Archives of Pathology & Laboratory Medicine
Context: C3GNs represent a rare type of glomerulopathy due to the activation of alternative complement pathway, including C3-dominant glomerulonephritis (C3D-GN) and dense deposit disease (DDD). The goal of this study was to demonstrate a spectrum of C3GNs.
Design: The study searched 3165 renal biopsies to identify C3GNs and their clinical indices over an 8-year period.
Conclusions: Our data indicate that C3GN cases had a consistent finding of dominant C3 staining, and low serum C3 in most, but exhibited a wide range of clinical and pathologic changes in pediatric to elderly patients. The findings support the previously reported characteristics of C3GN.
Results: Thirteen C3GNs out of 3165 biopsies (0.41%) were identified, including 11 C3D-GNs and 2 DDD, with 7 female and 6 male patients (Table). The median age was 44 years (ranging from 5 to 69). The average urine protein to creatinine ratio was 4.09 mg/mg (ranging from 1.1 to 21). The median serum creatinine (sCr) was 4.06 mg/dL (ranging from 1.10 to 9.09). All patients with C3/C4 levels showed normal (N) C4 levels and 78% showed low C3 levels. Light microscopy ranged from mesangial proliferative pattern to membranoproliferative pattern. Immunofluorescent stains were consistent with dominant 2+ to 3+ stronger C3 staining than other stains. Electron microscopy ranged from mesangial deposits to subendothelial deposits or ribbon type of intramembranous deposits in DDD.
Deebajah M, Li W, Kanaan HD, Zhang P. Spectrum of C3 glomerulopathies: a single-center experience. Arch Pathol Lab Med. 2022 Sep;146(9):e89-e90. doi:10.5858/arpa.2022-0231-AB.