[The prognosis of patients with multiple myeloma--the aspect of histological distribution to the renal tissue and serum level of beta 2-MG].

Beta-2-microglobulin (beta 2-MG) is a well-known tumor marker, particularly in patients with multiple myeloma (MM) in whom survival decrease in relation to high serum beta 2-MG concentrations. We investigated the level of serum beta 2-MG by radioimmunoassay (RIA) double antibody method in 14 cases of MM, 13 cases of benign monoclonal gammopathy, and 25 healthy controls. Beta-2-MG of the kidneys was stained by the MM by peroxidase-anti-peroxidase (PAP) method and clinical courses were compared. In controls, the serum beta 2-MG concentration increased with aging, and its concentration of MM was higher than that of controls. Most MM patients with positive beta 2-MG staining in glomeruli showed poor prognosis. Beta-2-MG staining of proximal and distal tubuli did not contribute to the prognosis of MM.