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SARS-CoV-2 IgG (Anti-Spike) (Southeast Michigan Only)

Coronavirus, Corona, Covid, Covid-19, Anti-Spike

Test Codes

EPIC: LAB1231374, Beaker: COIGGSP

Department

Chemistry

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)

Physician Office/Draw Specimen Preparation

Let SST specimens clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged SST tube within two hours of collection. (Minimum: 2.0 mL) 

Preparation for Courier Transport

Transport: Centrifuged SST tube or serum aliquot, refrigerated (2-8°C or 36-46°F). (Minimum: 2.0 mL serum) 

Rejection Criteria

• Hemolyzed specimens.
• Severely lipemic specimens.
• Specimens with obvious microbiological contamination

In-Lab Processing

Let SST specimens clot 30-60 minutes. Centrifuge SST or Microtainers^® to separate serum from cells. Deliver immediately to the appropriate testing station.

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers® with Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2 Days 
Refrigerated (2-8°C or 36-46°F): 7 Days
Frozen (-20°C/-4°F or below): 7 Days 

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2 Days 
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days 

Laboratory

Royal Oak Automated Chemistry Laboratory

Performed

Sunday – Saturday, 24 hours a day.
Results available within 4 hours of receipt by the Laboratory.

Reference Range

< 50 AU/mL = antibody negative

Reportable Range
50-50,000 AU/mL

Test Cutoff Value
≥ 50 AU/mL = antibody positive

Test Methodology

Abbott Chemiluminescent immunoassay.

Interpretation

This assay tests for IgG antibody specific for the Receptor Binding Domain of the spike protein. Presence of IgG antibodies to the spike protein of SARS-CoV-2 is a measure of immunological responsiveness to a previous viral exposure. Spike-specific antibodies can also be produced secondary to COVID-19 vaccination. A positive test result cannot be used to discriminate between an antibody response caused by a natural infection vs. vaccination. Test reports will include a qualitative result and a semi-quantitative determination of antibody level.

Antibody test result should always be interpreted together with clinical history and other results such as direct viral detection of SARS-CoV-2 (COVID-19). The performance characteristics of the Abbott assay were determined by Beaumont Laboratory. The test has been issued Emergency Use Authorization by the US Food and Drug Administration.

Clinical Utility

• Provides evidence of past exposure to SARS-CoV-2 or responsiveness to COVID-19 vaccination.
• A positive test result cannot be used to discriminate between an antibody response caused by a natural infection vs. vaccination
• Most individuals diagnosed with COVID-19 seroconvert within 3 weeks of exposure to the virus. If a specimen is collected too early (i.e. prior to seroconversion), the test will yield a negative result.
• It is not recommended to test for spike-specific antibodies until at least 3 weeks post-vaccination.
• The SARS-CoV-2 IgG assay is not a diagnostic test. Direct viral detection assays that employ molecular methods such as nucleic acid amplification, are the only laboratory tests that are diagnostic for COVID-19.
• IgG results should not be used to make decisions on infection status

Incubation Period

According to estimates from the World Health Organization (WHO), the incubation period for SARS-CoV-2 ranges from 2-14 days with a median incubation period of 5 days.

CPT Codes

86769

Contacts

Last Updated

11/19/2024