New neovascular age-related macular degeneration is associated with systemic leucocyte activity

The role of blood related inflammatory factors on age-related macular degeneration (AMD)

BACKGROUND

Age-related macular degeneration (AMD) is a significant retinal disease that leads to irreversible low vision, particularly in developing countries. The variation in AMD prevalence among different racial groups and highlighted role of inflammation on disease pathology from previous studies which yielded in inconsistent findings, It seems to be of great importance to do more investigation in this field.

METHODS

This case control study involved 204 participants, divided into four groups of equal size (51 individuals per group). Three groups represented AMD cases of varying severity according to Beckman classification (3 groups) and one healthy control group. Sampling was conducted exhaustively until the desired sample size was reached. The control group comprised healthy individuals without any infectious or inflammatory systemic, ophthalmic disease. Blood samples were collected to measure inflammatory factors, including lymphocytes, monocytes, neutrophils, neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein (CRP). Collected data were analyzed by statistical methods in SPSS version 21.

RESULTS

Of the participants, 51% were women, and their ages ranged from 47 to 89 years (62.2 ± 8). According to multiple logistic regression analysis, age exhibited a statistically significant positive association with AMD severity (P = 0.038, odds ratio [OR] = 1.034). ANOVA results indicated a significant association between neutrophil count and AMD severity (P < 0.001). As the disease severity increased, the number of neutrophils decreased. The mean ± SD neutrophil counts for early, intermediate and advanced AMD were 3849 ± 800, 3702 ± 734, and 3342 ± 823, respectively. No statistically significant associations were found between lymphocyte count, monocyte count, neutrophil-to-lymphocyte ratio, CRP, and AMD.

CONCLUSION

There was a significant relationship between the number of neutrophils in peripheral blood and the severity of AMD in study participants which needs more evaluation for the potential utility of this factor in the prognosis of AMD. There was not any significant relationship among the other factors and AMD.

The role of blood neutrophil lymphocyte ratio in predicting the initial response to anti-VEGF treatment in neovascular AMD patients

PURPOSE

Vascular endothelial growth factor (VEGF) has a critical role in age-related macular degeneration (AMD), and intravitreal injection of anti-VEGF drugs is the mainstay of neovascular AMD treatment. Blood neutrophil-to-lymphocyte ratio (NLR) is shown to be a biomarker of inflammation in AMD. We aimed to investigate the role of NLR in predicting favorable short-term anti-VEGF treatment results in neovascular AMD patients.

METHODS

A total of 112 patients diagnosed with exudative AMD and had taken 3 monthly intravitreal bevacizumab injections were analyzed retrospectively. Medical records were reached to obtain neutrophil and lymphocyte values to calculate NLR. Best-corrected visual acuity and central macular thickness (CMT) measurements were recorded at each visit. T test or Mann-Whitney U test was used to compare continuous variables, and chi-square test was used to compare categorical variables. Receiver operating characteristics curve (ROC) analysis was performed to determine cut-off, sensitivity, and specificity values. P value of ≤ 0.05 was considered statistically significant.

RESULTS

The mean age was 68.1 ± 7.2 years, and the mean NLR was 2.11 ± 0.81. The ROC analysis revealed a cut off value of 2.0 for NLR to predict at least 100 μm CMT change (sensitivity 87.1%; specificity 87.8%) and a cut off value of 2.4 for NLR to predict at least 0.1 logMAR visual improvement (sensitivity 77.2%; specificity 64.8%) after 3 monthly IVT bevacizumab injections.

CONCLUSION

NLR can provide additional prognostic information for the identification of patients with a good initial response to anti-VEGF therapy.

Evaluation of systemic immune-inflammatory index in patients with wet age-related macular degeneration

CLINICAL RELEVANCE

The systemic immune-inflammatory index is a relatively new parameter and has been shown to increase in inflammatory diseases.

BACKGROUND

The primary aim of this study was to investigate the systemic immune-inflammatory index in patients with wet-type age-related macular degeneration. The secondary aim was to determine the relationship between best-corrected visual acuity, central macular thickness, subfoveal choroidal thickness, systemic immune-inflammatory index, platelet-to-lymphocyte ratio, and neutrophil-to-lymphocyte ratio.

METHODS

This study retrospectively analysed patients with wet-type age-related macular degeneration between 2018 and 2022. Demographic data and peripheral complete blood count were obtained from the electronic medical record system. The most recent best-corrected visual acuity, central macular thickness, and subfoveal choroidal thickness values (within one month) for complete blood count were obtained from case sheets and the optical coherence tomography digital image database. The systemic immune-inflammatory index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio were calculated. Age- and sex-matched controls were also generated.

