Immunoconglutinin and Complement Studies in Congenital Nephrotic Syndrome and Nephritis of

in congenital nephrotic syndrome and nephritis of Henoch-Schonlein pur-pura in children. Evidence of complement activation in 6 children with congenital nephrotic syndrome and 9 children with nephritis associated with Henoch-Schonlein purpura was sought by estimating the concentration and by immunoelectrophoretic analysis of the complement component C3, and by immunoconglutinin titration (IK: an autoantibody to reacted complement components). IK and quantitative C3 levels did not differ significantly from control values in either disease; in vivo C3 conversion was not detected in plasma from congenital nephrotic patients, but was present in 2 of 9 patients with Henoch-Schonlein nephritis. The data do not provide consistent evidence of complement involvement in either disease. Several renal diseases are believed to have an immune pathogenesis; the evidence includes depres-sion of serum complement and the demonstration of the glomerular deposition of complement components and immunoglobulin by immuno-fluorescence. However, the congenital nephrotic syndrome and the nephritis associated with Henoch-Schonlein purpura (HSP) are two diseases in which the role of immunopathogenetic mechanisms is unclear. The congenital nephrotic syndrome is invariably resistant to therapy and virtually always fatal (Hallman et al., 1970; Kouvalainen, 1963). An immune pathogenesis has been suggested (Lang