Autoimmune hepatitis, formerly known as lupoid hepatitis, plasma cell hepatitis, or autoimmune chronic active hepatitis, is a chronic, autoimmune disease of the liver that occurs when the bodys immune system attacks liver cells, causing the liver to be inflamed. Common initial symptoms may include fatigue, nausea, muscle aches, or weight loss or signs of acute liver inflammation including fever, jaundice, and right upper quadrant abdominal pain. Individuals with autoimmune hepatitis often have no initial symptoms and the disease may be detected by abnormal liver function tests and increased protein levels during routine bloodwork or the observation of an abnormal-looking liver during abdominal surgery.Anomalous presentation of MHC class II receptors on the surface of liver cells, possibly due to genetic predisposition or acute liver infection, causes a cell-mediated immune response against the bodys own liver, resulting in autoimmune hepatitis. This abnormal immune response results in inflammation of the liver, which can lead to further symptoms and complications such as fatigue and cirrhosis. The disease is most often diagnosed in patients in their late teens or early 20s and between the ages of 40 and 50. It affects women more commonly than men. Signs and symptoms
Autoimmune hepatitis may present completely asymptomatic (12–35% of the cases), with signs of chronic liver disease, or acute or even fulminant hepatic failure.People usually present with one or more nonspecific, long-lasting symptoms such as fatigue, general ill health, lethargy, weight loss, mild right upper quadrant abdominal pain, malaise, anorexia, itching, nausea, jaundice or joint pain especially affecting the small joints.
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.