IgA nephropathy: perspectives on pathogenesis and classification.

IgA nephropathy has received growing attention since its recognition 18 years ago. In this review the salient demographic, clinical and pathologic features are summarized. Next follows a discussion of the pathogenesis of the disease in light of current clinical and experimental data, with a proposal for classification based upon immune response, disordered immunoregulation, and the impairment of clearance of immune complexes.