Test Code #
CPT Code(s) #
COVID-19 Immune Index™ — IgG, IgM, IgA Antibody Testing by CLIA Correlated with Virus Neutralization
If Profile, Includes Tests:
Type of Study:
• Negative <0.8
• Indeterminate 0.8 - <1.0
• Positive >/= 1.0
Assays are performed twice per week. Report availability is within 3-5 days from the time of specimen receipt.
Collect 5-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into red capped tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Transport at ambient temperature. If stored prior to shipment, the sample is stable refrigerated (2-8°C) for 7 days and frozen (-20°C or lower) up to one year.
This CLIA detects IgM, IgA and IgG antibodies to the spike (S) proteins of SARS-CoV-2 virus. Positive results to antibodies against SARS-CoV-2 are generally indicative of an individual’s current or prior infection with the SARS-CoV-2 virus or vaccination. However, the duration of these antibodies remaining in circulation is not yet known. These test results should be considered in the context of patient’s clinical history, physical examination, epidemiologic exposure and vaccination history. Serological testing should not be used to establish the presence or absence of acute SARS-CoV-2 infection. A negative finding by this test does not preclude acute infection. If acute infection is suspected, direct testing for SARS-CoV-2 is indicated.
In vaccinated individuals, a positive result with this test and a negative result for antibodies to nucleocapsid proteins (Test#051) suggests that they have produced vaccine-induced antibodies and that they were never infected with SARS-CoV-2.
IgM isotype antibodies develop within 5 to 7 days indicating recent exposure to the virus. IgG isotype antibodies develop after 10 days and remain in circulation longer. IgA isotype antibody development is variable in its response. Vaccine induced antibodies may be of IgG or IgM isotype.
Guo, L., Ren, L., Yang, S., Xiao, M., Chang, D., Yang, F., et. al. (2020). Profiling early humoral response to diagnose novel coronavirus disease (COVID-19). Clinical Infectious Diseases.
Zheng, Z et al. (2020) Profile of Specific Antibodies to SARS-CoV-2: The First Report Journal of Infection (2020), doi: https://doi.org/10.1016/j.jinf.2020.03.052
Long, Q et al. (2020). Antibody responses to SARS-CoV-2 in COVID-19 patients: the perspective application of serological tests in clinical practice. 10.1101/2020.03.18.20038018.