RESULTS

Thirty-three patients (23 males, 10 females) with wet-type age-related macular degeneration and 43 controls (24 males, 19 females) were included. The groups were similar in terms of age and sex (78.0 ± 6.3 vs. 75.6 ± 6.6 years, p = 0.59; p = 0.38 for sex). The systemic immune-inflammatory index was higher in the wet-type age-related macular degeneration group (460.5 vs. 440.4); however, this difference was not statistically significant. When the correlations between the systemic immune-inflammatory index, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, best-corrected visual acuity (logMAR), central macular thickness, and subfoveal choroidal thickness were examined, there was only a moderate positive correlation between best-corrected visual acuity and platelet-to-lymphocyte ratio (r = 0.46, p = 0.007).

CONCLUSION

There were no differences in the systemic immune-inflammatory index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio between the wet-type age-related macular degeneration and control groups. There was a positive correlation between the platelet-to-lymphocyte ratio and best-corrected visual acuity (logMAR). The systemic immune-inflammatory index was higher in patients with wet-type age-related macular degeneration than in the control group; however, this difference was not statistically significant.

Engineered Knockout of TRPA1 Inhibits Laser-Induced Choroidal Neovascularization Along With Associated TGFβ1 Expression and Neutrophil Infiltration

We examined the effects of gene ablation and chemical inhibition of transient receptor potential ankyrin 1 (TRPA1) on the growth of experimental argon laser-induced choroidal neovascularization (CNV) in mice. CNV was induced in the eyes of 6- to 8-week-old TRPA1-null (knockout [KO]) and wild-type (WT) mice by argon laser irradiation. Gene expression analysis was performed in laser-injured tissues at days 1 and 3. CNV growth was evaluated at day 14. Reciprocal bone marrow transplantation was performed between each genotype to identify the components responsible for either recipient tissue or bone marrow-derived inflammatory cells. Our results show that laser irradiation successfully induced CNV growth at the site of laser injury. The size of induced CNV was significantly smaller in KO mice than in WT mice at day 14, as determined by angiography with fluorescein isothiocyanate-dextran. Invasion of neutrophils, but not macrophages, was suppressed in association with suppression of the expression of transforming growth factor β1 and interleukin 6 in laser-irradiated KO tissue. Bone marrow transplantation indicated that the genotype of the recipient mouse, but not of inflammatory cells, is attributable to the KO phenotype. Systemic administration of a TRPA1 antagonist also reduced the CNV in a WT mouse. In conclusion, TRPA1 signaling in local cells is involved in growth of laser-induced CNV. The phenotype was not attributable to vascular endothelial cells and inflammatory cells. Blocking TRPA1 signal may therefore be a potential treatment strategy for CNV-related ocular diseases.

Is Erythrocyte Sedimentation Rate Necessary for the Initial Diagnosis of Giant Cell Arteritis?

Giant cell arteritis (GCA) is an ophthalmological emergency that can be difficult to diagnose and prompt treatment is vital. We investigated the sequential diagnostic value for patients with suspected GCA using three biochemical measures as they arrive to the clinician: first, platelet count, then C-reactive protein (CRP), and lastly, erythrocyte sedimentation rate (ESR). This retrospective cross-sectional study of consecutive patients with suspected GCA investigated platelet count, CRP, and ESR using diagnostic test accuracy statistics and odds ratios (ORs) in a sequential fashion. The diagnosis was established by experts at follow-up, considering clinical findings and tests including temporal artery biopsy. A total of 94 patients were included, of which 37 (40%) were diagnosed with GCA. Compared with those without GCA, patients with GCA had a higher platelet count (p < 0.001), CRP (p < 0.001), and ESR (p < 0.001). Platelet count demonstrated a low sensitivity (38%) and high specificity (88%); CRP, a high sensitivity (86%) and low specificity (56%); routine ESR, a high sensitivity (89%) and low specificity (47%); and age-adjusted ESR, a moderate sensitivity (65%) and moderate specificity (65%). Sequential analysis revealed that ESR did not provide additional value in evaluating risk of GCA. Initial biochemical evaluation can be based on platelet count and CRP, without waiting for ESR, which allows faster initial decision-making in GCA.

