Autoimmune hepatitis is a chronic progressive inflammatory disease of the liver mediated by autoimmune reactions, characterized clinically by varying degrees of elevated serum transaminases, hypergammaglobulinemia, positive autoantibodies, and histological features of interfacial hepatitis with predominantly lymphocytic and plasma cell infiltration, which can rapidly progress to cirrhosis and liver failure in severe cases. The disease occurs worldwide, with a relatively high incidence in Europe and the United States, and its exact incidence and prevalence in China is unknown, but the number of cases reported in the domestic literature is on a significant rise. 1, disease introduction Autoimmune hepatitis is one of the newly identified diseases in recent years, the disease has a high incidence in Europe and the United States, such as the United States, the disease accounts for 10% to 15% of chronic liver disease, China is also increasing the reports of the disease, it is necessary to raise awareness of the disease. Autoimmune hepatitis is a group of chronic hepatitis syndromes caused by autoimmunity, which is often confused with viral hepatitis because its manifestations are very similar to those of viral hepatitis, but the treatment of the two is very different. Autoimmune hepatitis was first proposed in 1950 and was initially referred to as “lupus-like hepatitis” due to the existence of certain similar clinical manifestations and autoantibodies to SLE. Later, it was found that there were significant differences in the clinical manifestations and autoantibodies between this disease and SLE patients. Recently, the international conference referred to “autoimmune liver disease” and “autoimmune chronic active hepatitis” collectively as “autoimmune hepatitis”, and removed the restriction of a disease duration of more than 6 months. The restriction of more than 6 months has been removed, and the disease is defined as a non-viral infectious autoimmune disease. The disease is a genetically predisposed disease and can be triggered by environmental, drug and infection factors in people with susceptibility genes. Patients have a defective immune control function, resulting in the body’s response to its own hepatocyte antigens, which is dominated by cell-mediated cytotoxic effects and immune responses resulting from the binding of hepatocyte surface-specific antigens to autoantibodies. 2, etiology Autoimmune liver disease (AHI) occurs with the need for an adequate breeding environment. the occurrence of IH must have the activation of antigens. The pathogenesis of AIH induced by environmental factors is also not elucidated, viruses (such as HBV, HCV, EBV, measles virus, etc.) are more certain in stimulating the immune response. Viral antigenic epitopes lead to cross-reactivity through “molecular mimicry” with certain liver antigens having the same determinant clusters, leading to autoimmune liver disease. For example, a variety of non-specific autoantibodies can be detected in the serum of some patients with HCV infection. 3.Clinical manifestations The clinical features of this disease are more common in women, showing chronic active hepatitis. The examination shows the presence of hyperglobulinemia and liver-associated autoantibodies, while the pathological changes are characterized by lamellar necrosis and bridging necrosis of hepatocytes with infiltration of plasma cells, lymphocytes and monocytes. The diagnosis of this disease requires the exclusion of other similarly presenting liver diseases, particularly viral infectious hepatitis. Autoimmune hepatitis has a slow onset in about 70% of cases and an acute onset in a minority of cases in about 30% of cases. Patients often present with symptoms such as malaise, jaundice, hepatosplenomegaly, itchy skin and insignificant weight loss. When the disease progresses to cirrhosis, ascites, hepatic encephalopathy, and esophageal variceal bleeding may occur. Patients with autoimmune hepatitis also often have extrahepatic systemic immune diseases, most commonly thyroiditis and ulcerative colitis. Laboratory tests are most notable for elevated gamma globulin, with igg predominating, usually more than twice the normal value. Liver function tests serum bilirubin, glutamic oxalacetic aminotransferase, glutamic alanine aminotransferase and alkaline phosphatase can be elevated, and serum albumin and cholesterol ester are reduced, reflecting the characteristics of autoimmune hepatitis with predominantly hepatocellular damage. Autoimmune hepatitis The principle of treatment for autoimmune hepatitis is mainly to suppress the abnormal autoimmune response, and the indication for treatment is mainly based on the degree of inflammatory activity rather than the degree of impaired liver function. Corticosteroid therapy may be considered if the patient presents with significant symptoms, rapid disease progression or gamma globulin ≥ 2 times normal, as well as glutamic oxalacetic aminotransferase ≥ 5 times normal and glutamic alanine aminotransferase ≥ 10 times normal. Clinical, biochemical and histological remission is achieved in 65% of patients after treatment with immunosuppressive drugs. The 10-year survival rates for patients with and without cirrhosis are 89% and 90%, respectively; therefore, it is necessary to strictly regulate the use of drugs. 4. diagnosis Laboratory tests 1 Transaminase activity often rises significantly, ALT is often more than 10 times higher than normal, ALT is higher than AST. serum bilirubin levels are moderately elevated. The typical manifestation of autoimmune hepatitis is prominent hypergammaglobulinemia. 