Autoimmune Hepatitis – Top USMLE Diseases

Primary sclerosing cholangitis (PSC) is an inflammatory disease that causes fibrosis and strictures of the bile ducts. The exact etiology is unknown, but there is a strong association with inflammatory bowel disease (IBD). Patients typically present with an insidious onset of fatigue, pruritus, and jaundice, which can progress to cirrhosis and complications related to biliary obstruction. The diagnosis is established with magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP). Liver transplantation is the only definitive treatment and is indicated in patients with advanced liver disease.

The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism (carbohydrates, proteins, lipids, hormones), nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. The liver can be divided into 4 lobes or 8 segments. Microscopically, it is divided into hepatic lobules. Its main neurovascular bundle is found within the transverse fissure of the liver, also called the porta hepatis.

Autoimmune hepatitis (AIH) is a rare form of chronic liver disease in which the immune system attacks the liver causing inflammation. It predominantly affects women. Clinical presentation ranges from asymptomatic cases to patients that present with symptoms of acute liver failure (jaundice, right upper quadrant pain). Because AIH has a 40% mortality in 6 months without treatment, early diagnosis and treatment are imperative. Diagnosis is established by detecting anti-smooth muscle antibodies and performing a confirmatory liver biopsy. Treatment includes corticosteroids and azathioprine. If treatment is initiated early in the disease course, the prognosis is favorable.

Viral hepatitis can be caused by different kinds of viruses which include hepatitis A, B, C, D, and E. These viruses cause targeted inflammation of the liver. In the acute stage, patients develop non-specific symptoms, such as nausea, vomiting, anorexia and abdominal pain. Later on, jaundice becomes evident. During this stage, supportive therapy is important. Antiviral therapy is indicated in the acute and chronic stages of hepatitis B and C.

Autoimmune diseases are a group of disorders that are characterized by abnormal reactions of the immune system against one’s own body. These usually manifest during the middle years and are, most of the time, chronic. Approximately 3.2 % of the global population is composed of people who are afflicted with these, being generally more common among women.