GPIHBP1 autoantibody syndrome during interferon β1a treatment

BACKGROUND: Autoantibodies against glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) cause chylomicronemia by blocking the ability of GPIHBP1 to bind lipoprotein lipase (LPL) and transport the enzyme to its site of action in the capillary lumen. OBJECTIVE: A patient with multiple sclerosis developed chylomicronemia during interferon (IFN) beta 1a therapy. The chylomicronemia resolved when the IFN beta 1a therapy was discontinued. Here, we sought to determine whether the drug-induced chylomicronemia was caused by GPIHBP1 autoantibodies. METHODS: We tested plasma samples collected during and after IFN beta 1a therapy for GPIHBP1 autoantibodies (by western blotting and with enzyme-linked immunosorbent assays). We also tested whether the patient's plasma blocked the binding of LPL to GPIHBP1 on GPIHBP1-expressing cells. RESULTS: During IFN beta 1a therapy, the plasma contained GPIHBP1 autoantibodies, and those autoantibodies blocked GPIHBP1's ability to bind LPL. Thus, the chylomicronemia was because of the GPIHBP1 autoantibody syndrome. Consistent with that diagnosis, the plasma levels of GPIHBP1 and LPL were very low. After IFN beta 1a therapy was stopped, the plasma triglyceride levels returned to normal, and GPIHBPI autoantibodies were undetectable. CONCLUSION: The appearance of GPIHBP1 autoantibodies during IFN Pla therapy caused chylomicronemia. The GPIHBP1 autoantibodies disappeared when the IFN beta 1a therapy was stopped, and the plasma triglyceride levels fell within the normal range. (C) 2018 National Lipid Association. All rights reserved.