A 41-year-old Japanese woman had plane xanthomatosis with complicated IgG monoclonal gammopathy, hyperlipemia, and cryoglobulinemia. No other manifestations of multiple myeloma were observed on examination of the bone marrow and roentgenograms of the bone. The cryoglobulin was thought to be a product of an autoimmune reaction between the IgG monoclonal globulin (autoantibody) and α1-lipoprotein and β-lipoprotein (antigen). This reaction occured in vitro only at low temperature. The reactivity of this autoantibody was not species specific. The antigenic determinant of β-lipoprotein against this autoantibody was not identical with that against conventional rabbit antihuman β-lipoprotein antiserum.
Kodama H, Nakagawa S, Tanioku K. Plane Xanthomatosis With Antilipoprotein Autoantibody. Arch Dermatol. 1972;105(5):722-727. doi:10.1001/archderm.1972.01620080048014