ASO (Anti-Streptolysin O)
Uncover a hidden or recent strep infection.
The Anti-Streptolysin O (ASO) test measures the level of antibodies to streptolysin O in the blood. Streptolysin O is a substance produced by Streptococcus pyogenes (group A streptococcus), the bacterium responsible for infections such as strep throat, scarlet fever, and certain skin infections. When the body is exposed to this bacterium, the immune system produces ASO antibodies in response. A raised or rising ASO level can therefore indicate a recent streptococcal infection, even after the infection itself has cleared.
The test is most useful for diagnosing conditions caused by an immune reaction following a streptococcal infection, including:
- Rheumatic fever: an inflammatory condition that can affect the heart, joints, and other tissues.
- Acute glomerulonephritis: inflammation of the kidneys that can develop after a streptococcal infection.
- PANDAS: paediatric autoimmune neuropsychiatric disorders associated with streptococcus.
ASO
No special preparation required.
For blood tests, we recommend drinking plenty of water beforehand to ensure smooth sample collection. If you are taking any regular medication, continue to do so unless advised otherwise by your doctor.
Important Clinical Information:
This test is a screening tool to monitor and support your overall health. It does not replace your GP or Consultant.
Always discuss your test results, especially any abnormal results, with your GP, who can interpret them in the context of your medical history and overall health.