DISCUSSION
Our patient exhibited no severe symptoms and fully recovered from
COVID-19 despite his immunosuppressed status. The clinical course of
COVID-19 was reportedly less severe in the pediatric population than
adults.1 His young age was possibly a contributing
factor for the mild clinical course. Other known risk factors for severe
COVID-19 include underlying diseases such as hypertension, diabetes,
obesity, and lung diseases. However, the relationship between
immunocompromised states due to the underlying disease or
immunosuppressive treatment and COVID-19 severity remains controversial.
Some studies reported that immunocompromised patients had favorable
outcomes compared to the general population.10,11Hyperactivation of immune response and excessive inflammatory reaction
were associated with the pathogenesis of severe
COVID-19.12 Among the previously reported nine cases
of COVID-19 in patients with AA, there was one patient who developed
COVID-19 during cyclosporine treatment and the patient fully
recovered.3 Therefore, immunosuppression from AA and
IST, including continued cyclosporine use, possibly contributed to the
uncomplicated course in our patient, despite an increased risk of viral
invasion and delayed viral elimination.
To evaluate the immune response to SARS-CoV-2 in this patient, a
serological assay was conducted. The anti-S1 and anti-RBD IgA levels
significantly increased before the changes in IgG and IgM levels. This
observation was consistent with the findings of a previous study, which
conducted a serological assay in a non-AA cohort.13Since spike proteins are integral to viral entry into
cells,14,15 IgA might play an important role for
effective control of the infection. The anti-S1 and anti-N IgG levels
subsequently increased, but they peaked at levels below the cutoff
values. The anti-RBD-specific IgG level was almost unchanged in our
patient. These differed from what was observed in other patients with
COVID-19 (mostly immunocompetent) in the University of Tokyo Hospital,
whose anti-SARS-CoV-2 IgG level increased significantly in all
cases.16 In addition, in a previous case series on
COVID-19 with AA, all four patients (with one on IST) had an elevated
anti-spike protein IgG level after COVID-19.3 However,
the effect of AA and IST on decreased IgG production and a favorable
outcome warrants additional investigation.
In summary, we reported a case of COVID-19 in a patient with AA
undergoing IST. Together with previous reports, our findings suggest
that AA patients do not necessarily have a higher risk of severe
COVID-19 compared with the general population. Future investigations are
needed to determine the optimal management for these patients and the
ability of patients with AA to produce sufficient protective antibodies.