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23209 21-Hydroxylase Ab, S (21OH)

21-Hydroxylase Ab, S (21OH)
Test Code: 21HDRSO
Synonyms/Keywords
 21 Hydroxylase Antibody, 21-OH Ab, Adrenal Antibody, Hydroxylase Antibody, Anti-Adrenal Antibody, Addison's Disease​
Useful For
​Investigation of adrenal insufficiency
Aid in the detection of those at risk of developing autoimmune adrenal failure in the future
 
Highlights:

Addison disease is the most frequent cause of primary adrenal insufficiency.

Auto-antibodies against 21-hydroxylase are present in up to 90% of Addison disease cases.

Measurement of anti-21-hydroxylase auto-antibodies is useful in the evaluation of the cause of established primary adrenal insufficiency.

Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Serum​ Red Top Tube (RTT)​ Serum Separator Tube (SST)​ 1 mL​ 0.20 mL​
Collection Processing Instructions

​Centrifuge and aliquot serum into plastic vial to remove from cells or gel prior to shipping.

Ship serum specimen frozen

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Frozen 14 days​
Rejection Criteria
Gross hemolysis
Gross lipemia​
Interference

Lipemic or grossly hemolyzed serum should not be used in this assay.

Results should be interpreted in the context of clinical symptoms and adrenal functional confirmatory tests.

Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Clinic Laboratories
Wednesday 2 days​
Enzyme-linked Immunosorbent Assay (ELISA)
Reference Lab
Test Information

Adrenal insufficiency is caused by failure of the adrenal cortex to produce cortisol. This failure can result from loss of function of the adrenal glands (ie, primary adrenal insufficiency). This is most frequently caused by autoimmune adrenalitis or Addison disease accounting for 68% to 94% of cases. It can occur sporadically or in combination with other autoimmune endocrine diseases that together comprise Type I or Type II autoimmune polyglandular syndrome (APS).

Antibodies that react with several steroidogenic enzymes (most often 21-hydroxylase) are present in the serum of up to 86% of patients with autoimmune primary adrenal insufficiency, but only rarely in patients with other causes of adrenal insufficiency. Therefore, anti-21-hydroxylase autoantibodies (21-OH Abs) are markers of autoimmune Addison disease, whether it's present alone, or as part of Type I or Type II APS. The measurement of 21-OH Abs is an important step in the investigation of adrenal insufficiency, and may also aid in the detection of those at risk of developing autoimmune adrenal failure in the future.

Reference Range Information
Negative
Interpretation

This is a qualitative test. A positive result indicates the presence of autoantibodies to 21-hydroxylase and is consistent with Addison disease.

Utilizing an index value of <45 as a negative cutoff, this assay has a clinical sensitivity and specificity of 87.0% (95% CI: 79.4%-92.2%) and 99.3% (95% CI: 97.5%-99.8%), respectively.

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​83516
Synonyms/Keywords
 21 Hydroxylase Antibody, 21-OH Ab, Adrenal Antibody, Hydroxylase Antibody, Anti-Adrenal Antibody, Addison's Disease​
Ordering Applications
Ordering Application Description
​Centricity ​21-Hydroxylase Ab
​Cerner ​21-Hydroxylase Ab (21OH) 
​COM ​21-Hydroxylase Antibodies 
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
Serum​ Red Top Tube (RTT)​ Serum Separator Tube (SST)​ 1 mL​ 0.20 mL​
Collection Processing

​Centrifuge and aliquot serum into plastic vial to remove from cells or gel prior to shipping.

Ship serum specimen frozen

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Frozen 14 days​
Rejection Criteria
Gross hemolysis
Gross lipemia​
Interference

Lipemic or grossly hemolyzed serum should not be used in this assay.

Results should be interpreted in the context of clinical symptoms and adrenal functional confirmatory tests.

Useful For
​Investigation of adrenal insufficiency
Aid in the detection of those at risk of developing autoimmune adrenal failure in the future
 
Highlights:

Addison disease is the most frequent cause of primary adrenal insufficiency.

Auto-antibodies against 21-hydroxylase are present in up to 90% of Addison disease cases.

Measurement of anti-21-hydroxylase auto-antibodies is useful in the evaluation of the cause of established primary adrenal insufficiency.

Reference Range Information
Negative
Interpretation

This is a qualitative test. A positive result indicates the presence of autoantibodies to 21-hydroxylase and is consistent with Addison disease.

Utilizing an index value of <45 as a negative cutoff, this assay has a clinical sensitivity and specificity of 87.0% (95% CI: 79.4%-92.2%) and 99.3% (95% CI: 97.5%-99.8%), respectively.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Clinic Laboratories
Wednesday 2 days​
Enzyme-linked Immunosorbent Assay (ELISA)
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​83516
For most current information refer to the Marshfield Laboratory online reference manual.