The role of the adaptive immune system and T cell dysfunction in neurodegenerative diseases

The adaptive immune system and associated inflammation are vital in surveillance and host protection against internal and external threats, but can secondarily damage host tissues. The central nervous system is immune-privileged and largely protected from the circulating inflammatory pathways. However, T cell involvement and the disruption of the blood-brain barriers have been linked to several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Under normal physiological conditions, regulatory T cells (Treg cells) dampen the inflammatory response of effector T cells. In the pathological states of many neurodegenerative disorders, the ability of Treg cells to mitigate inflammation is reduced, and a pro-inflammatory environment persists. This perspective review provides current knowledge on the roles of T cell subsets (e.g., effector T cells, Treg cells) in neurodegenerative and ocular diseases, including uveitis, diabetic retinopathy, age-related macular degeneration, and glaucoma. Many neurodegenerative and ocular diseases have been linked to immune dysregulation, but the cellular events and molecular mechanisms involved in such processes remain largely unknown. Moreover, the role of T cells in ocular pathologies remains poorly defined and limited literature is available in this area of research. Adoptive transfer of Treg cells appears to be a vital immunological approach to control ocular pathologies. Similarities in T cell dysfunction seen among non-ocular neurodegenerative diseases suggest that this area of research has a great potential to develop better therapeutic agents for ocular diseases and warrants further studies. Overall, this perspective review article provides significant information on the roles of T cells in numerous ocular and non-ocular neurodegenerative diseases.

Is there a relationship between hematological inflammatory parameters and age-related macular degeneration?

Purpose

We aimed to analyze blood inflammation parameters in patients with age-related macular degeneration (AMD).

Methods

In this retrospective study, patients were divided into three groups: wet-type AMD (n = 60), dry-type AMD (n = 60), and healthy controls (n = 71). The laboratory and demographic data of the patients were analyzed. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) were calculated manually.

Results

The mean NLR was 2.26 ± 1.42 in the dry-type AMD group, 3.90 ± 1.65 in the wet-type AMD group, and 1.84 ± 0.61 in the control group (p < 0.001). The mean MLR was 0.30 ± 0.20 in the dry-type AMD group, 0.47 ± 0.31 in the wet-type AMD group, and 0.28 ± 0.14 in the control group (p < 0.001). The mean PLR was 129.31 ± 79.82 in the dry-type AMD group, 156.67 ± 83.99 in the wet-type AMD group, and 135.59 ± 58.68 in the control group (p = 0.101). Receiver operating characteristic (ROC) curve analyses revealed that the area under the curve (AUC) for NLR and MLR was 0.920 and 0.717, respectively, for wet-type AMD. The sensitivity and specificity of NLR for wet-type AMD were 64% and 93%, respectively, whereas MLR was 63% and 75%, respectively.

Conclusion

Simple blood tests revealed that NLR and MLR were significantly higher in patients with wet-type AMD than in patients with dry-type AMD and healthy controls, which implies low-grade inflammation.

EX-vivo whole blood stimulation with A2E does not elicit an inflammatory cytokine response in patients with age-related macular degeneration

Age-related macular degeneration (AMD) is a highly prevalent degenerative disease and a leading cause of vision loss worldwide. Evidence for an inflammatory component in the development of AMD exists, yet the exact mechanisms remain unclear. Bisretinoid N-retinylidene-N-retinylethanolamine (A2E) in retinal pigmental epithelial (RPE) cells, and in extracellular deposits constitutes a hallmark of AMD, but its role in the pathology of AMD is elusive. Here, we tested the hypothesis that A2E is responsible for the heightened inflammatory activity in AMD. To this end, we measured ex vivo mRNA expression of the cytokines TNF-α, IL-6, and IL-10 in whole blood samples after stimulation with A2E in a clinical sample of 27 patients with neovascular AMD and 24 patients with geographic atrophy secondary to AMD. Patients’ spouses (n = 30) were included as non-affected controls. After stimulation with A2E, no statistical differences were found in the median expression level of TNF-α, IL-6, IL-10 between the control group, and the neovascular AMD and the geographic atrophy group. Our findings do not support evidence for the hypothesis, that A2E per se contributes to heightened inflammatory activity in AMD.

Deficits in Monocyte Function in Age Related Macular Degeneration: A Novel Systemic Change Associated With the Disease

Age-related macular degeneration (AMD) is characterized by the accumulation of debris in the posterior eye. In this study we evaluated peripheral blood monocyte phagocytic function at various stages of AMD and in aged matched control participants. Real-time tri-color flow cytometry was used to quantify phagocytic function of peripheral blood monocyte subsets (non-classic, intermediate and classic) isolated from subjects with intermediate or late AMD and compared with age matched healthy controls. Assessment of phagocytic function of monocytes isolated from those with and without reticular pseudodrusen was also made, and the effect of glatiramer acetate on phagocytic function assessed. Phagocytic function was reduced in all subjects with AMD, irrespective of stage of disease. However, there was no correlation between phagocytic function and drusen load, nor any difference between the level of phagocytosis in those with or without reticular pseudodrusen. Treatment with glatiramer acetate increased phagocytosis of classical and non-classical monocytes, normalizing the reduction in phagocytosis observed in those with AMD. These findings suggest that defective systemic phagocytosis is associated with both intermediate and late stages of AMD, highlighting a potential role in the accumulation of debris that occurs early in the disease process. Assessing peripheral monocyte phagocytic function provides further insights into the etiology of this disease and offer a novel therapeutic target.

