Multi-Marker Evaluation of Creatinine, Cystatin C and β2-Microglobulin for GFR Estimation in Stage 3-4 CKD Using the...

Area of Science:

• Nephrology
• Biomarker Discovery
• Clinical Diagnostics

Background:

• Accurate glomerular filtration rate (GFR) estimation is vital for chronic kidney disease (CKD) management.
• Serum creatinine is a common GFR marker but is affected by non-renal factors.
• Cystatin C and β2-microglobulin (β2M) offer potential complementary information regarding filtration, tubular function, and inflammation.

Purpose of the Study:

• To compare the discriminatory performance of creatinine, cystatin C, and β2M in staging CKD stages 3-4.
• To evaluate these markers within the 2021 CKD-EPI eGFR framework.
• To assess the utility of a multi-marker approach for CKD staging.

Main Methods:

• Study included 45 adults with CKD stages 3-4.
• CKD staging used 2021 CKD-EPI creatinine (eGFRcr) and creatinine-cystatin C (eGFRcr-cys) equations with a 30 mL/min/1.73 m² threshold.
• Receiver operating characteristic (ROC) analysis assessed marker performance for distinguishing moderate from severe CKD.

Main Results:

• Creatinine demonstrated high diagnostic accuracy (AUC up to 0.98).
• Cystatin C achieved 100% specificity for severe CKD and showed diagnostic accuracy comparable to creatinine (AUC 0.978 vs. 0.957) in the eGFRcr-cys framework.
• β2M showed AUCs up to 0.97 with >90% sensitivity and specificity.

Conclusions:

• The findings support using a multi-marker evaluation for CKD staging within the 2021 CKD-EPI framework.
• This approach may be more informative than relying on a single marker or validation against measured GFR alone.
• Larger studies are needed to incorporate measured GFR and clinical confounders.