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Pneumococcal Avidity Panel (23 Serotype)

Test Code: 401839P
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Clinical and Procedure
Clinical Utility

The avidity of antibody induced by a vaccine is an independent correlate of protection and this information is an important supplement to the measurement of antibody titer. The ability to generate higher avidity antibodies is a key aspect of a fully functional immune response. Measurement of antibody avidity is an important determinant of protective efficacy against pneumococci. There is a strong correlation between avidity and opsonophagocytic activity.


This is a multiplex immunofluorescence assay that uses anti-pneumococcal coated microspheres to select for specific pneumococcal polysaccharide antibodies in patient specimens. The index is calculated from signal reduction induced by a bond-interferingreagent. This index provides an indication of the strength (avidity) of the antibodies to the pneumococcal polysaccharide.

Turnaround Time

5-7 business days from receipt of specimen

Specimen Information
Specimen Type Test Code CPT Code NY Approved Volume Assay Range Special Instructions
serum 401839P 86317 x 23 Yes

1 mL

0.3 - 4.0 Avidity Index (AI)

  • Collect 1 mL, ambient, frozen, or refrigerated, no special shipping requirements.

Specimens are approved for testing in New York only when indicated in the Specimen Information field above.

The CPT codes provided are based on Viracor Eurofins' interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for general informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Viracor Eurofins assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.

This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.


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Pickering JW, Martins TB, Greer RW, et al. A multiplexed fluorescent microsphere immunoassay for antibodies to pneumococcal capsular polysaccharides. Am J Clin Pathol. 2002 April;117(4):589-96.

Quataert SA, Kirch CS, Wiedl LJ, et al. Assignment of weigh-based antibody units to a human antipneumococcal standard reference serum, lot 89-S. Clin & Diagn Lab Immunol. 1995 Sept;2:590-7.

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