Identification of circulating immune complexes in a subpopulation of patients with membranous glomerulonephropathy

Abstract

To investigate the relationship of circulating immune complexes to membranous nephropathy, complexes were assayed by the 125I-C1q-binding assay and the Raji cell radioimmune assay in 18 patients with this disorder. Immune complexes were detected by both assays in the sera of five patients who had a concurrent renal vein thrombosis. Immunoabsorption studies established the specificity of the C1q-reactive material as immune complexes. The generation of immune complexes by the thrombotic episode was excluded by control observations in patients with other types of venous thrombosis. It is suggested that analogous to animal models, patients with membranous nephropathy and concurrent renal vein thrombosis may represent a subpopulation with a more active phase of the disease resulting in the generation of higher (and detectable) levels of serum immune complexes.