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An Efficient Sieving Method to Isolate Intact Glomeruli from Adult Rat Kidney
Published on: November 1, 2018
[Prognostic Value of Isolated High Serum Cystatin C Levels Without Glomerular Filtration Rate Reduction]
Barbara Cancho1, Alvaro Alvarez Lopez1, Julian Valladares1
1Servicio de Nefrología. Hospital Universitario de Badajoz. Universidad de Extremadura, Badajoz, España.
Insights
Elevated cystatin C levels in patients with normal kidney function (GFR > 60mL/min) predict increased mortality. Routine measurement of cystatin C is recommended for comprehensive renal function assessment and patient risk stratification.
Area of Science:
- Nephrology
- Clinical Biochemistry
- Epidemiology
Background:
- Cystatin C is an emerging biomarker for renal function, complementing serum creatinine and estimated glomerular filtration rate (eGFR).
- Its role in predicting mortality in patients with preserved kidney function requires further investigation.
Purpose of the Study:
- To evaluate cystatin C as a predictor of mortality in patients with elevated cystatin C but a glomerular filtration rate (GFR) greater than 60 mL/min.
- To assess the association between cystatin C levels and overall survival in this specific patient cohort.
Main Methods:
- A cohort of 608 patients was analyzed, categorized into CONTROL (normal cystatin C, GFR > 60), INCREASED CYSTATIN (elevated cystatin C, GFR > 60), and CKD (elevated cystatin C, GFR < 60) groups.
- Kaplan-Meier survival analysis was employed to determine the relationship between cystatin C levels and overall mortality.
- Demographic and clinical data, including age, sex, diabetes mellitus, and GFR, were collected and analyzed.
Main Results:
- Patients with increased cystatin C and GFR > 60 mL/min (INCREASED CYSTATIN group) exhibited significantly lower 5-year survival rates (82.3%) compared to the CONTROL group (93.9%) (p < 0.001).
- While the CKD group showed the lowest survival (78.8%), the INCREASED CYSTATIN group demonstrated a significant reduction in survival compared to controls.
- Elevated cystatin C in patients with GFR > 60 mL/min predicted increased mortality but not progression to end-stage renal disease.
Conclusions:
- Increased plasma cystatin C levels in patients with a GFR > 60 mL/min are a significant predictor of heightened mortality.
- These findings underscore the clinical utility of routine cystatin C measurement for risk stratification beyond traditional markers.
- Cystatin C provides valuable prognostic information, particularly in individuals with seemingly preserved kidney function.
Objectives:
Cystatin C is increasingly used as a marker of renal function as a complement to serum creatinine and glomerular filtration rate (GFR). We have assessed its efficacy as a predictor of mortality in a group of patients with increased cystatin C but GFR> 60mL/min.
Design And Methods:
We included 608 patients, 65.9% male, 34.6% had diabetes mellitus. The mean age was 58.5±14.5 years and a mean GFR of 64.1±33.5mL/min. Patients were divided into 3 groups: CONTROL (normal cystatin C and GFR> 60mL/min, age 53.3±12.8years, GFR 96.6±22.4mL/min,n=193), INCREASED CYSTATIN (cystatin C>1.03mg/l and GFR>60mL/min, age 58.9±13,1years, GFR 72.2±10.4mL/min, n=40) and CKD (chronic kidney disease, increased cystatin C and GFR <60mL/min, age 61.4±14.8years, GFR 36.0±12.7mL/min, n=160). The relationship with overall mortality was analyzed using the Kaplan-Meier method.
Results:
Mean cystatin C was 0.75±0.13 versus 1.79±0.54 in CKD group and 1.14±0.14mg/l, p <0.001). In CONTROL group survival was 93.9% at 5y, compared to 78.8% in the ERC group and 82.3% in the INCREASED CYSTATIN group (p <0.001) Five-year survival before renal replacement therapy was also different for the ERC group (73%, p <0.001 Log Rank) but not between the other two groups (CONTROL 99.0%, INCREASED CYSTATIN 94.3% p=0.08).
Conclusions:
Increased plasmatic levels of cystatin C in patients with GFR> 60mL/min was a predictor of increased mortality but not of progression to end-stage renal failure. These results confirm the interest of routinely measuring cystatin C.
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