Alpha-1-Antitrypsin
| Label Mnemonic: | A1AC |
| Epic code: | LAB2565 |
| Downtime form: | Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Commercial Mailout Laboratory
6240-8 RCP
356-8593
6240-8 RCP
356-8593
Specimen(s):
Feces and Serum
Both feces and serum are required.
Blood must be drawn during the stool collection period.
Both feces and serum are required.
Blood must be drawn during the stool collection period.
Specimen
Instructions:
Feces and serum should be shipped together. Specimens shipped separately may delay testing.
Collection Medium:
) | and |  |
| 24, 48, 72 hour fecal specimen, stool container(s) | Red top tube 5 mL (Clot Activator) |
Minimum:
Collect a 24 hr fecal collection. If no specimen is obtained within 24 hours, extend collection time to 48 to 72 hours. Document time frame.
Also collect 1.0 mL serum (Min: 0.5 mL) from red top or serum gel tube.
Fecal specimen must be collected in special containers available from Mailouts at 356-8395 Monday-Friday, or Specimen Control (6240 RCP) at 356-3527. Draw serum sample during stool collection period. In the absence of either a 24-hour stool collection or a contemporary serum specimen, the fecal concentration of alpha-1-antitrypsin (A1A) can be used as a surrogate marker. The clearance is preferred in order to normalize the large range of serum A1A concentrations and the variability in random stool A1A concentration.
Also collect 1.0 mL serum (Min: 0.5 mL) from red top or serum gel tube.
Fecal specimen must be collected in special containers available from Mailouts at 356-8395 Monday-Friday, or Specimen Control (6240 RCP) at 356-3527. Draw serum sample during stool collection period. In the absence of either a 24-hour stool collection or a contemporary serum specimen, the fecal concentration of alpha-1-antitrypsin (A1A) can be used as a surrogate marker. The clearance is preferred in order to normalize the large range of serum A1A concentrations and the variability in random stool A1A concentration.
Rejection Criteria:
Specimens other than stool plus serum.
Delivery Instructions:
Submit specimen to laboratory as soon as possible after
collection period is completed.Testing Schedule:
Test performed Monday through Saturday.
Turn Around
Time:
1 day 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
Fecal alpha-1-antitrypsin concentration: < or = 54 mg/dL
Serum alpha-1-antitrypsin concentration: 100 - 190 mg/dL
Interpretive Data:
Elevated alpha-1-antitrypsin (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 greater than 50 mL/24 hours and A1A fecal concentrations above 100 mg/mL.
Borderline elevations above the normal range are equivocal for protein-losing enteropathies.
Patients with protein-losing enteropathies generally have A1A clearance values greater than 50 mL/24 hours and A1A fecal concentrations above 100 mg/mL.
Borderline elevations above the normal range are equivocal for protein-losing enteropathies.
Comments:
Useful for: Diagnosing protein-losing enteropathies
Cautions: In the absence of either a 24-hour fecal collection or a contemporary serum specimen, the fecal concentration of alpha-1-antitrypsin (A1A) can be used as a surrogate marker. The clearance is preferred in order to normalize the large range of serum A1A concentrations and the variability in random fecal A1A concentration.
Cautions: In the absence of either a 24-hour fecal collection or a contemporary serum specimen, the fecal concentration of alpha-1-antitrypsin (A1A) can be used as a surrogate marker. The clearance is preferred in order to normalize the large range of serum A1A concentrations and the variability in random fecal A1A concentration.
Methodology:
Nephelometry
CPT Code:
82103 x2