Correlation between Interleukin-6 and Thrombin-Antithrombin III Complex Levels in Retinal Diseases

Presence of CoV-2 antibody in vitreous humor after Cov-2 infection

Purpose

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a life-threatening disease with largely unknown intraocular pathogenesis. Herein, we determined the presence of SARS-CoV-2-specific ribonucleic acid (RNA) and virus-associated antibodies in the vitreous humor of people who have recently recovered from SARS-CoV-2 infection.

Design

This cross-sectional study included 33 patients (33 eyes) who have recently recovered from SARS-CoV-2 infection. Vitreous humor and blood serum samples were tested for the SARS-CoV-2 RNA and virus-associated antibodies.

Results

Among 33 participants, blood serum and vitreous humor were all tested negative for SARS-CoV-2 RNA. SARS-CoV-2-specific IgM was detected in 87.88 % (29/33) patients in blood serum and 6.10 % (2/33) in vitreous humor; SARS-CoV-2-specific IgG was detected in 96.97 % (32/33) patient in blood serum and 81.82 % (27/33) in vitreous humor. Statistical significance was found for IgM expression between blood serum and vitreous humor (P < 0.01), while IgG was not (P = 0.11). The days after recovery were statistically longer both in IgM-positive blood serum samples group and IgG-positive vitreous humor samples group compared with negative samples of each group (P < 0.01). Additionally, no statistical difference could be detected in antibody expression in vitreous humor between different groups divided on the condition of the risk of blood-retina-barrier (BRB) failure (P = 0.49 for IgM; P = 0.37 for IgG).

Conclusion

After recovering from COVID-19, no SARS-CoV-2 RNA was detected in vitreous humor, but anti-CoV-2 IgM was detected in 6.1 % and IgG in approximately 80 % of vitreous humor samples of participants. We also found that the positivety rate of SARS-CoV-2-specific antibodies in the blood serum and vitreous humor were both correlated with the days after recovery since the infection.

Changes in aqueous and vitreous inflammatory cytokine levels in proliferative diabetic retinopathy: a systematic review and meta-analysis

BACKGROUND

Diabetic retinopathy is a major complication of diabetes mellitus, where in its most advanced form ischemic changes lead to the development of retinal neovascularization, termed proliferative diabetic retinopathy (PDR). While the development of PDR is often associated with angiogenic and inflammatory cytokines, studies differ on which cytokines are implicated in disease pathogenesis and on the strength of these associations. We therefore conducted a systematic review and meta-analysis to quantitatively assess the existing body of data on intraocular cytokines as biomarkers in PDR.

METHODS

A comprehensive search of the literature without year limitation was conducted to January 18, 2021, which identified 341 studies assessing vitreous or aqueous cytokine levels in PDR, accounting for 10379 eyes with PDR and 6269 eyes from healthy controls. Effect sizes were calculated as standardized mean differences (SMD) of cytokine concentrations between PDR and control patients.

RESULTS

Concentrations (SMD, 95% confidence interval, and p-value) of aqueous IL-1β, IL-6, IL-8, MCP-1, TNF-α, and VEGF, and vitreous IL-2, IL-4, IL-6, IL-8, angiopoietin-2, eotaxin, erythropoietin, GM-CSF, GRO, HMGB-1, IFN-γ, IGF, IP-10, MCP-1, MIP-1, MMP-9, PDGF-AA, PlGF, sCD40L, SDF-1, sICAM-1, sVEGFR, TIMP, TNF-α, and VEGF were significantly higher in patients with PDR when compared to healthy nondiabetic controls. For all other cytokines no differences, failed sensitivity analyses or insufficient data were found.

CONCLUSIONS

This extensive list of cytokines speaks to the complexity of PDR pathogenesis, and informs future investigations into disease pathogenesis, prognosis, and management.

The Vitreous Ecosystem in Diabetic Retinopathy: Insight into the Patho-Mechanisms of Disease

Diabetic retinopathy is one of the leading causes of blindness in the world with the incidence of disease ever-increasing worldwide. The vitreous humor represents an extensive and complex interactive arena for cytokines in the diabetic eye. In recent decades, there has been significant progress in understanding this environment and its implications in disease pathophysiology. In this review, we investigate the vitreous ecosystem in diabetic retinopathy at the molecular level. Areas of concentration include: the current level of knowledge of growth factors, cytokine and chemokine mediators, and lipid-derived metabolites in the vitreous. We discuss the molecular patho-mechanisms of diabetic retinopathy based upon current vitreous research.

Inflammation, angiogenesis and coagulation interplay in a variety of retinal diseases

PURPOSE

To evaluate and correlate levels of various proteins involved in coagulation, inflammation and angiogenesis processes in the vitreous of patients with different vitreoretinal pathologies.

