Demonstration of acute or recent streptococcal infection using both antistreptolysin O and anti-DNase B titers
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
ASO | Antistrep-O Titer, S | Yes | Yes |
ADNAS | Anti-DNase B Titer, S | Yes | Yes |
Nephelometry
ADB (Antideoxyribonuclease B)
Anti-Dnase B
Anti-Hyaluronidase (possible equivalent test)
Antideoxyribonuclease B (ADB)
Antideoxyribonuclease
Antistreptolysin-O (ASO) Titer
ASO (Antistreptolysin-O) Titer
DNA Streptococcal Antibody
DNase-B, Anti
Hyaluronidase (possible equivalent test)
Streptococcal Antibodies, Serum
Serum
Patient Preparation: Fasting preferred but not required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
0.5 mL
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 7 days |
Demonstration of acute or recent streptococcal infection using both antistreptolysin O and anti-DNase B titers
A number of bacterial antigens have been identified in cultures of
Infections by the group A streptococci are unique because they can be
Glomerulonephritis and rheumatic fever occur following the infection, after a period of latency following the infection, during which the patient is asymptomatic. The latency period for glomerulonephritis is
ANTISTREP-O TITER
<5 years: < or =70 IU/mL
5-17 years: < or =640 IU/mL
> or =18 years: < or =530 IU/mL
ANTI-DNase B TITER
<5 years: < or =250 U/mL
5-17 years: < or =375 U/mL
> or =18 years: < or =300 U/mL
Elevated values are consistent with an antecedent infection by group A streptococci.
The use of the antistreptolysin O (ASO) for the diagnosis of an acute group A streptococcal infection is rarely indicated, unless the patient has received antibiotics that would render the culture negative. There are certain limitations to the use of the ASO test in these circumstances due to the delay and attenuation of the immune response following early antibiotic therapy.
False-high titers may be obtained with sera that are contaminated by certain bacterial organisms during shipment or storage and in patients with liver disease where the presence of high lipoprotein concentrations in the serum may mimic antibody activity.
Although the antistreptolysin O (ASO) test is quite reliable, performing the anti-DNase is justified for 2 primary reasons. First, the ASO response is not universal. Elevated ASO titers are found in the sera of about 85% of individuals with rheumatic fever; ASO titers remain normal in about 15% of individuals with the disease. The same holds true for other streptococcal antibody tests: a significant portion of individuals with normal antibody titers for 1 test will have elevated antibody titers for another test. Thus, the percentage of false-negatives can be reduced by performing 2 or more antibody tests. Second, skin infections, in contrast to throat infections, are associated with a poor ASO response. Patients with acute glomerulonephritis following skin infection (post-impetigo) have an attenuated immune response to streptolysin O. For such patients, performance of an alternative streptococcal antibody test such as anti-DNase B is recommended.
Ayoub EM, Harden E: Immune response to streptococcal antigens: diagnostic methods. In Manual of Clinical and Laboratory Immunology. Fifth edition. Edited by NR Rose, EC de Marco, JD Folds, et al. Washington, DC, ASM Press, 1997, pp 450-457
In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.
A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with an LED, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.
Monday through Friday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
86060
86215
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
SABP | Streptococcal Antibodies Profile | 58713-9 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
ADNAS | Anti-DNase B Titer, S | 5133-4 |
ASO | Antistrep-O Titer, S | 5370-2 |