The Role of Inflammation in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a blinding eye disease which incidence gradually increases with age. Inflammation participates in AMD pathogenesis, including choroidal neovascularization and geographic atrophy. It is also a kind of self-protective regulation from injury for the eyes. In this review, we described inflammation in AMD pathogenesis, summarized the roles played by inflammation-related cytokines, including pro-inflammatory and anti-inflammatory cytokines, as well as leukocytes (macrophages, dendritic cells, neutrophils, T lymphocytes and B lymphocytes) in the innate or adaptive immunity in AMD. Possible clinical applications such as potential diagnostic biomarkers and anti-inflammatory therapies were also discussed. This review overviews the inflammation as a target of novel effective therapies in treating AMD.

Chemokine Profile and the Alterations in CCR5-CCL5 Axis in Geographic Atrophy Secondary to Age-Related Macular Degeneration

Purpose

Geographic atrophy (GA) secondary to age-related macular degeneration (AMD) is a progressive disease with no treatment option. Previous studies show chemokine-mediated recruitment of immune cells in the retina, and therefore we investigated systemic levels of chemokines and chemokine receptors in patients with GA.

Methods

This observational prospective study was conducted at a single center. We included 122 participants with no immune disease: 41 participants with GA and no choroidal neovascularization, 51 patients with neovascular AMD, and 30 healthy control individuals. Flow cytometric analysis was used to detect expression level of C-C chemokine receptor (CCR)1, CCR2, CCR3, CCR5, and C-X-C motif chemokine receptor (CXCR)3 on peripheral blood mononuclear cells (CD14+ monocytes, CD4+ T cells, CD8+ T cells). Plasma levels of C-C motif ligand (CCL)11, C-X-C motif chemokine (CXCL)10, and CCL5 were measured by specific immunoassays. Enlargement rate of GA lesion was measured from autofluorescence images.

Results

Participants with GA have a specific chemokine profile with a higher expression of CCR5 than healthy controls in peripheral blood mononuclear cells, and a higher plasma levels of CCL-5. Further, GA was associated with higher monocytic expression of CCR2 than in neovascular AMD. We found that a high expression level of CCR5 on CD8+ T cells was associated with slower enlargement rate of atrophic lesion.

Conclusions

The study showed an association between systemic chemokine profile and GA formation. Further studies are needed to fully elucidate the possible role of systemic chemokine regulation in mediating pathogenesis of GA.

The role of lymphocytes and phagocytes in age-related macular degeneration (AMD)

Age-related macular degeneration (AMD) is a leading cause of visual impairment of the elderly population. Since AMD is a multifactorial age-related disease with various genetic risk factors, the understanding of its complex pathophysiology is still limited. However, animal experiments, genome-wide association data and the molecular profiling of AMD patient samples have highlighted a key role of systemic and local immune processes that contribute to this chronic eye disease. In this overview article, we concentrate on the role of lymphocytes and mononuclear phagocytes and their interplay in triggering a persistent immune response in the AMD retina. We preferentially review findings from human immune cell analyses and complement these with related findings in experimental models. We conclude that both immune cell types as their signaling network may be a rich source to identify novel molecular targets for immunomodulation in AMD.

Association of CD11b+ Monocytes and Anti-Vascular Endothelial Growth Factor Injections in Treatment of Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Importance

CD11b+ immune cells have been implicated in the formation of choroidal neovascularization in experimental studies on animals and disease-association studies on humans. However, the clinical importance of such observations remains unknown.

Objective

To investigate whether the proportion of CD11b+ circulating monocytes is associated with the number of anti-vascular endothelial growth factor (anti-VEGF) injections in neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV).

Design, Setting, and Participants

These observational cohort studies collected data from January 1, 2010, through December 31, 2013, and from January 1, 2015, through December 31, 2018. Fresh venous blood samples were acquired for flow cytometric immune studies in patients with neovascular AMD or PCV receiving treatment with aflibercept or ranibizumab as needed for 36 months. Patients (n = 81) without immune diseases were consecutively recruited from a single center in Denmark.

Exposures

Proportion of CD11b+ circulating monocytes.

Main Outcomes and Measures

The estimation of the number of intravitreal anti-VEGF injections given at 12, 24, and 36 months by the proportion of CD11b+ circulating monocytes and the correlation between these values. The angiogenic role of CD11b+ circulating monocytes was further evaluated by investigating the expression of the known proangiogenic receptor CCR2.

