Abstract
Our understanding of the clinical aspects of IgA nephropathy (IgAN) has advanced since the 10th International Symposium on IgA Nephropathy in 2004. In this review we discuss new developments in areas of familial IgAN, the emerging field of biomarkers, and prognostic features.
Familial disease continues to account for a significant number of newly diagnosed patients with IgAN. These patients have clinical manifestations and long-term outcomes similar to those of patients with sporadic disease.
Characterization of the IgAN1 gene linked to IgAN in some Italian and American multiplex families has remained elusive. Other multiplex IgAN pedigrees have shown no linkage to any locus.
With advances in technology to better measure and characterize polypeptides in small concentrations, the area of biomarkers has generated substantial interest since 2004. New potential disease-specific biomarkers of IgAN include the IgA1 neoepitope at the threonine228 and/or serinc230IgA1 hinge-region residues, serum levels of galactose-deficient IgA, and urinary IgA-IgG immune complexes.
Other investigators have used proteomic approaches to find panels of urinary polypeptides (many of which have not been sequenced) that discriminate patients with IgAN from normal healthy controls as well as patients with various other proteinuric renal diseases. These or other related findings may provide the necessary tools to better classify phenotypes in multiplex pedigrees and to improve monitoring of disease progression or response to therapy.