PLA2R1 and allergic disease: In addition, 2 patients with new-onset anti-PLA2R-positive membranous nephropathy were observed in patients with COVID-19, and it is speculated that COVID-19 may reduce the tolerance of PLA2R antigens.[45] It is not clear whether the recurrence of these diseases is related to direct immune activation after vaccination or to chronic immune activation after an asymptomatic allergic reaction.