Xanthomes plans normolipémiques et myélome IgGĸ à activité anti-lipoprotéine

Abstract
Clinicopathologic findings are reported of a woman with plane xanthomatosis, multiple myeloma (IgGĸ) and normolipemia. Plasma lipoproteins were bound to the monoclonal immunoglobulin. The complex was separated by ultracentrifugation, then the proteins were measured by radial immunodiffusion and laser immunonephelometry. Monoclonal IgGĸ interact with the low-density lipoproteins. The literature about the association between normolipemic or hyperlipemic xanthomatosis and myeloma was reviewed and the physiopathology of this association discussed. Several hypotheses are suggested but, at present, it is shown that lipoprotein-paraprotein complexing in some patients may be due to autoantibody activity of the myeloma protein against serum lipoprotein; immune complexes interfere with normal lipoprotein catabolism resulting in xanthomas and normolipemia or hyperlipemia.