Prognostic factors and validation of the histologic chronicity score for C3 glomerulopathy: a registry analysis

• Published in: Clinical kidney journal Vol. 17; no. 8; p. sfae077
• Main Authors: Mirioglu, Safak, Cebeci, Egemen, Yazici, Halil, Derici, Ulver, Sahin, Gulizar, Coban, Ganime, Eren, Necmi, Gungor, Ozkan, Dede, Fatih, Dincer, Tamer, Turkmen, Kultigin, Basturk, Taner, Duranay, Murat, Arikan, Hakki, Tunca, Onur, Elcioglu, Omer Celal, Tatar, Erhan, Aydin, Zeki, Oygar, Deren, Demir, Serap, Tanrisev, Mehmet, Kurultak, Ilhan, Oruc, Aysegul, Turkmen, Aydin, Akcay, Omer Faruk, Cetinkaya, Hakki, Ozturk, Savas
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-08-2024
• Subjects: Development and progression; Diagnosis; Glomerulonephritis; Original; Prognosis; Turkey; chronicity; CKD; prognosis; C3 glomerulopathy; anemia
• ISSN: 2048-8505; 2048-8513
• DOI: 10.1093/ckj/sfae077

Background
Data on the prognostic factors for C3 glomerulopathy (C3G) are limited, and validation of the new C3G histologic index (C3G-HI) in different settings is still needed. We aimed to evaluate the chronicity score of C3G-HI and probable prognostic factors in our population.
Methods
In this registry study, 74 patients from 20 centers with adequate follow-up data were included. Total chronicity score (TCS) was calculated according to percentages of glomerulosclerosis, interstitial fibrosis, tubular atrophy, and presence of arterio- and arteriolosclerosis. Primary composite outcome was defined as doubling of serum creatinine from baseline, undergoing dialysis or transplantation, development of stage 5 chronic kidney disease, or death.
Results
Median age was 34 [interquartile range (IQR) 24–46] years, and 39 patients (52.7%) were male. Median follow-up duration was 36 (IQR 12–60) months, and median TCS was 3 (IQR 1–5). Overall, 19 patients (25.7%) experienced primary composite outcome. Multivariate Cox regression model showed that only hemoglobin [adjusted HR (aHR) 0.67, 95% confidence interval 0.46–0.97, P = .035] predicted primary composite outcome, and TCS fell short of the statistical significance (aHR 1.26, 0.97–1.64, P = .08). Receiver operating characteristic analysis demonstrated that TCS showed an area under the curve value of 0.68 (0.56–0.78, P = .028) in discriminating primary composite outcome at 3 years, and 3-year kidney survival was lower in patients with TCS ≥4 (72.4%) compared with TCS <4 (91.1%) in Kaplan–Meier analysis (P = .036).
Conclusions
Low hemoglobin levels predicted dismal outcomes in patients with C3G. TCS ≥4 was associated with a worse 3-year kidney survival, which validated the 3-year prognostic value of the TCS of C3G-HI in our population.
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