High prevalence of Helicobacter pylori infection in Japanese patients with membranous nephropathy

Summary Background Membranous nephropathy is the most common cause of nephrotic syndrome in Japanese adults, and is often precipitated by systemic diseases such as infection, neoplasm, and autoimmune conditions. Recently, the Helicobacter pylori antigen was detected histochemically in the glomeruli of membranous nephropathy patients, raising the possibility that H. pylori may be the pathogen that causes. Aim To reveal the p1revalence of H. pylori infection in the Japanese membranous nephropathy population and to test the therapeutic efficacy of H. pylori eradication on the course of disease in membranous nephropathy patients. Methods The prevalence of H. pylori infection was investigated by the HM-CAP method in 32 membranous nephropathy patients and an age-matched control group (C: n = 243). Results A significantly higher H. pylori infection rate was found in membranous nephropathy patients than in the control group (positive/total: membranous nephropathy 21/32 vs. C 108/243, P < 0.05 by chi-squared test). Eradication of H. pylori was achieved in four membranous nephropathy patients with proteinuria who were receiving glucocorticoid therapy, three of whom experienced a reduction of proteinuria after eradication. Conclusions We found a higher prevalence of H. pylori infection in Japanese membranous nephropathy patients than in age-matched control subjects, which suggests the possible involvement of H. pylori infection in the pathogenesis of membranous nephropathy.