Anti‑Streptolysin O Antibody (ASO)
Also known as: Streptolysin-O Antibody, ASO, Streptococcus, Group A, Strep A
Use
This test is a sensitive indicator of recent Group A streptococcal infection. ASO titers begin to rise approximately one week post‑infection, peaking two to four weeks later. Although useful in diagnosing recent infections, ASO does not increase in cutaneous streptococcal infections. In uncomplicated cases, ASO levels gradually decline over 6 to 12 months. Elevated ASO titers are observed in over 80% of acute rheumatic fever cases and about 95% of acute post‑streptococcal glomerulonephritis cases, underscoring its clinical utility. This overview is based on Quest diagnostics‑associated lab info.
Special Instructions
Not provided.
Limitations
False‑positive ASO results can occur due to elevated serum beta‑lipoprotein levels from liver disease or contamination by organisms such as Bacillus cereus and Pseudomonas species. Additionally, ASO is not sensitive for diagnosing streptococcal pyoderma.
Methodology
Other
Biomarkers
Anti‑Streptolysin O (ASO)
Analyte
LOINC Codes
- 5370-2 - ASO Ab SerPl-aCnc
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL serum
Minimum Volume
0.5 mL serum
Container
Serum separator tube (SST) / Gold top
Storage Instructions
Refrigerate
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Room temperature: 72 hours |
| Refrigerated | Refrigerated: 5 days |
| Frozen | Frozen: 30 days |
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