Application of Interferon-γ Release Assay in the Assessment of T-Cell Immunity to SARS-CoV-2 Antigens in the Cohort of Pediatric Patients with Juvenile Idiopathic Arthritis

Abstract

Background: an accurate assessment of the immunity against SARS-CoV-2 can facilitate a better understanding and management of not only the recent coronavirus but similar pathogens as well. Objective: the aim of this study was to evaluate T-cell immunity with reference to antibody titers in a group of pediatric patients with autoimmune arthritides utilizing the widely known Interferon-γ Release Assay (IGRA). Materials and Methods: This study was conducted in the cohort of 55 children suffering from Juvenile Idiopathic Arthritis (JIA). This research analyzed the SARS-CoV-2 T-cell response measured by a specific quantitative IGRA, followed by a serological ELISA test measuring the presence and quantity of IgG, IgM, and IgA antibodies in serum. Results: The cellular response to SARS-CoV-2 measured by the IGRA test significantly correlated with the antibody titers, IgA (p < 0.00003, R = 0.537), IgG (p < 0.0001, R = 0.668), and IgG nucleocapsid protein (NCP) (p < 0.003, R = 0.0399), with no correlation with IgM levels. The antibody levels in patients receiving biological agents were significantly lower compared to the rest of the cohort (p = 0.0369), while traditional disease-modifying antirheumatic drugs had no such effect. Limitations: the main limitation of the research is the small sample size, mostly due to the specific cohort of patients and the lack of a healthy control. Conclusions: IGRA appears to be a viable tool in the accurate evaluation of T-cell responses to SARS-CoV-2, and serodiagnostics alone is not always sufficient in the assessment of immune responses.