Kidney Week

Abstract: TH-PO1073

Tubular and Glomerular Functions and Their Associations with Histological Components of CKD Chronicity

Session Information

• Pathology and Lab Medicine
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pathology and Lab Medicine

• 1700 Pathology and Lab Medicine

Authors

• Hallan, Stein I., Norges teknisk-naturvitenskapelige universitet, Trondheim, Trøndelag, Norway

Stein I. Hallan, MD, PhD

• Øvrehus, Marius Altern, Norges teknisk-naturvitenskapelige universitet, Trondheim, Trøndelag, Norway

Marius Altern Øvrehus, MD, PhD

• Haaskjold, Yngvar Lunde, St Olav's Hospital HF, Trondheim, Trøndelag, Norway

Yngvar Lunde Haaskjold, MD, PhD

• Shlipak, Michael G., University of California San Francisco, San Francisco, California, United States

Michael G. Shlipak, MD, MPH

• Ix, Joachim H., University of California San Diego, La Jolla, California, United States

Joachim H. Ix, MD, FASN

Background

Tubular reabsorption and secretion have recently been suggested as additional markers of kidney health to complement estimated glomerular filtration rate (eGFR) and albuminuria (ACR). However, their relationship to the histopathological dimensions of chronic kidney disease (CKD) are not well defined

Methods

We measured alpha-1-microglobulin (A1M; higher urine concentrations indicate lower tubule reabsorption ) and a summary secretion score (SSS; lower urine/plasma ratios of 12 secreted compounds indicate lower tubular secretion) in the Norwegian Kidney Biopsy Biobank (NorKiBB). The Mayo Clinic Chronicity Score was used for semiquantitative assessments of glomerulosclerosis, tubular atrophy, and interstitial fibrosis (scores 0-3 for <10%, 10-25%, 26-50%, and >50%, respectively). Vascular sclerosis was scored 0-1 based on intimal thickening. Cross-sectional correlations were calculated with p<0.05 considered significant to explore the relationship between biomarkers and histopathology

Results

We included 565 patients with clinical kidney biopsy. Their mean (SD) age was 52 (19) years with eGFR 54 (34) ml/min/1.73m2, and the prevalence of diabetes, obesity, and CVD was 17%, 27%, and 24%, respectively. Correlations of glomerulosclerosis with eGFR, secretion, and reabsorption were moderate, weak, and very weak, respectively (Table). Tubular atrophy and interstitial fibrosis were very strongly correlated with each other, and their correlations were moderate to eGFR and weak to reabsorption and secretion. Vascular sclerosis had a weak correlation with eGFR, but none or very weak to the other biomarkers. The albuminuria correlations were very weak or non-significant.

Conclusion

eGFR was moderately correlated with all histopathological CKD chronicity components, while tubular reabsorption and secretion displayed more divergent relationships. Further studies, preferable with more accurate biopsy measures, are needed to better understand the information of these biomarkers

Weak, moderate, strong and very strong correlations are marked with yellow, orange, red, and dark red, respectively.

Funding

• Government Support – Non-U.S.