Kidney Week

Abstract: FR-PO0225

Clinical Significance of Renal Foam Cells in Human Kidney Disease: A Scoping Review

Session Information

• CKD: Mechanisms of Injury and Fibrosis - 2
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2203 CKD (Non-Dialysis): Mechanisms

Authors

• Sugiura, Takuya, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Takuya Sugiura, MD

• Maeda, Kayaho, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Kayaho Maeda, MD

• Nakano, Akihito, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Akihito Nakano, MD

• Shibata, Katsuaki, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Katsuaki Shibata, MD

• Ozeki, Takaya, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Takaya Ozeki, MD, PhD

• Furuhashi, Kazuhiro, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Kazuhiro Furuhashi, MD, PhD

• Kato, Noritoshi, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Noritoshi Kato, MD, PhD

• Kosugi, Tomoki, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Tomoki Kosugi, MD, PhD

• Maruyama, Shoichi, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan

Shoichi Maruyama, MD, PhD

Background

Kidney lipid dysmetabolism is emerging as a driver of chronic kidney disease beyond systemic dyslipidemia, linking abnormal lipid handling to podocyte and tubular injury, inflammation, and fibrosis. Experimental Alport syndrome and FSGS-related models show renal cholesterol accumulation, glomerular lipid deposition, and macrophage-derived foam cells associated with oxidized phospholipids and chemokine expression. These findings suggest that renal foam cells may be morphological clues to lipid-driven immune activation and tissue injury. However, in human kidney disease, the diseases in which renal foam cells appear, their compartment-specific distribution, and their diagnostic, pathological, or prognostic significance have not been systematically characterized. We therefore conducted a scoping review to map the clinical and pathological landscape of foam cells in human kidney disease.

Methods

We conducted a PRISMA-ScR scoping review. PubMed and Scopus were searched to January 30, 2026, with Google Scholar and reference-list screening. We included original human kidney studies reporting foam cells, foamy macrophages, lipid-laden macrophages, or equivalent foamy changes. Non-human, non-renal, non-English, review/editorial, conference-only, inaccessible, infection-associated, and tumor-only reports were excluded.

Results

1,432 records, 108 studies from 1961 to 2025 were included, mostly case reports or small series. Foam cells or foamy changes were reported in glomeruli in 72 studies, interstitium in 37, tubules in 17, and vascular/intimal lesions in 10. They appeared across podocytopathies, lipid/lipoprotein and storage disorders, hereditary nephropathies, transplant-related lesions, TMA/anti-VEGF lesions, and other glomerular diseases. Only 10 studies explicitly defined foam cells, and 8 provided partial definitions Ancillary methods included electron microscopy in 42 studies, immunohistochemistry in 24, and lipid/special stains in 16. Foam cells were descriptive, but some studies treated them as diagnostic clues or correlates.

Conclusion

Renal foam cells are heterogeneous findings whose significance depends on disease background and compartment. Standardized definitions, quantitative assessment, and outcome-linked studies are needed. Future studies of macrophage state, lipid handling, and renal-cell interactions may clarify their role as markers or mediators.