[Myelomatous G-kappa immunoglobulin with antistreptolysin O activity].

A new case of myeloma with antistreptolysin O activity is described. The myeloma protein is Kappa IgG. By precipitation of this myeloma IgG with anti-Kappa antiserum, the antistreptolysin O activity is completely inhibited. For the antibody activities of the myeloma protein described in the litterature, the antistreptolysin O activity is the most frequently found. With this 19th case the authors discuss the fundamental problems of the antibody activities of myeloma protein.