Elevating Precision in Kidney Injury Management: Unraveling the Impact of Serum Cystatin C Levels – A Cohort Study in Lahore Hospitals

Abstract

Background: Chronic Kidney Disease (CKD) and Acute Kidney Injury (AKI) pose significant challenges in clinical diagnostics due to late presentation and the influence of non-renal factors on traditional biomarkers. Serum creatinine, while commonly used, lacks sensitivity in early-stage kidney dysfunction due to its delayed elevation post-reduction in glomerular filtration rate (GFR). Serum cystatin C, on the other hand, is not influenced by muscle mass, age, gender, or ethnicity, and thus presents as a potential early biomarker for kidney injury. Objective: The objective of this study was to evaluate the efficacy of serum cystatin C compared to serum creatinine in early detection of renal dysfunction in AKI patients, assessing its correlation with renal decline and potential as a predictor for patient outcomes. Methods: In a cohort study over two years at a tertiary care hospital, 200 healthy individuals and 130 AKI patients were assessed. Serum cystatin C and creatinine levels were measured using ELISA and chemiluminescent immunoassay (CLIA) respectively. Demographics, clinical statistics, and Pearson correlation coefficients were calculated, followed by multiple logistic regression analyses for GFR. Statistical significance was established at P<0.001. Results: Results indicated that in the early phase of AKI, 56.2% of patients had normal serum creatinine levels, whereas serum cystatin C levels were elevated in all patients. The Pearson Correlation Coefficient between serum creatinine and cystatin C was significant (<0.01). Multiple logistic regression revealed cystatin C-based GFR was a more reflective indicator of declining GFR than creatinine-based GFR (P<0.001). Conclusion: Serum cystatin C is a superior biomarker to serum creatinine for early detection of kidney dysfunction in AKI patients, facilitating earlier and potentially more effective therapeutic interventions. This finding could lead to significant improvements in patient prognosis and the management of kidney disease.