IGHE and COVID-19: Moreover, no increase in IgG4 or IgE is observed in four other inflammatory fibrotic conditions that display T and B cell infiltrates similar to those seen in IgG4-RD and LatY136F DLSP and correspond to fibrosing mediastinitis (Allard-Chamard et al., 2021), systemic sclerosis (Maehara et al., 2020), Grave’s orbitopathy (Zhang et al., 2023), and severe COVID-19 (Kaneko et al., 2022; Perugino et al., 2021).