Cryoglobulins in glomerulonephritis not related to systemic disease

Abstract

The sera of 39 patients with persistent proteinuria from whom a renal biopsy had been obtained were examined for the presence of cryoglobulins. A cryoprecipitate was found in 28 of the 139 patients and the cryoglobulins were identified in 19 of the 28 sera. IgG was always present in the cryoprecipitate, in 6 sera it was only immunoglobulin, and in one it was associated with β1C globulin. In 2 other patients the cryoglobulin was mixed IgG IgM. Cryoglobulins were mostly found in patients having a glomerulonephritis characterized by a conspicuous and diffuse cellular proliferation such as occurs in acute glomerulonephritis, and crescentic glomerulonephritis. Cryoglobulins were not found in a control group of patients not suffering from glomerulonephritis. Serial renal biopsies and repeated examination for cryoglobulins were performed in 7 patients whose initial biopsy showed diffuse proliferative glomerulonephritis. Persistence of cryoglobulinemia was accompanied by persistence of diffuse proliferation and, conversely, when the circulating cryoglobulins were no longer present, the proliferation had subsided. Whether circulating cryoglobulins can act as immune complexes to induce or aggravate a glomerulonephritis is discussed.