IgA nephropathy (IgAN) is a chronic kidney disease occurring in young adults and is one of the most common reasons for kidney transplantation in this age group. IgAN is the most common form of glomerulonephritis (GN), i.e., immunologically induced inflammation of the renal glomeruli. It is characterized by glomerular deposition of immune complexes containing immunoglobulin A (IgA), and by a complex inflammatory response and progressive loss of kidney function. For many decades, IgAN has therefore been treated with anti-inflammatory or strong immunosuppressive agents. However, the STOP-IgAN study and its ten-year follow-up showed that the addition of immunosuppressive therapy to optimal supportive therapy (strict blood pressure control, proteinuria treatment with RAS blockers, dietary and lifestyle measures), has no additional benefit: During the follow-up period, approximately half of all patients reached the primary combined endpoint (progressive loss of renal function > 40%, dialysis requirement or mortality). However, immunosuppression increased the incidence of adverse effects, especially infections. The use of immunosuppressants in IgAN has since been increasingly questioned by experts and should only be applied to rapid-progressive courses. Long-term outcomes are generally unfavorable, so targeted therapy is still urgently needed in addition to optimization of supportive therapy.
