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
6240 RCP
356-3527
Specimen:
Serum and Feces
Collection Medium:
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| 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)
