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Test ID: OH21    
21-Hydroxylase Antibodies, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Investigation of adrenal insufficiency

 

Aid in the detection of those at risk of developing autoimmune adrenal failure in the future

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Chronic primary adrenal insufficiency (Addison's disease) is most commonly caused by the insidious autoimmune destruction of the adrenal cortex and is characterized by the presence of adrenal cortex autoantibodies in the serum.  It can occur sporadically or in combination with other autoimmune endocrine diseases, that together comprise Type I or Type II autoimmune polyglandular syndrome (APS).

 

The microsomal autoantigen 21-hydroxylase (55 kilodalton) has been shown to be the primary autoantigen associated with autoimmune Addison's disease.  21-Hydroxylase antibodies are markers of autoimmune Addison's disease, whether it presents alone, or as part of Type I or Type II (APS).

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

<1 U/mL

 

Reference values apply to all ages.

Interpretation Provides information to assist in interpretation of the test results

Positive results (> or =1 U/mL) indicate the presence of adrenal autoantibodies consistent with Addison's disease.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Lipemic or grossly hemolyzed serum should not be used in this assay. The assay reagents are labeled "For Research Use Only"; therefore interpretation of test results requires consideration of other factors such as the clinical status of the patient, other test results, etc.

Supportive Data

Reagent Manufacturer's Data

 

Patient Group

Positive Rate

Healthy blood donors

6/243

Isolated Addison's disease

43/60

Addison's disease due to tuberculosis

0/9

APS type I

11/12

APS type II

27/27

Insulin dependent diabetes mellitus

4/150

Non-insulin dependent diabetes mellitus

0/32

Grave's disease

1/77

Hashimoto's disease

1/67

Myasthenia gravis

0/35

 

 

Mayo Data

 

Patient Group

Positive Rate

Normals from Mayo NV Study

1/50

+ Insulin Antibody

0/5

+ Thyroid stimulating Immunoglobin

0/5

+ Anti-nuclear Antibodies

0/10

+ Rheumatoid Factor

0/10

                                                                       

  

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

Tanaka H, Perez M, Powell M, et al: Steroid 21-hydroxylase autoantibodies: measurements with a new immunoprecipitation assay. J Clin Endocrinol Metab 1997;82:1440-1446