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: PO2328

Evaluation of the Cambridge GFR Estimating Equation in a Diverse Population

Session Information

Category: CKD (Non-Dialysis)

  • 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

  • Couture, Sara J., Tufts Medical Center, Boston, Massachusetts, United States
  • Tighiouart, Hocine, Tufts Medical Center, Boston, Massachusetts, United States
  • Costa e Silva, Veronica Torres, Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
  • Inker, Lesley Ann, Tufts Medical Center, Boston, Massachusetts, United States
  • Levey, Andrew S., Tufts Medical Center, Boston, Massachusetts, United States

Group or Team Name

  • CKD-EPI
Background

Evaluation of GFR is not standardized in oncology; serum creatinine (Scr), estimated creatinine clearance (eClcr) using the Cockcroft Gault equation, and estimated GFR (eGFR) using Scr (eGFRcr) using the MDRD Study or CKD-EPI equation are often used interchangeably. KDIGO guidelines recommend eGFRcr, using standardized Scr and the CKD-EPI equation as the initial test in adults, and confirmatory tests using serum cystatin C (eGFRcys or eGFRcr-cys), measured creatinine clearance (mClcr) or measured GFR (mGFR) using exogenous filtration markers.

Methods

Janowitz and colleagues recently reported a new equation developed in patients with cancer that can be used with or without IDMS-traceable assays, CamGFRv2 (Williams et al. Clin Cancer Res 2021), which performed better than CKD-EPI eGFR in the development population, but which has not been evaluated in an external validation population. To determine if CamGFRv2 could be used in other settings, we evaluated CamGFRv2 and other commonly used equations in two large, diverse study populations.

Results

Study populations included the CKD-EPI 2009 external validation population [n=3771, mean (SD) age 49.2 (14.6), mGFR 69.2 (35.5) ml/min/1.73 m2), men 54.1%, African American 10%, diabetes 28.2%, and CKD-EPI 2012 external validation population [n=1119, mean (SD) age, 49.9 (16.6) years, mGFR 69.8 (41.0) ml/min/1.73 m2, men 59.3%, African American 3%, diabetes 53.1%]. (Note: study participants were not included in the development of the CKD-EPI equations.) No eGFRcr equation, including CamGFRv2, performed better than the CKD-EPI equation. As previously reported, CKD-EPI eGFRcr-cys performed better than CKD-EPI eGFRcr or eGFRcys (Inker et al. NEJM 2012).

Conclusion

In conclusion, eGFRcr using CamGFRv2 is not more accurate than using CKD-EPI in a diverse population. Studies comparing CamGFRv2 vs. CKD-EPI equations in patients with cancer are needed

Performance of eGFR Equations in Diverse Study Populations