What is antistreptolysin O titre?

Definition. Antistreptolysin O (ASO) titer is a blood test to measure antibodies against streptolysin O, a substance produced by group A streptococcus bacteria. Antibodies are proteins our bodies produce when they detect harmful substances, such as bacteria.

What is the principle of ASO?

PRINCIPLE OF THE TEST ASO test method is based on an immunologic reaction between streptococcal exotoxins bound to biologically inert latex particles and streptococcal antibodies in the test sample. Visible agglutination occurs when increased antibody level, are present in the test specimen.

What does high ASO titre mean?

If you have elevated levels of ASO antibodies, it means that you have probably had a recent strep infection. If your levels are taken again later and are higher, it also means you’ve probably had a recent strep infection.

What is normal range for ASO titer?

The estimated titers that were 80% of the upper limit or normal at age 10 years were 276 IU/ml for ASO and 499 IU/ml for ADB.

What happens when ASO is positive?

An elevated titer of antibody (positive ASO) or an ASO titer that is rising means that it is likely that the person tested has had a recent strep infection. ASO titers that are initially high and then decline suggest that an infection has occurred and may be resolving.

Why ASO titre test is done?

The antistreptolysin O (ASO) titer test is a blood test that checks for a strep infection. When you come into contact with harmful bacteria, your body produces antibodies to defend itself against these bacteria. Your body produces antibodies specific to the bacteria they fight.

What are the symptoms of ASO positive?

When is it ordered?

• Fever.
• Joint swelling and pain in more than one joint, especially in the ankles, knees, elbows and wrists, sometimes moving from one joint to another.
• Small, painless nodules under the skin.
• Rapid, jerky movements (Sydenham’s chorea)
• Skin rash.

Does ASO affect heart?

We found that 50% of the patients with elevated ASO had valve thickening (5/10), including 3 patients with aortic valve and 2 patients with mitral valve, which were significantly higher than those in ASO negative group (10.0%, 4/40) (3 patients with aortic valve and 1 patient with mitral valve) (p = 0.003).