COVID-19 serology, IgG

Alphabetical Test listing

COVID-19 serology, IgG-14331

Fact sheets:

Healthcare providers

Recipients - all individuals whose specimens are tested with this assay should receive this fact sheet

 

  
COVID-19 serology, IgG
  
14331
  
LAB14331
  
COV-2 IGG
  
COVID-19
CoV-2 IgG
SARS-CoV-2-IgG
  

Qualitative detection of IgG antibodies to SARS-CoV-2 in human serum and plasma

  

This test should only be considered on these patient populations:

  • COVID symptoms that began >14 days ago
  • and no COVID PCR test or negative PCR

Also note:

  • COVID-19 antibody testing CANNOT be performed STAT
  • This test cannot be used as the sole basis to diagnose or exclude COVID-19
  • Results cannot be used to infer immunity or reduce PPE
  • The SARS-CoV-2 IgG test performed at Allina Health does NOT detect antibody to spike protein and thus is NOT useful when trying to evaluate response to vaccination. The current antibody testing available at Allina detects antibodies against the nucleocapsid. If evidence of spike antibody formation after vaccination is needed in select patients, there is a sendout test available
    • SARS-CoV-2 Antibody, IgG, Spike
    • Because the threshold to indicate protective immunity is still unknown, at this time a positive test result is considered suggestive of vaccine response and/or past exposure
  
Serum
  
  
2.0 mL
  
1.0 mL
  

Spin

  

Serum separator (Gold SST) tube

  
Lithium heparin (Li hep) plasma
EDTA plasma
  

Lt green plasma separator (PST):

Spin

Lavender (EDTA), 4mL/Red:

  1. Spin
  2. Transfer 2.0 mL (minimum 1.0 mL) of plasma or serum to a False bottom plasma/serum transport vial/tube (AHL)
  

Li heparin plasma: Lt green plasma separator (PST)

 

Serum - red/EDTA plasma: False bottom plasma/serum transport vial/tube (AHL)

  
  • Date of onset of symptoms
  

Refrigerated (preferred) - 7 days

Ambient - 2 days

Frozen (OK)

Freeze/thaw cycles: stable x2

  
5 days
  
  • Heat-inactivated specimens
  • Pooled specimens
  • Grossly hemolyzed specimens
  • Specimens with obvious microbila contamination
  • Specimens with fungal growth
  • Improper labels (unlabeled or mislabeled)
  • Hemolysis (some procedures)
  • Improper anticoagulant or ratio
  • Delay in transport
  • Improper storage temperature affecting results
  • Inappropriate timing of collection
  • Improper container
  • Leaking container resulting in compromised specimen
  • Quantity not sufficient (QNS)
  
AHL - Chemistry
  
Mo - Fr
  
1 - 3 days
  

Chemiluminescent microparticle immunoassay (CMIA)

  

Signal to cut-off index value (S/C) interpretation:

< 1.4 Negative

≥ 1.4 Positive

  

Coronavirus (CoV) belongs to the Coronaviridae family and is divided into three types: α, β and γ. Alpha and beta are only pathogenic to mammals and gamma mainly causes bird infections. CoV is mainly transmitted through direct contact with secretions or through aerosols and droplets. There is also evidence that it can be transmitted through the fecal-oral route as well. So far there are seven types of human coronavirus (HCoV) that cause human respiratory diseases: HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV, MERS-CoV and the novel coronavirus (2019). The novel coronavirus (2019) was discovered in 2019 in Wuhan, China with viral pneumonia cases and clinical manifestations were fever, fatigue, cough, and other symptoms which can rapidly develop into severed pneumonia, respiratory failure, septic shock, multiple organ failure, severe acid-base metabolism disorders, etc. and is life threatening.

  • This test has not been reviewed by the FDA.
  • Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic should be considered to rule out infection in these individuals.
  • Results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status.
  • Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.

SARS-CoV-2 Antibody testing after vaccination:

To know:

  • Providers have been asking if they should be ordering COVID antibody testing following vaccination. Both the Pfizer-BioNTech and Moderna COVID-19 vaccines contain mRNA that encodes and creates antibodies to the spike protein.
  • At this time, there is no guidance promoting antibody testing after vaccination. In the vaccine studies, there was no significant antibody detected (vs. placebo) until after the second dose.
  • It is yet undetermined what level of antibody to SARS-CoV-2 spike protein correlates to immunity against developing symptomatic SARS-CoV-2 disease. Studies are underway to measure the quantitative levels of specific SARS-CoV-2 antibodies following vaccination.  Such studies will provide valuable insights into the correlation between protection from vaccination and antibody levels.
    • With the unknowns it is not recommended to routinely test for immunity following COVID vaccination.
  • The SARS-CoV-2 IgG test performed at Allina Health does NOT detect antibody to spike protein and thus is NOT useful when trying to evaluate response to vaccination. The current antibody testing available in Allina detects antibodies against the nucleocapsid. If evidence of spike antibody formation after vaccination is needed in selected patients, there is a sendout test available.
  • To order the test: Order LAB994/MSO for “SARS-CoV-2 Antibody, IgG, Spike”.
  • Results will be reported as qualitative results (reported as either positive or negative).
    • Since the threshold to indicate protective immunity is still unknown at this time a positive result is considered suggestive of vaccine response and/or past exposure.

 

Expected antibody results after vaccination vs. prior COVID infection:

Expected results

Vaccination (after the second dose has been given)

Prior COVID infection (14 days or longer after symptom onset)

Antibody to Spike Protein (sendout)

Positive

Positive

Antibody to Nucleocapsid protein (performed at Allina)

Negative

Positive

 

To do

  • Do not routinely order serology testing following COVID vaccination.
  • If serology following vaccination is needed order LAB994/MSO for “SARS-CoV-2 Antibody, IgG, Spike”. Since the threshold to indicate protective immunity is still unknown at this time a positive result is considered suggestive of vaccination and/or past exposure.
  
86769
  
17030004
  
308676900
  
04/21/2020
  
07/14/2020