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: PO1842

IgA Nephropathy: Quantifying Remission Duration on Clinical Outcome

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Canney, Mark, The University of British Columbia, Vancouver, British Columbia, Canada
  • Barbour, Sean, The University of British Columbia, Vancouver, British Columbia, Canada
  • Zheng, Yuyan, BC Provincial Renal Agency, Vancouver, British Columbia, Canada
  • Coppo, Rosanna, Fondazione Ricerca Molinette, Torino, Piemonte, Italy
  • Zhang, Hong, Peking University, Beijing, Beijing, China
  • Liu, Zhihong, Nanjing University, Nanjing, Jiangsu, China
  • Matsuzaki, Keiichi, Juntendo University, Bunkyo-ku, Tokyo, Japan
  • Suzuki, Yusuke, Juntendo University, Bunkyo-ku, Tokyo, Japan
  • Katafuchi, Ritsuko, Fukuoka Higashi Medical Center, Koga, Fukuoka, Japan
  • Reich, Heather N., Toronto General Hospital, Toronto, Ontario, Canada
  • Cattran, Daniel C., Toronto General Hospital, Toronto, Ontario, Canada

Group or Team Name

  • The International IgA Nephropathy Network
Background

A relative reduction in proteinuria has been proposed as a surrogate outcome for therapeutic trials in IgA nephropathy (IgAN). We sought to quantify the association between duration of proteinuria remission and the risk of disease progression in IgAN.

Methods

In this retrospective international cohort of adult patients with biopsy-proven IgAN, we defined remission based on: (i) a ≥25% reduction in proteinuria from the peak value after biopsy; (ii) an absolute reduction in proteinuria to <1g/day; (iii) peak proteinuria prior to remission ≥1g/day. The total duration of first remission was treated as a time-varying exposure using longitudinal proteinuria measurements. Time-dependent Cox proportional hazards models were used to quantify the association between duration of remission and the primary outcome (ESKD or 50% reduction in eGFR).

Results

Of 1864 patients who entered a first remission, 274 (14.7%) experienced the outcome during median follow-up of 3.9 years. The relationship between duration of proteinuria remission and the primary outcome was non-linear (Figure). Each 3 months in sustained remission up to 51 months was associated with an additional 9% reduction in the risk of disease progression (HR 0.91, 95% CI 0.89-0.93). Each additional 3 months in remission beyond 51 months was associated with a non-significant risk reduction (HR 0.99, 95% CI 0.96-1.03). Results were robust to multivariable adjustment and consistent across subgroups including immunosuppression exposure.

Conclusion

We observed a non-linear dose-response relationship between the duration of proteinuria remission and the risk of disease progression in IgAN. When considering proteinuria as a surrogate outcome, our findings illustrate the need to consider the duration of remission in addition to the magnitude of proteinuria reduction when evaluating the anticipated impact on long-term clinical endpoints.