Results

Eighty-one patients were included in the analysis (54% women; mean [SD] age, 76 [7] years). The proportion of CD11b+ monocytes at baseline positively estimated the future number of anti-VEGF injections at 12 (ρ = 0.77; 95% CI, 0.35-0.93; P = .004), 24 (ρ = 0.82; 95% CI, 0.44-0.95; P = .002), and 36 (ρ = 0.78; 95% CI, 0.34-0.94; P = .005) months. This association was also found retrospectively in a larger sample of patients with neovascular AMD at 12 (ρ = 0.46; 95% CI, 0.16-0.68; P = .004), 24 (ρ = 0.49; 95% CI, 0.20-0.70; P = .002), and 36 (ρ = 0.65; 95% CI, 0.41-0.80; P < .001) months and patients with PCV at 12 (ρ = 0.27; 95% CI, -0.28 to 0.68; P = .30), 24 (ρ = 0.60; 95% CI, 0.12-0.85; P = .02), and 36 (ρ = 0.70; 95% CI, 0.27-0.90; P = .005) months, suggesting that this association is not specific to AMD but rather reflects VEGF activity in neovascularization. CD11b+ monocytes highly coexpressed CCR2, an important monocytic marker of proangiogenic activity.

Conclusions and Relevance

Results of this study demonstrated that the proportion of circulating CD11b+ monocytes estimated and correlated with the number of anti-VEGF injections in patients with neovascular AMD and PCV. Additional longitudinal studies are needed to determine whether these findings have clinical relevance to influence treatment algorithms or provide novel targets for medical therapy.

Contribution of microglia and monocytes to the development and progression of age related macular degeneration

PURPOSE

Age related macular degeneration (AMD) is the leading cause of irreversible vision loss in industrialised nations. Based on genetics, as well as proteome analysis of drusen, the role the innate immune system in the development and/or progression of the disease is well established. Mononuclear phagocytes, such as microglia and monocytes, play critical roles in innate immunity. Here, the role of retinal microglia in mediating normal retinal function, and how these cells change with age is discussed, so as to understand their role in the development and progression of AMD.

RECENT FINDINGS

It is now known that microglia dynamically survey the neural environment, responding rapidly to even the most subtle neural injury. The dynamic and phagocytic roles of microglia can change with age contributing to alteration in the response of these cells to damage with age. Accumulation of innate immune cells in the subretinal space is a hallmark feature of the development of AMD, reflecting either an increase in migration of monocytes into the retina, or a failure of immune cell elimination from the retina. Furthermore, changes in phagocytic ability of immune cells could contribute to the accumulation of drusen deposits in the posterior eye.

SUMMARY

An overview of how retinal microglia maintain retinal homeostasis under normal conditions is provided, and then how they contribute to each stage of AMD. In addition, circulating monocytes are altered in those with AMD, contributing to the overall inflammatory state. Understanding the role of cells of the innate immune system in AMD may uncover novel therapeutic targets with which to reduce either the development or progression of disease.

Effects of senescent secretory phenotype acquisition on human retinal pigment epithelial stem cells

Regenerative medicine approaches based on mesenchymal stem cells (MSCs) are being investigated to treat several aging-associated diseases, including age-related macular degeneration (AMD). Loss of retinal pigment epithelium (RPE) cells occurs early in AMD, and their transplant has the potential to slow disease progression.

The human RPE contains a subpopulation of cells - adult RPE stem cells (RPESCs) – that are capable of self-renewal and of differentiating into RPE cells in vitro. However, age-related MSC changes involve loss of function and acquisition of a senescence-associated secretory phenotype (SASP), which can contribute to the maintenance of a chronic state of low-grade inflammation in tissues and organs.

In a previous study we isolated, characterized, and differentiated RPESCs. Here, we induced replicative senescence in RPESCs and tested their acquisition of the senescence phenotype and the SASP as well as the differentiation ability of young and senescent RPESCs.

Senescent RPESCs showed a significantly reduced proliferation ability, high senescence-associated β-galactosidase activity, and SASP acquisition. RPE-specific genes were downregulated and p21 and p53 protein expression was upregulated.

These findings document the effects of senescence and SASP acquisition on RPESC differentiation ability and highlight the need for a greater understanding of their role in AMD pathogenesis.

Polypoidal Choroidal Vasculopathy Associate With Diminished Regulatory T Cells That Are Polarized Into a T Helper 2-Like Phenotype

Purpose

To investigate possible roles of T helper (Th) cells, regulatory T cells (Tregs), and the recently mapped Th-like Tregs in patients with polypoidal choroidal vasculopathy (PCV).

