Anti-streptolysin O Antibodies
(ASO)

- Sample type:

Serum

- Uses:

Document exposure to streptococcal streptolysin O. A marked rise in titer or a persistently elevated titer indicates that a Streptococcus infection or poststreptococcal sequelae are present

- Precautions:

1) The patient may need to refrain from eating or drinking anything for six hours before the test.

2) Stop taking corticosteroids and certain antibiotics because may reduce ASO antibody levels.

- Interfering Factors:

False-positive ASO titers can be caused by increased levels of serum β-lipoprotein produced in liver disease and by contamination of the serum with Bacillus cereus and Pseudomonas sp ASO titers are elevated in 85% of patients with rheumatic fever but may not be elevated in cases involving skin or renal sequelae. For patients suffering from skin or renal involvement, anti-DNase B test may be a better choice.

- Pre analytical errors:

1) The sample is Gross hemolysis; lipemia.

2) Labelling errors.

3) Inadequate sample/anticoagulant volume ratio.

- Corrective action:

If your results show that you have an elevated ASO value, you may have a post-streptococcal complication.

If your test is negative and your doctor still thinks you might have a post-streptococcal complication, they may order a second type of antibody test for a follow-up.

- Post analytical errors:

1) Failure in reporting.

2) Erroneous validation of analytical data.

- Reference range:

0.0−200.0 IU/mL