ObjectivesNumerous serologic
immunoassays have been launched to detect
antibodies to
SARS-CoV-2, including rapid tests. Here, we validate use of a lateral flow
immunoassay (LFI) intended for rapid
screening and qualitative
detection of anti-
SARS-CoV-2 IgM and
IgG in
serum,
plasma, and whole
blood, and compare results with
ELISA. We also seek to establish the value of LFI testing on
blood obtained from a
capillary blood sample. MethodsSamples collected by venous
blood draw and
capillary finger stick were obtained from
patients with
SARS-CoV-2 detected by RT-qPCR and
control patients negative for
SARS-CoV-2. Samples were tested with the
2019-nCoV IgG/
IgM Detection Kit (
Colloidal Gold) lateral flow
immunoassay, and antibody calls were compared with results obtained by
ELISA. ResultsThe Biolidics LFI kit shows clinical
sensitivity of 92% at 7 days after
PCR diagnosis of
SARS-CoV-2 on venous
blood. Test
specificity was 92% for
IgM and 100% for
IgG. There was no significant difference in detecting
IgM and
IgG with Biolidics LFI and
ELISA at D0 and D7 (p=1.00), except for
detection of
IgM at D7 (p=0.04).
Finger stick whole
blood of
SARS-CoV-2 patients showed 93%
sensitivity for antibody
detection. ConclusionsClinical performance of Biolidics
2019-nCoV IgG/
IgM Detection Kit (
Colloidal Gold) is comparable to
ELISA and showed consistent results across different sample types. Furthermore, we show that
capillary blood obtained by
finger stick shows
similar sensitivity for detecting anti-
SARS-CoV-2 IgM and
IgG antibodies as venous
blood samples. This provides an opportunity for decentralized rapid testing in the
community and may allow
point-of-care and longitudinal
self-testing for the presence of anti-
SARS-CoV-2 antibodies.