2 Immunoserological examination A variety of autoantibodies positive is characteristic of this disease. (1) Anti-nuclear antibodies (ANA) are present in 80% of patients, and their titers are consistent with serum 7-a-globulin levels. (2) Smooth muscle antibody (SMA) is positive in about 70% of cases and is IgM. Its antigen is related to S-actin of smooth muscle and skeletal muscle, and is also present in the contractile components of the hepatocyte membrane and cytoskeleton, thus SMA can also be seen as a result of hepatocyte damage. (3) Soluble liver antigen antibodies (anti-SLA) are non-organ-specific antibodies against a soluble liver antigen and are mainly present in young female cases, which respond well to steroid hormone therapy. (4) Anti-liver one kidney microsomal antibody (LKM), which is the main feature of type II AIH. Cytochrome P450 II D6 is the target antigen of LKMl, which is mainly present in young or young female patients, mostly with high titer positivity. These patients have severe symptoms and respond better to corticosteroids. (5) Mitochondrial antibody (AMA) is positive in 30% of cases. 3 Serological typing of autoimmune hepatitis Autoantibodies are the special markers of autoimmune hepatitis, and autoimmune hepatitis can be classified into three types according to autoantibodies. Diagnostic criteria (a) General diagnostic criteria for AIH In view of the fact that the old diagnostic criteria are no longer applicable and the new international diagnostic criteria are cumbersome. We hereby refer to the revised Japanese diagnostic indications for AIH in 1996 and the Western criteria, which are synthesized as follows. 1 Main criteria (l) High γ-Glemia or IgG elevated above 2g/dl. (2) Negative hepatitis virus markers (e.g. HBV, HCV, etc.) (occasionally accompanied by HCVemia or markers of prior viral infection). (3) Positive autoantibodies (ANA, SMA, SLA, LKM, ASGPR) in blood. Especially ANA and SMA. (4) Positive HLA-B8, DR3, DR4 (non-white HLA type is not the main diagnostic criterion, when good response to immunosuppressants can be relied on). (5) Histological evidence of liver (chronic hepatitis or cirrhosis with hepatocyte necrosis and debris-like necrosis. Significant plasma cell infiltration is common, sometimes showing signs of acute hepatitis). 2 Adjunctive criteria (l) Prevalent in females below middle age. (2) Often associated with the pathogenic features of autoimmune diseases or related diseases. (3) Arthralgia. (4) Persistent or recurrent elevation of serum transaminases. The course of the disease shows fluctuating changesc (5) Excluding other liver diseases such as alcoholic, drug-related, and metabolic. Anyone meeting 1~4 major criteria can be considered for AIH and further liver histological examination. If all 5 main criteria are met, the diagnosis is confirmed. Ancillary criteria can be used for reference. For difficult cases, the following international standards should be referred to for diagnosis. (B) International diagnostic criteria of AIH In 1992, an international symposium on AIH was held in Brighton, England, and the diagnostic criteria of AIH and scoring system were proposed. This international diagnostic standard has significantly improved the diagnosis of difficult cases of AIH and the differentiation from other liver diseases. For cases provisionally classified as “probable”, the “probable” diagnosis can be upgraded to “confirmed” once the required indicators are observed, or if the patient shows a good response to hormone therapy. and the “minimum necessary items” scoring method of the diagnostic criteria can be useful in the absence of liver biopsy specimens or specific sensitive indicators (e.g., HCV RNA-PCR). However, for “confirmatory diagnosis”, only the total score should not be considered without liver histology. This shows the importance of the “additional items” scoring method, especially in difficult cases. This diagnostic criterion, in principle, excludes viral hepatitis, but sometimes serological markers of incidental co-infection or previous infection are present and evaluated with a reduced score as specified. Recently Labrecque et al. reported that anti-neutrophil cytoplasmic antibody (antineuLrophil cytoplasmic antibody, ANCA) can be present in 90% of patients with AIH-I and noted to be helpful in diagnosing those patients with AIH-I who are routinely autoantibody negative. 5. Differential diagnosis Viral hepatitis The clinical features of this disease are similar to those of AIH, but extrahepatic multisystemic manifestations are less common, with more males than females, and the prevalent population is yellow in Southeast and East Asia. The laboratory tests are characterized by the detection of viral marker antigens in the serum. The difference in clinical manifestations is that AIH is more common in women, more common in Caucasians in Northern and Western Europe, and extrahepatic multisystem manifestations are common. AIH has hypergammaglobulinemia and high titers of autoantibodies such as ANA, SMA, LKM, and anti-SLA in the serum, while patients with viral hepatitis have mainly positive serum markers of hepatitis virus. Both have good response to corticosteroids for AIH and poor response to corticosteroids for viral hepatitis. Alcoholic liver disease Most patients with alcoholic liver disease have a history of alcohol abuse, drinking more than 40g of alcohol per day for more than 5 years, more men than women, clinical manifestations are fatigue, loss of appetite, abdominal distension, nausea, vomiting, malnutrition, etc. Signs include enlargement of the liver, the development of cirrhosis may appear splenomegaly, ascites, upper gastrointestinal