ANA or Anti-Nuclear Antibody

ANA or Antinuclear Antibody is an autoantibody that is formed against normal proteins in cell nucleus. Antibodies are produced by B cells to fight infections and usually they form small amounts of autoantibodies as well. At times these B cells produce large amounts of autoantibodies that result in inflammation and autoimmune disease.

– Systemic Lupus
– Scleroderma
– Sjogren’s Syndrome
– Polymyositis
– Autoimmune Hepatitis
– Rheumatoid Arthritis
– Juvenile Chronic Arthritis
– Vasculitis
– Drug-induced Lupus
– Hashimoto’s Thyroiditis
– Grave’s Disease
– Other connective tissue diseases
– Family members of Lupus patients

1:40
1:80
The above titers are seen with conditions other than lupus. These include:
1. Rheumatic Diseases such as Rheumatoid Arthritis, Psoriatic Arthritis, Spondyloarthritis, etc
2. Autoimmune Hepatitis
3. Autoimmune Thyroiditis

ANA Titers of 1:160 and above are usually seen in Lupus patients
1:160
1:320
1:640
1:1280
1:2560

Titers are very important as to decide the significance of the actual test.
Examination by a rheumatologist along with blood testing will help formulate the diagnosis.

ANA patterns are not always helpful as to determine the type of the connective tissue disease.

ANA patterns:

  1. Speckled
  2. Homogeneous
  3. Nucleolar
  4. Anti-centromere
  5. Peripheral

Once ANA is positive and if it appears that patient may have a connective tissue disease on examination, then additional tests are ordered including:

DSDNA
SSA
SSB
C3 C4
Anti-cardiolipin antibodies
Anti-Smith
Anti- RNP
Anti-Histones
Anti-Smooth muscle antibody
Urinalysis

DSDNA, C3, C4 do fluctuate depending on the Lupus activity and can be followed.

In patients with low titer ANA of 1:40 and 1:80, additional testing may need be done to look at other possible causes here:

Anti-centromere antibody (limited Scleroderma)
SCL70 (Scleroderma)
Anti-thyroglobulin antibodies (Autoimmune thyroiditis)
Anti-thyroid peroxidase antibodies (Autoimmune thyroiditis)
Anti-thyroid-stimulating hormone receptor antibodies (Graves’ disease)