GAN and COVID-19: In this analysis, anti-COVID-19 IgM and anti-COVID-19 IgG were 3.80 μg/mL and 20.40 μg/mL, respectively (the reference values of IgM and Ig G anti-COVID 19 were described as negative < 0.9, borderline 0.9–1.1, or positive > 1.1).