RESistance of IgA Nephropathy to Conventional and Newly-approved Therapies: an Observational, Real-life Study (RESIGAN)

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, characterized by glomerular mesangial IgA deposits, often with IgG and C3. Despite its prevalence, the pathophysiology of IgAN is poorly understood. The prognosis varies significantly, from benign hematuria to rapidly progressive glomerulonephritis, potentially leading to end-stage renal disease within months. The MEST-C classification enhances prognosis characterization and informs integrated scoring systems; however, while useful for assessing overall prognosis, these scores do not reliably predict treatment responses and are unvalidated for IgA vasculitis nephritis. Given the disease's heterogeneity, treatment options for IgAN, with or without vasculitis, are controversial. Nephroprotective strategies that lower intraglomerular pressure through RAS blockade are essential in managing IgAN. Steroids are considered for rapidly progressive cases, yet their effectiveness in persistent proteinuria despite optimized nephroprotection is debated. Other immunosuppressive therapies, such as B cell targeting and complement inhibition, are under investigation. Recently developed nephroprotective strategies, including SGLT2 inhibitors and endothelin-1 receptor antagonists, may significantly influence future therapeutic approaches. Although available in many European countries, their real-world effectiveness has not been evaluated. Identifying factors linked to persistent proteinuria and renal dysfunction despite optimized nephroprotection is a critical unmet need. We hypothesize that innovative nephroprotective strategies will reduce the risk of persistent proteinuria and renal dysfunction in an IgAN cohort.