Development of high-performance point-of-care aqueous VEGF detection system and proof-of-concept validation in RVO patients.

OBJECTIVES: To develop a sensitive point-of-care testing (POCT) aqueous vascular endothelial growth factor (VEGF) detection system, and assess its role for predicting the response to anti-VEGF treatment in macular edema secondary to retinal vein occlusion (RVO-ME) patients. METHODS: An automatic point-of-care aqueous humor Magnetic Particle Chemiluminescence Enzyme Immuno-Assay (MPCLEIA) VEGF detection system was developed. The predictive values of aqueous cytokine levels, in combination with imaging parameters, on anatomical treatment response (ATR, the relative central macular thickness change [ΔCMT/bl-CMT]) were analyzed. RESULTS: The automatic MPCLEIA system was able to provide results in 45 min with only 20 µL sample. Among the 57 eyes with available pre- and post-treatment evaluation, ATR significantly correlated with levels of interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1) and VEGF measured by Luminex xMAP platform, and VEGF measured by MPCLEIA. Optimal cut-off values for these biomarkers were 13.26 ng/L, 23.57 ng/L, 1,110.12 ng/L, 105.52 ng/L, and 85.39 ng/L, respectively. Univariate analysis showed significant associations between ATR category (good response if ATR≤-25 % or poor response otherwise) and IL-6, IL-8, MCP-1, VEGF-xMAP, and VEGF-MPCLEIA (p<0.05). Multivariate logistic regression revealed that ATR category was significantly associated with aqueous VEGF-MPCLEIA (p=0.006) and baseline(bl)-CMT (p=0.008). Receiver operating characteristics analysis yielded an AUC of 0.959 for the regression model combining VEGF-MPCLEIA and bl-CMT, for predicting ATR category. CONCLUSIONS: Our novel MPCLEIA-based automatic VEGF detection system enables accurate POCT of aqueous VEGF, which shows promise in predicting the treatment response of RVO-ME to anti-VEGF agents when combined with bl-CMT.