ABSTRACT
Many skin manifestations of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection reflect activation of cutaneous and systemic immune responses involving effector pathways of both the innate and adaptive arms of the immune system. This article reviews evidence from the recent clinical and scientific literature that informs the current understanding of the consequences of coronavirus disease 2019 (COVID-19)-induced immune cell activation, as relevant to dermatology. Topics include the clinical consequences of autoantibody production in patients with COVID-19, immunologic evidence for chilblains as a manifestation of SARS-CoV-2 infection, and the relationship between type I interferons and COVID-19 disease severity.
Subject(s)
COVID-19/physiopathology , Skin Diseases/physiopathology , Chilblains/physiopathology , Erythema Multiforme/physiopathology , Exanthema/physiopathology , Humans , Pityriasis Rosea/physiopathology , Skin/physiopathology , Skin Diseases, Vesiculobullous/physiopathologySubject(s)
COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Skin Diseases/diagnosis , Skin Diseases/virology , Skin/virology , Adult , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Female , Humans , Male , Middle Aged , Skin Diseases/immunology , Skin Diseases/pathology , Young AdultABSTRACT
Appropriate use and interpretation of serological tests for assessments of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure, infection and potential immunity require accurate data on assay performance. We conducted a head-to-head evaluation of ten point-of-care-style lateral flow assays (LFAs) and two laboratory-based enzyme-linked immunosorbent assays to detect anti-SARS-CoV-2 IgM and IgG antibodies in 5-d time intervals from symptom onset and studied the specificity of each assay in pre-coronavirus disease 2019 specimens. The percent of seropositive individuals increased with time, peaking in the latest time interval tested (>20 d after symptom onset). Test specificity ranged from 84.3% to 100.0% and was predominantly affected by variability in IgM results. LFA specificity could be increased by considering weak bands as negative, but this decreased detection of antibodies (sensitivity) in a subset of SARS-CoV-2 real-time PCR-positive cases. Our results underline the importance of seropositivity threshold determination and reader training for reliable LFA deployment. Although there was no standout serological assay, four tests achieved more than 80% positivity at later time points tested and more than 95% specificity.