Berger disease redux.

Glomerular deposition of IgA, IgG, and C3 has been a continued focus of the study of IgA nephropathy (formerly Berger disease) and IgA vasculitis. Until recently, direct immunofluorescence with standard optical microscopy was the preferred method for the study of these phenomena. Through the use of high-resolution confocal immunofluorescent microscopy for colocalization of these immune markers, new insights have emerged concerning the participation of these proteins in inflammatory injury in IgA nephropathy and IgA vasculitis.