Kidney Week

Abstract: PUB357

Retrospective Analysis of a Large Brazilian Center on Systemic Vasculitis and Evaluation of C3 Levels Behavior

Session Information

• Publication Only

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Kassar, Liliana M L, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Liliana M L Kassar, MD

• Carvalho Barros Sousa, Felipe, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Felipe Carvalho Barros Sousa, MD

• Silva, Karoline W C, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Karoline W C Silva, MD

• Gonçalves, José Guilherme Rezende Ramos Salles, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

José Guilherme Rezende Ramos Salles Gonçalves, MD

• Silveira, Vinícius Sousa da, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Vinícius Sousa da Silveira, MD

• Woronik, Viktoria, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Viktoria Woronik, MD

• Yu, Luis, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Luis Yu, MD, PhD

• Dias, Cristiane B., Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Cristiane B. Dias, MD

• Jorge, Lectícia, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil

Lectícia Jorge, MD, PhD

Background

Systemic small vessel vasculitis are characterized by necrotizing inflammation with little or no deposition of immune complexes. Activation of the alternative complement pathway is part of the disease's pathophysiological mechanism. This study aims to identify the profile of these vasculitis in a large Brazilian center and the behavior of complement levels over time.

Methods

Patients diagnosed with vasculitis between February 2012 and September 2023 were included. The evaluated data included age, sex, creatinine, estimated glomerular filtration rate by CKD-EPI, proteinuria, hematuria, ANCA positivity, serum C3 levels at diagnosis, and the average C3 levels after 6-12 months of follow-up.

Results

48 patients were diagnosed with vasculitis through biopsies during this period, with 60% being women. The median age was 60 years (14-83), serum creatinine 3.7 mg/dL (SD ± 1.7), eGFR 17 mL/min (7-79), proteinuria 1.43g (0.05-8.4), 96% had hematuria, admissional C3 was 107 (41-174), 38% c-ANCA positive and 43% p-ANCA positive. Chi-square test was conducted to assess the association between serum C3 and the intensity of C3 in renal biopsy (p 0.56). Tukey and Bonferroni tests were performed to evaluate C3 variation during treatment, no statistically significant difference was found (p 0.29).

Conclusion

We couldn't identify changes in the behavior of C3 levels in the present study. The local activation of the alternative complement pathway is well established in ANCA-associated vasculitis, however this could be difficult to identify in the usual laboratory assays. Therefore, identifying patterns of mild changes on systemic C3 levels in patients with vasculitis might be feasible utilizing larger samples.