hospital because of acute liver injury. Since she had a history of having used a diet product, drug-induced liver injury (DILI) was initially considered. However, the patient was subsequently diagnosed as suffering from primary biliary cirrhosis (PBC) based on the findings of liver histology and serum anti-mitochondrial antibody positivity. Overlap syndrome between PBC and autoimmune hepatitis (AIH) was also suspected, however, serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase became normal three months later, after treatment with combination therapy comprising ursodeoxycholic acid plus bezafibrate. We therefore concluded that the liver disease in this patient was actually PBC, but that it resembled overlap syndrome or DILI. In cases of PBC, a rapid onset, as frequently seen in the case of DILI, viral hepatitis or AIH, is not common. We herein report a rare case of PBC which resembled DILI.     

Autoimmunerkrankungen der Leber

Autoimmune liver diseases are divided into autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). They play an important role in the differential diagnosis of acute and chronic liver diseases. Diagnostic criteria consist of biochemical parameters (liver function tests, immunoglobulins, autoantibodies), imaging (ultrasound, MRCP, ERCP) and histopathologic characteristics. The treatment of choice in AIH is a combined immunosuppressive therapy of prednisolone and azathioprine. Ursodeoxycholic acid is the treatment of choice for PBC and improves liver biochemistry and prolongs transplant-free survival by slowing histological progression in the majority of patients. To date, there is no effective medical treatment option for patients with PSC.     

Diagnosing clinical subsets of autoimmune liver diseases based on a multivariable model

Background Diagnosing autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis, and other autoimmune liver diseases remains an imperfect process. We need a more accurate, evidence-based diagnostic system. Methods We conducted a national survey and identified 988 cases of liver disease which did not satisfy the inclusion criteria for any liver disease of known etiology. We expected these cases to include autoimmune liver disease (AILD) and its variant forms. We selected 269 prototype cases for which histological re-evaluation of liver biopsy by independent expert hepatopathologists and the original diagnosis coincided. We did a multiple logistic regression analysis to determine explanatory variables that would distinguish cases of AIH and PBC from those of non-AIH and non-PBC, respectively. We constructed a multivariable diagnostic formula that gave AIH and PBC disease probabilities and validated it in a study of an additional 371 cases (validation group). Results Based on the results of the statistical analysis, we selected three laboratory tests and four histological features as independent variables correlated to the diagnosis of both AIH and PBC. For the validation group, assuming that the original diagnosis was correct, the sensitivity and specificity for AIH were 86.3% and 92.4%, respectively. For PBC the sensitivity and specificity were 82.5% and 63.7%, respectively. A detailed analysis of inconsistent cases showed that the diagnosis based on the formula had given the correct diagnosis, for either AIH or PBC, except for 5 cases (1.3%) in which disease probability was low for both. Conclusions A seven-variable formula based on three laboratory tests and four histological features gives significant information for the diagnosis of AILD.     

肿瘤坏死因子α基因多态性与中国人自身免疫肝病相关性研究

目的 探讨肿瘤坏死因子α(TNFα)启动子基因多态性与中国人自身免疫性肝炎(AIH)、原发性胆汁性肝硬化(PBC)发病的相关性。方法 采用序列特异性聚合酶链式反应方法分析49例AIH、58例PBC患者外周血单核细胞基因组DNA TNFα启动子308、-238G／A基因多态性，并与160例正常对照组比较。结果 正常对照组中国人与白种人TNFα*2携带率差异较大。虽然从百分率上可以看出中国人PBC患者TNFα*2携带率低于正常对照组(10．34％与16.88％)，但统计学上两者差异无显著性，TNFα-238位基因多态性分布也与正常对照组差异无显著性；AIH患者TNFα启动子-308、-238G／A基因多态性均与正常人差异无显著性。结论 不同人种自身免疫肝病的免疫相关基因不同，中国人AIH、PBC与TNFα启动子基因的多态性间不存在基因连锁关系。     

Overlap of autoimmune hepatitis and primary biliary cirrhosis: an evaluation of a modified scoring system

OBJECTIVE: The coexistence of autoimmune hepatitis (AIH) with primary biliary cirrhosis (PBC) as an overlap syndrome has been previously described. The ability to detect AIH overlap with a revised version of the International Autoimmune Hepatitis Group (IAHG) scoring system, however, remains unknown. Our specific aim was to evaluate the revised IAHG scoring system and its ability to identify AIH overlap in PBC. MErHODS: One hundred forty-one PBC patients with first-time visits to the Mayo Clinic from January 1, 1990 to December 31, 1992 were evaluated. The calculation of individual revised IAHG scores was performed and compared to original IAHG scores. RESULTS: Among 137 PBC patients with available liver histologies, use of the original IAHG scoring system detected "definite" and "probable" AIH overlap among 2.2% and 62% of cases, respectively. Application of the revised IAHG scoring system, however, revealed no individuals (0%) with definite AIH overlap (>15 points). Twenty-six subjects (19%) fulfilled IAHG criteria for probable AIH overlap (10-15 points). The presence of antinuclear antibody and/or smooth muscle antibody positivity (p = 0.05), other autoimmune disorders (p < 0.01), and total histological score (p < 0.001) were significantly greater in the PBC plus probable AIH group than in subjects with PBC alone. CONCLUSION: A reduction in the prevalence of definite 2.2% vs 0%) and probable (62% vs. 19%) AIH overlap among PBC subjects was observed with use of the revised IAHG coring system relative to the original criteria. Applicability of the revised IAHG scoring system, however, remains questionable, as nearly 20% of PBC patients will be classified with probable AIH overlap.     

Frequency and predictive factors for overlap syndrome between autoimmune hepatitis and primary cholestatic liver disease

OBJECTIVES: To evaluate the frequency of cholestatic pattern in patients with autoimmune hepatitis (AIH) and to identify predictive factors associated with the development of the overlap syndrome. METHODS: Eighty-two consecutive patients diagnosed with AIH at the referral centre between January 1998 and June 2002 were included in the study. The new scoring system modified by the International Autoimmune Hepatitis Group was used to classify patients as definite/probable. Overlap syndrome was considered when the patient had clinical, serological and histological characteristics of two conditions: AIH and primary biliary cirrhosis (PBC) or AIH and primary sclerosing cholangitis (PSC). RESULTS: From the 82 AIH patients (76 female and six male), 84.1% presented definite AIH (> 15 points) and 15.9% probable AIH (10 - 15 points). The frequency of the overlap syndrome was 20%: 13% with PBC and 7% with PSC. In the univariate analysis the overlap syndrome was associated with male gender (P = 0.01), age < 35 years (P < 0.0001), histopathological aspect of cholestasis (P < 0.0001), suboptimal response to treatment (P < 0.0001) and probable AIH (P < 0.0001). Age < 35 years, probable AIH and the absence of anti-nuclear antibody (ANA) have been identified as independent indicators of the overlap diagnosis by the logistic regression analysis. CONCLUSION: Patients with overlap syndrome between AIH and primary cholestatic liver disease are frequently diagnosed in clinical practice, representing 20% of AIH cases in our study. The independent predictive factors associated with the diagnosis of overlap syndrome are young age, ANA(-) profile, and probable diagnosis according with the scoring system for AIH.