Advanced Diagnostic Laboratories

Collect

Collect in a plain red top or SST tube.

Specimen Preparation

Serum Separator (SST):
Fill tube completely. Thoroughly mix the blood by inverting the tube five times. Allow blood to clot for 30 to 60 minutes (tube standing upright). Promptly centrifuge at 1500 to 2000 x g for no less than 15 minutes until clot and serum are separated. Use pipette provided, avoid touching the surface of the gel with the pipette tip, and promptly transfer all the serum into the appropriately labelled plastic vial(s).  Re-cap immediately.
 

• Serum Clot Activator (Red Top):
  Fill the tube. Thoroughly mix the blood by inverting the tube five times. Allow blood to clot for 30 to 60 minutes (tube standing upright). Centrifuge at 1500 to 2000 x g for no less than 15 minutes until clot and serum are separated. Use pipette provided to promptly transfer all the serum into the appropriately labelled plastic vial plastic vial (s).

Preferred volume: 1 mL serum

Patient Prep

N/A

Pediatric Collection

Minimum Volume: 0.5mL serum

Unacceptable Conditions

Plasma, lipemic, grossly hemolyzed, microbially contaminated specimens, or specimens with visible particulates should not be used.

Storage Transport Temp

Preferred: Frozen  Send serum Priority Overnight via FedEx and in a well insulated container on dry ice.

Also Acceptable: Refrigerated (2-8C) within 48hrs.

Stability

Up to 8 hours ambient or 48 hours refrigerated at 2-8°C. Freeze at or below -20°C for longer storage or shipping.

Notes

2019 novel coronavirus (COVID-19) is a single–stranded RNA coronavirus. Comparisons of the genetic sequences of this virus have shown similarities to SARS-CoV and bat coronaviruses. In humans, coronaviruses cause respiratory infections.3 Coronaviruses are composed of several proteins including the spike (S), envelope (E) , membrane (M) and nucleocapsid (N). Results suggest that the spike protein retains sufficient affinity to the Angiotensin Converting Enzyme 2 (ACE 2) receptor to use it as a mechanism of cell entry. Human to human transmission of coronaviruses is primarily thought to occur among close contacts via respiratory droplets generated by sneezing and coughing. IgM is the first immunoglobulin to be produced in response to an antigen and will be primarily detectable during the early onset of the disease. IgG is the most abundantly found immunoglobulin to be produced in response to an antigen and will be maintained in the body after initial exposure for long term response.

Performed

Monday-Friday

Methodology

Qualitative Enzyme-Linked Immunosorbent Assay (ELISA)

Reported

5-7 Days

Department

Core Lab

Synonyms

COVID, COVID-19, IgG antibody

Ordering Recommendations

N/A

Reference Interval

IgG antibodies to SARS-CoV-2 NOT DETECTED
IgG antibodies to SARS-CoV-2 BORDERLINE
IgG antibodies to SARS-CoV-2 DETECTED

Interpretation

The antibody test to SARS-CoV-2 is an ELISA that detects IgG antibodies to the nucleoprotein of the SARS-CoV-2 virus.  The United States (U.S.) FDA has made this test available under an emergency access mechanism called an Emergency Use Authorization (EUA). The EUA is supported by the Secretary of Health and Human Service’s (HHS’s) declaration that circumstances exist to justify the emergency use of in vitro diagnostics (IVDs) for the detection and/or diagnosis of the virus that causes COVID-19. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes. FDA is not aware of an antibody test that has been validated for diagnosis of SARS-CoV-2 infection.
 
Test result from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status. Validation of the assay performance has been carried out at NJH.  Testing is limited to National Jewish Health laboratories that are CLIA and 42 U.S.C. §263a certified high-complexity laboratories.
 
NOT DETECTED.  Negative results for IgG antibodies do not rule out SARS-CoV-2 infection, In the first week of the onset of the infection, the IgG response may be negative or of low level. In addition, patients with low immunity or other diseases that affect immune function, failure of important systemic organs, and use of drugs that suppress immune function can also lead to negative results IgG antibodies to SARS-CoV-2. The amount of coronavirus antibodies may be below the detection level of the assay.
 
BORDERLINE. Borderline result indicates the detection of IgG antibodies, but it did not meet the threshold for positivity. This may indicate cross reactivity or very early infection. Repeat collection recommended. 
 
DETECTED.  A positive test indicates that there are IgG antibodies present in the patient’s sera suggesting a past infection. However a positive result does not rule out a past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.

CPT Code

86328