Lab Test

Hydroxylase Antibody, 21

21-Hydroxylase, 21-OH Ab, Adrenal antibody, ARUP #70265, EPIC: LAB7121, SOFT: X21HO

Test Codes

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/Draw 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)

Rejection Criteria

  • Hemolyzed specimens.
  • Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

Deliver specimen to Laboratory immediately after collection for processing.

In-Lab Processing

Let specimen clot 30-60 minutes then immediately cintrifuge to separate serum from cells.  Transport serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.0mL serum, refrigerated (2-8°C or 36-46°F) (Min: 0.2 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable

Refrigerated (2-7°C or 36-46°F): 1 week

Frozen (-20°C/-4°F or below): 6 months

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory.  Contact the Sendout Laboratory with any questions.

 

Laboratory

Sent to ARUP Laboratories, Salt Lake City, UT.

Performed

Tuesday

Results available in 3-10 days.

Reference Range

0.0-1.0 U/mL.

Test Methodology

Semi-Quantitative Radioimmunoassay.

Interpretation

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..

CPT Codes

83519.

Contacts

Last Updated

10/23/2019

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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.