Complement activation as a cause of transient hypotension during plasmapheresis

Hypotension is one of the most common adverse effect of plasmapheresis (PP) and often is attributed to hypovolemia due to extracorporeal circulation a nd the vasovagal reflex. Complements are activated during PP, and the activ ated complements are strong anaphylatoxins and potent vasodilators. Therefo re, we studied the relationship between the transient hypotension and the p lasma levels of activated complements during and after PP in 8 sessions of 7 patients using the Plasmafro OF-08 as a plasma separator. Five of the pat ients underwent immunoadsorption PP using the IM-TR 350 or IM-PH 350 as the adsorption column. The other underwent double filtration PP using the Evaf lux 4A as a second filter. In 4 of 8 sessions, patients experienced transie nt hypotension with significantly elevated plasma levels of activated compl ements C3a and C5a. In contrast, patients without hypotension showed no inc reases in C3a and C5a values during PP. In this report, we emphasize the cr itical role of activated complements for hypotension during PP.