What is the Anti-dsDNA Antibody Test?
The Anti-double-stranded DNA (Anti-dsDNA) Antibody test detects autoantibodies that attack double-stranded DNA. It is primarily used to diagnose and monitor systemic lupus erythematosus (SLE), an autoimmune disease that affects multiple organs.
Normal Range:
Negative: <1:10 titer (No detectable antibodies)
Borderline/Indeterminate: 1:10 - 1:40 titer
Positive: ≥1:40 titer (May indicate autoimmune disease, especially SLE)
(Reference values may vary depending on laboratory methods)
Purpose of the Test:
✅ Diagnose Systemic Lupus Erythematosus (SLE) – A high anti-dsDNA level is a strong indicator of lupus.
✅ Monitor Disease Activity – Helps track lupus flare-ups and response to treatment.
✅ Assess Lupus Nephritis (Kidney Involvement) – Elevated levels may indicate kidney damage in lupus patients.
✅ Differentiate Autoimmune Disorders – Helps distinguish SLE from other autoimmune diseases.
✅ Evaluate Symptoms – Ordered if experiencing joint pain, fatigue, skin rash, kidney issues, or unexplained inflammation.
What Can Affect Anti-dsDNA Test Results?
🔹 High Anti-dsDNA Levels: Strongly associated with active lupus and kidney complications.
🔹 Low or Negative Anti-dsDNA: Does not rule out lupus—other autoantibodies (e.g., ANA) may be positive.
🔹 Transient Elevations: Infections or other autoimmune diseases can cause mild increases.
How is the Test Performed?
A blood sample is drawn and analyzed using methods such as:
🔸 ELISA (Enzyme-Linked Immunosorbent Assay)
🔸 IFA (Indirect Immunofluorescence Assay)
🔸 Crithidia luciliae immunofluorescence test (CLIFT)
📌 When to Get Tested? If experiencing lupus symptoms or monitoring an existing SLE diagnosis.