Alpha-1-Antitrypsin Clearance, Timed




Test Mnemonic

A1ACL

CPT Codes

  • 82103 - QTY (2)

Includes

  • Alpha-1-Antitrypsin, Stool
  • Clearance
  • Alpha-1-Antitrypsin, Serum

Performing Laboratory

Mayo Clinic Dpt of Lab Med & Pathology


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mLSerumSST (Gold) FrozenMULTIPLE SPECIMENS ARE REQUIRED FOR THIS TEST. Centrifuge within 2 hours of collection and transfer serum into a standard plastic aliquot tube. Blood must be drawn during the stool collection period.
Entire collectionStool, 24 hrClean container FrozenMULTIPLE SPECIMENS ARE REQUIRED FOR THIS TEST.

Alternate Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mLSerumNo additive (Red) FrozenMULTIPLE SPECIMENS ARE REQUIRED FOR THIS TEST. Centrifuge within 2 hours of collection and transfer serum into a standard plastic aliquot tube. Blood must be drawn during the stool collection period.
Entire collectionStool, 24 hrClean container FrozenMULTIPLE SPECIMENS ARE REQUIRED FOR THIS TEST.

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
N/A    Requires 1 mL homogenized stool and 0.5 mL serum

Stability

Environmental Condition Description
AmbientSerum : 28 days; Stool: 14 days
RefrigeratedSerum : 28 days; Stool: 14 days
FrozenSerum : 28 days; Stool: 14 days

Days Performed

Mon - Sat

Turnaround Time

2 - 3 days

Methodology

Name Description
Nephelometry (NEPH) 

Reference Range

Clearance
Sex Age From Age To Type Range Range Unit
   Years99 YearsNormal<= 27mL/24 hrs
Serum
Sex Age From Age To Type Range Range Unit
   Years99 YearsNormal100 - 190mg/dL
Stool
Sex Age From Age To Type Range Range Unit
   Years99 YearsNormal<= 54mg/dL

Special Info

If no specimen is obtained in 24 hours, extend collection to 48 or 72 hours. Note collection time frame. Serum must be collected during the stool collection period. Stool and serum should be shipped together.

Clinical Info

This test is 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.