Rationales for therapeutic apheresis

Bloodletting seems to have held tremendous appeal for practitioners of the past. It was a treatment favored by barbers, physicians and naval surgeons from medieval times through the Renaissance, through the Enlightenment and well into the 19 century. It’s likely that the trust and confidence it inspired were based in part on its compelling rationale (the depletion of evil humors), while additional support may have come from its obvious effects on complexion and vital signs, plus a generous amount of placebo value. The advent of the scientific method exposed the theoretical basis for bloodletting for what it was / preposterous / and revealed that, with a very few exceptions, the benefits attributed to it for centuries were pure fiction. There are lessons here for contemporary physicians; namely to be clear about reasons for implementing a therapy and cautious about claims for clinical benefit. Therapeutic apheresis may be fairly described as the modern descendant of bloodletting. Providers of this service/treatment often encounter expectations among patients and other physicians that differ very little from those associated with bloodletting in the past; i.e.; they expect that ‘‘cleaning the blood’’ in some vaguely understood manner will be good for what ails them. Such expectations are sometimes met in individual patients, resulting in case reports suggesting efficacy, but many of these claims have not stood the test of time.