Presentation Authors: Go Anan*, Sendai, Japan, Tohru Yoneyama, Yuki Tobisawa, Shingo Hatakeyama, Mihoko Yoneyama, Hirosaki, Japan, Hiromichi Iwamura, Jun Ito, Yasuhiro Kaiho, Sendai, Japan, Hayato Yamamoto, Hirosaki, Japan, Atsushi Imai, Sendai, Japan, Takahiro Yoneyama, Yasuhiro Hashimoto, Hirosaki, Japan, Makoto Sato, Sendai, Japan, Chikara Ohyama, Hirosaki, Japan
Introduction: Osteopontin (OPN) is one of the most important components in calcium stone matrix. However, the mechanism by which OPN glycosylation affects stone formation processes is unclear. The aim of this study, to compare the glycosylation profile of OPN between stone former and healthy volunteer.
Methods: Between 2015 and 2018, glycan profile of OPN in urine were measured in 133 stone former patients and 157 healthy volunteers using a lectin immunoblotting analysis and lectin array. The OPN concentration in urine was measured by ELISA method. The protocol was approved by the institutional committee on ethics in human investigation.
Results: To examined glycan profile of OPN, lectin immunoblotting and lectin array analysis showed that polylactosamine carrying O-glycosylated OPN (PolyLacNAc-OPN) in urine was significantly increased in stone former patients than that of healthy volunteers, whereas OPN concentration in urine was significantly decreased in stone former patients than that of healthy volunteers (p < 0.001). We investigated whether urinary OPN concentration and PolyLacNAc-OPN can predict urinary calculi, and it was possible to detect stone former with sensitivity of 90% and specificity of 92% (AUC 0.953) from ROC analysis. Furthermore, we prospectively investigated that urinary PolyLacNAc-OPN in stone former patients has tended to decrease after urinary calculi treatment compared with before treatment, whereas OPN concentration in urine has tended to increase after urinary calculi treatment compared with before treatment.
Conclusions: PolyLacNAc-OPN was significantly increased in stone former patients, suggesting the possibility of becoming a biomarker of urolithiasis formation.