“…The filtration membrane used in DFPP can threoretically remove 70% of IgG antibodies with a molecular weight of 150,000. Some studies have indicated that plasmapheresis therapy is a steroid‐sparing treatment for BP (2, 10). However, in the treatment of BP, plasmapheresis is used only for patients with severe, progressive disease, that is unresponsive to other therapies, because plasmapheresis is expensive and time consuming, and it has some side effects ( e.g., fever, chills, hypotension, and difficulties with venous access) (1, 2, 10).…”