Extractable Nuclear Antigens (ENA) Quantitative Profile Test

Extractable Nuclear Antigens (ENA) Quantitative Profile Test

It is a laboratory test used to quantify antibodies (IgG auto antibodies) against ENA (extractable nuclear antigen) in blood of patients suffering from various autoimmune disorders. This test is also called ENA quantitative profile test.

Antibodies (also called immunoglobulin) are specific proteins that are produced in our body by the immune system against foreign substances like disease causing bacteria, virus, parasites, and fungi. These foreign invading substances are called antigens. Antibodies act and destroy these antigens and thus protect our body from these disease causing antigens. Autoimmune diseases are those disorders in which antibodies are produced by mistake against body own healthy cells and tissues. These antibodies attack body tissues and cause damage and inflammation. These antibodies are called auto antibodies.

The various types of autoimmune disorders are as follows:

• Systemic lupus erythematosus(SLE) Sjogren’s syndrome
• Arthritis
• Polymyositis
• Dermatomyositis
• Mixed connective tissue disease
• Scleroderma

The initial test done in suspected autoimmune disease is called antinuclear antibody test(ANA test).This test is used to detect presence of antinuclear antibodies in patient blood with suspected autoimmune disorder. This test is done especially in those patients who have symptoms of autoimmune diseases like:

• Fever
• Fatigue
• Muscle pain
• Joint pain/swelling
• Rashes
• Hair lossli>Sensitivity to UV light

ENA test is done in patients where ANA profile test is positive. The purpose of ENA quantitative test is to diagnose and differentiate between different types of autoimmune diseases and also monitor the progress of the disease.

Why is ENA quantitative profile test prescribed?

The healthcare practitioner may prescribe this test in the patients with positive ANA blood test and associated symptoms of specific autoimmune disease. This test helps to diagnose and distinguish autoimmune disease. It also helps to monitor the disease progression.

What are the components of ENA quantitative test?

The panel of seven auto antibodies detected in this test are:

• Sm (smith)
• Centromere
• U1RNP
• SS-A/Ro
• SS-B/La
• Scl-70(scleroderma)
• Jo-1

Procedure and prerequisites

The sample for ENA quantitative test is taken from blood by inserting a small needle into vein of your arm. A small amount of blood is then collected in test tube or vial. You may feel pain due to needle prick. No preparation is needed before this test.

Results

The results for ENA quantitative a test for above 7 antigens can be either positive or negative. It also tells the blood levels of specific antibody if found positive