When a functional deficiency of AT is suspected it is necessary to determine whether there is a type I deficiency (reduced synthesis) or type II deficiency (synthesis of an abnormal protein). When a type II deficiency is confirmed further assays can be requested to fully characterise the deficiency as different mutations may carry varying thrombotic risk.
Tube
Coagulation Tube
05 (CP) – Citrate
Availability
Weekly
Additional Information
When a borderline or low level of antithrombin activity is detected, AT antigen is normally assayed to determine if the patient has a type I or II defect/deficiency. A repeatedly low ratio of AT activity/antigen can indicate the presence of a type II AT mutation capable of causing type II deficiency even in the absence of AT deficiency in the individual tested.
Turnaround Time
14 days
Send to
Specialist Coagulation
Centre for Laboratory Medicine
St James University Hospital
Beckett Street
Leeds
LS9 7TF
Contact
Link to Advice
OR Haemostasis/Haematology Consultant
Collection Con
1 x citrate sample filled to the line please. 2 x citrate samples if further investigations are required. Samples must be processed within 6 hours.
Frequency
Weekly
Sample REQ
Blood
Sample Storage REQ
Plasma aliquots from primary samples (post-analysis) stored frozen at -20 degrees – 1 month or -80 degrees for 2 months (Specialist Coagulation Assays SJUH)
Ref. Range (Male)
0.83 – 1.24 iu/mL
Ref. Range (Female)
0.83 – 1.24 iu/mL
Units
iu/mL
IP Acute TAT
N/A
IP Routine TAT
N/A
GP Acute TAT
N/A
GP Routine TAT
N/A