Urinary cyclophilin A (uCypA) has been identified as a potential early marker for chronic kidney disease (CKD) in patients with type 2 diabetes (T2DM), according to a new study. The research highlights the potential of uCypA as a non-invasive biomarker for early detection of CKD, which could lead to earlier intervention and improved patient outcomes.
The study, which recruited 375 patients with metabolic syndrome from the Chronic Kidney Disease Northeast Thailand (CKDNET) project, was approved by the Human Ethics Committee of Khon Kaen University (HE 601035). Participants were divided into seven groups based on their T2DM and CKD status, including control subjects, patients with T2DM diagnosed less than five years prior, patients with T2DM diagnosed more than five years prior, and patients with early- or late-stage CKD with or without T2DM. Patients with inflammation, infection, liver disease, malignancy, or autoimmune diseases were excluded.
Elevated uCypA Levels in Early-Stage CKD
The research team analyzed uCypA levels using an indirect ELISA method. The results indicated that uCypA levels were significantly higher in patients with T2DM and early-stage CKD compared to those with T2DM alone or healthy controls. This suggests that uCypA could serve as an early indicator of kidney damage in individuals with T2DM, even before traditional markers such as albuminuria become apparent.
Development of a Lateral Flow Strip Assay
To facilitate rapid and point-of-care detection of uCypA, the researchers developed a lateral flow strip (LFS) assay. The LFS assay utilizes gold nanoparticles conjugated with anti-CypA antibodies to detect uCypA in urine samples. The test line intensities were visualized and quantified using a RapidScan ST5-W Lateral Flow Test Strip Reader. The LFS assay demonstrated the feasibility of quickly detecting elevated uCypA levels, potentially enabling timely screening for CKD in diabetic patients.
Clinical Implications and Future Directions
These findings have significant clinical implications for the management of T2DM patients at risk of developing CKD. Early detection of CKD allows for timely implementation of renoprotective strategies, such as blood pressure control and glucose management, which can slow down the progression of kidney disease. The study highlights the need for further research to validate uCypA as a reliable biomarker in larger and more diverse populations. Additionally, the LFS assay requires further refinement and validation before it can be widely adopted in clinical practice.
Study Limitations
The authors noted several limitations, including the relatively small sample size and the focus on a specific population in Northeast Thailand. Further studies are needed to confirm these findings in different ethnic groups and geographical locations. The study also relied on eGFR to define CKD stages, which may not fully capture the complexity of kidney disease progression.
