IgA Nephropathy

Primary IgA nephropathy (IgAN) is the most common cause of glomerulonephritis worldwide. The diagnostic hallmark is mesangial IgA staining on kidney biopsy. Patients may present with different clinical pictures, ranging from the classic form of macroscopic hematuria with proteinuria starting after upper respiratory tract infection, microhematuria with varying degrees of proteinuria with or without hypertension and with or without chronic kidney disease, and less frequently nephrotic syndrome, acute kidney injury (AKI), or rapidly progressive glomerulonephritis. The clinical course is highly variable. Approximately 15% of patients progress to end-stage chronic kidney disease within 15 years and 40% within 20 years of follow-up. Patients with persistent proteinuria of more than 1 g per day, impaired renal function at diagnosis, and high MEST score are considered to be at high risk for disease progression. Treatment of IgA nephropathy aims to reduce progression and prevent chronic kidney disease. The KDIGO 2021 guidelines recommend supportive treatment including ACEI/ARB to maintain proteinuria below 1 g per day and blood pressure < o = 120/70. If proteinuria of more than 1 g persists after 3 months of optimized supportive treatment, glucocorticoids may be considered in patients with eGRF greater than 30 mL/min.