Kidney Week

Abstract: FR-PO860

Studying IgA Nephropathy at a Population Level over a 21-Year Period

Session Information

• IgA Nephropathy: Clinical, Outcomes, and Therapeutics
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Stoneman, Sinead, Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

Sinead Stoneman, MBChB

• Han, Jialin, Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

Jialin Han

• Barratt, Jonathan, University of Leicester Department of Cardiovascular Sciences, Leicester, United Kingdom

Jonathan Barratt, MBChB, PhD

• Atiquzzaman, Mohammad, Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

Mohammad Atiquzzaman, PhD

• Barbour, Sean, Division of Nephrology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada

Sean Barbour, MD, MS, MSc

Background

Individuals with IgA nephropathy [IgAN] risk progression to end-stage kidney disease [ESKD] and death. Studies in IgAN to date have been mostly single- or multi-center research cohorts with inclusion criteria and selection bias that limits generalizability. Herein we report the methodology used to study outcomes of adult IgAN at the population level in a large Canadian province.

Methods

This is a population-level cohort study of adults ≥18 years with IgAN using the British Columbia [BC] Glomerulonephritis [GN] Registry. All kidney biopsies are processed by nephropathologists in a single center. Any biopsy with GN is automatically registered in the BC GN Registry, which links with healthcare administrative databases to capture comorbidities, laboratory data, treatment and outcomes.

Results

The BC GN Registry successfully captured 1382 individuals with primary IgAN over 21 years from 2000 to 2020. At the time of biopsy, median age was 44.3 years, eGFR was 54.1 ml/min/1.73m², and proteinuria was 1.4 g/day (Table 1); 92.4% and 88.1% of patients had available eGFR and proteinuria. During follow-up, there were 19 (IQR 9, 38) and 12 (IQR 4, 25) eGFR and proteinuria measurements per patient, which were measured every 1.2 (IQR 0.4, 3.0) and 2.8 months (IQR 1.1, 4.8) respectively. The 20-year risk of ESKD was 49.4% and of death was 15.6% (Figure 1).

Conclusion

We demonstrate the feasibility of using a provincial biopsy registry linked with administrative databases to study IgAN at the population-level in a large multi-ethnic Canadian province. The structure of the BC GN Registry captures all patients in BC with IgAN without selecting bias. Future steps will be to study treatment patterns, clinical outcomes, and healthcare utilization.

Table 1

Figure 1

Funding

• Commercial Support – Novartis AG