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Liver Function Test AbnormalityAka: LFT Abnormality

See Also
1. Liver Function Test
Epidemiology
1. Mild transaminase elevations (<5x normal) are common
Focus of evaluation
1. Iatrogenic or Treatable disease
2. Communicable or Inheritable disease
3. True abnormality versus false positive testing
History
1. Medications
  1. Aminotransferase Elevations (ALT, AST)
    1. See Hepatotoxin
  2. Cholestatic Elevations (Alkaline Phosphatase, GGT)
    1. Sulfonamides
    2. Augmentin
    3. Erythromycin
    4. Captopril
    5. Oral Hypoglycemics
    6. Chlorpromazine
    7. Imuran
2. Alcohol Abuse (Alcoholic Hepatitis)
3. Contagious Contacts (Viral Hepatitis)
  1. Sexually Transmitted Disease
  2. Intravenous Drug Abuse
  3. Transfusions
  4. Needle sticks
Symptoms(mild elevations are usually asymptomatic)
1. Constitutional Symptoms
  1. Fever
  2. Weight loss
  3. Fatigue
  4. Malaise
  5. Nausea or Vomiting
2. Pruritus
3. Arthralgias
Signs
1. Weight loss
2. Stigmata of Chronic Liver Disease or Cirrhosis
  1. Gynecomastia
  2. Testicular atrophy
  3. Spider nevi
  4. Finger nail Clubbing
  5. Asterixis
3. Abdominal exam
Differential Diagnosis (Transaminase elevation)
1. Alcohol (27%)
2. Idiopathic Fatty Liver (19%)
3. Hepatitis C (18%)
4. Hemochromatosis (3%)
5. Autoimmune causes (1%)
6. Alpha-1 antitrypsin deficiency (1%)
7. Primary biliary Cirrhosis (0.3%)
Labs
1. See Liver Function Test
2. Markers of hepatocyte injury
  1. Alanine transaminase (ALT)
    1. Most specific for hepatocyte injury
  2. Aspartate transaminase (AST)
    1. Less specific than ALT (present outside liver)
    2. AST/ALT ratio >2 in Alcoholism and Wilson's Disease
  3. Lactate Dehydrogenase (LDH)
    1. Least specific for hepatocyte injury
    2. Dramatically increased in ischemic hepatitis
    3. Increased with alk phos in liver metastases
3. Markers of cholestasis
  1. Serum Alkaline Phosphatase
  2. Gamma glutamyl transferase (GGT)
  3. Serum Bilirubin
4. Marker of liver function and protein synthesis
  1. Serum Albumin
  2. Prothrombin Time
Imaging
1. Abdominal ultrasound right upper quadrant
  1. Preferred cost-effective evaluation
2. Abdominal CT
  1. Consider if ultrasound is non-diagnostic
Management: Increased serum transaminases (ALT, AST)
1. See Alkaline Phosphatase for cholestasis causes
2. Step 1: Obtain initial lab work
  1. Hepatic panel (as above)
  2. Prothrombin Time
  3. Serum Albumin
  4. Complete Blood Count with platelets
  5. Viral Hepatitis Serology
    1. Hepatitis A Serology
    2. Hepatitis B Serology (HBsAg)
    3. Hepatitis C Serology
    4. Consider Monospot
  6. Ferritin, Serum Iron and TIBC (Hemochromatosis)
  7. Fasting lipid profile and fasting glucose
3. Step 2: Evaluate labs, history and examination
  1. Treat specific causes
4. Step 3: General measures if no cause identified
  1. Avoid Hepatotoxins
    1. Withdraw suspected medications
    2. Abstain from alcohol use
  2. Reduce hepatic Steatosis risks
    1. Weight loss if overweight
    2. Improve blood sugar control in Diabetes Mellitus
    3. Treat Hyperlipidemia (esp. serum Triglycerides)
  3. Repeat Liver Function Tests in 2-6 months
    1. Obtain imaging as above if elevations persist
5. Step 4: Abnormal transaminases persist on recheck
  1. Obtain Ultrasound of right upper quadrant
  2. Obtain disease specific markers
    1. Complete initial labs in Step 1 if not done
    2. Ceruloplasmin (Wilson's Disease)
    3. Antinuclear Antibody
    4. Anti-Smooth Muscle Antibody
    5. Alpha-1-antitrypsin
    6. Anti-tissue transglutaminase antibody: Celiac Sprue
  3. If testing as above is negative for specific cause
    1. Obese patient: See Steatosis
    2. Non-obese Patient
      1. Aminotransferases exceed twice normal
        
        Refer to Gastroenterology for biopsy
      2. Aminotransferases mildly elevated
        
        Follow serial Aminotransferases (AST, ALT)
References

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This page was written by Scott Moses, MD, and was last revised 1/26/2008. Please send comments and questions to the editor. Contact information may be found on the page About the Family Practice Notebook. These pages are best viewed with Microsoft Internet Explorer 5.0.