Alpha-1-Antitrypsin Clearance
Order Code: A1AC
Epic Lab Code: LAB2565
Order Form: A-1a Miscellaneous Request or Epic Req
Commercial Mail-out Laboratory
6240 RCP
356-3527
Specimen:
Serum and Feces
Collection Medium:
and
Red top tube Sterile container
Minimum:
24 hr fecal collection and 1.0 mL serum
Rejection Criteria:
Specimens other than stool plus serum. No gel top tubes for serum collection.
Delivery Instructions:
Submit specimen to laboratory as soon as possible after collection period is completed.
Analytic Time:
2 working days upon receipt at reference laboratory
Reference Range:
Clearance: < or = 27 mL/24 hours Fecal alpha-1-antitrypsin concentration: < or = 54 mg/dL Serum alpha-1-antitrypsin concentration: 100 - 190 mg/dL
Interpretive Data:
Elevated A1A clearance suggests excessive gastrointestinal protein loss. (The positive predictive value of the test has been found to be 97.7% and the negative predictive value is 75%.) Patients with protein-losing enteropathies generally have A1A clearance values >50 mL/24 hours and A1A stool concentrations >100 mg/mL. Borderline elevations above the normal range are equivocal for protein- losing enteropathies.
Comments:
Fecal specimen must be collected in special containers available from Specimen Control, 6240 RCP. Draw serum sample during stool collection period. If no fecal specimen obtained in 24 hours, extend collection to 48-72 hours and note time frame on requisition.
Methodology:
Nephelometry
CPT Code:
82103(x2)