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Anti-Nuclear Factor ( ANF )

Anti-nuclear factor or Anti-nuclear Antibody (ANA)


This test is done on the serum(clotted blood 3 to 5 ml).

Important facts

The antinuclear antibodies are produced in connective tissue diseases(autoimmune diseases ) against various antigens in the nucleus like RNA, DNA ,and histones.

Normal These are negative.


  1. It helps in the diagnose of Autoimmune diseases and particulary Systemic lupus erythematosus(98%) but with poor specificity.
  2. This test is positive 30 to 50 % in other autoimmune diseases such as Rheumatoid arthritis, Sjogren sysndrome ( 70 %)and Polymyositis and other related diseases.

There are ANA-negative cases of SLE.

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