INTRODUCTION
The increase in the cumulative incidence of COVID-19 cases was accompanied by a gradual increase in reported pediatric cases.1 However, the clinical course of COVID-19 in pediatric patients with aplastic anemia (AA) has not been thoroughly investigated. As of May 2021, only one pediatric and eight adult cases of COVID-19 in patients with AA have been reported. Some patients exhibited mild and transient symptoms, while others suffered from severe manifestations with fatal outcomes.2-6 Data on the ability of these patients to produce antibodies against the virus under insufficient immune function are also limited.
We report our experience with COVID-19 in a patient with AA receiving immunosuppressive therapy (IST) and the dynamic results of the serological assay. We analyzed the change in immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) titers against three different proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): S1 subunit of spike protein (S1); receptor-binding domain (RBD) within the S1 subunit, which is a major target of anti-SARS-CoV-2 neutralizing antibodies7-9; and nucleocapsid protein (N).