The diagnosis of autoimmune hepatitis is best achieved with a combination of clinical, laboratory, and histological findings after excluding other etiological factors (e.g. viral, hereditary, metabolic, cholestatic, and drug-induced liver diseases). The requirement for histological examination necessitates a liver biopsy, typically performed with a needle by the percutaneous route, to provide liver tissue. Autoantibodies A number of specific antibodies found in the blood (antinuclear antibody (ANA), anti-smooth muscle antibody (SMA), anti-liver kidney microsomal antibodies (LKM-1, LKM-2, LKM-3), anti soluble liver antigen (SLA), liver–pancreas antigen (LP), and anti-mitochondrial antibody (AMA)) are of use, as is finding an increased immunoglobulin G level. The presence of anti-mitochondrial antibody is more suggestive of primary biliary cholangitis. Hypergammaglobulinemia is also of diagnostic value. Histology Autoimmune hepatitis can be characterized histologically by the following nonspecific findings: * Portal mononuclear cell infiltrate that invades the boundary surrounding the portal triad and infiltrates the surrounding lobule. * Periportal lesions, also known as interface hepatitis, that spare the biliary tree (may include centrizonal necrosis). * Bile duct abnormalities (cholangitis, ductal injury, ductular reaction) can be seen and should prompt evaluation for primary biliary cholangitis or sarcoidosis if granulomas are observed. * Plasma cell infiltrate, rosettes of hepatocytes, and multinucleated giant cells. * Varying degrees of fibrosis (except in the mildest form of autoimmune hepatitis). Bridging fibrosis that connects the portal and central areas can distort the structure of the hepatic lobule and result in cirrhosis. Diagnostic scoring The Internal Autoimmune Hepatitis Group developed a standardized scoring system for clinical diagnosis in population studies but lacks value in individualized cases. A simplified scoring system for clinical use incorporates titers of autoantibodies, total IgG levels, liver histology, and the exclusion of viral hepatitis for diagnostic scoring. Classification On the basis of detected autoantibodies, autoimmune hepatitis can be classified into three subtypes but have no distinct clinical presentations. * Type 1 autoimmune hepatitis. Positive antibodies include: * Antinuclear antibody (ANA) * Anti-smooth muscle antibody (ASMA) - 65% of people * Anti-actin antibodies * Anti-mitochondrial antibodies - rare except for overlap syndromes with primary biliary cholangitis * Anti-soluble liver antigen/liver pancreas antibody antigen - 20% of people * Anti-double stranded DNA - 30% of people * Atypical perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) * Type 2 autoimmune hepatitis. Positive antibodies include: * Liver Kidney Microsomal antibody (LKM-1) * Anti-liver cytosol antibody-1 (SLC-1) * Autoantibody negative autoimmune hepatitis. * Lack positive ANA, ASMA, LKM-1, etc. antibody panels but present with clinical features of autoimmune hepatitis that resolve with standard treatment. Differential diagnosis Other diagnoses to consider include conditions that may cause acute hepatitis or chronic liver inflammation that may be accompanied by cirrhosis: * Other autoimmune diseases that involve the liver: * Primary biliary cholangitis - the presence of isolated elevated AMA antibodies usually signifies primary biliary cholangitis rather than autoimmune hepatitis and further diagnostic evaluation is needed. * Overlap syndromes - autoimmune hepatitis may present similarly to primary sclerosing cholangitis but people with primary sclerosing cholangitis have stricturing and dilatation of intra/extra-hepatic ducts while people with autoimmune hepatitis generally have a spared biliary tree. * Other causes of hepatitis: * Viral hepatitis - it is necessary to distinguish autoimmune hepatitis from acute hepatitis caused by Hepatitis A/B/C/D/E, herpes simplex, varicella zoster, EBV, CMV virus * Drug-induced liver injury - portal neutrophils are more prevalent in drug-induced liver injury on liver biopsy and can help distinguish the two * Nonalcoholic steatohepatitis - related medical history and liver biopsy showing fatty infiltration and the presence of neutrophils and central fibrosis can distinguish the two * Lupus-associated liver disease - rarely presents with elevated ASMA or AMA antibodies * Acute liver failure - people with acute liver failure may have elevated autoantibodies but the antibodies alone are not enough for the diagnosis of autoimmune hepatitis * Iron overload - elevated iron in the body can cause liver inflammation
medical cause of Hepatitis
complications of Hepatitis B
complications of Hepatitis E
complications of Hepatitis A
complications of Hepatitis
medical cause of Cirrhosis
medical cause of Liver cancer
symptom of Hepatitis D