What does anti-O mean in medicine?

Anti-streptolysin O test. Based on the principle of antigen-antibody neutralization test, reduced hemolysin O with hemolytic ability was used to detect whether neutralizing antibody was produced in serum. If the titer of secondary antibody in the patient's serum is obviously higher than 400 units, it can be considered that the patient has been infected by hemolytic streptococcus recently, which can be used for the auxiliary diagnosis of rheumatic fever, glomerulonephritis and other patients. -Ziyi Health