Protein S Antigen, Free
| Label Mnemonic: | PSAF |
| Epic code: | LAB8982 |
| Downtime form: | A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Hematology
6240 RCP
356-3527
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
 |
| Light Blue top tube 2.7 mL (Na Citrate) |
Minimum:
Full draw, 2.7 mL light blue top tube
Rejection Criteria:
Short drawn tube, clot, traumatic tap (excessive hemolysis).
Testing Schedule:
0800-1630 Monday, Wednesday and Friday. If you need results STAT, call Hematology resident (0800-1630, M-F) at 356-8628. All other times page the Pathology resident on-call at 3404.
Turn Around
Time:
1-3 days upon receipt in laboratory
Reference Range:
Females: 66-147%
Males: 73-139%
Males: 73-139%
Interpretive Data:
Patients on warfarin may have decreased free protein S antigen concentrations. Warfarin therapy should be discontinued for at least two weeks prior to protein S testing. Decreased concentrations of free protein S antigen are also associated with liver disease, vitamin K deficiency, acute thrombosis, and DIC. Pregnancy, estrogen therapy, nephrotic syndrome, and inflammatory syndromes increase C4b binding protein concentrations, thus decreasing free protein S levels.
Methodology:
Immunoturbidimetric assay
CPT Code:
85306