Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (167 page)

FATTY LIVER

   Nonalcoholic steatohepatitis in most cases may have a history of metabolic syndrome. Nutritional (e.g., alcoholism, malnutrition, starvation, rapid weight loss)

   Causes

   Drugs (e.g., aspirin,
^†
glucocorticoids,
*
synthetic estrogens,
*
some antiviral agents,
*
^,
†
calcium channel blockers,
^†
cocaine,
^†
methotrexate,
*
valproic acid
^†
)

   Metabolic/genetic (e.g., acute fatty liver of pregnancy, dysbetalipoproteinemia, Weber-Christian disease, cholesterol ester storage,
^‡
Wolman disease
^‡
)

   Other (e.g., HIV infection,
B. cereus
toxins, liver toxins [e.g., organic solvents, phosphorus], small bowel disease [inflammatory, bacterial overgrowth], fatty liver of pregnancy)

   Laboratory Findings

   
Histology
: Biopsy of the liver establishes the diagnosis. Fatty liver may be the only postmortem finding in cases of sudden, unexpected death.

   
Core laboratory
: Most commonly, serum AST and ALT are increased 2–3×; usually ALT > AST in NAFL. Serum ALP is normal or slightly increased in <50% of patients. Other liver function tests are usually normal. Increased serum ferritin (≤5×) and transferrin saturation occur in approximately 60% of cases.

   
Serology
: Tests for viral hepatitis are negative.

Considerations

   Laboratory findings are due to underlying conditions (most commonly alcoholism; nonalcoholic fatty liver [NAFL] is commonly associated with type 2 DM [≤75%], obesity [69–100%], hyperlipidemia [20–81%]; hypertension malnutrition, toxic chemicals). NAFL is distinguished by negligible history of alcohol consumption and negative random blood alcohol assays. Cirrhosis occurs in ≤50% of alcoholic and ≤17% of nonalcoholic cases.

FATTY LIVER OF PREGNANCY, ACUTE

   The incidence is ≤1 per 15,000 deliveries; usually occurs >35th week of pregnancy.

   This is a medical emergency because of high maternal and fetal mortality that is markedly improved by termination of pregnancy.