Seroprevalence and clinical outcomes of SARS-CoV-2 in paediatric patients with rheumatic disease.

Objectives: Immunosuppressed paediatric patients with rheumatic disease (RD) may be at risk for severe or critical disease related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Data remain scarce on coronavirus disease 2019 (COVID-19) outcomes in paediatric RD patients. The aim of this study was to determine the seroprevalence of SARS-CoV-2 IgG and to describe COVID-19 outcomes in immunosuppressed paediatric RD patients.

Methods: Patients diagnosed with RD before age 18 years and treated with at least one immunosuppressive medication for at least 3 months were enrolled from a tertiary paediatric rheumatology practice in New York and also underwent routine SARS-CoV-2 IgG testing from May to November 2020. A total of 571 patients were screened and 262 were enrolled. SARS-CoV-2 IgG-positive subjects were assessed for symptoms of COVID-19 infection. SARS-CoV-2 PCR results were recorded where available. Demographic, diagnostic, medication and outcome data were collected.

Results: Of 262 subjects (186 female), 35 (13%) were SARS-CoV-2 IgG positive; 17 (49%) had symptoms suggestive of COVID-19. Of the 17 patients who had SARS-CoV-2 PCR testing, 11 (65%) were PCR positive, 7 of whom were IgG positive. Most SARS-CoV-2 IgG-positive subjects were not PCR tested. The most common symptoms in IgG- and/or PCR-positive subjects were fever, fatigue and cough. No SARS-CoV-2 IgG- or PCR-positive subject developed severe or critical COVID-19 or required hospitalization.

Conclusions: This is the first report of clinical outcomes of SARS-CoV-2 infection and seroprevalence of SARS-CoV-2 IgG in a large cohort of paediatric RD patients. Most SARS-CoV-2 IgG-positive subjects had no symptoms of COVID-19 infection. Symptomatic subjects all had mild COVID-19 symptoms, suggesting that the risk of severe or critical COVID-19 in immunosuppressed paediatric RD patients is minimal.