Kidney Week

Abstract: FR-PO0913

Urine YKL-40 Is a Novel Diagnostic Biomarker of Cystinosis

Session Information

• Pediatric Nephrology: Genetic Diseases, Development, Neonatal Nephrology, Glomerular Diseases, and More
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1800 Pediatric Nephrology

Authors

• Greenberg, Jason Henry, Yale School of Medicine, New Haven, Connecticut, United States

Jason Henry Greenberg, MD

• D Souza, Serena, Johns Hopkins University, Baltimore, Maryland, United States

Serena D Souza, PhD

• Thiessen Philbrook, Heather, Johns Hopkins University, Baltimore, Maryland, United States

Heather Thiessen Philbrook

• Obeid, Wassim, Johns Hopkins University, Baltimore, Maryland, United States

Wassim Obeid, PhD

• Rosenberg, Avi Z., Johns Hopkins University, Baltimore, Maryland, United States

Avi Z. Rosenberg, MD, PhD, FASN

• Veys, Koenraad, UZ Leuven, Leuven, Flanders, Belgium

Koenraad Veys, MD, PhD

• Levtchenko, Elena, Amsterdam UMC Locatie AMC, Amsterdam, NH, Netherlands

Elena Levtchenko, MD, PhD

• Furth, Susan L., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Susan L. Furth, MD, PhD

• Parikh, Chirag R., Johns Hopkins University, Baltimore, Maryland, United States

Chirag R. Parikh, MD, PhD, FASN

Background

Early diagnosis of cystinosis is critical to initiate cysteamine therapy before irreversible renal damage occurs. YKL-40, a glycoprotein involved in inflammation and tissue remodeling, is a candidate urinary biomarker for cystinosis.

Methods

In a case-control study of 10 children with cystinosis and 20 children with non-cystinosis CKD from the CKiD cohort, matched by age and baseline eGFR, we measured urine YKL-40, urine NGAL, urine EGF, and plasma YKL-40. A rapid point-of-care lateral flow device (LFD) for YKL-40 was also developed and tested. We then confirmed our findings in urine samples of 5 additional children with cystinosis. We performed YKL-40 staining in the kidneys of 2 patients with cystinosis and 8 healthy controls.

Results

Urine YKL-40 was over 200-fold higher in children with cystinosis (64.6 ng/ml [IQR: 23.4, 83.8]) compared to controls (0.3 [0.3, 0.79]; p=0.0001) with excellent diagnostic discrimination (AUC=0.99) that was superior to plasma YKL-40, urine NGAL, and urine EGF (Figure). The point-of-care LFD also demonstrated excellent diagnostic discrimination (AUC 0.93). YKL-40 results were verified in 5 cystinosis patients, and YKL-40 staining was markedly higher in kidney biopsies from cystinosis patients than in healthy controls.

Conclusion

Urine YKL-40 has excellent diagnostic potential for cystinosis, and a point-of-care lateral flow device may facilitate early diagnosis and treatment, particularly in settings where LC-MS/MS is unavailable.

Funding

• NIDDK Support