Methods

In this prospective case-control study, we obtained fresh venous blood from patients with PCV (n = 24), age-matched healthy controls (n = 32), and patients with neovascular AMD (n = 45). All participants underwent a comprehensive ocular examination including fluorescein and indocyanine green angiography for where retinal disease was suspected. Using flow cytometry, we identified Th subsets, Tregs, and Th-like Tregs. Plasma samples were stored at -80°C to investigate plasma cytokines of interest.

Results

Compared to healthy controls, patients with PCV had lower percentages of Tregs (8.7% ± 2.8% vs. 7.3% ± 1.7%, P = 0.027), which were significantly more Th2-like polarized (42.6% ± 13.3% vs. 50.5% ± 13.0%, P = 0.029). These changes differed from that observed in neovascular AMD, which compared to healthy controls had fewer Th1/Th17 cells (3.6% ± 2.7% vs. 2.4% ± 2.5%, P = 0.049), comparable Treg levels, and no distinct polarization of Th-like Tregs. Because of these findings, we measured plasma IL-4 and IL-33 levels. Plasma IL-33 in patients with PCV (median 0.30 pg/mL) was twice as high compared to healthy controls (median 0.16 pg/mL; P = 0.037).

Conclusions

PCV associate with diminished Tregs that are polarized more into a Th2-like phenotype. This is correlated to IL-33 levels, which we also find increased in patients with PCV. Our findings suggest a possible role for Th2-like Tregs and IL-33 in PCV.

Neutrophil-to-lymphocyte ratio in age-related macular degeneration: a systematic review and meta-analysis

Age-related macular degeneration (AMD) is aetiologically linked to immunological ageing and dysfunction. One aspect of this is the altered neutrophil-to-lymphocyte ratio (NLR), which in other domains have been associated with inflammation and angiogenesis, and therefore investigated in patients with AMD in several papers. In this systematic review and meta-analysis, we summarize findings in patients with AMD in relation to NLR, both qualitatively and quantitatively. We searched PubMed/MEDLINE, EMBASE, Web of Science, and the Cochrane Central and identified six studies from where we extracted data on 1178 individuals (777 patients with AMD and 401 healthy controls). Patients with AMD had a higher NLR (weighted mean difference: 0.37, CI 95% 0.08 to 0.66, p = 0.013) when compared to healthy controls. In subgroup analyses, we did not find a significant difference between patients with dry AMD and healthy controls (weighted mean difference: 0.34, CI 95% -0.03 to 0.69, p = 0.068), but did find a strong significant difference between patients with neovascular AMD and healthy controls (weighted mean difference: 0.54, CI 95% 0.23 to 0.86, p = 0.00068). Hence, we find that the association between AMD and elevated NLR may have stronger relevance to the neovascular subtype of AMD. However, the clinical value of measuring the NLR remains unclear.

The transcriptome of peripheral blood mononuclear cells in patients with clinical subtypes of late age-related macular degeneration

Background

Peripheral blood mononuclear cells (PBMCs) are implicated in the pathogenesis of age-related macular degeneration (AMD). We here mapped the global gene transcriptome of PBMCs from patients with different clinical subtypes of late AMD.

Results

We sampled fresh venous blood from patients with geographic atrophy (GA) secondary to AMD without choroidal neovascularizations (n = 19), patients with neovascular AMD without GA (n = 38), patients with polypoidal choroidal vasculopathy (PCV) (n = 19), and aged control individuals with healthy retinae (n = 20). We isolated PBMCs, extracted RNA, and used microarray to investigate gene expression. Volcano plots identified statistically significant differentially expressed genes (P < 0.05) at a high magnitude (≥30% higher/lower) for GA (62 genes), neovascular AMD (41 genes), and PCV (41 genes). These clinical subtypes differed substantially across gene expression and the following pathways identified in enrichment analyses. In a subgroup analysis, we investigated presence vs. absence of subretinal fibrosis and found 826 differentially expressed genes (≥30% higher/lower, P < 0.05) with relation to mRNA splicing, endothelial migration, and interleukin-1 signaling.

Conclusions

We here map the global gene transcriptome of PBMCs related to clinical subtypes of late AMD and find evidence of subtype-specific immunological involvement. Our findings provide a transcriptomic insight into the systemic immunity associated with AMD.

Electronic supplementary material

The online version of this article (10.1186/s12979-019-0160-0) contains supplementary material, which is available to authorized users.

Plasma markers of chronic low-grade inflammation in polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

PURPOSE

Ageing is the strongest predictor of neovascular age-related macular degeneration (AMD), where neuroinflammation is known to play a major role. Less is known about polypoidal choroidal vasculopathy (PCV), which is an important differential diagnosis to neovascular AMD. Here, we report plasma markers of inflammation with age (inflammaging) in patients with PCV, patients with neovascular AMD and a healthy age-matched control group.

