Cystatin C as a GFR Estimation Marker in Acute and Chronic Illness: A Systematic Review

Rationale & ObjectiveCreatinine based GFR estimating (eGFRcr) equations may be inaccurate in populations with acute or chronic illness. Accuracy of that use cystatin C (eGFRcys) creatinine-cystatin (eGFRcr-cys) is not well studied these populations.Study DesignSystematic review original articles identified from PubMed and expert sources. Two reviewers screened independently those meeting inclusion criteria.Setting Study PopulationsAdults children illnessSelection Criteria for StudiesStudies published since 2011 compared performance eGFRcr, eGFRcys eGFRcr-cys relative to measured (mGFR), used standardized assays creatinine C, eGFR developed using such assays. Studies ambulatory clinical research studies only CKD, kidney transplant recipients, diabetes, donor candidates, community-based cohorts were excluded.Data ExtractionData extracted full text.Analytical ApproachBias percentage estimates within 30% mGFR (P30) was evaluatedResultsOf the 179 citations, 26 met criteria; 24 adults 2 cancer (n=5), HIV cirrhosis (n=3), liver heart failure (n=2), neuromuscular diseases (n=1) critical illness obesity (n=2). In general, had greater accuracy than eGFRcr amongst study cancer, obesity, but did perform consistently better cirrhosis, transplant, failure, disease illness.LimitationsParticipants selected because concern which bias results. Most small sample sizes, limiting generalizability.ConclusionseGFRcr-cys improves estimation a variety illnesses, providing indications measurement. Performance poor many studies, suggesting need more frequent mGFR.