autoimmune hepatitis
Introduction
Introduction to autoimmune hepatitis Autoimmune hepatitis is a chronic progressive hepatic inflammatory disease mediated by autoimmune response. Its clinical features are elevated levels of serum transaminases, high gamma globulinemia, autoantibodies, and histological features of lymphoid Intercellular hepatitis, which is mainly infiltrated by cells and plasma cells, can rapidly progress to cirrhosis and liver failure in severe cases. The disease has occurred in the world, and the incidence rate is relatively high in Europe and the United States. The exact incidence and prevalence rate in China is still unclear, but the number of cases reported in the domestic literature shows a clear upward trend. According to serum autoantibodies, AIH can be divided into type 3, type I AIH is the most common, related antibodies are ANA and/or SMA; type II AIH is characterized by anti-LKM1 positive; type III AIH is characterized by serum anti-SLA/ LP positive. Some scholars believe that type III should be classified as type I. There is no significant difference in the etiology of various types and the efficacy of glucocorticoids, so the classification is of little significance for clinical guidance. basic knowledge The proportion of illness: 0.003% Susceptible people: no specific population Mode of infection: non-infectious Complications: jaundice, nausea and vomiting
Cause
Cause of autoimmune hepatitis
Genetic factors (45%)
At present, genetics is considered to be the main factor of autoimmune hepatitis. Genetic susceptibility can affect the immunoreactivity and clinical manifestations of the body's own antigen. Human leukocyte antigen and DR are independent risk factors for autoimmune research hepatitis.
Viral infections and drugs (15%)
Viral infections and drugs can act as triggers, causing the body to respond to autologous hepatocyte antigens, manifested by cell-mediated cytotoxicity and the immune response of hepatocyte surface-specific antigens combined with autoantibodies. Mainly. Promote the onset of autoimmune hepatitis.
Environmental factors (5%)
Some scholars believe that the environment is also a predisposing factor for the disease.
Pathological change
The most important histological change in AIH is interface hepatitis, where a large number of plasma cells infiltrate in the portal area and invade the surrounding liver parenchyma to form interfacial inflammation. Hepatocytes can be seen in the hepatic lobules to form rosettes (multiple hepatocytes surrounding the bile duct) and/or punctate, fragmented necrosis. Bridge necrosis and even multiple leaflet necrosis may also occur when the disease progresses, but the inflammation in the portal area generally does not invade the biliary system, and there is no steatosis and granuloma. Almost all AIH have different degrees of fibrosis, and cirrhosis can occur in severe cases. Although the above pathological changes have certain characteristics, they are not specific, and sometimes they are not easily distinguished from chronic viral hepatitis, alcoholic hepatitis, drug-induced hepatitis, PBC, and PSC. Liver biopsy histology combined with serum immunological tests contributes to the differentiation of AIH from these diseases.
Prevention
Autoimmune hepatitis prevention
Autoimmune hepatitis is closely related to genetic factors, so this kind of hepatitis is difficult to prevent, but it can be controlled. Therefore, it is extremely important to find early treatment. In particular, patients with liver disease who are not at risk of alcohol, drugs, and viral pathogens should be alert to autoimmune hepatitis. Develop good habits, and a healthy diet can reduce the burden on the liver and protect it.
Complication
Autoimmune hepatitis complications Complications jaundice nausea and vomiting
The prognosis of AIH varies widely. Untreated patients can progress to cirrhosis slowly, or develop into acute, subacute, and fulminant liver disease, and eventually die with various complications. Retrospective analysis showed that patients with severe AIH had a survival rate of 50% if not treated for 3 years and 10% for 5 years. After treatment, the patient's 20-year survival rate reached 80%, and his life expectancy was not significantly different from that of normal healthy people matched by gender and age. Asymptomatic patients with HLA-DR3 have a relatively good prognosis. Early diagnosis and proper treatment are important means to improve prognosis.
Symptom
Autoimmune hepatitis symptoms common symptoms fever with joint swelling and pain jaundice
AIH lacks characteristic symptoms and signs. Although pathological changes have certain characteristics, they are also non-specific. Some patients have acute hepatitis and occasionally have fulminant hepatitis. The disease is more common in women, with two peaks at 10 to 30 years old and 40 years old. Symptoms vary in severity and mildness can be asymptomatic. Generally manifested as fatigue, upper abdominal discomfort, itching, loss of appetite and so on. Early liver, usually splenomegaly, jaundice, spider mites and so on. Late development of cirrhosis, may have ascites, hepatic encephalopathy.
