Serum and Vitreous Levels of Placenta Growth Factor in Diabetic Retinopathy Patients: Correlation With Disease Severity and Optical Coherence Tomographic Parameters

Joana Mesquita; Fátima Milhano Santos; João Paulo Sousa; Sara Vaz-Pereira; Paulo Tavares-Ratado; Arminda Neves; Rita Mesquita; Cândida Teixeira Tomaz

doi:10.7759/cureus.54862

Serum and Vitreous Levels of Placenta Growth Factor in Diabetic Retinopathy Patients: Correlation With Disease Severity and Optical Coherence Tomographic Parameters

Cureus. 2024 Feb 25;16(2):e54862. doi: 10.7759/cureus.54862. eCollection 2024 Feb.

Authors

Joana Mesquita¹, Fátima Milhano Santos², João Paulo Sousa³, Sara Vaz-Pereira⁴, Paulo Tavares-Ratado⁵, Arminda Neves³, Rita Mesquita⁶, Cândida Teixeira Tomaz⁷

Affiliations

¹ Pharmacy, Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior (CICS-UBI), Covilhã, PRT.
² Biochemistry, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz, Madrid, ESP.
³ Ophthalmology, Centro Hospitalar de Leiria, Leiria, PRT.
⁴ Ophthalmology, Hospital de Santa Maria, Lisbon, PRT.
⁵ Clinical Research, Medical Sciences, Universidade da Beira Interior, Covilhã, PRT.
⁶ Medicine, Faculty of Medicine, Universidade de Lisboa, Lisbon, PRT.
⁷ Pharmacology and Therapeutics, Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior (CICS-UBI), Covilhã, PRT.

Abstract

Purpose The primary objective of this study was to compare placenta growth factor (PlGF) levels in the serum and vitreous of diabetic retinopathy (DR) patients to non-diabetic controls. Additionally, the study aimed to establish associations between serum and vitreous PlGF concentrations and to examine the correlation between vitreous PlGF in DR patients and morphological parameters. Methods This study included serum and vitreous samples from 38 patients, including 21 patients with DR and 17 non-diabetic controls. The control group included non-diabetic patients with rhegmatogenous retinal detachment with retinal tears secondary to posterior vitreous detachment or trauma. PlGF levels were quantified in vitreous and serum samples using an enzyme-linked immunosorbent assay (ELISA). Optical coherence tomography (OCT) scans from DR patients were evaluated to measure the central retinal thickness (CRT) and macular volume (MV). Results DR patients had significantly higher mean vitreous PlGF levels compared to non-DR patients (70.0±39.2 vs. 46.47±9.7 pg/mL, p-value=0.004). However, no significant increase in mean serum PlGF levels was observed in DR patients (p-value=0.232). Within the DR group, proliferative DR (PDR) patients presented significantly higher vitreous PlGF levels than non-PDR (NPDR) patients (76.5±41.0 vs. 42.5±5.0 pg/mL, p-value=0.009). There was no association between serum and vitreous PlGF levels. The correlation between vitreous PlGF levels and morphological parameters was r_sp=0.175, p-value=0.488 for CRT, and r_sp=0.288, p-value=0.262 for MV. Conclusion This study emphasizes the important role of PlGF in neovascularization, specifically highlighting its overexpression exclusively in vitreous from PDR patients. The observed increase in PlGF levels may be indicative of disease severity. The lack of correlation between vitreous and serum PlGF levels suggests a potential dissociation between intravitreal and systemic PlGF synthesis. Consequently, targeting PlGF in therapeutic approaches may offer an additional strategy for ocular pathologies with a neovascular component.

Keywords: diabetic retinopathy; novel therapeutic approaches; placenta growth factor (plgf); vascular endothelial growth factor; vitreous humor.