Protein C antigen

Description: 
Quantitative determination of Protein C antigen by immune-turbidimetric method.

This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2012.
Clinical details: 
Protein C, thrombin, and endothelial cells, through complex interactions with other factors in the coagulation cascade, contribute to the maintenance of normal haemostatic mechanisms by down-regulating clot formation and by promoting fibrinolysis. Protein C is a vitamin K dependent glycoprotein, which inhibits and regulates coagulation through specific cleavages of Factors Va and VIIIa, suppressing their pro-coagulant cofactor activity. Protein C is commonly measured along with other factors, including protein S and antithrombin, to identify heritable thrombophilia.Protein C deficiency, either congenital or acquired, may lead to serious thrombotic events. A decreased Protein C activity in plasma may be the result of low concentrations and thus function (type 1), or only low function (type II). The measurement of Protein C Antigen levels aids classification of Protein C deficiency and would normally be used a second line test following Protein C Activity testing.
Related condition or disease: 
Venous thromboembolism, thrombophilia
Reference range: 

68 – 142 iu/dL

Synonyms or keywords: 
PC AG, protein C
Units: 
iu/dL
Department: 
Haemostasis and Thrombosis Department
Location: 
St Thomas' Hospital
Sample type and Volume required: 
External requests: Citrated platelet poor plasma (500µL x 1 aliquot).
Internal requests: please refer to EPR label
Call in advance: 
Yes
Turnaround time: 
1 month
Special sample instructions: 

The sample should be analysed or processed & stored within 8 hours of venepuncture. Please ensure sample tubes are filled exactly to the fill-line as underfilling or overfilling creates a dilution error and leads to inaccurate results.

Criteria for acceptance / rejections of sample
Storage and transport: 
It is advised that citrated plasma is frozen prior to transport and sent to the laboratory on dry ice to maintain sample quality and integrity. If whole blood citrate sample is sent, it is required to be sent at room temperature and must arrive to the laboratory within 8 hours of venepuncture.
Contacts:
Diagnostic Haemostasis and Thrombosis Department
St Thomas': 020 7188 2797; Guy's: 020 7188 7188 ext. 53860
St Thomas' Hospital
North Wing - 4th and 5th Floors
Westminster Bridge Road
London SE1 7EH

Laboratory opening times
24/7

Guy's Hospital
Southwark Wing - 4th Floor
Great Maze Pond
London SE1 9RT

Outside core hours, contact Duty Haemostasis Biomedical Scientist
For clinical advice or interpretation of results, please contact the laboratory in the first instance.
Laboratory: 
Diagnostic Haemostasis and Thrombosis Laboratory at Guy's and St Thomas'

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Last updated: 06/04/2023