Extrahepatic manifestations may have persistent fever with acute, recurrent, migratory arthritis; female patients usually have amenorrhea; may have bleeding gums, nosebleeds; full moon face, hemorrhoids, multiple body hair, skin purple lines; Inflammation and glomerulonephritis and other manifestations. When combined with extrahepatic manifestations, it is often suggested that the disease is in active phase.
Examine
Autoimmune hepatitis check
Liver function test
At the beginning of the disease, almost all patients have elevated serum transaminases, and transaminase levels are associated with liver necrosis, but if the number reaches several thousand, it indicates acute hepatitis or other diseases. Most of bilirubin and alkaline phosphatase are mild to moderately elevated, and a sharp rise in alkaline phosphatase often suggests a possible concurrent PBC or liver cancer.
Immunological examination
Serum gamma-globulin and IgG are elevated in AIH patients, and their levels reflect the patient's response to treatment. Changes in the level of autoantibodies can help assess disease, clinical typing, and guide treatment. These antibodies include antinuclear antibodies (ANA), anti-smooth muscle antibodies (SMA), anti-liver kidney microsomal antibodies (LKM1), anti-type 1 hepatocyte lysate antigen antibodies (LCl), anti-sweet liver antigen antibodies (anti-SLA)/ Anti-liver pancreatic antibody (anti-LP), anti-sialyl glycoprotein receptor antibody (ASGPR), anti-neutrophil cytoplasmic antibody (pANCA).
Histological examination
Hepatic biopsy histological examination helps to confirm the diagnosis and distinguish it from other diseases.
Diagnosis
Diagnosis and diagnosis of autoimmune hepatitis
diagnosis
For the clinical diagnosis of autoimmune hepatitis, clinical symptoms, signs, biochemical indicators, immunological examination, pathological examination, etc. should be combined. The basic points include: 1 to exclude viral hepatitis, alcohol, drugs and chemical hepatotoxic effects and hereditary liver disease; 2 significant abnormalities in transaminase; 3 hyperglobulinemia, gamma-globulin or IgG> 1.5 times the upper limit of normal; 4 serum autoantibodies positive, ANA, SMA or LMK1 antibody titer 1:80 (child 1:20); 5 liver histology see interfacial hepatitis and large infiltration of plasma cells in the portal area, without bile duct damage, granuloma, etc. Other liver disease lesions; 6 female patients, with other immune diseases and glucocorticoid treatment is effective to help diagnose.
Differential diagnosis
Primary biliary cirrhosis
Similar to AIH in clinical symptoms and laboratory tests, but more common in middle-aged women, with fatigue, jaundice, skin itching as the main performance, liver function tests alkaline phosphatase, -glutamyl transpeptidase Increased serum total cholesterol, triglyceride, low-density lipoprotein can be increased, and immunoglobulins are highlighted by IgM. Serum anti-mitochondrial antibody M2 is a disease-specific antibody, pathologically appearing biliary epithelial damage inflammation, bile duct disappearance and granuloma in the portal area contribute to the diagnosis of the disease.
2. Primary sclerosing cholangitis
It is characterized by extensive inflammation and fibrosis of the intrahepatic and extrahepatic biliary system. It is more common in young and middle-aged men, often with ulcerative colitis, and 84% of patients are positive for ANCA, but not specific. Cholangiography can be seen in the intrahepatic and extrahepatic bile duct stenosis and expansion and bead-like changes, the diagnosis needs to exclude tumors, stones, surgery, trauma and other secondary causes, the lesion only involving the intrahepatic small bile duct diagnosis requires histological examination, typically changed to fiber Sexual cholangitis.
3. Acute and chronic viral hepatitis
Hyperglobulinemia and circulating autoantibodies can also occur, but antibody titers are low and transient for a short period of time. Detection of serum viral antigens and antibodies is helpful for identification.
4. Alcoholic steatohepatitis
There is a history of drinking, mostly elevated serum IgA levels, although ANA and SMA can be positive, but the general titer is low, and few anti-LKM1 and PANCA positive.
5. Drug-induced liver damage
Most patients have a history of taking special drugs. After stopping the drug, the liver abnormalities can completely disappear. Generally, they will not develop into chronic hepatitis. Histopathological examination reveals necrosis of the lobular or acinar zone, eosinophil infiltration, simple cholestatic, granulation. Swelling hepatitis, hepatocyte steatosis, etc. can indicate drug-induced liver damage. However, it should be noted that some drugs can induce autoimmune reactions, clinical manifestations and laboratory tests are very similar to AIH, and the identification depends on pathology and the relief or recovery of the disease after stopping the drug.
