Gene variant C3 glomerulonephritis with chronic urinary tract infection: A case report and literature review

Abstract

Rationale: C3 glomerulonephritis (C3GN) is 1 type of C3 nephropathy 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. Patient concerns: A 44-year-old woman was admitted to our hospital because of proteinuria increased for more than 8 years. Diagnoses: The patient was finally diagnosed with C3GN by renal biopsy and gene testing. Interventions: The patient was worried about the side effects of drugs and strongly refused to use glucocorticoids and immunosuppressants, so she was given angiotensin II receptor blocker monotherapy for glomerulonephritis and quinolones for urinary tract infection. Outcomes: Serum creatinine, proteinuria, and serum complement c3 levels remained stable. Our case is still under continuous follow-up. Lessons: Clinical diagnosis of C3GN is difficult to make as there are many differential diagnoses, 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.