Radiocrossed immunoelectrophoretical heterogeneity of β2-microglobulin in blood from patients with germ cell tumors and with colorectal cancer

A new sensitive radiocrossed immunoelectrophoretic method has been used to analyse β2-microglobulin heterogeneity in serum samples from 20 healthy controls, 127 patients with germ cell tumors (GCT) (102 testicular, 15 mediastinal and 10 infantile GCT) and 90 patients with colorectal cancer. Overall, 95% of cancer patients showed an abnormal β2-microglobulin pattern (precipitate with β1 or α2 mobility before treatment) whereas all healthy controls only had one normal precipitate in the β2 region. The β2-microglobulin heterogeneity was correlated with disease stage in both GCT and colorectal cancer, and to some extent also with the outcome. The exact clinical relevance of β2-microglobulin heterogeneity in cancer patients is still unknown. The phenomenon may be due to proteolytic enzymes, increased turnover of surface membrane constituents, complex formation between tumor antigen and β2-microglobulin, polymers of β2-microglobulin or activation of the reticuloendothelial system. (Auth.)