Purpose of review: This review will analyze contemporary information concerning the possible pathogenetic mechanisms involved in IgA nephropathy, emphasizing studies in humans rather than experimental animals.
Recent findings: Deposition of IgA in the glomeruli, the hallmark of IgA nephropathy, may be a quite common phenomenon. Aberrant O-linked galactosylation of IgA subclass (IgA1) appears to play a central role and 'auto-immunity' to a conformational epitope related to glycans at the hinge region of IgA1 is apparently required. Both a circulating immune complex and an in-situ immune complex mechanism have been advanced. Mediator systems, such as complement activation and engagement of innate immune system, also play prominent roles in determining the clinical onset and severity of disease. Genetic influences are evident but the fine details of genetic predisposition and its impact on outcomes still need to be further elucidated.
Summary: Progress in understanding the details of the pathogenesis of IgA nephropathy will lead to a better means of diagnosis (including noninvasive tests for diagnosis), more accurate individualized prognosis and personalized treatment regimens for this globally distributed and very common primary glomerular disease.