IgG-B1C cryoglobulins in acute glomerulonephritis

Eight children have been examined with cryoglobulinemia in association with acute post-streptococcal glomerulonephritis, representing 31% of patients admitted with that diagnosis in a 28-month period. The clinical features distinguishing these eight children include anemia (Hct 60 mm/hr) and hypergammaglobulinemia (>20%). The cryoglobulins have persisted from 2 weeks to 3 months after the onset of the renal lesion. Electrophoresis of fresh serum disclosed a distinct band with a mobility in the fast gamma region which disappeared with removal of the cryoglobulin; in these instances, the electrophoretic mobility of the isolated cryoglobulin was similar to the band seen in whole serum. All isolated cryoglobulins contained IgG and B1C globulins by immunodiffusion and immunoelectrophoresis; one of them contained trace amounts of IgA in addition and another contained small amounts of IgM. Renal biopsy in four cases confirmed acute proliferative glomerulonephritis, and granular deposition of IgG and B1C along capillary loops has been observed by fluorescence microscopy in the three cases examined. Although their significance is unknown, the presence of a cold precipitable complex of IgG and B1C globulins in the serum and the presence of these same proteins in the glomeruli of children with this disease would suggest that cryoglobulins might be of immunopathologic importance in certain cases of acute glomerulonephritis.