Natural antibody and complement activation characterize patients with idiopathic nephrotic syndrome
Howard Trachtman, Jennifer Laskowski, Cameron Lee, Brandon Renner, Andrew Feemster, Samir M. Parikh, Sarah E. Panzer, Weixiong Zhong, Paolo Cravedi, Chiara Cantarelli, Liudmila Kulik, Zhiying You, Simon C. Satchell, Brad H. Rovin, Fei Liu, Susan L. Kalled, V. Michael Holers, Diana Jalal, Joshua M. Thurman
Abstract
IgM is detected in biopsies from some patients with nephrotic syndrome, although this has been attributed to passive trapping of the protein. We found, however, that IgM colocalizes with complement activation fragments in some glomeruli. We also found that affected patients had higher levels of IgM reactive to glomerular endothelial cell epitopes. Thus, IgM activates the complement system in the glomeruli of some patients with nephrotic syndrome and may contribute to injury.