What does the Anti-Deoxyribonuclease B Antibody test measure?

Why is Anti-Deoxyribonuclease B Antibody measured?

Anti-DNase B antibodies are serological evidence of recent group A streptococcal infection. Clinicians order the test when a post-streptococcal sequela — acute rheumatic fever or acute post-streptococcal glomerulonephritis — is suspected and to corroborate a streptococcal aetiology in patients with a negative or borderline ASO. Because the antibody response is more reliable after skin infection, anti-DNase B is especially useful for glomerulonephritis cases following impetigo, and dual testing (ASO plus anti-DNase B) captures the majority of true streptococcal exposures.

Reference ranges

Standard reference

Typically <170–340 U/mL or titre <1:170 in adults; paediatric thresholds higher (often <480 U/mL). Assay-specific.

Functional medicine optimal

Reference laboratories report positive or elevated when the titre exceeds the age-specific upper limit; there is no single 'optimal' healthy value, and a negative result is expected in the absence of recent streptococcal infection.

Units

titre (dilution), U/mL

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.