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Quiz

Pathology and Laboratory Medicine

Serum Cystatin C for Estimation of GFR

Educational Objective
To understand how to interpret the results of diagnostic tests and apply them clinically.

1 Credit CME

JAMA

Published Online: August 8, 2022

JAMA Diagnostic Test Interpretation

Article Information and Disclosures

Michael G. Shlipak, MD, MPH¹;

Lesley A. Inker, MD, MS²;

Josef Coresh, MD, PhD³

Author Affiliations

¹University of California San Francisco, San Francisco VA Medical Center
²Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
³Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland

Read article on JAMA Network

Original Investigation

Risk Prediction Equations for Incident Chronic Kidney Disease

Robert G. Nelson, MD, PhD; Morgan E. Grams, MD, PhD; Shoshana H. Ballew, PhD; Yingying Sang, MS; Fereidoun Azizi, MD; Steven J. Chadban, MD, PhD; Layal Chaker, MD, PhD; Stephan C. Dunning, MBA; Caroline Fox, MD; Yoshihisa Hirakawa, MD; Kunitoshi Iseki, MD, PhD; Joachim Ix, MD, MAS; Tazeen H. Jafar, MD, MPH; Anna Köttgen, MD, MPH; David M. J. Naimark, MD, MSc; Takayoshi Ohkubo, MD, PhD; Gordon J. Prescott, BSc, MSc, PhD, CStat; Casey M. Rebholz, PhD; Charumathi Sabanayagam, PhD; Toshimi Sairenchi, PhD; Ben Schöttker, PhD; Yugo Shibagaki, MD; Marcello Tonelli, MD, SM; Luxia Zhang, MD; Ron T. Gansevoort, MD, PhD; Kunihiro Matsushita, MD, PhD; Mark Woodward, PhD; Josef Coresh, MD, PhD; Varda Shalev, MD; for the CKD Prognosis Consortium
Original Investigation

eGFR With vs Without a Race Coefficient and Time to Kidney Transplant Eligibility

Leila R. Zelnick, PhD; Nicolae Leca, MD; Bessie Young, MD, MPH; Nisha Bansal, MD, MAS
Original Investigation

Difference in Estimated Glomerular Filtration Rate by Creatinine vs Cystatin C and End-stage Kidney Disease and Mortality

Debbie C. Chen, MD; Michael G. Shlipak, MD, MPH; Rebecca Scherzer, PhD; Scott R. Bauer, MD, ScM; O. Alison Potok, MD; Dena E. Rifkin, MD, MS; Joachim H. Ix, MD, MAS; Anthony N. Muiru, MD, MPH; Chi-yuan Hsu, MD, MSc; Michelle M. Estrella, MD, MHS
Original Investigation

Association of eGFR Calculated Using Race-Free Equations With Kidney Failure and Mortality by Black vs Non-Black Race

Orlando M. Gutiérrez, MD, MMSc; Yingying Sang, MS; Morgan E. Grams, MD, MHS, PhD; Shoshana H. Ballew, PhD; Aditya Surapaneni, PhD; Kunihiro Matsushita, MD, PhD; Alan S. Go, MD; Michael G. Shlipak, MD, MPH; Lesley A. Inker, MD, MS; Nwamaka D. Eneanya, MD, MPH; Deidra C. Crews, MD, ScM; Neil R. Powe, MD, MPH, MBA; Andrew S. Levey, MD; Josef Coresh, MD, PhD; Chronic Kidney Disease Prognosis Consortium; Morgan E Grams; Andrew S Levey; Lesley A Inker; Michael Shlipak; Orlando M Gutierrez; Paul Muntner; Suzanne Judd; Katharine Cheung; Josef Coresh; Yingying Sang; Nisha Bansal; Chi-yuan Hsu; James Sondheimer; Jonathan Taliercio; Milda Saunders; Elizabeth Selvin; Dan Wang; Shoshana H Ballew; Ron T Gansevoort; Tsuneo Konta; Kunihiro Matsushita; Kevan Polkinghorne; Elke Schaffner; Jingsha Chen; Aditya Surapaneni; Mark Woodward
Correction

Error in Table

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An 80-year-old man with type 2 diabetes and hypertension was referred to the nephrology clinic for assessment of persistent hyperkalemia despite discontinuation of his angiotensin-converting enzyme inhibitor. The patient was frail, sedentary, and had a body mass index of 37. Select blood testing results are shown in Table 1. His estimated glomerular filtration rate (eGFR) was calculated using 3 equations that incorporated creatinine (eGFRcr), cystatin C (eGFRcys), and both creatinine and cystatin C (eGFRcr-cys), as shown in Table 2.

