Neutrophil extracellular traps drive peritoneal inflammation and tissue remodeling in pediatric peritoneal dialysis

TL;DR

This study shows that peritoneal dialysis in children causes inflammation and tissue changes linked to neutrophil extracellular traps.

Contribution

The study is the first to link neutrophil extracellular traps to peritoneal inflammation and remodeling in pediatric dialysis.

Findings

Chronic PD increases microvessel density, submesothelial thickness, and immune-cell infiltration in children.

NET markers like cell-free DNA and citrullinated histone H3 rise significantly during PD, indicating sterile inflammation.

DNase1 and DNase1L3 levels correlate with structural changes, suggesting limited NET clearance.

Abstract

Peritoneal dialysis (PD) sustains children with chronic kidney disease stage 5 (CKD5) but promotes peritoneal membrane remodeling. Neutrophil extracellular traps (NETs) orchestrate antimicrobial defense and sterile inflammation; their involvement in PD-induced transformation is unknown.

Forty-five children were enrolled in the International Pediatric Peritoneal Biobank. Peritoneal biopsies taken at PD initiation and after ≥ 12 months of low-glucose-degradation-product PD were compared with surgical biopsies from non-uremic peers. Histomorphometry quantified microvessel density, submesothelial thickness, leukocyte infiltration, collagen I/III, and NET markers (citrullinated histone H3, neutrophil elastase, myeloperoxidase). Dialysate and plasma collected every 2 months for 18 months were assayed for cell-free DNA, NET proteins, DNase1, and DNase1L3.

After chronic PD, the peritoneum displayed doubled microvessel density, tripled submesothelial thickness, and marked immune-cell infiltration (all p < 0.01). NET structures were prominent in tissue, while dialysate and plasma concentrations of cell-free DNA, citrullinated histone H3, neutrophil elastase, and myeloperoxidase increased two- to fourfold versus baseline (p < 0.05). DNase1 levels correlated with membrane thickness (r = 0.46, p = 0.003) and DNase1L3 with vascular density (r = 0.51, p = 0.001), suggesting limited compensatory NET clearance.

Chronic PD elicits NET-driven sterile inflammation that parallels structural remodeling of the pediatric peritoneum. Supplementing PD fluids with exogenous NET-degrading enzymes may preserve membrane integrity and prolong PD suitability in children.

A higher resolution version of the Graphical abstract is available as Supplementary information

A higher resolution version of the Graphical abstract is available as Supplementary information

The online version contains supplementary material available at 10.1007/s00467-025-07003-w.

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