Detection of specific neutralizing antibodies capable of inhibiting SARS-CoV-2-virus.
Virus Neutralizing Antibody Test
SARS
SARS-CoV2
SARS-CoV-2
IMMUNO-COV
FSAR2
Serum
Molecular testing is recommended for diagnosis of coronavirus disease 2019 (COVID-19) in symptomatic patients.
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Draw blood in a serum gel tube(s), plain red-top tube(s) is acceptable. Centrifuge and aliquot serum; send one aliquot. DO NOT heat-inactivate. Ship 1 mL serum in a plastic vial, frozen.
0.2 mL
Gross Hemolysis | Reject |
Gross Lipemia | Reject |
Gross Icterus | Reject |
Other | NA |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 30 days | |
Refrigerated | 72 hours | ||
Ambient | 24 hours |
Detection of specific neutralizing antibodies capable of inhibiting SARS-CoV-2-virus.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a positive-sense, single-stranded RNA virus that causes coronavirus disease 2019 (COVID-19). Like other coronaviruses that infect humans, SARS-CoV-2 can cause both upper and lower respiratory tract infection. Symptoms can range from mild (ie, the common cold) to severe (ie, pneumonia) in both healthy and immunocompromised patients. SARS-CoV-2 transmission occurs primarily via respiratory droplets. During the early stages of COVID-19, symptoms maybe nonspecific and resemble other common respiratory tract infections, such as influenza. The incubation period for COVID-19 ranges from 3 to 14 days. Typically, immunocompetent individuals with COVID-19 develop detectable antibodies against SARS-CoV-2 approximately 8 to 11 days following onset of symptoms or vaccination. Patients tested prior to this time may be negative for SARS-CoV-2 antibodies.
22 - 20,862 IU/mL
POSITIVE: Neutralizing antibodies recognizing SARS-CoV-2 were detected in the blood at a level higher than the test threshold of 22 IU/mL. Results suggest prior infection with SARS-CoV-2 or vaccination against SARS-CoV-2.
BORDERLINE: No determination regarding the titer of neutralizing antibodies can be made. Borderline samples have either very low antibody titers or are negative for antibodies that neutralize SARS-CoV-2.
Titer values represent the level of neutralizing antibodies present in a blood sample. IMMUNO-COV titers have been calibrated to World Health Organization International Units per milliliter (IU/mL). Current scientific literature describes the degree of protection from COVID-19 conferred by different neutralizing antibody titers. Please refer to the Imanis website for the most up to date information: www.imanis-immunocov.com.
Note: Before October 2021, titers were reported in IMMUNO-COV VNT units. VNT and WHO IU/mL units are comparable. Multiply VNT result by 0.6954 to get equivalent WHO IU/mL value. Multiply WHO IU/mL result by 1.4380 to get equivalent VNT value.
This test was performed in the Imanis CLIA laboratory as a high complexity laboratory developed test. The test quantitatively measures the level (titer) of antibodies in a blood sample capable of blocking a live SARS-CoV-2 mimic virus from infecting Vero-ACE2 cells. The test limit of detection (LOD) is 22 IU/mL. The test upper limit of quantitation is 20,862.
More detailed information about the test is available at the Imanis website: www.imanis-immunocov.com or in the following reference: Vandergaast et al. (2021) mSphere 6: e0017021. doi: 10.1128/mSphere.00170-21.
Convert from | Convert to | Multiply by |
IU/mL | VNT | 1.4380 |
VNT | IU/mL | 0.6954 |
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, OC63 or 229E.
The Neutralizing Antibody Assay is a functional assay that detects the presence of specific neutralizing antibodies capable of inhibiting VSV-SARS2-Fluc infection. Vero cells (African green monkey-derived kidney epithelial cells) that have been stably transduced to overexpress angiotensin converting enzyme 2 (ACE2) are infected with a virus displaying the SARS-CoV-2 spike glycoprotein on its surface and encoding the same SARS-CoV-2 spike glycoprotein and a firefly luciferase (Fluc) reporter in its genome. When this virus infects the Vero cells, the cells begin to produce firefly luciferase. A luciferase substrate is then added to assay plates to allow for a luminescence readout, wherein total luminescence (relative light units, RLU) corresponds to the extent of virus infection. The ability of antibodies in human serum or plasma to block infection of Vero-ACE2 cells by VSV-SARS2-Fluc, and thereby to prevent luciferase expression serves as a proxy readout for antibodies capable of neutralizing SARS-CoV-2 infection.
Monday through Friday
This test was developed, and its performance characteristics determined by Imanis Life Sciences, LLC in a manner consistent with CLIA requirements. This test has not been reviewed, cleared, or approved by the U.S. Food and Drug Administration.
86409
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
FSAR2 | SARS-CoV-2 Neutralizing Antibody | 95410-7 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
FSAR2 | SARS-CoV-2 Neutralizing Antibody | 95410-7 |