Streptococcal Antibodies Profile, Serum
Use
This test is useful for demonstrating an acute or recent streptococcal infection by measuring both antistreptolysin O and anti-DNase B titers. Group A streptococcal infections can lead to serious nonpurulent complications such as rheumatic fever and glomerulonephritis, which follow a latent period after infection. Rheumatic fever is associated with rheumatogenic serotypes, while glomerulonephritis follows nephritogenic serotypes. This test identifies bacterial antigen-specific enzymes that are indicators of these conditions, offering insights into the patient's history of infection.
Special Instructions
Patient preparation is preferred with fasting for 8 hours, though it is not required. The test requires a serum sample, which should be collected in a red top tube (preferred) or serum gel (acceptable), then centrifuged, and aliquoted into a plastic vial for submission. The test is available for New York clients and the sample must be sent to Mayo Clinic Laboratories for analysis. Gross lipemia specimens will be rejected.
Limitations
The antistreptolysin O (ASO) test may not be reliable if the patient has taken antibiotics that render the culture negative, delaying the immune response. False-high titers can result from contaminated specimens or conditions such as liver disease where high lipoprotein concentrations mimic antibody activity. Additionally, the ASO response is not universal, seen in only 85% of individuals with rheumatic fever, necessitating additional testing with anti-DNase B, especially post-skin infections. Lipemic sera may lead to imprecise results due to light scattering properties, affecting nephelometric quantitation.
New York Approved
Methodology
Immunoassay (Nephelometry)
Biomarkers
LOINC Codes
- 58713-9
- 5133-4
- 5370-2
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red top tube (preferred) or Serum gel (acceptable), submitted in a plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Patient Preparation
Fasting: 8 hours, preferred but not required
Causes for Rejection
Gross lipemia specimens will be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 28 days |
| Frozen | 28 days |