A 38-year-old woman is evaluated for elevated results of liver chemistry tests detected in an evaluation for new-onset fatigue, joint pains, and jaundice. The patient recently started a job in a hospital and received a hepatitis B vaccination. She has a history of hypothyroidism, and her only medications are levothyroxine and a multivitamin. She has never used illicit drugs and does not drink alcohol. Her mother has rheumatoid arthritis.

On physical examination, the patient is afebrile; the blood pressure is 130/75 mm Hg, the pulse rate is 80/min, and the respiration rate is 14/min. The BMI is 26. There is scleral icterus; the rest of the examination is normal.

Laboratory studies:
Leukocyte count
3400/µL (3.4 × 109/L) with a normal differential
Bilirubin (total)
6.0 mg/dL (102.6 µmol/L)
Bilirubin (direct)
3.6 mg/dL (61.6 µmol/L)
Aspartate aminotransferase
890 U/L
Alanine aminotransferase
765 U/L
Alkaline phosphatase
120 U/L
Antinuclear antibody
Titer 1:40
Anti–smooth muscle antibody
Titer 1:640
Antimitochondrial antibody
Negative

Viral serologic tests are negative.

Which of the following is the most likely diagnosis?

Correct

Answer and Critique (Correct Answer: B)

Educational Objective:Diagnose autoimmune hepatitis.

Key Point

  • Laboratory findings in patients with autoimmune hepatitis include elevated serum aminotransferase values, hypergammaglobulinemia, mild hyperbilirubinemia, elevated serum alkaline phosphatase values, and the presence of autoantibodies.

This patient has autoimmune hepatitis, a disorder that occurs most commonly in girls and young women. Like this patient with hypothyroidism, many affected patients have other autoimmune disorders and a family history of autoimmunity. These patients usually present with vague symptoms. Fatigue, which occurs in 85% of patients, is the most common presenting symptom, followed by jaundice (46%), anorexia (30%), myalgias (30%), and diarrhea. On physical examination, 78% of patients have an enlarged liver. Others have a normal examination despite the presence of advanced disease. The results of liver chemistry tests can be quite elevated, with aminotransferase concentrations into the thousands, but typically less than 500 IU at presentation, with elevated bilirubin, often with near-normal alkaline phosphatase. Autoimmune serologic tests, specifically antinuclear antibodies, anti–smooth muscle antibodies, and antibody to liver/kidney microsome type 1 (anti-LKM1), may be positive but are not detected in up to 25% of patients. Antibody levels are not prognostic of the disease course.

Primary biliary cirrhosis is a chronic progressive cholestatic liver disease of unknown cause. It is an autoimmune disorder that occurs predominantly in women (80% to 90% of cases) between 40 and 60 years of age. The diagnostic triad associated with primary biliary cirrhosis includes a cholestatic liver profile, positive antimitochondrial antibody titers, and compatible histologic findings on liver biopsy. Serum alkaline phosphatase level is usually elevated ten times or more above normal. The patient’s near normal alkaline phosphatase concentration and negative antimitochondrial antibody essentially rule out primary biliary cirrhosis. Although drug-induced liver injury can cause similar liver test abnormalities, the patient has not taken any new medications recently, making this diagnosis unlikely. She has no pain to suggest cholecystitis. Primary sclerosing cholangitis is a chronic cholestatic liver disease of unknown cause that is characterized by progressive bile duct destruction and may lead to secondary biliary cirrhosis. Laboratory findings include a cholestatic liver profile, with serum alkaline phosphatase levels three to five times greater than normal and mild hyperbilirubinemia. This patient’s alkaline phosphatase level is minimally elevated making primary sclerosing cholangitis unlikely.

Bibliography

  • Krawitt EL. Autoimmune hepatitis. N Engl J Med. 2006;354(1):54-66. [PMID:16394302] - See PubMed
Incorrect

Chưa chính xác. Xin chọn lại

Leave a Reply

Your email address will not be published. Required fields are marked *