Glomerular Filtration Rate Estimation Using β₂-Microglobulin and β-Trace Protein in Adults With Solid Tumors: A...

Area of Science:

• Nephrology
• Oncology
• Biomarker Discovery

Background:

• Estimated glomerular filtration rate (eGFR) is crucial for assessing kidney function.
• Creatinine and cystatin C (eGFRcr-cys) are current standard markers, but novel markers may improve accuracy.
• β2-microglobulin (B2M) and β-trace protein (BTP) are endogenous filtration markers with potential for enhanced eGFR.

Purpose of the Study:

• To evaluate the utility of B2M and BTP in improving eGFR accuracy in patients with active solid tumors.
• To compare the performance of multi-marker eGFR equations (2-, 3-, or 4-marker panels) against standard eGFRcr-cys.
• To assess the influence of cancer site on serum B2M and BTP levels.

Main Methods:

• Cross-sectional analysis of a prospective cohort of 1,200 patients with active solid tumors.
• Development and evaluation of CKD-EPI equations incorporating B2M and/or BTP with creatinine, with or without cystatin C.
• Measured GFR (mGFR) determined using 51Cr-EDTA plasma clearance; bias and 1-P30 used for performance comparison.

Main Results:

• 3-marker and 4-marker panel eGFR equations demonstrated superior performance (lesser bias, lower 1-P30) compared to eGFRcr-cys.
• 2-marker panel equations showed comparable performance to eGFRcr-cys (lesser bias, similar 1-P30).
• Serum B2M and BTP levels were not significantly affected by cancer type.

Conclusions:

• B2M and BTP can enhance the accuracy of eGFR in patients with solid tumors.
• These markers are valuable as confirmatory tests, either in multi-marker panels or as replacements for cystatin C.
• The findings suggest potential for improved kidney function monitoring in cancer patients.