Immunoglobulin A nephropathy.

There are three classes of IgA nephropathy defined morphologically by the presence of predominant or co-dominant mesangial IgA deposits. In idiopathic IgA an aetiologic agent is not identified and the patients may be thus rendered a diagnosis of Bergeris disease honouring the French physician who first described it. Secondary IgA nephropathy may accompany hepatobiliary, autoimmune diseases, bacterialu viral infections, or neoplasia w1x. The third category is the vasculitic form of the disease, Henoch–Schönlein Purpura (HSP). The diagnostic hallmark of all three IgA nephropathies is diffuse IgA mesangial deposits detected by immunofluorescence (IF).