Disease Correlation

Enzyme testing is a cornerstone of clinical diagnostics. Connecting enzyme levels to specific diseases is crucial for accurate diagnoses and treatment

  • Key Considerations: Tissue Distribution, Kinetics, and Sensitivity/Specificity

  • Clinical Significance: Aid in differential diagnoses and disease stages

Cardiac Markers

  • Creatine Kinase - MB (CK-MB)
    • Laboratory Findings: Elevated in serum, peaks within 24 hours
    • Disease State Correlation: Myocardial Infarction
      • Elevated CK-MB confirms myocardial necrosis
    • Clinical Significance: To support a diagnosis of myocardial infarction
    • Troponin (I or T): A protein that is a more specific indicator of myocardial damage than CK-MB

Liver Function

  • Alanine Aminotransferase (ALT)
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Hepatitis
    • Clinical Significance: High level can confirm that hepatitis is present
  • Aspartate Aminotransferase (AST)
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Liver Damage, Myocardial Infarction, Muscle Injury
    • Clinical Significance: Used to assess liver damage
  • Alkaline Phosphatase (ALP)
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Biliary Obstruction, Bone Disease
    • Clinical Significance: Help determine liver damage vs bile duct restriction
  • Gamma-Glutamyl Transferase (GGT)
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Alcohol-Induced Liver Disease, Biliary Obstruction
    • Clinical Significance: Help to confirm liver damage and bile duct restrictions, but moreso from alcohol

Pancreatic Function

  • Amylase
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Pancreatitis
    • Clinical Significance: Support a diagnosis of pancreatitis
  • Lipase
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Pancreatitis
    • Clinical Significance: Help diagnose pancreatitis - more specific to the pancreas

Muscle Damage

  • Creatine Kinase (CK) - Total
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Rhabdomyolysis
    • Clinical Significance: Confirm if muscles are damaged

Other Enzymes

  • Acid Phosphatase
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Prostate Cancer
    • Clinical Significance: To check for prostate cancer
  • Angiotensin-Converting Enzyme (ACE)
    • Laboratory Findings: Elevated in serum
    • Disease State Correlation: Sarcoidosis
    • Clinical Significance: Help support a diagnosis of sarcoidosis

Key Considerations

  • To confirm if the appropriate tissues are damaged
  • To rule out other causes for the elevated enzymes
  • To test for other isoenzymes or biomarkers that may correlate with the current lab results

Caveats

  • Enzymes can be elevated due to injury or damage to cells
  • Enzyme activity can be influenced by interfering substances
  • Normal range can vary