4 x 1mL dedicated plain top (red) tubes
All patients are tested by the Roche Elecsys Total (IgG and IgM) antibody SPIKE and NCP assays.
The SPIKE assay reports quantitatively, the NCP assay reports qualitatively.
SPIKE assay units: U/mL
SPIKE
assay UOM
= 10%
| Age Range | Either Sex |
|---|---|
| All | < 0.8 |
SARS-CoV-2 (IgG and IgM) SPIKE assay
SARS-CoV-2 (IgG and IgM) NCP assay
Coronaviruses are a large and diverse family of viruses which include some known to cause illness in animals and humans, including the common cold, severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS).
SARS-CoV-2 is the causative agent of coronavirus disease (COVID-19). The clinical signs and symptoms of COVID-19 infection range from non-specific respiratory symptoms such as cough, fever, sore throat and anosmia, to shortness of breath and symptoms of pneumonia and severe acute respiratory infection. Most cases in New Zealand have had a mild illness, with approximately six percent having more severe illness requiring hospitalisation. The virus has an approximately one percent fatality rate with most of those who have died from the virus to date suffering from pre-existing health problems. The most common reported symptoms to date in New Zealand cases are cough, followed by headache, sore throat, and fever.Serology Considerations:
Testing is not useful in the acute diagnosis of COVID-19 as a significant proportion of patients will test negative for antibodies until two weeks after the onset of symptoms. Further, antibodies most notably directed against NCP target can decline over time may become undetectable several months after initial infection.Antibody status has not been correlated with immunity in studies to date so no conclusions should be made on safety of re-exposure to potential infection.
Additionally, consideration of the clinical, epidemiological and laboratory information is required in order to interpret the result.
From the 8th November 2021, at LabPLUS, every serology request will be dually tested using the Roche Laboratories SPIKE target and NCP target Total (IgG and IgM) antibody assays. A reactive SPIKE target result (>/=0.8 U/mL) implies either exposure at some time to or vaccination against SARS-CoV-2 virus. Individuals vaccinated with the Pfizer vaccine will not develop an NCP target antibody response.
In infected individuals, the SPIKE target assay antibody response rises rapidly and predictably. As such, the quantitated result can be used to determine if an unexpected SPIKE antibody reactive result is part of an evolving immune response by repeat testing 7 days after the original blood specimen.Who and when to test:
RT-PCR is the diagnostic method of choice for the diagnosis of acute COVID-19 infection.Given the lag time from onset of infection to detection of antibody, serological testing has no role in the acute diagnosis of COVID-19.
Serology is likely to be of most benefit for individuals with symptoms consistent with COVID-19 but who were PCR negative or not tested, particularly those who are being investigated as part of an outbreak. It may also play a role to identify immunised individuals in selected populations or groups.
For further information contact the laboratory (contact via Lablink: 22000 or (09) 307-8995 or 0800 522 7587) ,or:
the Virology team
virology@adhb.govt.nz
Send with chiller packs.
SST blood specimens may be centrifuged before referral.