High incidence of false-positive results of IgG antibody against SARS-CoV-2 with rapid immunochromatographic antibody test due to human common cold coronavirus infection

Shun Shibata; Takashi Ishiguro; Yasuhito Kobayashi; Mayumi Koike; Tsuyoshi Numano; Yoshihiko Shimizu; Noboru Takayanagi

doi:10.1016/j.rmcr.2020.101180

High incidence of false-positive results of IgG antibody against SARS-CoV-2 with rapid immunochromatographic antibody test due to human common cold coronavirus infection

Respir Med Case Rep. 2020 Jul 25:31:101180. doi: 10.1016/j.rmcr.2020.101180. eCollection 2020.

Authors

Shun Shibata¹, Takashi Ishiguro¹, Yasuhito Kobayashi², Mayumi Koike³, Tsuyoshi Numano³, Yoshihiko Shimizu², Noboru Takayanagi¹

Affiliations

¹ Department of Respiratory Medicine, Kumagaya, Saitama, 360-0105, Japan.
² Pathology, Kumagaya, Saitama, 360-0105, Japan.
³ Laboratory Medicine, Kumagaya, Saitama, 360-0105, Japan.

Abstract

We experienced a 72-year-old man who developed laboratory-confirmed human coronavirus HKU1 pneumonia. PCR testing for SARS-CoV-2 from a nasopharyngeal specimen was negative twice, and rapid immunochromatographic antibody test (RIAT) using a commercially available kit for IgM and IgG against SARS-CoV-2 showed him turning positive for IgG against SARS-CoV-2. We then performed RIAT in stored serum samples from other patients who suffered laboratory-confirmed human common cold coronaviruses (n = 6) and viruses other than coronavirus (influenza virus, n = 3; rhinovirus, n = 3; metapneumovirus, n = 1; adenovirus, n = 1) admitted until January 2019. Including the present case, four of 7 (57%) showed false-positive RIAT results due to human common cold coronaviruses infection. Two of the 4 patients showed initial negative to subsequent positive RIAT results, indicating seroconversion. RIAT was positive for IgG and IgM in viruses other than coronavirus in 2 (25.0%) and 1 (12.5%) patient. Because of high incidence of false positive RIAT results, cross antigenicity between human common cold coronaviruses and SARS-CoV-2 can be considered. Results of RIAT should be interpreted in light of epidemics of human common cold coronaviruses infection. Prevalence of past SARS-CoV-2 infection may be overestimated due to high incidence of false-positive RIAT results.

Keywords: Coronavirus disease 2019; Coronavirus disease 2019, COVID-19; Immunity passport; Prevalence; Rapid immunochromatographic antibody testing; Rapid immunochromatographic antibody testing, RIAT; Severe acute respiratory syndrome coronavirus 2; Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2.

Publication types

Case Reports