Test Details
Methodology
Latex immunoturbidimetry
Result Turnaround Time
1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
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.
Limitations
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 (096289) may be a better choice.
Custom Additional Information
Streptolysin is a hemolysin produced by group A streptococci. In an infected individual streptolysin O acts as a protein antigen, and the patient mounts an antibody response. A rise in antibody level begins about one week after infection and peaks two to three weeks later. In the absence of complications or reinfection, the ASO titer will usually fall to preinfection levels within 6 to 12 months. Both clinical and laboratory findings should be correlated in reaching a diagnosis.
Specimen Requirements
Specimen
Serum
Volume
2 mL
Minimum Volume
0.5 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube or gel-barrier tube
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
0.0−200.0 IU/mL
Storage Instructions
Room temperature
Causes for Rejection
Gross hemolysis; lipemia
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 006031 | Antistreptolysin O Ab | 5370-2 | 006031 | Antistreptolysin O Ab | IU/mL | 5370-2 |
| Order Code | 006031 | |||||
| Order Code Name | Antistreptolysin O Ab | |||||
| Order Loinc | 5370-2 | |||||
| Result Code | 006031 | |||||
| Result Code Name | Antistreptolysin O Ab | |||||
| UofM | IU/mL | |||||
| Result LOINC | 5370-2 |