HOMOCYSTEINE, SERUM

LAB93

5.0 mL Gold SST

Centrifuge the specimen immediately. Hemolyzsed, turbid or severly lipemic specimens are not recommended.Collect on ice and centrifuge immediately

SST

Refrigerate

Gross hemolysis

Set Up:Daily Report Available:8 hours

Specimens from patients who are on drug therapy involving S‑adenosylmethionine may show falsely elevated levels of homocysteine. Patients who are taking methotrexate, carbamazepine, phenytoin, nitrous oxide, anticonvulsants, or 6‑azauridine triacetate may have elevated levels of homocysteine due to their effect on the pathway. 

Female: 4.60-12.44 umol/L Male: 6.26-15.01 umol/L

Homocycteine (Hcy) is a thiol- containing amino acid produced by the intracellular demethylation of methionine. Total Homocysteine (tHcy) represents the sum of all forms of Hcy including forms of oxidatized, protein-bound and free. Elevated levels of tHcy has emerged as an important risk factor in the assessment of cardiovascular disease. Excess Hcy in the blood stream may cause injuries to arterial vessels due to its irritant nature, and result in inflammation and plaque formation,which may eventually cause blockage of blood flow to the heart. Elevated tHcy levels are caused by four major factors, including; 1. genetic deficiencies in enzymes involved in Hcy metabolism such as cystathiol beta-synthase(CBS), methionine synthase (MS), and methyleneterahdrofolate reductase(MTHFR): 2. nutritional deficiency in B vitamine such as B6, B12and folate 3. renal failure for effective amino acid clearance 4. drug interactions, such as with nitric oxide, methotrexate and phenytoin that interfere with hcy metabolism. Elevated levels of tHcy are also linked with Alzheimers disease and osteoporosis. Guidelines for tHcy determination in clinical laboratories have recently been established.