Conclusion Overlap syndrome of autoimmune hepatitis and primary biliary cirrhosis was not rare in Chinese patients with clinical manifests of autoimmune liver diseases. overlap syndrome. If it was difficult to make a definite diagnosis, liver biopsy was necessary. Keywords: autoantibody, overlap syndrome, autoimmune hepatitis, primary biliary cirrhosis 1. Background Autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC) are three major clinicopathologic entities of autoimmune liver diseases. Besides, some patients with autoimmune liver disease present with characteristics of a second autoimmune liver disease (i.e. AIH and PBC overlapping). These cases have been defined as overlap syndrome. Patients with overlap syndrome usually present with nonspecific symptoms, including lethargy, arthralgias, and myalgias. A combination of clinical and laboratory or pathologic criteria is necessary for the diagnosis of the disease. In the laboratory test, autoantibodies are the serological hallmarks. Serum antinuclear antibody (ANA), smooth muscle antibody (SMA) and antimitochondrial antibody (AMA) are routinely detected in these patients [1]. Although combined features of both PBC and PSC have been reported in single cases, there is no clear evidence for the existence of an overlap of PBC and PSC [2]. The overlap syndrome of AIH and PBC is the most common form, and it shows a more progressive course towards liver cirrhosis and liver failure than AIH or PBC alone [3-5]. However, up to now, the pathogenesis of overlap syndrome is poorly understood [6], and few data are available regarding the clinical characteristics of this disease, and moreover, reports on the prevalent and serological features of this condition in Chinese population are still lacking. The aim of this retrospective study is to investigate and analyze the prevalent and clinical features of Chinese patients with AIH and PBC overlap syndrome. 2. Methods 2.1. Patients Patients diagnosed as overlap syndrome of AIH and PBC in 302 hospital from January 2001 to December 2006 were included in the retrospective study. The diagnosis was based on the criteria established by Chazouillres O, et al [7]. Exclusion criteria included coinfection with Hydrocortisone(Cortisol) hepatitis A, C, D, E, Epstein-Barr virus, cytomegalovirus or HIV; the presence of other Hydrocortisone(Cortisol) forms of liver diseases such as alcoholic liver disease, drug hepatitis or Wilson’s disease. 146 patients Mouse monoclonal to His Tag were eventually enrolled in our study. Informed written consent for the analysis was obtained from each patient. The study was approved by the ethics committee of Beijing 302 Hospital. 2.2. Serological markers and liver histopathology Serum autoantibodies, including antinuclear antibody (ANA), smooth muscle antibody (SMA) and antimitochondrial antibody (AMA) were tested using indirect immunofluorescence with the standard methods (Euroimmun Medizinnische Labordiagnostika AG, Germany), and sera were considered to be positive when they produced a reaction at a dilution of 1:100. Immunoglobulin (Ig) assay were taken with the mothod of immunological Hydrocortisone(Cortisol) turbidimetry (Diasys Diagnostic Systems, China). The normalized levels of IgG, IgM and IgA were respectively 7.23-16.6 Hydrocortisone(Cortisol) g/L, 0.63-2.77 g/L and 0.69-3.82 g/L. Biochemical profiles, including alanine transarninase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) were measured using standard laboratory procedure. The normalized levels of ALT, AST, TBil, GGT and ALP were respectively < 40 U/L, < 40 U/L, < 17.1 umol/L, 7-32 U/L, and 40-150 U/L. Liver biopsy was performed in some cases for definite diagnosis, and biopsy specimens were examined in the Pathology Department. 2.3. Statistical analysis Data analysis were performed using SAS 9.2 software (SAS Institute Inc., Cary, NC, USA) and the quantitative data were expressed as mean and standard deviation. 3. Results 3.1. Baseline characteristics and prevalent features In this six-year retrospective survey based on our hospital, a total of 1413 patients was diagnosed as autoimmune liver diseases, of which, 577 were AIH, 685 were PBC, 5 were PSC, 146 were overlap syndrome of AIH and PBC, and none were overlap syndrome of AIH and PSC. Overlap syndrome of AIH and PBC accounts for 10.33% of patients with.