ASO (Anti-Streptolysin O)

What does this test measure?

Anti-streptolysin O (ASO), the specific antibodies to streptolysin O, an enzyme produced by group A β-haemolytic streptococci (Streptococcus pyogenes).

Why is it ordered?

Detectable from one week to one month after a streptococcal infection; helps identify recent infection and its complications such as glomerulonephritis, rheumatic fever, endocarditis and scarlet fever.

Normal range

Adults: < 200 IU/mL · Children: < 150 IU/mL

Per the original BioSystems insert

Sample type

Serum