Assessment of ELISA-based method for the routine examination of serum indoxyl sulfate in patients with chronic kidney diseaseSummary

• Published in: Heliyon 2022-12, Vol.8 (12), p.e12220
• Main Authors: Shuangdi Duan, Jiayi Pi, Chun-Hsiang Wang, Yi-Chou Hou, Chung-Ying Andy Lee, Cheng-Jui Lin, Liyang Shi, Kung-Chia Young, Hung-Yu Sun
• Format: Article
• Language: English
• Subjects: Chronic kidney disease; ELISA; Indoxyl sulfate; UPLC-MS/MS
• ISSN: 2405-8440; 2405-8440

Introduction: Indoxyl sulfate (IS), a protein-bound uremic toxin, is associated with kidney function and chronic kidney disease (CKD)-related complications. Currently, serum IS levels are primarily quantified using mass spectrometry-based methods, which are not feasible for routine clinical examinations. Methods: The efficiencies of three commercial ELISA kits in determination of serum IS were validated by comparing with ultra-performance liquid chromatography (UPLC)-MS/MS-based method using Bland-Altman analysis. The associations between kidney parameters and serum IS levels determined by ELISA kit from Leadgene and UPLC-MS/MS were evaluated by Spearman correlation coefficient in a CKD validation cohort. Results: ELISA kit from Leadgene showed clinical agreement with UPLC-MS/MS in the determination of serum IS levels (p = 0.084). In patients with CKD, Spearman's correlation analysis revealed a perfect correlation between the IS levels determined using the Leadgene ELISA kit and UPLC-MS/MS (r = 0.964, p < 0.0001). IS levels determined using the Leadgene ELISA kit were associated with the estimated glomerular filtration rate (r = -0.772, p < 0.0001) and serum creatinine concentration (r = 0.824, p < 0.0001) in patients with CKD, and on dialysis (r = 0.557, p = 0.006). Conclusions: The Leadgene ELISA kit exhibits comparable efficacy to UPLC-MS/MS in quantifying serum IS levels, supporting that ELISA would be a personalized method for monitoring the dynamic changes in serum IS levels in dialysis patients to prevent the progression of CKD.