Autoantibodies to GPIHBP1 Identified in Chylomicronemia
Autoantibodies identified in six patients with chylomicronemia; three of these had SLE
THURSDAY, April 6, 2017 (HealthDay News) -- Some patients with chylomicronemia have autoantibodies to glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1), causing severe hypertriglyceridemia, according to a study published online April 5 in the New England Journal of Medicine.
Noting that two plasma samples, both from patients with chylomicronemia, contained an interfering substance that made it impossible to measure GPIHBP1, Anne P. Beigneux, Ph.D., from the University of California in Los Angeles, and colleagues tested these samples, and those of other patients with chylomicronemia, for the presence of GPIHBP1 autoantibodies.
The researchers identified GPIHBP1 autoantibodies in six patients with chylomicronemia. These autoantibodies blocked the binding of lipoprotein lipase to GPIHBP1. Patients with GPIHBP1 autoantibodies had lower plasma levels of lipoprotein lipase, similar to patients with GPIHBP1 deficiency. Of the six patients, three had systemic lupus erythematosus. One patients with GPIHBP1 autoantibodies delivered a baby with plasma containing maternal GPIHBP1 autoantibodies; severe but transient chylomicronemia was seen in the infant. Response to treatment with immunosuppressive agents was seen for two of the patients with GPIHBP1 autoantibodies and chylomicronemia.
"In six patients with chylomicronemia, GPIHBP1 autoantibodies blocked the ability of GPIHBP1 to bind and transport lipoprotein lipase, thereby interfering with lipoprotein lipase-mediated processing of triglyceride-rich lipoproteins and causing severe hypertriglyceridemia," the authors write.