Extractable Nuclear Antigens (ENA) Qualitative Profile Test

ENA (extractable nuclear antigens) qualitative profile test

It is a laboratory test used to detect antibodies against ENA (extractable nuclear antigen) in blood of patients suffering from various autoimmune disorders. This test is also called ENA qualitative 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 loss

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

Why is ENA qualitative profile test prescribed?

The healthcare practitioner may prescribe this test in the patients with positive ANA blood test to diagnose and distinguish autoimmune disease s.it also helps to monitor the disease progression.

What are the components of ENA qualitative test?

This panel test screens for 15 antigens as follows:

• Jo-1
• Scl -70
• Pm –Scl
• Sm
• SSA/Ro
• SSB/La
• Rib- Protein
• U1-nRNP,
• CENP-B
• ds-DNA,
• Histone,
• Nucleosomes
• Ro-52
• PCNA
• AMA-M2

Procedure and prerequisites

The sample for ENA qualitative 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 antibody test for above 15 antigens can be either positive or negative