bleeding, etc.. Laboratory tests AST>ALT and GGT are elevated. The difference between the two is that patients with alcoholic liver disease have negative tests for various autoantibodies such as ANA, SMA, IKM and anti-SLA. Primary biliary cirrhosis (PBC) This disease occurs in middle-aged women and is characterized clinically by malaise, pruritus, and later jaundice and yellow warts. Laboratory tests are characterized by elevated ALP and Y a globulin, elevated serum IgM and bilirubin, only slightly elevated transaminases (ALT or AST) in most patients, positive anti-mitochondrial antibodies (AMA), and histological manifestations of chronic non-suppurative cholangitis mainly in the interlobular and border plate bile ducts. Primary sclerosing cholangitis (PSC) This disease occurs in males aged 25-40 years, with clinical manifestations of progressive obstructive jaundice, often associated with ulcerative colitis, Crohn’s disease or retroperitoneal fibrosis; laboratory tests are characterized by elevated ALP; elevated transaminases; and segmental diffuse lesions of the bile ducts, typically candida-like lesions, seen on ERC37 and PTC. The typical lesion is candida-like. Drug-related liver disease Drug-related liver disease is characterized by a history of liver-damaging drugs, such as paracetamol, rifampin, methyldopa, furantadine, etc., within 1-4 weeks prior to the onset of the disease, with clinical symptoms such as fever, rash, pruritus, malaise, poor appetite, and jaundice. Laboratory tests may show elevated ALT and AST if liver parenchymal damage is the main cause, or elevated ALP if cholestasis is the main cause, and increased eosinophils in the peripheral blood. Serum markers for various hepatitis viruses are negative. The difference between the two in clinical manifestations is that shed patients are mostly women, and the typical manifestations are pruritus, joint pain and jaundice, and the occurrence and remission of symptoms are not related to medication is the key point of differentiation; the differentiation between the two in biochemical examination is that AIH has various autoantibodies such as ANA, SMA, LKM and anti-SLA. 6.Treatment Through comprehensive treatment and reasonable conditioning, autoimmune diseases can be controlled in a range that does not affect normal life. However, it cannot be cured at present. Patients of any age need long-term medication, but it is difficult to be cured. Patients with autoimmune liver disease exist in all age groups, and the treatment methods vary from age to age. The following is a summary of different treatment methods for each different age group according to experts. Therefore, extra attention must be paid to the post-surgical care. Conventional treatment of autoimmune liver disease Corticosteroids are the drugs of choice for initial anti-inflammatory and immunosuppressive therapy. Prednisone or prednisolone monotherapy or combination therapy with azathioprine is now commonly used. Conventional treatment can lead to remission in 60% to 80% of patients, and in some cases fibrosis can be reversed, and the 10-year survival rate of treated cirrhotic patients exceeds 90%, so it is essential for patients with active cirrhosis to receive corticosteroid therapy. Dosage and Administration Prednisone or prednisolone should be administered at 20-30rag daily, or up to a higher dose of 40-60mg in children. Azathioprine should be administered at l-2mg/kg, and the dose of prednisone may be reduced after 4-8 weeks if the transaminase level is normalized. With monitoring of transaminase, total bilirubin and 7-globin levels, the dose is reduced in 4 to 8 week intervals to a maintenance dose of 5 to lOmg/d. The dose of azathioprine remains unchanged and the total cycle of treatment continues for 2 years, with the possibility of starting another course of treatment in case of relapse. A common guideline is to consider discontinuation only when transaminase levels have decreased to normal for at least 1 year and biopsies show minimal or no inflammation. [1] Liver transplantation Although there have been significant advances in the treatment of AIH, some patients are still treated with immunosuppressive drugs. However, some patients still fail immunosuppressive therapy and eventually progress to end-stage liver disease or develop other related serious complications. At this point, liver transplantation becomes the only treatment option. The survival rate of patients and grafts after liver transplantation is 84% to 92%, and the survival rate at 10 years after transplantation is 75%, and all patients disappear within 2 years with autoantibodies and hypergammaglobulinemia. The recurrence rate about 5 years after the operation is 17%. 7.Dietary advisories Diet should be high sugar, high calorie, high protein and low fat. Quantitative and regular, to ensure adequate vitamins and fiber. In the acute period, the diet should be light; it is appropriate to use foods with therapeutic effects, such as barley seedlings, pumpkin root, grapefruit, water chestnuts, loach, tofu, clams, snails, wild rice, sweet potatoes, golden needles, barley, mussels, corn husk, celery; foods to improve liver function; loach, carp, fish bladder, scallops, lean pork, snapper, golden needles, fungus, duck, sandworms, silverfish, rabbit, red dates, peanuts, rock sugar. Avoid alcohol, smoking; avoid spicy and stimulating food, such as onion, garlic, leek, cinnamon, pepper, chili; avoid fatty and high-fat food, such as fatty pork, dog meat, etc.; ascites patients avoid salty food, limit the amount of water intake; cirrhosis patients avoid multiple bone spurs, coarse fiber food.