Ordering Recommendation

Acceptable screening test for disorders of methionine metabolism (congenital hyperhomocysteinemia). Not recommended for risk assessment of cardiovascular disease or venous thromboembolism.

Mnemonic
HOMOCY-QNT
Methodology

Quantitative Enzymatic

Performed

Sun-Sat

Reported

Within 24 hours

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Green (lithium heparin) or serum separator tube.

Specimen Preparation

Serum or plasma must be separated immediately after collection. If immediate centrifugation is not possible, collected blood specimens should be kept on ice and centrifuged within one hour. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Sodium citrate.

Remarks
Stability

Ambient: 4 days; Refrigerated: 1 month; Frozen: 10 months

Reference Interval

Less than 11 µmol/L, for both male and female

Interpretive Data

Elevated total homocysteine (tHcy) concentrations may be associated with vitamin B12 deficiency, folate deficiency, or inherited disorders of methionine metabolism. tHcy may also be used as a weak-graded risk factor for cardiovascular disease or stroke.

Compliance Category

FDA

Note

False elevations of plasma or serum homocysteine may occur if the plasma or serum is not promptly separated from the cells at the time of collection. Fasting specimen preferred.

Hotline History
N/A
CPT Codes

83090

Components
Component Test Code* Component Chart Name LOINC
0099869 Homocysteine, Total 13965-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Plasma Total Homocysteine
Homocysteine, Total