Concordance between two rapid diagnostic tests for the detection of antibodies against SARS-CoV-2

Abstract

Objective: To assess the agreement between two rapid detection tests (RDT) for antibodies against SARS-CoV-2 infection. Materials and methods: This was a cross-sectional study that used a random sample of nonhospitalized patients from the primary care management division of the Healthcare Area of Leon (58 RT-PCR-positive cases and 52 RT-PCR-negative cases). Information regarding symptoms was collected and all patients were simultaneously tested using two RDTs (Combined -cRDT and Differentiated -dRDT). The results of both tests were evaluated using the chi-square test and, for degree of agreement, the kappa coefficient. Results: About 52% of the participants were women (mean age: 48.2 ± 11.0 years). A total of 58.2% were positive for d-RDT and 41.2% were positive for c-RDT. In the subjects who were RT-PCR-positive, d-RDT was positive in 72.4% and c-RDT in 55.2%; in those who were RT-PCRnegative, the percentages were 42.3% and 26.9%, respectively. The kappa coefficient observed between the two RDTs was 0.644, and was higher in patients without a fever or anosmia (0.725) and lower in those with a fever or anosmia (0.524).

Comparison of Five Serological Assays for the Detection of SARS-CoV-2 Antibodies

“…The study was conducted to provide information on performance characteristics of commercially available serological assays. Thus, it contributes to previously described assessments [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ] and provides an additional piece of the puzzle in terms of interpreting the results of serological approaches for the retrospective diagnosis of infections with SARS-CoV-2.…”

“…To close this diagnostic gap, there was an early focus on the implementation of antibody-based surveillance. By doing so, a more realistic view on the real dimensions of the spread of SARS-CoV-2 in the population was aspired to and numerous benchtop-based and point-of-care-testing (POCT)-based serological assays were introduced [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. However, the limitations of this strategy rapidly emerged as well.…”

“…However, the limitations of this strategy rapidly emerged as well. While specificity was usually at least >95% in the geographic regions where the tests were developed, a broad variety of sensitivities, usually between 70% and 90% depending on the subpopulation assessed [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] and sometimes even lower [ 47 ], were recorded with an optimum sensitivity two weeks after infection [ 29 ] and decreasing positivity rates afterwards [ 30 ]. Further, age-dependency of serological sensitivity has been demonstrated [ 33 ] next to higher specificity but lower sensitivity of neutralizing antibodies compared to non-neutralizing ones [ 34 ].…”

Antibody Response Following SARS-CoV-2 Infection and Implications for Immunity: A Rapid Living Review

“…(2) 45 cross-sectional or cohort studies [18][19][20][21][22][23]25,26,29,31,32,35,37,[39][40][41][42][43][44]47,48,[51][52][53][54][55][56][58][59][60][61][62][63][64][67][68][69]71,[74][75][76][77][78][79][80] characterizing the antibody response (i.e., antibody types, levels, and duration) among adults with SARS-CoV-2 infection; and 317 studies validating the diagnostic performance of one or more immunoassays. 16,17,24,27,…”

“…18,20,41,43,47,52,55,58,67,69,77,78,80 In the immunoassay validation studies, inadequate reporting of patient selection methods and unclear or inconsistent criteria for interpreting immunoassay results meant we could not rule out high risk of bias and limited the clinical applicability of results. 16,17,24,27,28,33,34,38,45,46,49,57,65,66,70,72,73 Abbreviations: IgM/G/A = immunoglobulin M/G/A; Nab = neutralizing antibody; RT-PCR+ = reverse transcription polymerase chain reaction positive result; RT-PCR = reverse transcription polymerase chain reaction.…”