Hydroxylase Antibody, 21
21-Hydroxylase, 21-OH Ab, Adrenal antibody , ARUP #70265, EPIC: LAB7121, SOFT: X21HO
Specimen Collection Criteria
Collect (preferred specimen): One plain Red-top tube.
Also acceptable: One Gold-top SST tube.
- Send specimen for processing immediately afte collection.
- Separate samples must be submitted when multiple test are ordered.
Physician Office/Drawsite Specimen Preparation
Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Transport serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).
Preparation for Courier Transport
Transport: 1.0mL serum, refrigerated (2-8°C or 36-46°F) (Min: 0.2mL)
- Hemolyzed specimens.
- Specimens not collected and processed as indicated.
Results available in 3-10 days.
A value greater than 1.0 Kronus Units/mL is considered positive for 21-OH Antibody. Kronus units are arbitary. Kronus Units = U/mL.
The 21-Hydroxylase Antibody assay is intended for the semi-quantitative determination of anitbodies to steroid 21-hydroxylase in human serum.
The presence of antibodies to 21-hydroxylase (greater than 1.0 U/mL) is indicative of primary adrenal insufficiency (Addison disease). Results should be interpreted in the context of clinical symptoms including functional adrenal testing.
In males with adrenal insufficiency and 21-hydroxylase antibodies within the reference interval (less than 1.0 U/mL), X-Linked Adrenoleukodystrophy (X-ALD) should be excluded by using Very Long-Chain Branched Fatty Acids in plasma (ARUP Test Code 2004250) for screening..
ARUP #70265, EPIC: LAB7121, SOFT: X21HO