AntiDnase-B (Dnb)

A normal Anti‑DNase B antibody titer is generally below about 200 units per milliliter, though laboratory reference ranges vary (commonly ~100–200 U/mL and sometimes higher in children). Levels above the lab’s upper limit suggest recent or recent-past streptococcal infection; results should be interpreted alongside symptoms, age and the specific laboratory reference range.

Cost varies by country and lab. In systems with public coverage it’s usually free; privately it often ranges about $30–150 in the US, £20–80 at private UK labs, and roughly ₹400–1,200 in India. Prices depend on facility, included interpretation, and whether bundled with other streptococcal antibody tests—call your local lab for exact pricing.

Anti‑DNase B and ASOT detect antibodies to different streptococcal antigens: Anti‑DNase B targets deoxyribonuclease B, while ASOT measures anti‑streptolysin O. ASO often rises earlier after pharyngitis; Anti‑DNase B rises later and is more sensitive for skin (impetigo) infections and in children. Both confirm recent Group A strep; combined testing increases diagnostic sensitivity. ASO peaks ~3–5 weeks, Anti‑DNase B ~6–8 weeks.

Anti‑DNase B antibodies are directed specifically against Streptococcus pyogenes deoxyribonuclease B and thus indicate a recent group A streptococcal (GAS) infection. They are highly specific for streptococcal exposure and are especially useful when ASO titers are negative (e.g., skin infections). Levels begin rising 1–3 weeks after infection and can remain elevated for several months; interpret alongside clinical findings and other tests.

A normal anti–double-stranded DNA (anti-dsDNA) result is typically reported as negative or below the laboratory’s reference cutoff. Numeric thresholds vary by lab (commonly <30 IU/mL), so interpret results using your lab’s range. A positive or rising anti-dsDNA can suggest systemic lupus erythematosus or increased disease activity; discuss findings with your clinician alongside symptoms and other test results.

PANDAS is diagnosed clinically by sudden, dramatic onset or exacerbation of OCD and/or tics in a child (typically prepubertal), temporal association with a recent Group A streptococcal infection, and presence of neurologic signs (e.g., motor hyperactivity or choreiform movements). Evaluation includes throat culture and streptococcal antibody titers, careful psychiatric/neurologic assessment, and exclusion of other causes.