METHODS

Vitreous samples were collected from patients scheduled for pars plana vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD), vitreous haemorrhage or tractional retinal detachment associated with proliferative diabetic retinopathy (PDR). Macular hole and epiretinal membrane served as controls. Levels of vascular endothelial growth factor, thrombin-antithrombin III complex, interleukin-8, tissue factor, thrombomodulin, P-selectin, D-dimer and tissue factor pathway inhibitor were compared among the vitreoretinal pathology groups.

RESULTS

Compared to controls, patients with PDR had significantly higher levels of thrombin-antithrombin III complex (p < 0.001), vascular endothelial growth factor (p < 0.001), D-dimer (p = 0.038) and interleukin-8 (p = 0.04), and patients with RRD group had significantly higher levels only of thrombin-antithrombin III complex (p < 0.001). There was a significant linear correlation between levels of P-selectin and D-dimer (p = 0.003), P-selectin and interleukin-8 (p < 0.001), and D-dimer and IL-8 (p = 0.007). These correlations were particularly strong in the PDR group compared to the other groups.

CONCLUSION

Patients with PDR manifest high coagulative and angiogenic activity in the vitreous. These pathways are highly correlated with the inflammatory cascade.

Risk Factors of Neovascular Glaucoma After 25-gauge Vitrectomy for Proliferative Diabetic Retinopathy with Vitreous Hemorrhage: A Retrospective Multicenter Study

Neovascular glaucoma (NVG) is a terminal severe complication in eyes with proliferative diabetic retinopathy (PDR), and PDR eyes with vitreous hemorrhage (VH) which undergo vitrectomy may have higher risk of postoperative NVG. The incidence and the prognostic factor of postoperative NVG after 25-gauge vitrectomy with advanced surgical options remain unclear. We retrospectively reviewed medical records of 268 eyes of 268 consecutive PDR patients with VH who underwent 25-gauge vitrectomy and 12 months follow-up at seven centers. Preoperative ocular factors (visual acuity, tractional retinal detachment, panretinal photocoagulation [PRP]), demographics and clinical factors (sex, age, diabetic duration, HbA1c, hypertension, anticoagulant medication, and kidney function), surgical procedures, and postoperative complications were compared between patients who developed postoperative NVG (9.3%) and those who did not. NVG eyes was significantly younger (P = 0.026), had shorter diabetic duration (P = 0.022), higher HbA1c (P = 0.028), absence of PRP (P = 0.039) and higher frequency of postoperative VH (P = 0.0075) than non-NVG eyes. Logistic regression analysis identified postoperative VH (P = 0.014), shorter diabetic duration (P = 0.029), and no PRP (P = 0.028) as prognostic factors for postoperative NVG. This multicenter study indicates that younger age, uncontrolled diabetes, no PRP, and postoperative VH are risk factors of post-vitrectomy NVG.

Review of Biomarkers in Ocular Matrices: Challenges and Opportunities

Biomarkers provide a powerful and dynamic approach to improve our understanding of the mechanisms underlying ocular diseases with applications in diagnosis, disease modulation or for predicting and monitoring of clinical response to treatment. Defined as measurable indicator of normal or pathological processes, biomarker evaluation has been used extensively in drug development within clinical settings to better comprehend effectiveness of treatment in ocular diseases. Biomarkers in the eye have the advantage of access to multiple ocular matrices via minimally invasive methods. Repeat sampling for biomarker assessment has enabled reproducible objective measures of disease process or biological responses to a drug treatment. This review describes the usage of biomarkers with respect to four commonly sampled ocular matrices in clinic: tears, conjunctiva, aqueous humor and vitreous. Issues that affect the evaluation of biomarkers are discussed along with opportunities to leverage biomarkers such that ultimately, they can be used for customized targeted therapy.

Thrombin Generation in Vitreous and Subretinal Fluid of Patients with Retinal Detachment

PURPOSE

To measure prothrombin fragments (F1+2) and thrombin-antithrombin complex (TAT) in vitreous and subretinal fluid (SRF) of rhegmatogenous retinal detachment (RRD) patients and to validate and further specify our earlier finding of increased thrombin activity in patients with proliferative vitreoretinopathy (PVR).

METHODS

F1+2 and TAT were measured in 31 vitreous and 16 SRF samples using the Enzygnost® immunoassays.

RESULTS

We found significant levels of F1+2 and TAT in the vitreous of all patients with RRD compared to patients with macular hole or macular pucker. However, there was no significant difference between patients who would develop PVR in the future, had established PVR, and patients with uncomplicated RRD both in vitreous concentrations of F1+2 (Kruskal-Wallis p = 0.963) and TAT (p = 0.516).

CONCLUSION

The analysis of F1+2 and TAT confirmed significant thrombin generation in both vitreous and SRF of patients with RRD. An imbalance between the thrombin regulation mechanisms TAT and α2-macroglobulin possibly explains the difference from our previous findings.