Uric Acid Determination - Almaaqal University PDF

Almaaqal University Biochemistry Determination of Uric acid in Serum Dr/ Wael Sobhy Darwish Biochemistry PhD  Uric acid Uric acid is produced by the breakdown of purines, which are n...

Almaaqal University Biochemistry Determination of Uric acid in Serum Dr/ Wael Sobhy Darwish Biochemistry PhD  Uric acid Uric acid is produced by the breakdown of purines, which are nitrogen-containing compounds found in the body in substances such as nucleic acids (DNA, RNA). Uric acid formation occurs in the liver. Food and drinks high in purines include: Red meat, liver, seafood (especially salmon, shrimp, and sardines). Food and drinks with high fructose corn syrup, spinach, mushrooms, green peas, beans, and wheat germ , and alcohol. Excretion: Most uric acid is removed by the kidneys and the remainder is excreted in the stools  Increased levels of uric acid in the blood can accumulate in the body and cause in the joints leading to gout. Excess uric acid can also lead to kidney disease, as a result of deposition in the kidneys or kidney stone formation, as a result of increased urinary excretion. The accumulation of too much uric acid is due to either increased production, decreased elimination or a combination of both.  Symptom of gout Arthritis that causes pain, swelling and redness in the joints. Fatigue. Renal issues, including kidney stones, weight loss, joint heaviness or sensitivity.  Why Uric acid test is done? 1. Help diagnose and monitor treatment gout. 2. Check to see if kidney stones may be caused by high uric acid levels in the body. 3. Check to see if medicine that increases or decreases uric acid levels is working. 4. Check uric acid levels in people who are taking chemotherapy or radiation therapy  ASSAY PRINCIPLE It was determined by Enzymatic, colorimetric method with uricase and 4-aminoantipyrine. The intensity of the color produced is directly proportional to uric acid concentration. It is determined by measuring the increase in absorbance at 500 – 550 nm  PROCEDURE 1. Assay conditions: Wavelength: 500 - 550 nm Cuvette: 1 cm light path Temperature: 37ºC /15-25ºC Sample Serum or plasma with out any preparation Fasting for 4 hours is better  PROCEDURE Blank Standard Sample WR(mL) 1.0 1.0 1.0 Standard (µL) -- 20 -- Sample (µL) -- -- 20 Mix and incubate for 5 min. at 37ºC or 10 min. at room temperature Read the absorbance (A) of the samples and Standard, against the Blank. The colour is stable for at least 60 minutes  Calculation Total Protein concentration = Expected Value Male : 3.4 – 7.0 mg/dl Female: 2.4 – 6.0 mg/dl Hyperuricemia: Purine -rich diet. Obesity or Metabolic Syndrome Hypothyroidism Certain medicines like Diuretics or Immune-suppressing/ Chemotherapy drugs or certain vitamins replacement therapy Excessive alcohol intake Genetics or familial (Hereditary) Kidney disease (inability of the kidneys to filter waste) Certain type of Cancers  Treatment Treatment has two objectives: Manage symptoms of acute attacks Take one or more of the following medicine 1. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ketoprofen 2. Colchicine prevents gout attacks 3. Corticosteroids Note: Avoid aspirin because it may abruptly change uric acid levels in the blood and may make symptoms worse. Prevent recurrent attacks such as: Uricosuric agents increase elimination of uric acid by the kidneys. Allopurinol decreases production of uric acid by the body.