METHODS

We isolated plasma from fresh venous blood obtained from participants (n = 90) with either PCV, neovascular AMD, or healthy maculae. Interleukin(IL)-1β, IL-6, IL-8, IL-10 and tumour necrosis factor receptor 2 (TNF-R2) were measured using U-PLEX Human Assays. Routine plasma C-reactive protein (CRP) was measured using Dimension Vista 1500.

RESULTS

Patients with PCV had plasma levels of IL-1β, IL-6, IL-8, IL-10 and TNF-R2 similar to that in healthy controls. Patients with neovascular AMD had significantly higher plasma IL-1β, IL-6 and IL-10 than healthy controls, whereas no significant differences were observed for plasma IL-8 and TNF-R2. Differences between plasma IL-1β, IL-6 and IL-10 possessed a positive but weak ability in discriminating neovascular AMD from PCV. Both patients with PCV and patients with neovascular AMD had significantly higher levels of routine plasma CRP.

CONCLUSION

Patients with PCV differ from patients with neovascular AMD in terms of plasma inflammaging profile. Apart from increased CRP, no signs of inflammaging were observed in patients with PCV. In patients with neovascular AMD, we find a specific angiogenesis-twisted inflammaging profile.

Altered proportion of CCR2+ and CX3CR1+ circulating monocytes in neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

BACKGROUND

We investigated the expression of chemokine receptors CCR2 (C-C chemokine receptor) 2 and CX3CR1 (C-X3-C receptor 1) on circulating monocyte subsets in patients with neovascular age-related macular degeneration (AMD) and patients with polypoidal choroidal vasculopathy (PCV).

METHODS

We recruited patients with neovascular AMD, patients with PCV and age-matched healthy controls for this prospective case-control study. All participants underwent comprehensive clinical examination and imaging. Freshly sampled venous blood was prepared for flow cytometry, where we determined the proportion of CCR2⁺ - and CX3CR1⁺ -positive cells in monocyte subsets identified using monocyte identification and subgrouping surface markers CD14, CD16 and HLA-DR.

RESULTS

Patients with neovascular AMD had significantly increased proportion of CCR2⁺ and CX3CR1⁺ non-classical monocytes. PCV type 1 was associated with significantly increased CCR2⁺ and CX3CR1⁺ in all monocyte subsets when compared to PCV type 2.

CONCLUSIONS

Neovascular AMD is associated with increased expression of angiogenesis-associated chemokine receptors in the pro-inflammatory non-classical monocytes. PCV differs from neovascular AMD immunologically and show immunological heterogeneity across angiographic subtypes.

T-cell differentiation and CD56+ levels in polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

Polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) are prevalent age-related diseases characterized by exudative changes in the macula. Although they share anatomical and clinical similarities, they are also distinctly characterized by their own features, e.g. vascular abnormalities in PCV and drusen-mediated progression in neovascular AMD. PCV remains etiologically uncharacterized, and ongoing discussion is whether PCV and neovascular AMD share the same etiology or constitute two substantially different diseases. In this study, we investigated T-cell differentiation and aging profile in human patients with PCV, patients with neovascular AMD, and age-matched healthy control individuals. Fresh venous blood was prepared for flow cytometry to investigate CD4⁺ and CD8⁺ T-cell differentiation (naïve, central memory, effector memory, effector memory CD45ra⁺), loss of differentiation markers CD27 and CD28, and expression of aging marker CD56. Patients with PCV were similar to the healthy controls in all aspects. In patients with neovascular AMD we found significantly accelerated T-cell differentiation (more CD28^-CD27^- cells) and aging (more CD56⁺ cells) in the CD8⁺ T-cell compartment. These findings suggest that PCV and neovascular AMD are etiologically different in terms of T cell immunity, and that neovascular AMD is associated with T-cell immunosenescence.

Effect of aging and lifestyle on photoreceptors and retinal pigment epithelium: cross-sectional study in a healthy Danish population

Photoreceptors and their supporting retinal pigment epithelium constitute the key functional parts of the retina. Here, a study was undertaken to show how aging and lifestyle factors affect the photoreceptor layer and the retinal pigment epithelium and Bruch's membrane complex (RPE-BM) in vivo in a healthy Danish population using spectral-domain optical coherence tomography. This was a cross-sectional study of healthy humans aged ≥50 years. All participants were interviewed for medical history and lifestyle factors. Maculae of all participants were scanned using spectral-domain optical coherence tomography. The thickness of the photoreceptor layer and the RPE-BM was measured on one eye from each participant. In 150 eyes of 150 participants, it was found that aging was associated with a decrease in the thickness of the photoreceptor layer (-0.143 μm/year, P = 0.031) and an increase in the thickness of the RPE-BM layer (0.100 μm/year, P = 0.029) at the foveal minimum. Regarding lifestyle factors, alcohol intake or BMI were not associated with any significant trend, but physical inactivity and smoking had effects on the photoreceptor layer (decreased thickness) and the RPE-BM layer (increased thickness) indicating an accelerated aging process of the macula. Taken together, aging affects photoreceptors and the RPE-BM, and these aging trends are accelerated in smokers and the physically inactive.

