You should know about autoimmune liver disease

Autoimmune liver disease is a common clinical disease type, which mainly refers to liver inflammatory lesions mediated by autoimmunity, including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC).

This paper briefly introduces the clinical manifestations, diagnosis, complications and treatment of autoimmune liver disease.

►AIH：The clinical manifestations are diverse, generally chronic and occult onset, but it can also be acute attack, and even cause acute liver failure. Some patients with AIH have no symptoms, and most of them see a doctor because of the increase of transaminase level found in physical examination. Some patients may have symptoms such as fatigue, joint pain, nausea, diarrhea and loss of appetite. Physical examination can find signs such as hepatomegaly, splenomegaly and ascites, and occasionally peripheral edema. Patients with acute onset may have acute liver failure, severe jaundice and prolonged prothrombin time.

►PBC：Most of the early patients have no obvious clinical symptoms, but most asymptomatic patients will have symptoms within 5 years. The most common clinical manifestations were fatigue and skin pruritus. PBC patients may also have cholestasis related manifestations, such as abnormal bone metabolism, lack of fat soluble vitamins, hyperlipidemia, etc. In the later stage of the disease, a series of complications of liver cirrhosis and portal hypertension can occur.

►PSC：The clinical manifestations were varied, 15% to 55% of the patients were asymptomatic. The most common manifestation of patients with symptoms may be asthenia, but not specific. Other possible symptoms and signs include body mass reduction, pruritus, jaundice and hepatosplenomegaly. Patients can also have recurrent upper right abdominal pain, similar to cholelithiasis and biliary tract infection.

►AIH：The diagnosis is mainly based on a series of typical clinical features. One of the diagnostic markers of AIH is the existence of autoantibodies. According to the autoantibodies, AIH can be divided into two types: type 1 is anti nuclear antibody (ANA), anti smooth muscle antibody (ASMA) or anti soluble liver antigen (SLA), and type 2 is liver kidney microsomal antibody type 1, LKM1) and / or type 1 (LC1) were positive. The latter is rare and mainly seen in children.

►PBC：PBC can be diagnosed when alkaline phosphatase (ALP) increases at least 1.5 times the upper limit of normal value and anti mitochondrial antibody (AMA) is positive. AMA has high diagnostic accuracy for PBC. Anti gp210 and anti Sp100 have high specificity in the diagnosis of PBC, but their sensitivity is low. 5% - 10% of PBC patients had negative or low titer of PBC specific antibody, so liver biopsy was needed.

►PSC：After excluding the evidence of secondary sclerosing cholangitis, the diagnosis of PSC is usually based on abnormal liver function chronic cholestasis index (ALP), accompanied by typical cholangiography results (endoscopic retrograde cholangiography or magnetic resonance cholangiography shows "beaded" changes of intrahepatic and / or extrahepatic bile ducts caused by multifocal stenosis). The typical pathological feature of liver biopsy is "onion skin like" fibrosis, but it rarely occurs.

The progression of acute AIH to fulminant liver failure is an uncommon but poor prognosis complication. Chronic AIH, PBC and PSC can progress to liver cirrhosis within several years. Liver cirrhosis can be further complicated by portal hypertension and hepatocellular carcinoma. In rare cases, PBC can develop portal hypertension before liver cirrhosis due to the compression of hepatic venules by inflammatory infiltration. PSC can also have unique complications, including bacterial cholangitis, cholangiocarcinoma, gallbladder cancer and inflammatory bowel disease associated colorectal cancer.

►AIH：The overall goal of treatment is to obtain liver histological remission, prevent the development of liver fibrosis and liver failure, and improve the survival time and quality of life of patients. Treatment mainly induces remission by glucocorticosteroids (most commonly prednisone) and maintains remission by immunomodulators such as azathioprine (first-line drug) or mycophenolate mofetil. Steroids are discontinued within weeks to months. The discontinuation of immunomodulators after clinical remission needs to be extremely cautious.

►PBC：Ursodeoxycholic acid (ucda) is a first-line treatment recognized by PBC, which can slow down the progress of most patients. When ucda response is poor, obectacholate is approved as an adjuvant treatment, or when ucda is intolerable, obectalic acid can be treated as a single drug.

►PSC：Several drug treatments (such as ucda, immunomodulators and antibiotics) have been tested in PSC patients. Although many of them show the ability to improve liver enzymes, there is still no strong evidence that these drugs reduce mortality or prevent disease progression.

 

Cindy