ENAE - Clinical: Antibody to Extractable Nuclear Antigen Evaluation, Serum

Test Catalog

Test Name

Test ID: ENAE    
Antibody to Extractable Nuclear Antigen Evaluation, Serum

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

Evaluating patients with signs and symptoms of a connective tissue disease in whom the test for antinuclear antibodies is positive

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

See Connective Tissue Disease Cascade (CTDC) in Special Instructions.

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

SSA, SSB, SM, and RNP are extractable nuclear antigens (ENA) that occur in patients with several different connective tissue diseases.  Scl 70 (topoisomerase 1) is a 100-kD nuclear and nucleolar enzyme. Scl 70 antibodies are considered to be specific for scleroderma (systemic sclerosis) and are found in up to 60% of patients with this connective tissue disease. Scl 70 antibodies are more common in patients with extensive cutaneous involvement and interstitial pulmonary fibrosis, and are considered a poor prognostic sign.(1) JO1 is a member of the amino acyl-tRNA synthetase family of enzymes found in all nucleated cells and a marker for the disease polymyositis.

 

For more information, see individual unit codes.

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.

SS-A/Ro ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

 

SS-B/La ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

 

Sm ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

 

RNP ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

 

Scl 70 ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

 

Jo 1 ANTIBODIES, IgG

<1.0 U (negative)

> or =1.0 U (positive)

Reference values apply to all ages.

Interpretation Provides information to assist in interpretation of the test results

A positive result is consistent with a connective tissue disease. 

 

For more information, see individual unit codes.

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

Testing is not useful in patients without demonstrable antinuclear antibodies.

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

1. Homburger H, Larsen S: Detection of specific antibodies. In Clinical Immunology: Principles and Practice. First edition. Edited by R Rich, T Fleisher, B Schwartz, et al. St. Louis, Mosby-Year Book, Inc, 1996, pp 2096-2109

2. Targoff I: Autoantibodies in polymyositis. Rheum Dis Clin North Am 1992;18:455

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test