Sorted By Test Name - Mayo Medical Laboratories

SPNC
89971
SPNEU
83150
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 is
recommended.
Reference Values:
ANTISTREP-O TITER
or =18 years: < or =530 IU/mL
ANTI-DNase B TITER
or =18 years: < or =300 U/mL
Clinical References: Ayoub EM, Harden E: Immune response to streptococcal antigens: diagnostic
methods. In Manual of Clinical and Laboratory Immunology. 5th edition. Edited by NR Rose, EC de
Marco, JD Folds, et al. Washington, DC, ASM Press, 1997, pp 450-457
Streptococcus pneumoniae Antigen, Spinal Fluid
Clinical Information: Streptococcus pneumoniae is the most frequently encountered bacterial agent
of community acquired pneumonia, and can also be an agent of bacterial meningitis. Because of the
significant morbidity and mortality associated with pneumococcal pneumonia, septicemia, and meningitis,
it is important to have diagnostic test methods available that can provide a rapid diagnosis. In instances
where empirical antibiotics are being considered prior to culture confirmation, antigen testing may be
useful.
Useful For: Rapid diagnosis of pneumococcal meningitis
Interpretation: A positive result supports a diagnosis of pneumococcal meningitis. A negative result
suggests that pneumococcal antigen is absent in the cerebrospinal fluid (CSF). However, infection due to
Streptococcus pneumoniae cannot be ruled out since the antigen present in the specimen may be below
the lower limit of detection of the test. If pneumococcal meningitis is suspected, CSF should also be
submitted for bacterial culture and Gram-stain analysis.
Reference Values:
Negative
Clinical References: 1. Plouffe JF, Moore SK, Davis R, et al: Serotypes ofStreptococcus
pneumoniae blood culture isolates from adults in Franklin County, Ohio. J Clin Microbiol
1994;32:1606-1607 2. Johnston RB Jr: Pathogenesis of pneumonococcal pneumonia. Rev Infect Dis
1991;13:509-517
Streptococcus pneumoniae Antigen, Urine
Clinical Information: Streptococcus pneumoniae is the most frequently encountered bacterial agent
of community-acquired pneumonia (CAP). Because of the significant morbidity and mortality associated
with pneumococcal pneumonia, septicemia, and meningitis, it is important to have diagnostic test methods
available that can provide a rapid diagnosis. In instances where empirical antibiotics are provided for CAP
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