The role of lipoprotein(a) in clotting reactions during lipoprotein apheresis--A case report.

In individuals with familial hypercholesterolemia (FH) who are unable to reach a target low-density lipoprotein level on a drug regimen, lipoprotein apheresis (LA) may be the treatment of choice. Severe reactions involving clotting during LA are not well described in the literature. We report a case of a 63-year-old woman with FH and markedly elevated lipoprotein(a) (Lp[a]) levels who experienced such a reaction while undergoing LA with a dextran-sulfate cellulose column on the Kaneka MA-01 Liposorber system. Owing to the clotting as well as a blood pressure drop to <100 mm Hg systolic, the procedure was stopped early. Before her second procedure, she was given an increased loading dose of unfractionated heparin. She did not develop clotting during this second procedure. A growing body of literature on the role of Lp(a) in atherothrombotic complications and hemostasis supports a possible mechanism by which clotting in the instrument could occur during apheresis. Our patient's initial pretreatment Lp(a) was 3.5 times greater than the mean Lp(a) levels in patients with FH. This theory is consistent with our case in that the patient's Lp(a) levels progressively declined with each procedure, and she had no subsequent clotting.