Chylomicronaemia in multiple myeloma

A patient with multiple myeloma presented with an accumulation of chylomicron‐like particles. This rare finding resembled that of the type V hyperlipoproteinaemia phenotype. The lipid and lipoprotein concentration and composition were compared with values obtained from other patients with multiple myeloma, patients with the type V hyperlipoproteinaemia phenotype (accumulation of chylomicrons and very low density lipoproteins), and normal subjects. An immunoglobulin‐lipid complex was demonstrated in our patient. This complex was found not to be associtated with the chylomicrons and was detected only in the lipoprotein‐dificient plasma. Lipid and lipoprotein concentration and composition differed from the other groups. Very low density lipoprotein concentration was reduced, and there was thus a marked difference from the type V phenotype. The chylomicrons derived from this patient were also richer in apolipoprotein C compared to chylomicrons derived from the patients with type V hypolipoproteinaemia. It appears that the abnormal composition of the triglyceride‐rich lipoproteins observed in this patient renders her refractory to the normal pathways of metabolism.