Predicting kidney function from renal biopsy. Semiquantitative versus quantitative approach

Area of Science:

• Nephrology
• Pathology
• Renal Disease Research

Background:

• Glomerulonephritis encompasses diverse diseases, a leading cause of end-stage renal disease.
• Extraglomerular lesions are key prognostic factors, yet quantitative assessment is often lacking in practice.
• Semiquantitative approaches are common, but quantitative methods have dominated significance studies.

Purpose of the Study:

• To compare the effectiveness of quantitative and semiquantitative assessments of extraglomerular lesions in glomerulonephritis.
• To identify the most significant correlates of renal function in patients with glomerulonephritis.

Main Methods:

• Analysis of 120 renal biopsies using the AnalySIS 3.0 pro image analysis system.
• Semiquantitative assessment included sclerosed glomeruli, interstitial fibrosis, interstitial infiltration, tubular atrophy, and mesangial matrix expansion.
• Quantitative measurements involved relative interstitial volume, interstitial infiltrate volume, and tubular cross-sectional areas via point counting.

Main Results:

• Relative interstitial volume strongly correlated with creatinine and urea levels, indicating its significance in renal function.
• Semiquantitative and quantitative assessments of interstitial infiltrate showed high correlation (gamma = 0.81).
• Tubular atrophy and interstitial infiltration, assessed semiquantitatively, also correlated significantly with renal function markers.

Conclusions:

• Relative interstitial volume is confirmed as the most potent correlate of renal function in glomerulonephritis.
• While some semiquantitative parameters correlate with kidney function, quantitative assessment provides more robust prognostic information.
• This study highlights the importance of quantitative analysis for accurately evaluating extraglomerular lesions in glomerulonephritis.