Tonsillectomy and steroid pulse therapy for IgA nephropathy.

IgA nephropathy (IgAN) is the common cause of primary glomerulonephritis worldwide. The clinical course of IgAN is extremely variable and ranges from asymptomatic microscopic hematuria to rapidly progressive renal failure. The pathogenetic mechanisms of IgAN are still unclear, but a hypothesis consisting of two pathways has been proposed. The first pathway is continuous antigenic stimulation of the innate immune system by the tonsillar mucosa via the mucosa-bone marrow axis. In the second pathway, the anomalous stimulated immune response in the bone marrow results in the production of aberrantly glycosylated IgA1 and its subsequent deposition within the mesangial area. Based on the hypothesis, tonsillectomy plus steroid pulse therapy were introduced. A recent meta-analysis showed that tonsillectomy with or without steroid pulse therapy resulted in clinical remission with favorable long-term efficacy in IgAN patients. Tonsillectomy plus steroid pulse therapy now seems to be an effective treatment for IgAN patients with hematuria and minimal proteinuria, and it is more effective in patients with less severe histological findings. The efficacy of the combination therapy depends on the duration of the IgAN. Randomized, controlled trials are needed to examine the efficacy of tonsillectomy plus steroid pulse therapy in different clinical stages of IgAN.