Antistreptolysin O titre

Antistreptolysin O titre (AS(L)O titre or AS(L)OT) - titre of (serum) antistreptolysin O antibodies; a blood test used to assist in the diagnosis of a streptococcal infection or indicate a past exposure to streptococci.

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The ASOT helps direct the antimicrobial treatment and is used to assist in the diagnosis of scarlet fever, rheumatic fever and post infectious glomerulonephritis.

A positive test usually is >200 units/mL,^[1] but normal ranges vary from laboratory to laboratory and by age.^[2]

The false negatives rate is 20-30%.^[1] If a false negative is suspected then an anti-DNase B titre should be sought. False positives can result from liver disease and tuberculosis.^[1]

References

1. ^ ^{a b c} Antistreptococcal antibody titres. gpnotebook. URL: http://www.gpnotebook.co.uk/cache/-1630535637.htm. Accessed on: March 31, 2007.
2. ^ Danchin M, Carlin J, Devenish W, Nolan T, Carapetis J (2005). "New normal ranges of antistreptolysin O and antideoxyribonuclease B titres for Australian children". J Paediatr Child Health 41 (11): 583-6. PMID 16398843.

See also

• List of medical abbreviations
• streptococcus