Sci Rep. 2026 Jul 19. doi: 10.1038/s41598-026-59791-2. Online ahead of print.
ABSTRACT
Patients with seronegative spondyloarthropathies (SpA) have an increased risk of kidney involvement. The aim of the study was to assess early kidney injury markers (EKIMs) in SpA patients without clinically recognized kidney disease compared with control group (CG), and to analyze associations with SpA subtypes and therapy. In this cross-sectional study, 125 SpA patients (ankylosing spondylitis, psoriatic arthritis, non-radiographic axial SpA) and 53 GC were included. Serum and urinary NGAL, KIM-1, RBP4, FGF23, NAG, and IL-18 were measured. Our findings indicate subclinical kidney involvement in SpA. Serum and urinary KIM-1 levels were elevated in SpA patients compared to CG (serum: p = 0.039; urine: p = 0.024). Urinary RBP4 was higher in SpA patients (p = 0.005), while serum RBP4 was lower (p < 0.001) compared to CG. Urinary FGF23 concentrations were higher in SpA patients than in CG (p < 0.001). Serum NAG levels differed between SpA and CG (p = 0.018). While no overall differences were observed for urinary NGAL or IL-18 between the SpA group and CG, subgroup analyses revealed specific differences. Psoriatic arthritis patients showed distinct profiles, including lower serum FGF23 (p = 0.028 vs. nr-axSpA and CG), lower serum NAG (p = 0.013 vs. CG), and higher urinary IL-18 (p = 0.012 vs. CG) compared to CG. Levels of most EKIMs did not significantly differ between patients on first-line versus second-line therapies, except for serum FGF23, which was lower in patients receiving bDMARDs/tsDMARDs (p = 0.018). SpA patients without overt kidney disease demonstrate subclinical tubular injury and altered biomarker profiles, supporting the potential role of EKIMs in early renal assessment.
PMID:42472898 | DOI:10.1038/s41598-026-59791-2
