{"id":"egfr-cystatin-c","name":"eGFR (Cystatin C-based)","shortName":"eGFR (cystatin C)","aliases":["eGFR Cystatin C","eGFRcys","Cystatin C-based eGFR","GFR Estimated, Cystatin C","eGFR (CKD-EPI Cystatin C)","eGFR (cystatin C)","eGFRcys (CKD-EPI)","Estimated GFR, Cystatin C","Estimated GFR (Cystatin C)","Cystatin C eGFR","eGFR CysC","eGFR (CKD-EPI Cystatin C 2012)"],"abbreviations":["eGFRcys","eGFR cys","eGFRcysC"],"loinc":[{"code":"50210-4","primary":true}],"specimen":"calculated","units":[{"ucum":"mL/min/{1.73_m2}","display":"mL/min/1.73 m²"},{"ucum":"mL/s/{1.73_m2}","display":"mL/s/1.73 m²"}],"referenceRanges":[{"population":"18+","low":60,"high":null,"unit":"mL/min/{1.73_m2}","unitDisplay":"mL/min/1.73 m²","note":"Mayo Clinic Laboratories prints the cystatin C eGFR as '>60 mL/min/BSA' (body surface area), and KDIGO 2024 asks labs to flag eGFR values below 60 as low. This is a flagging cutoff, not the middle 95% of healthy people. Averages are much higher in younger adults and decline with age. Mayo uses the CKD-EPI cystatin C equation for adults and the Schwartz cystatin C equation for children, so the adult row starts at 18.","sources":[{"title":"CSTCE - Cystatin C with Estimated Glomerular Filtration Rate (eGFR), Serum","url":"https://schnecklab.testcatalog.org/show/CSTCE","publisher":"Mayo Clinic Laboratories (via the Schneck Medical Center test catalog)"},{"title":"KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease","url":"https://kdigo.org/wp-content/uploads/2024/03/KDIGO-2024-CKD-Guideline.pdf","publisher":"Kidney International 105(4S):S117-S314","year":2024}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"An estimate of how well your kidneys filter blood, worked out from your cystatin C level, age and sex, without using creatinine.","url":"https://bloodtesttracker.com/markers/egfr-cystatin-c","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}