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A. The estimated glomerular filtration rate calculated using creatinine (eGFRcr) may be inaccurate because the patient is frail and sedentary.

Chronic kidney disease (CKD) is typically defined as GFR less than 60 mL/min/1.73 m² or urinary albumin-creatinine ratio (ACR) greater than or equal to 30 mg/g that is present for 3 months or more.² Accurate assessment of GFR and albuminuria is important to determine the presence, stage, and prognosis of CKD and to inform important treatment decisions, such as when to initiate hemodialysis or consider kidney transplant. In 2021, the National Kidney Foundation and American Society of Nephrology Task Force encouraged all US clinical laboratories to adopt the CKD Epidemiology Collaboration 2021 eGFR equations without race,² which were developed and validated using large, diverse populations.³^,4

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Article Information

Corresponding Author: Josef Coresh, MD, PhD, Johns Hopkins Bloomberg School of Public Health, 2024 E Monument St, Ste 2-630, Baltimore, MD 21287 (ckdpc@jhmi.edu).

Published Online: August 8, 2022. doi:10.1001/jama.2022.12407

Correction: This article was corrected on December 13, 2022, to correct an error in the SI conversion for creatinine to µmol/L in Table 1.

Conflict of Interest Disclosures: Dr Shlipak reported receiving grants from the National Institutes of Health/National Heart, Lung, and Blood Institute/National Institute on Aging/National Institute of Diabetes and Digestive and Kidney Diseases during the conduct of the study and grants from Bayer Pharmaceuticals and personal fees from Cricket Health, Intercept Pharmaceuticals, Bayer Pharmaceuticals, AstraZeneca, and Boehringer Ingelheim outside the submitted work. Dr Inker reported receiving grants from the National Institutes of Health and providing consultancy to Health Logics outside the submitted work. Dr Coresh reported consulting for Health.io during the conduct of the study and consulting for SomaLogic and receiving grants from the National Institutes of Health and National Kidney Foundation outside the submitted work.

References

Inker LA , Titan S . Measurement and estimation of GFR for use in clinical practice: Core Curriculum 2021. Am J Kidney Dis. 2021;78(5):736-749. doi:10.1053/j.ajkd.2021.04.016 PubMed Google Scholar Crossref

Inker LA , Eneanya ND , Coresh J , et al; Chronic Kidney Disease Epidemiology Collaboration. New creatinine- and cystatin C-based equations to estimate GFR without race. N Engl J Med. 2021;385(19):1737-1749. doi:10.1056/NEJMoa2102953 PubMed Google Scholar Crossref

Delgado C , Baweja M , Crews DC , et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN Task Force on reassessing the inclusion of race in diagnosing kidney disease. Am J Kidney Dis. 2022;79(2):268-288.e1. doi:10.1053/j.ajkd.2021.08.003 PubMed Google Scholar Crossref

Gutiérrez OM , Sang Y , Grams ME , et al; Chronic Kidney Disease Prognosis Consortium. Association of estimated GFR calculated using race-free equations with kidney failure and mortality by black vs non-black race. JAMA. 2022;327(23):2306-2316. doi:10.1001/jama.2022.8801 PubMed Google Scholar Crossref

Levey AS , Inker LA , Coresh J . GFR estimation: from physiology to public health. Am J Kidney Dis. 2014;63(5):820-834. doi:10.1053/j.ajkd.2013.12.006 PubMed Google Scholar Crossref

Clinical laboratory fee schedule files. Centers for Medicare and Medicaid Services. Accessed May 1, 2022. https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/ClinicalLabFeeSched/Clinical-Laboratory-Fee-Schedule-Files

Tangri N , Grams ME , Levey AS , et al; CKD Prognosis Consortium. Multinational assessment of accuracy of equations for predicting risk of kidney failure: a meta-analysis. JAMA. 2016;315(2):164-174. doi:10.1001/jama.2015.18202 PubMed Google Scholar Crossref

AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
1.00 CME points in the American Board of Surgery’s (ABS) Continuing Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.