Introduction:
C3 glomerulonephritis (C3 GN) is a rare and heterogeneous disease caused by dysregulated activation of the alternative complement pathway. The diversity in clinical presentation and pathogenesis are it’s unique features. There is no approved treatment for C3 GN, and current recommendations are largely based on limited evidence. In this report, we describe a series of 10 cases of C3 GN.
Methods:
This is a retrospective study conducted at our institute in India. We enrolled biopsy-proven cases of C3GN diagnosed between January 2021 and August 2024. Clinical data were obtained from patient records, and laboratory values were retrieved from the hospital information system and analysed.
Results:
The present case series included a total of 10 patients with C3GN. The mean age at presentation was 39 years (range: 13-60 yrs). The mean serum creatinine level was 3.95 mg/dl (range: 0.88 to 7.6 mg/dl), and the mean 24-hour urinary protein was 3.49 gm/day (range: 1.2 to 6 gm/day). Five patients had hypertension, and five had macroscopic hematuria. Seven out of 10 patients had low serum C3 levels. The clinical presentations included rapidly progressive glomerulonephritis (RPGN) in 3, nephrotic syndrome in 3, chronic glomerulonephritis in 3, and acute nephritic syndrome in 1 patient. Histologically, six patients had a Mesangioproliferative pattern and four had a MPGN pattern of injury on light microscopy. Crescentic changes were observed in five biopsies: fibro cellular crescents in > 40% of glomeruli in four cases, and cellular crescents in over 10% of glomeruli in one case. Two patients had mild (20-30%), two had moderate to severe (>30%), and the rest had 15-20% IFTA. The electron-dense deposits were found in the mesangial, subendothelial, and subepithelial regions of glomeruli in all cases. Treatment regimens included cyclophosphamide with prednisolone for 3, mycophenolate mofetil (MMF) with prednisolone for 3, and prednisolone alone for 3 patients. One patient with CGN did not receive any immunosuppressive therapy. Five are continuing with MMF and prednisolone as maintenance therapy, three patients received only prednisolone for 6 months. All patients received maximally tolerated doses of ramipril. Three patients required hemodialysis at presentation: two became dialysis-independent by the third month, while one remains on hemodialysis. Among patients with nephrotic syndrome, three achieved complete remission(CR) within 3-6 months. Two of the 3 patients with RPGN reached CR at 3 months, and the third patient stabilized serum creatinine and achieved remission of proteinuria at 6 months. Two patients with CGN achieved CR by 6 months, while one progressed to end-stage kidney disease (ESKD).. The patient with acute nephritic syndrome is currently undergoing treatment (induction phase).
Conclusions:
This study highlights the heterogeneity in the clinical presentations of C3GN. Standard treatments led to clinical improvement in a substantial number of patients, with only one patient progressed to ESKD. Therefore, early and individualized treatment approaches are crucial, as they can significantly enhance the outcomes for patients with C3GN.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.