Specimen:

Serum and Feces

Collection Medium:

Minimum:

24 hr fecal collection and 1.0 ml serum

Rejection Criteria:

Specimens other than stool plus serum.

Delivery Instructions:

Submit specimen to laboratory as soon as possible after
collection period is completed.

Analytic Time:

1 week

Reference Range:

Clearance: < or = 27 mL/24 hr
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)