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Test ID: RBPG Rubella Antibodies, IgG, Serum

Reporting Name

Rubella Ab, IgG, S

Useful For

Determining immune status to the rubella virus

Clinical Information

Rubella (German or 3-day measles) is a member of the Togavirus family and humans remain the only natural host for this virus. Transmission is typically through inhalation of infectious aerosolized respiratory droplets and the incubation period following exposure can range from 12 to 23 days.(1) Infection is generally mild, self-limited, and characterized by a maculopapular rash beginning on the face and spreading to the trunk and extremities, fever, malaise, and lymphadenopathy.(2)

 

Primary in utero rubella infections can lead to severe sequelae for the fetus, particularly if infection occurs within the first 4 months of gestation. Congenital rubella syndrome is often associated with hearing loss and cardiovascular, and ocular defects.(3)

 

The United States 2-dose measles, mumps, rubella  vaccination program, which calls for vaccination of all children, leads to seroconversion in 95% of children following the first dose.(1) A total of 4 cases of rubella were reported to the Centers for Disease Control and Prevention in 2011 without any cases of congenital rubella syndrome.(4) Due to the success of the national vaccination program, rubella is no longer considered endemic in the United States (www.cdc.gov/rubella). However, immunity may wane with age as approximately 80% to 90% of adults will show serologic evidence of immunity to rubella.

Interpretation

The reported AI value is for reference only. This is a qualitative test and the numeric value of the AI is not indicative of the amount of antibody present. AI values above the manufacturer recommended cutoff for this assay indicate that specific antibodies were detected, suggesting prior exposure or vaccination.

 

Positive: Antibody index (AI) value of 1.0 or higher

-The presence of detectable IgG-class antibodies indicates immunity to the rubella virus through prior immunization or exposure. Individuals testing positive are considered immune to rubella infection.

 

Equivocal: AI value 0.8-0.9

Submit an additional sample for testing in 10 to 14 days to demonstrate IgG seroconversion if recently vaccinated or if otherwise clinically indicated.

 

Negative: AI value of 0.7 or lower

The absence of detectable IgG-class antibodies suggests the lack of a specific immune response to immunization or no prior exposure to the rubella virus.

Report Available

Same day/1 to 3 days

Day(s) Performed

Monday through Saturday

Clinical Reference

1. AAP Committee on Infectious Diseases: Rubella. In: Pickering LK, Baker CJ, Kimberlin DW, eds. Red Book. 2012 Report of the Committee on 1. AAP Committee on Infectious Diseases: Rubella. In: Pickering LK, Baker CJ, Kimberlin DW, eds. Red Book. 2012 Report of the Committee on Infectious Diseases. 29th ed. American Academy of Pediatrics; 2012

2. Best JM: Rubella. Semin Fetal Neonatal Med. 2007;12(3):182. doi: 10.1016/j.siny.2007.01.017

3. Duszak RS: Congenital rubella syndrome-major review. Optometry. 2009;80(1):36. doi: 10.1016/j.optm.2008.03.006

4. Notifiable Diseases and Mortality Tables. MMWR Morb Mortal Wkly Rep. 2016;65(3):ND-38

Method Name

Multiplex Flow Immunoassay (MFI)

Specimen Type

Serum


Specimen Required


Collection Container/Tube: 

Preferred: Serum gel

Acceptable: Red top

Submission Instructions: Plastic vial

Specimen Volume: 0.5 Ml

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reference Values

Vaccinated: positive (≥1.0 AI)

Unvaccinated: negative (≤0.7 AI)

Reference values apply to all ages.

Test Classification

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.

CPT Code Information

86762

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RBPG Rubella Ab, IgG, S 5334-8

 

Result ID Test Result Name Result LOINC Value
RBG Rubella Ab, IgG, S 40667-8
DEXG2 Rubella IgG Antibody Index 5334-8

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Mayo Clinic Laboratories | Microbiology and Infectious Disease Catalog Additional Information:

mml-pregnancyneonate, mml-immunization