Clinical significance

CLINICAL SIGNIFICANCE

  • In man and all primates, uric acid is the end product of purine metobolism.                                           
  • In plasma at pH 7.4, uric acid is in the ionized form of monosodium/potassium urate, and only a minor portion as a free acid.
  • Its determination help in differentiating gout from non-gout arthritis.
  • Increased levels are observed in gout , leukemia, broncho and lobar pneumonia and polycythemia.

Gouty hands

Physiologic changes in serum concentration of uric acid 

  • About 350 mg of uric acid are daily produced by endogenous synthesis, while about 300 mg/day are taken by food. 

    • About 90% of uric acid filtered in glomeruli are normally reabsorbed in renal tubules. Uric acid is normally excreted from the body via kidneys (80%) and intestine (20%). About 4.76 mmol (800 mg) are excreted per day.
    • Extreme physical exercise induces a significant increase in the concentration of uric acid.
    • Starvation and fat rich diet increase the concentration of uric acid in serum.

Pathologic changes in serum concentration of uric acid

  • Increased values of uric acid in:

  • coronary artery disease  
  • Down’s syndrome (some cases) 
  • gout  
  • hyperlipoproteinemia
  • myeloid leukemia    
  • pneumonia
  • uremia 
  • diabetic keto-acidosis following intravenous fructose
  • tissue destruction 
  • hemolytic anemias    
  • lead poisoning 
  • pernicious anemia (especially after treatment)
  • primary and secondary polycythemia

  •  Decreased values of uric acid in
    • acromegaly (some cases)
    • administration of uricosuric drugs
    • Fanconi syndrome
    • hepatolenticular degeneration 
    • xanthiuria.     
Last modified: Saturday, 26 November 2011, 6:43 AM