Serum α-macroglobulins in renal disease and preeclampsia

The serum levels of α₂-macroglobulin and pregnancy-associated globulin (another α-macroglobulin) have been measured by means of a radial immunodiffusion technique in (1) renal disease with and without proteinuria, (2) in age- and sex-matched controls, (3) in preeclampsia with and without proteinuria, and (4) in normal pregnant controls. There are significant increases in α₂-macroglobulin and pregnancy-associated globulin in renal disease accompanied by proteinuria but normal levels are found in renal disease without proteinuria. Compared with normal pregnancy, α₂-macroglobulin is significantly raised in preeclampsia with proteinuria but normal in preeclampsia without proteinuria. In contrast, serum pregnancy-associated globulin is significantly reduced in preeclampsia both with and without proteinuria when compared with normal pregnancy.