21‑Hydroxylase Antibody
Use
Measurement of autoantibodies against the adrenal steroidogenic enzyme 21‑hydroxylase is used in the evaluation of suspected adrenal insufficiency and in differentiating autoimmune Addison’s disease (primary adrenal insufficiency) from other causes. A positive result supports the presence of autoimmune adrenalitis and identifies individuals at risk of developing autoimmune adrenal failure.
Special Instructions
Serum specimen collected in a red‑top or serum separator tube (SST), centrifuged and aliquoted into a plastic vial; ship frozen on dry ice. Gross hemolysis, lipemia, or icterus may interfere and lead to rejection.
Limitations
This is a qualitative assay; a positive result indicates presence of autoantibodies consistent with Addison’s disease but should be interpreted alongside clinical findings and confirmatory adrenal functional testing. Interference may occur from lipemic or hemolyzed samples or from heterophile/HAMA antibodies.
New York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 85363-0
- 85363-0
Result Turnaround Time
2-7 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.2 mL
Container
Red top or SST tube; plastic vial for submission
Collection Instructions
Centrifuge and aliquot serum into plastic vial to remove cells or gel prior to shipping
Storage Instructions
Ship frozen on dry ice
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus
Other tests from different labs that may be relevant