Ultracentrifuge investigation of the serum proteins in Waldenström's macroglobulinaemia

Data on 90 cases of WaldenstrÖm's macroglobulinaemia collected from the literature, and personal observations on 75 cases, showed that the sedimentation constant of the pathological macroglobulin component was above 13 5 in fully 95% of cases. The sedimentation constant of the physiological macroglobulin component — calculated from data on 200 patients not suffering from Waldenström's macroglobulinaemia — is about 175; that in cases of macroglobulinaemia is about 235. The possible influence of the pathological macroglobulins on the sedimentation constant of the physiological macroglobulin component is discussed and elucidated by results obtained with sera containing cryo-macroglobulins. Difficulties in the interpretation of the ultracentrifuge diagram are discussed, with special reference to the problem of so-called atypical macroglobulins.