Elevated MCP-1 in DR patients suggests its potential use as a biomarker for DR, and the study supports the potential feasibility of point-of-care testing of MCP-1 in dried blood spots for DR risk stratification.
Key Findings
Results
In the discovery phase, MCP-1 was the inflammatory protein identified as significantly higher in male DR patients than in male diabetic patients without retinopathy who had 5 to 10 years of diabetes.
Part I recruited 74 patients with diabetic retinopathy (DR) and 82 diabetic patients without retinopathy (DM no DR).
Plasma concentrations of inflammatory proteins were compared between the two groups.
The MCP-1 difference was found in a subgroup: male patients with 5 to 10 years of diabetes.
Results
After controlling for clinical characteristics, MCP-1 levels were elevated in DR patients compared with control patients without diabetes.
Parts II and III included 39 patients: 13 DR, 13 DM no DR, and 13 without diabetes.
Multivariable regression gave a coefficient of 22.36 pg/mL (P = 0.008) for the DR group versus non-diabetic controls.
Results
A direct comparison between DR and DM no DR patients showed only a nonsignificant trend toward higher MCP-1 in DR patients.
The comparison was made in the part II/III cohort of 13 DR and 13 DM no DR patients.
The abstract describes the difference as a 'nonsignificant trend'.
Results
MCP-1 measured in dried blood spots (DBSs) showed moderate discrimination for DR in ROC analysis, with an optimal threshold of 20.47 pg/mL.
The area under the curve was 0.754 (95% confidence interval, 0.594-0.915).
The optimal DR threshold of 20.47 pg/mL yielded a sensitivity of 100% and a specificity of 53.8%.
Conclusions
The study assessed the feasibility of measuring MCP-1 in DBSs by comparing DBS with vial blood measurements, and concluded that the results support potential point-of-care testing for DR risk stratification.
Part II directly compared MCP-1 between vial blood and DBSs.
The authors state they identified MCP-1 thresholds in DBS for DR screening.
The authors conclude the findings suggest potential use of MCP-1 as a DR biomarker.
What This Means
This study looked for blood-based inflammation markers that differ between people with diabetes who have eye damage (diabetic retinopathy) and those who do not. In a first group of 156 diabetic patients, a protein called MCP-1 stood out as higher in men with diabetic retinopathy who had had diabetes for 5 to 10 years.
The researchers then tested MCP-1 in a smaller group of 39 people, including people with retinopathy, people with diabetes but no retinopathy, and people without diabetes. They also measured it using dried blood spots, which are drops of blood from a finger prick dried on paper. MCP-1 was higher in people with retinopathy than in people without diabetes. However, the difference between people with and without retinopathy among those with diabetes was only a trend and was not statistically significant. A threshold for MCP-1 in dried blood spots detected all retinopathy cases in this sample but also flagged nearly half of those without retinopathy (sensitivity 100%, specificity 53.8%).
This research suggests MCP-1 in dried blood spots might eventually help with simple, point-of-care screening for diabetic retinopathy risk. The sample sizes were small and the key comparison within diabetic patients was not significant, so larger studies would be needed to confirm whether the test is useful in practice.
Chen X, El-Sabrout H, Le S, Tran M, Huh M, Mackenzie M, et al.. (2026). Monocyte Chemoattractant Protein-1 Level Measured in Dried Blood Spots as a Biomarker for Diabetic Retinopathy.. Translational vision science & technology. https://doi.org/10.1167/tvst.15.10.31