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Haematology


Full details for "Homocysteine (Hcy.)".  

Name

 Homocysteine (Hcy.)

Alternative name/Profile

 Hcy

Department

 Haematology

Investigation

 Homocysteine can be used by clinicians as an aid in the diagnosis of inherited disorders of methionine metabolism including cystathionine synthase deficiency (homocystinuria), methylenetetrahydrofolate reductase deficiency and its thermolabile variants, and methionine synthase deficiency. It can be used for evaluating patients for suspected deficiency of vitamin B12 or folate also.

Specimen type

 Peripheral Blood

Sample type

Sample container & volume

 4mL purple EDTA on ice

Frequency of analysis

 Once a fortnight

Turnaround time

 14 working days

Availability

 Routine hours 9am to 5pm Monday-Friday Available to internal SJH patients, External Hospitals and GP patients.

Notes

Essential Sample Processing Requirements:

Inpatients: EDTA sample must be sent immediately to the laboratory on ice within 1 hour of collection.

External Sources: EDTA sample must be sent immediately to own hospital laboratory on ice within 1 hour of collection. Plasma must then be separated immediately and transported to St James' Hospital on ice on the same day. Do not send frozen plasma.

GP Requests: Please refer patient to St James' Hospital phlebotomy for specimen collection due to sample stability requirements.

This assay is now run on the Abbott Alinity platform. Please note new reference range.

Limitations:

  • The following drugs may elevate levels of homocysteine: methotrexate, carbamazepine, phenytoin, nitrous oxide, anticonvulsants and 6-azauridine triacetate. The mechanism of action of these drugs affects different parts of the metabolic pathway of homocysteine.
  •  S-adenosyl-methionine is an antidepressant whose molecular form is similar to S-adenosyl-homocysteine. This drug may interfere with the Alinity i Homocysteine assay.
  • Specimens from patients who have received preparations of mouse monoclonal antibodies for diagnosis or therapy may contain human anti-mouse antibodies (HAMA). Such specimens may show either falsely elevated or depressed values when tested with assay kits such as Alinity Homocysteine that employ mouse monoclonal antibodies. Additional information may be required for diagnosis.
  • Heterophilic antibodies in human specimens can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference and anomalous values may be observed. Additional information may be required for diagnosis.

Please contact the laboratory 01 4162012 for further information regarding limitations to this assay.

 

Related links

Reference range

Female 4.4- 13.6 µmol/L

Male 5.5- 16.2 µmol/L

Last updated

Fri, 23 Jan 2026 08:29:05 GMT


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