The Anti-Nuclear Antibody (ANA) – Indirect Immunofluorescence Assay (IFA) using Hep-2 cells is the gold standard for detecting ANA. It helps diagnose autoimmune diseases by identifying antibodies that target cell nuclei.
✅ Screens for autoimmune diseases (e.g., lupus, scleroderma, Sjögren’s syndrome)
✅ Detects ANA patterns that help differentiate diseases
✅ More sensitive than ELISA for ANA detection
✅ Guides further testing based on fluorescence patterns
Reported as a ratio (e.g., 1:40, 1:160, 1:640, etc.)
Higher titers (>1:160) are more likely associated with autoimmune diseases.
Low titers (1:40 – 1:80) may be seen in healthy individuals or mild inflammation.
| Pattern | Possible Autoimmune Disease |
|---|---|
| Homogeneous (Diffuse) | Systemic Lupus Erythematosus (SLE), Drug-induced lupus |
| Speckled | SLE, Sjögren’s syndrome, Mixed Connective Tissue Disease (MCTD), Scleroderma |
| Centromere | Limited Scleroderma (CREST syndrome) |
| Nucleolar | Systemic Sclerosis (Scleroderma), Polymyositis |
| Cytoplasmic | Autoimmune hepatitis, Myositis, Primary Biliary Cholangitis (PBC) |
| Rim/Peripheral | SLE (specific for Anti-dsDNA antibodies) |
🔹 Homogeneous & Speckled patterns are the most common.
🔹 Centromere & Nucleolar patterns are more specific for scleroderma and related disorders.
✔ Anti-dsDNA & Anti-Smith (Anti-Sm) → Specific for SLE
✔ Anti-Ro/SSA & Anti-La/SSB → Sjögren’s Syndrome, Lupus
✔ Anti-Scl-70 & Anti-Centromere → Scleroderma
✔ Anti-RNP → Mixed Connective Tissue Disease (MCTD)
✔ Anti-CCP & Rheumatoid Factor (RF) → Rheumatoid Arthritis
🔹 If ANA titer is high (>1:160) and you have symptoms like:
Joint pain/swelling
Skin rashes (butterfly rash in lupus)
Fatigue, fever
Dry eyes/mouth
Raynaud’s phenomenon (cold-induced color changes in fingers)