Kidney Week

Abstract: TH-PO997

Cystatin C as a Marker for GFR Estimation in Clinical Populations: A Systematic Review

Session Information

• CKD Epidemiology, Risk Factors, Prevention - I
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2301 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Adingwupu, Ogechi M., Tufts Medical Center, Boston, Massachusetts, United States

Ogechi M. Adingwupu,

• Barbosa, Ernesto Rodolpho, Tufts University School of Medicine, Boston, Massachusetts, United States

Ernesto Rodolpho Barbosa,

• Palevsky, Paul M., VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States

Paul M. Palevsky,

• Vassalotti, Joseph A., Icahn School of Medicine at Mount Sinai, New York, New York, United States

Joseph A. Vassalotti,

• Levey, Andrew S., Tufts Medical Center, Boston, Massachusetts, United States

Andrew S. Levey,

• Inker, Lesley Ann, Tufts Medical Center, Boston, Massachusetts, United States

Lesley Ann Inker,

Group or Team Name

• CKD-EPI.

Background

GFR estimated using creatinine (eGFRcr) is often inaccurate in populations with acute and chronic illness. The accuracy of GFR equations that use cystatin C (eGFRcys) or creatinine-cystatin C (eGFRcr-cys) is not well studied in these populations.

Methods

Using a systematic review, we identified 21 studies of populations with comorbid illnesses that evaluated eGFRcr and eGFRcys compared to measured GFR (mGFR) using standardized assays for the markers: cancer (5); HIV (5); cirrhosis (2); liver transplant (3); heart failure (1); critical illness (3); and obesity (2). The performance of each equation was the unit of analyses (“report”). We assessed equation performance using bias as the median or mean difference between eGFR and mGFR, and accuracy as the percentage of eGFR within 30% of mGFR (P₃₀).

Results

eGFRcr had more reports of moderate-to-large bias than for eGFRcys and eGFRcr-cys, and of overestimation, than underestimatation, of mGFR. There were large inconsistencies in the relative performance of eGFRcr vs eGFRcys even for populations with the same illness. eGFRcr-cys was most accurate in populations with cancer, HIV and obesity, but did not perform consistently better in cirrhosis, liver transplant, heart failure and critical illness populations. Notable limitations are that participants were selected because of concern for inaccurate eGFRcr, and most studies had small sample sizes, limiting generalizability.

Conclusion

eGFRcr-cys improves GFR estimation in populations with a variety of acute and chronic illnesses, supporting current recommendations for more frequent use of cystatin C into more clinical practice. These data provide early evidence base for indications for cystatin C.

Funding

• NIDDK Support