[Analysis of urinary proteins from 50 patients with multiple myeloma by discelectrophoresis (author's transl)].

Urinary proteins from 50 patients with multiple myeloma (37 Ig G, 6 Ig A, 7 Bence Jones) were investigated by discelectrophoresis in polyacrylamidgels containing sodium dodecylsulfat. All samples were also characterized by immunelectrophoresis. Quantitatively and qualitatively normal proteinuria was found in 13 patients (26%). 22 patients (44%) had monoclonal free light chains in the urine, kappachains were eliminated mainly in the monomeric form, lambdachains in all samples in the dimeric form. In 2 patients were found to exist light chains as monomers and dimers. 11 other patients (22%) had peaks of monoclonal Ig G or Ig A in the urine, always associated with the elimination of other nonmonoclonal proteins. Non-specific proteinuria was found in the remaining 4 patients. The clinical validity of the findings is discussed.