C3 Glomerulonephritis With Chronic Urinary Tract Infection: a Case Report and Literature Review

Abstract

Background: C3 glomerulonephritis(C3GN) is one type of C3 nephropathy(C3G) which is a rare glomerular disease associated with abnormal regulation of the alternative complement pathway. This review reports a rare case of C3GN with repeated urinary tract infection and summarizes the clinical features, differential diagnosis, treatment, and outcome of patients with C3GN. Case Presentation: A 44-years-old woman was pathologially diagnosed as C3GN. We were confused with her recently upper respiratory tract infection and repeated urinary tract infection before the diagnosis is confirmed. We conducted gene testing and found C3 and CD46 gene mutations, which were related to C3G and atypical thermochemical syndrome in previous reports. After antibiotic treatment, the level of complement C3 was higher than before. We strongly suspect that the urinary tract infection are related to C3 glomerulonephritis.Conclusion: Clinical diagnosis of C3GN is difficult to make due to there are many differential diagnosis, especially post infection nephritis. This case emphasizes the importance of renal biopsy in the diagnosis of C3GN, but the relationship between gram-negative bacilli and C3GN is still unclear. In addition, gene mutation is also involved in the pathogenesis of C3GN, and the treatment of C3GN still needs to be explored.