ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO1817

Clinical Biomarker Trend in C3 Glomerulopathy

Session Information

Category: Glomerular Diseases

  • 1202 Glomerular Diseases: Immunology and Inflammation

Authors

  • Hall, Monica D., Molecular Otolaryngology and Renal Resesarch Laboratories, Iowa City, Iowa, United States
  • Culek, Christopher, Molecular Otolaryngology and Renal Resesarch Laboratories, Iowa City, Iowa, United States
  • Zhang, Yuzhou, Molecular Otolaryngology and Renal Resesarch Laboratories, Iowa City, Iowa, United States
  • Smith, Richard J., Molecular Otolaryngology and Renal Resesarch Laboratories, Iowa City, Iowa, United States
  • Nester, Carla Marie, Molecular Otolaryngology and Renal Resesarch Laboratories, Iowa City, Iowa, United States
Background

There is a paucity of data defining the natural history of the clinical and complement biomarker characteristics of C3 Glomerulopathy (C3G) patients. Whether there are disease defining trends and/or relationships between the markers of disease is unknown. In a series of C3G patients, we sought to describe the trend in three commonly available markers of disease: complement C3, urine protein-to-creatinine ratio (UPCR), and GFR. We hypothesized that lower C3 levels, as a reflection of ongoing complement activity would be associated with progressive renal disease as represented by changes in UPCR and/or GFR.

Methods

All patients met the consensus, renal biopsy definition of C3G. Thirty-two native kidney disease subjects with an age > 12 years and GFR > 30 ml/min were included. Trends in C3, UPCR and GFR were monitored in 1-year spans. Ninety spans with matched C3, UPCR and GFR data were identified. Mean and median statistics across all spans were reported as percent change per year and standard regression analyses were used to define the relationship between variables.

Results

54% of patients retained a C3 within 10 mg/dL of their span entry C3; 86% had a C3 within 25 mg/dL of their entry C3. In only three 1-year spans did a patient start with a low C3 and finish with a normal C3. Mean and median change in GFR per year were a decrease of 4.5% and 2.9% respectively, with the greatest GFR decreases in those spans with the lowest C3. Mean and median change in UPCR per year was a decrease of 8.3% and 10.9%. When considering baseline GFR, baseline UPCR, baseline C3 and change in UPCR, loss of GFR most closely correlated with baseline C3 (Figure, p <0.01).

Conclusion

These data indicate that C3 levels vary little from baseline over a 1 year period and that loss of GFR correlates with baseline C3. These results suggest that treatment approaches that effect an improvement in C3 may have a beneficial effect on GFR.

Funding

  • Commercial Support