LAB ANTIBODY
Detect a Recent COVID-19 Infection
Serology antibody tests determine whether a person has recently had a COVID-19 infection. These tests should not be used to determine immunity status. Results available 48 to 72 hours after sample arrival at the laboratory.
Assays: DiaSorin IgM and IgG, Beckman Coulter IgG, Siemens and DIaSorin IgM, IgG and Total*
*These tests are only for use under the Food and Drug Administration’s Emergency Use Authorization. This laboratory-developed test has been validated in accordance with CLIA and FDA’s Guidance Document (Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency Immediately in Effect Guidance for Clinical Laboratories, Commercial Manufacturers, and Food and Drug Administration Staff Document). This test service has not been FDA cleared or approved.
How to Use
STICK
Stick finger with lancet
DROP
Add 4 large drops of blood
WAIT
Wait 3 minutes for sample to dry
CLOSE & SHIP
Close lid and ship
What Will My Results Tell Me?
Antibody testing is done with blood samples because we look for evidence of the body’s immune response to the virus. After your body is exposed to a foreign pathogen, your white blood cells make antibodies to neutralize it. When an antibody test comes back positive for COVID-19 it means that you were exposed to SARS-CoV-2 at some point in the past, and your immune system was robust enough to launch an antibody-forming immune response.
You will have the opportunity to speak with a licensed physician to discuss your test results.
The antibody test will tell us if a person currently has or had a COVID-19 (SARS-CoV-2) infection, unlike a throat or nasal swab-based test that looks for virus indicating only an active infection.
Typically, Immunoglobulin G (IgG) is the most abundant antibody to be produced our immune system’s in response to an infection and is maintained in the body after initial exposure for long-term immune response. Immunoglobulin M (IgM) is the first antibody to be produced by our immune system in response to an infection and is primarily detected during the early stages of infection. While, these are the typical responses to most viruses, the body may not respond to COVID-19 this way.
Together, the presence of these two antibodies in a person’s blood is indicative of a COVID-19 infection within the past ~3-40 days. Note this test is only for qualitative detection and should not be the sole basis for clinical diagnosis and treatment or used in place of FDA-authorized molecular viral tests.
- IgM is usually the first, specific antibody type generated by the body in response to infection.
- The IgG antibody type is then generated and replaces IgM as the predominant antibody in the response to infection for most viruses.
- IgM and IgG fight infections by targeting specific antigens on the surface of the SARS-CoV-2 virus.
Beckman Coulter Access IgG Assay
POSITIVE PERCENT AGREEMENT:
The positive percent agreement (PPA) of the Access SARS-CoV-2 IgG assay was evaluated in 192 serum and plasma samples from symptomatic individuals diagnosed with SARS-CoV-2 by PCR methods from France and the United States. The positive percent agreement for the 51 samples taken >18 days after a positive PCR was 100%.
NEGATIVE PERCENT AGREEMENT:
The negative percent agreement (NPA) of the Access SARS-CoV-2 IgG assay was evaluated in a study of 1,400 samples collected prior to December 2019 in France and the United States. This total includes 1,000 samples from blood donors in France and 200 samples each from routine clinical laboratory diagnostic samples in France and the United States. Based on this evaluation, the overall negative percent agreement of the Access SARS-CoV-2 IgG assay was 99.6% (1395/1400).
Siemens ADVIA Centaur SARS-CoV-2 IgG (COV2G) Assay
POSITIVE PERCENT AGREEMENT:
Positive percent agreement was determined by testing 189 retrospective samples collected over the course of time from 89 unique donor subjects with a clinical diagnosis of COVID-19 based on a positive SARS-CoV-2 polymerase chain reaction (PCR) method. For the 42 samples taken ≥ 14 days after PCR positive, the PPA was 100%.
NEGATIVE PERCENT AGREEMENT:
Negative percent agreement was determined by testing 1831 samples collected prospectively prior to the COVID-19 outbreak (before November 2019) from apparently healthy individuals and apparently healthy pregnant women in the United States. The negative percent agreement was 99.9% (1829/1831).
Siemens ADVIA Centaur SARS-CoV-2 Total Antibody (COV2T) Assay
POSITIVE PERCENT AGREEMENT:
Positive percent agreement was determined by testing 262 samples collected over the course of time from 67 unique donor subjects with a clinical diagnosis of COVID-19 based on a positive polymerase chain reaction (PCR) method. The positive percent agreement for the 47 samples taken ≥14 days following a positive PCR result for was 100%.
NEGATIVE PERCENT AGREEMENT:
Negative percent agreement was determined by testing 1589 samples collected prior to the COVID-19 outbreak (before November 2019) from apparently healthy individuals and apparently healthy pregnant women in the United States. The negative percent agreement was 99.8% (1586/1589).
DiaSorin LIAISON SARS-CoV-2 IgM Assay
POSITIVE PERCENT AGREEMENT:
The positive percent agreement between the LIAISON SARS-CoV-2 IgM assay and the PCR comparator was determined by investigating 223 samples collected from 223 European patients. Infection with SARS-CoV-2 was confirmed by RT-PCR test at the time of the diagnosis. The positive percent agreement for the 81 samples taken 15 – 30 days after diagnosis was 92.6% (75/81).
NEGATIVE PERCENT AGREEMENT:
2473 presumed SARS-CoV-2 negative samples collected before the COVID19 outbreak from a European laboratory routine (n=1072), a US laboratory routine (n=400) and European blood donors (n= 1001) were tested LIAISON® SARS-CoV-2 IgM assays resulting in a NPA of 99.3% (2455/2473).
DiaSorin LIAISON SARS-CoV-2 S1/S2 IgG Assay
POSITIVE PERCENT AGREEMENT:
The positive percent agreement between the LIAISON SARS-CoV-2 S1/S2 IgG assay and the PCR comparator was determined by investigating 135 samples collected over the course of time from 76 European patients. Infection with SARS-CoV-2 was confirmed by RT-PCR test at the time of the diagnosis. The LIAISON SARS-CoV-2 S1/S2 IgG test was performed on samples collected at the time of admission and thereafter up to 36 days for 44 patients hospitalized with moderate symptoms and 11 admitted to the ICU with severe symptoms. The PPA of the 41 samples that were taken ≥15 days after diagnosis was 99.6% (40/41).
NEGATIVE PERCENT AGREEMENT:
One thousand ninety (n=1090) presumed SARS-CoV-2 negative samples from a European laboratory routine (n=90) and European blood donors (n=1000) were collected prior to COVID-19 and tested with the LIAISON SARS-CoV-2 S1/S2 IgG. From the samples tested, 1082 out of 1090 were negative resulting in a NPA of 99.3%.
These assay are intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection. At this time, it is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity. These assays should not be used to diagnose acute SARS-CoV-2 infection. Testing is limited to laboratories certified under the Clinical Laboratory Improvement Amendments (CLIA) of 1988, 42 U.S.C 263a, that meet requirements to perform moderate or high complexity tests.
Results are for the detection IgM, IgG, and total antibodies. Antibodies to SARS-CoV-2 are generally detectable in blood several days after initial infection, although the duration of time antibodies are present post‑infection is not well characterized. Individuals may have detectable virus present for several weeks following seroconversion. Laboratories within the United States and its territories are required to report all results to the appropriate public health authorities. The sensitivity of these assays early after infection is unknown. Negative results do not preclude acute SARS-CoV-2 infection. If acute infection is suspected, direct testing for SARS-CoV-2 is necessary. False positive results may occur due to cross-reactivity from pre-existing antibodies or other possible causes. These assays are only for use under the Food and Drug Administration’s Emergency Use Authorization.
