To further examine the persistence of autoreactive peripheral blood B cells in pemphigus, we sought to characterize Dsg3-specific B cell subpopulations (i.e., mature naïve, memory, and plasmablasts) in PV patients at different stages of disease utilizing fluorescently labeled recombinant human Dsg3 (Dsg3-AF647) like it has been previously demonstrated for other antigens like tetanus toxin (22, 23). Here, DSG3 is linked to acquired polycythemia vera.