Dados do Trabalho

Título

Urinary testing for anti-SARS-CoV-2 antibodies: A sensitive and non-invasive approach to assess COVID-19 immune conversion

Introdução

The alarming incidence and mortality of the COVID-19 pandemic have highlighted the importance of readily available diagnostic tests to contain emerging and reemerging diseases.The serum-based ELISA method has been widely used to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, no study has investigated patient urine as a biological sample for the detection of specific antibodies against SARS-CoV-2 to date.

Objetivo (s)

This study developed a new urine-based ELISA method using recombinant SARS-CoV-2 nucleocapsid protein.

Material e Métodos

ELISA was used to evaluate the presence of anti-SARS-CoV-2 nucleocapsid-specific antibodies in 209 urine samples from 139 previously confirmed qRT-PCR patients, who were either hospitalized or not, collected between the 2nd and 60th day after symptom onset. We used serum-based ELISA to compare the diagnostic accuracy of rSARS-CoV-2 N protein with a panel of 187 sera collected on the same day as the urine samples. In addition, we included unmatched negative samples collected before 2019 and from individuals who maintained strict quarantine and did not exhibit any symptoms. Data obtained were analyzed using the GraphPad Prism program. Results with p<0.05 are considered significant and confidence intervals (CIs) were defined with a 95% confidence level (95% CI). Diagnostic performance was assessed by calculating sensitivity, specificity, positive and negative predictive values, area under the curve, and Youden's index.

Resultados e Conclusão

The urine-based ELISA was able to detect the presence of antibodies with a sensitivity of 94% and specificity of 100%, compared to 88% sensitivity and 100% specificity of the serum-based method. Thus, it is a non-invasive method with potential for use as a COVID-19 immunodiagnostic platform, allowing for the evaluation of exposure at the population level and/or the risk of infection at the individual level in an easy and practical manner.

Palavras-chave

SARS-CoV-2; COVID-19; immunodiagnostic; urine; antibody; Nucleocapsid protein.

Agradecimentos

CAPES; Fapemig; CNPq; MCTI – Iniciativa Rede Vírus; SESU/MEC