Rheumatology

Antinuclear Antibody (ANA) Screen

Normal Range
Negative (Titer < 1:40 or 1:80 depending on lab)
Sample Type
Standard
Fasting
No
Unit
Titer

The ANA Screen is a fundamental screening test for Systemic Autoimmune Rheumatic Diseases (SARD). In an Arthritis Basic Screen, it is used to identify the presence of autoantibodies that attack the body's own cell nuclei. While highly sensitive for Systemic Lupus Erythematosus (SLE) (95-98% sensitivity), it is not specific and can be positive in various conditions like Sjogren's syndrome, scleroderma, or even healthy individuals.

Why Context Matters

A 'false positive' ANA is common, especially in the elderly or during viral infections. Since a positive result can cause significant patient anxiety, a second opinion is often needed to interpret the 'pattern' (e.g., homogeneous, speckled) and to order specific follow-up tests (like Anti-dsDNA or Anti-Smith) to confirm if a true autoimmune disease exists.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Antinuclear Antibody (ANA) Screen:

Related Indicators

DR

Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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