Altered activation state of circulating neutrophils in patients with neovascular age-related macular degeneration

Background

Neutrophil dysfunction plays a key role in the development of diseases characterized by inflammation and angiogenesis. Here, we studied the systemic expression of neutrophil markers reflecting activation, adhesion, and resolution of inflammation in patients with neovascular age-related macular degeneration (AMD).

Results

This was a prospective case-control study of patients with neovascular AMD and age-matched healthy control individuals. Patients were recruited from an outpatient program, and control individuals were recruited amongst patients’ relatives. Current smokers and individuals with either active immune-disease or ongoing cancer were not included, as these factors are known to affect neutrophil function. Fresh-drawn venous blood was processed for flow cytometric analysis of neutrophil markers. We determined percentages of positive cells and compared expression levels using fluorescence intensity measures. We found conditional differences on marker expression between patients with neovascular AMD (n = 29) and controls (n = 28): no differences were found when looking broadly, but several differences emerged when focusing on non-smokers. Here, patients with neovascular AMD had increased expression of the activity marker cluster of differentiation (CD) 66b (P = 0.003; Mann-Whitney U test), decreased expression of adhesion marker CD162 (P = 0.044; Mann-Whitney U test), and lower expression of the resolution of inflammation marker C-X-C chemokine receptor 2 (P = 0.044; Mann-Whitney U test).

Conclusions

We present novel evidence suggesting that the activity of circulating neutrophils, sensitive to smoking, may differ in patients with neovascular AMD.

Neovascular Age-Related Macular Degeneration in the Very Old (≥90 Years): Epidemiology, Adherence to Treatment, and Comparison of Efficacy

PURPOSE

To investigate neovascular age-related macular degeneration (AMD) in patients aged ≥90 years from several perspectives for a comprehensive overview: prevalence, presenting characteristics, treatment adherence, reasons for discontinuation, and efficacy of antivascular endothelial growth factor (VEGF) treatment comparing Ranibizumab and Aflibercept.

METHODS

In this retrospective chart review, we determined the prevalence and presenting characteristics by reviewing all data for patients referred to our department with treatment-naïve neovascular AMD. By looking at historical cohorts, we determined adherence to treatment, reasons for discontinuation, and treatment outcomes after loading dose, 12 months, and 24 months.

RESULTS

Patients aged ≥90 years constituted 7% of the patients. Treatment was discontinued in 51%, primarily because of death and treatment burden. Mean change in best-corrected visual acuity was 3.2, 1.5, and -2.2 ETDRS letters at 4, 12, and 24 months, respectively. Aflibercept was superior to Ranibizumab in visual and anatomic outcomes. After two years of treatment, patients losing ≥15 ETDRS letters made up 19% in the Aflibercept group and 26% in the Ranibizumab group.

CONCLUSIONS

We propose that the very old patients with neovascular AMD may constitute a distinctive group warranting special attention and possibilities for individualized therapy. Possible differences between anti-VEGF agents need further investigations.

Systemic frequencies of T helper 1 and T helper 17 cells in patients with age-related macular degeneration: A case-control study

Age-related macular degeneration (AMD) is a degenerative disease of the retina and a leading cause of irreversible vision loss. We investigated the systemic differences in the frequency of T helper (Th) 1 and Th17 cells in patients with non-exudative and exudative AMD and compared to age-matched controls. Flow cytometry was used to determine the systemic frequency of Th1 (CD4⁺CXCR3⁺IL12RB2⁺) and Th17 (CD4⁺CCR6⁺IL23R⁺) cells, and percentage of CD4⁺ T-cells expressing CXCR3, IL12RB2, CCR6, IL23R, and co-expressing CXCR3 and CCR6. The frequency of Th1 cells and CXCR3⁺ CD4⁺ T-cells was lower in patients with exudative AMD. A significant age-dependent decrement in Th1 was observed in controls, but not in non-exudative or exudative AMD. This may be related to the CXCR3⁺ CD4⁺ T-cells, which showed similar pattern in controls, but not in non-exudative or exudative AMD. No significant group differences were observed for the frequency of Th17 cells. Correlation networks found several differences between controls and AMD. These data suggests the involvement of the adaptive immune system in AMD and supports the notion of AMD as a systemic disease. Our observations warrant further investigation into the role of the adaptive immune system in the pathogenesis of AMD.