Trial of Plasma Exchange for Severe Crescentic IgA Nephropathy

IgA nephropathy (IgAN) is one of the most common glomerulonephritides and is characterized by a highly variable clinical course and diverse histopathological lesions. Although most affected individuals develop chronic, slowly progressive renal injury, a subgroup of patients (\<5% of all IgAN patients) with diffuse crescent formation, which is termed as crescentic IgA nephropathy (CreIgAN) and often leads to rapidly progressive kidney failure. The recent Kidney Disease: Improving Global Outcomes (KDIGO) guidelines suggest high-dose steroids and cyclophosphamide therapy for CreIgAN. However, this suggestion is mainly based on several small observational studies, and the 1- and 5-year renal survival rates of patients treated with this regimen were as low as 65% and 28%, respectively, in one large cohort of CreIgAN patients. The efficacy of plasma exchange (PE) in severe CreIgAN is not well evaluated, although several anecdotal reports have indicated benefit of PE in combination with immunosuppressive therapies in IgAN patients. Retrospective cohort study in our unite also supported the benefit of PE as additional therapy for CreIgAN patients. However, randomized controlled trial is needed to evaluate the efficacy and safety of plasma exchange as adjunctive therapy for crescentic IgA nephropathy compared to pulse methylprednisolone on a background of oral prednisolone and cyclophosphamide in prevent kidney failure.