TY - JOUR
T1 - In-house assays for detecting anti-SARS-CoV-2 antibodies in serum and urine
T2 - Correlation with COVID-19 severity from a cohort study in Qatar
AU - Vaikath, Nishant N.
AU - Al-Nesf, Maryam Ali
AU - Majbour, Nour
AU - Abdesselem, Houari B.
AU - Gupta, Vijay
AU - Bensmail, Ilham
AU - Abdi, Ilham Y.
AU - Elmagarmid, Khalifa Ahmed
AU - Shabani, Shadah
AU - Sudhakaran, Indulekha P.
AU - Ghanem, Simona S.
AU - Al-Maadheed, Mohammed
AU - Mohamed-Ali, Vidya
AU - Blackburn, Jonathan M.
AU - Decock, Julie
AU - El-Agnaf, Omar M.A.
N1 - Publisher Copyright:
© 2025
PY - 2025/6
Y1 - 2025/6
N2 - Background: Serological assays targeting antibodies against key viral proteins, including the Spike (S1), Receptor Binding Domain (RBD), and Nucleocapsid, play a critical role in understanding immunity and supporting diagnostic efforts during COVID-19 pandemic, and afterward. This study aimed to develop and validate in-house assays for detecting anti-SARS-CoV-2 antibodies in serum and urine. Methods: ELISA-based assay was developed to detect IgG and IgM antibodies against SARS-CoV-2. The assay was examined in serum and urine samples of two different cohort of patients affected by COVID-19 disease with different severity and compared to age and sex matched control group. Neutralizing antibody activity was evaluated using an RBD-ACE2 binding inhibition assay. Additionally, a Sengenics protein microarray platform was employed to assess epitope-specific antibody responses. Results: The in-house ELISA assay reliably detected antibodies in both 163 serum and 64 urine samples compared to 50 serum samples from healthy control, with strong correlations observed between antibody levels in the two biofluids. Neutralizing antibody levels correlated positively with disease severity, highlighting their clinical relevance. The performance of the in-house assays was comparable to commercial kits, and the Sengenics microarray provided detailed insights into antibody profiles, identifying dominant epitopes within the Nucleocapsid core domain and RBD. Conclusions: The developed in-house assay demonstrated robust performance and versatility, offering a cost-effective and scalable alternative to commercial kits. Their ability to detect antibodies in both serum and urine highlighted their potential as non-invasive diagnostic tools. These findings contribute to advancing sero-diagnostic capabilities, improving understanding of immune responses to SARS-CoV-2, and supporting global efforts to monitor and manage COVID-19 effectively.
AB - Background: Serological assays targeting antibodies against key viral proteins, including the Spike (S1), Receptor Binding Domain (RBD), and Nucleocapsid, play a critical role in understanding immunity and supporting diagnostic efforts during COVID-19 pandemic, and afterward. This study aimed to develop and validate in-house assays for detecting anti-SARS-CoV-2 antibodies in serum and urine. Methods: ELISA-based assay was developed to detect IgG and IgM antibodies against SARS-CoV-2. The assay was examined in serum and urine samples of two different cohort of patients affected by COVID-19 disease with different severity and compared to age and sex matched control group. Neutralizing antibody activity was evaluated using an RBD-ACE2 binding inhibition assay. Additionally, a Sengenics protein microarray platform was employed to assess epitope-specific antibody responses. Results: The in-house ELISA assay reliably detected antibodies in both 163 serum and 64 urine samples compared to 50 serum samples from healthy control, with strong correlations observed between antibody levels in the two biofluids. Neutralizing antibody levels correlated positively with disease severity, highlighting their clinical relevance. The performance of the in-house assays was comparable to commercial kits, and the Sengenics microarray provided detailed insights into antibody profiles, identifying dominant epitopes within the Nucleocapsid core domain and RBD. Conclusions: The developed in-house assay demonstrated robust performance and versatility, offering a cost-effective and scalable alternative to commercial kits. Their ability to detect antibodies in both serum and urine highlighted their potential as non-invasive diagnostic tools. These findings contribute to advancing sero-diagnostic capabilities, improving understanding of immune responses to SARS-CoV-2, and supporting global efforts to monitor and manage COVID-19 effectively.
KW - Covid-19
KW - IgM and IgG
KW - Neutralization assay
KW - SARS-CoV-2
KW - Sengenics
KW - Serological assays
KW - Urine diagnostics
UR - https://www.scopus.com/pages/publications/105000435627
U2 - 10.1016/j.jiph.2025.102744
DO - 10.1016/j.jiph.2025.102744
M3 - Article
AN - SCOPUS:105000435627
SN - 1876-0341
VL - 18
JO - Journal of Infection and Public Health
JF - Journal of Infection and Public Health
IS - 6
M1 - 102744
ER -