Anaphylactoid reactions and bradykinin generation in patients treated with LDL-apheresis and an ACE inhibitor.

An anaphylactoid reaction was observed in a patient treated with low density lipoprotein (LDL) apheresis using a dextran sulfate cellulose (DSC) column and administration of an angiotensin converting enzyme (ACE) inhibitor. The authors have investigated to determine the causes and countermeasures. When using heparin as the anticoagulant, large increases in bradykinin levels in plasma were observed after its passage through the column during the procedure. Increase in bradykinin levels in blood were observed, to a lesser but still significant degree, after terminating the procedure. When withholding the ACE inhibitor for a few days before LDL-apheresis, the increase in bradykinin levels was much weakened and the anaphylactoid reactions became mild. Such anaphylactoid reactions were not observed when the ACE inhibitor was withheld for a few weeks, or when using Futhan instead of heparin as the anticoagulant. Although the critical level of bradykinin needed to cause the anaphylactoid reaction and the other possible causal factors remained unclear, the bradykinin levels are thought to be related to the reactions.