In patients with neovascular age-related macular degeneration, physical activity may influence C-reactive protein levels

PURPOSE: Association of neovascular age-related macular degeneration (AMD) with C-reactive protein (CRP) was previously reported, indicating a relation to systemic low-grade inflammation. However, visual impairment limits physical activity, and physical activity modulates CRP levels. Here, we investigated the impact of physical activity on CRP levels in patients with neovascular AMD and control individuals.SUBJECTS AND METHODS: We recruited participants from our outpatient AMD program, and control individuals from non-AMD patients, visitors, and department staff. After initial screening of 191 individuals, we included 98 patients with neovascular AMD and 77 controls. All were screened using digital fundus photography and optical coherence tomography, and interviewed about medical history and physical activity. Venous blood samples were obtained for high-sensitivity CRP.RESULTS: Physically active individuals had lower CRP than physically inactive individuals (P=0.003), and physical activity was associated with lower CRP in patients (P=0.038) and controls (P=0.031). Patients and controls did not differ in percentage physically active (P=0.807) or in overall CRP levels (P=0.394). The independent contribution of physical activity on CRP was confirmed in a multiple regression analysis (P=0.009), in which the presence of neovascular AMD did not contribute significantly (P=0.913).CONCLUSION: Our findings suggest that elevated CRP levels in patients with neovascular AMD are at least partly explained by physical inactivity. Future studies of systemic inflammation among the visually impaired should include disease-related implications, such as the impact of physical activity

The association between plasma 25-hydroxyvitamin D and subgroups in age-related macular degeneration: a cross-sectional study.

To evaluate potential differences in plasma 25-hydroxyvitamin in subtypes of age-related macular degeneration (AMD), and in patients in Clinical Age-Related Maculopathy Staging (CARMS) group 5 with or without subretinal fibrosis.This single-center cross-sectional study included 178 participants during a period of 20 months. Ninety-five patients belonged to CARMS 5; twelve belonged to CARMS 4; twenty-two belonged to CARMS 2 or 3; and 49 individuals did not have AMD (CARMS 1). Following a structured interview, a detailed bilateral retinal examination was performed and participants were allocated to their respective subgroups in accordance with the Clinical Age-Related Maculopathy Staging system. Plasma 25-hydroxyvitamin D2 and D3 were analyzed using liquid chromatography-tandem mass spectrometry. Genomic DNA was extracted from leukocytes and genotyped for single nucleotide polymorphisms (SNPs) in the vitamin D metabolism. Differences in plasma 25-hydroxyvitamin D were determined in the subgroups as well as between patients in CARMS 5 with or without subretinal fibrosis.Plasma 25-hydroxyvitamin D was comparable in patients across CARMS groups 1 to 5 (p = 0.83). In CARMS 5, the presence of subretinal fibrosis was associated with significantly lower concentrations of 25-hydroxyvitamin D as compared to the absence of subretinal fibrosis (47.2 versus 75.6 nmol/L, p<0.001). Patients in CARMS 5 with subretinal fibrosis were more likely to have insufficient levels of 25-hydroxyvitamin D compared to patients without subretinal fibrosis (p = 0.006). No association was found between the SNPs rs10877012, rs2228570, rs4588, or rs7041 and AMD subgroups or plasma 25-hydroxyvitamin levels.This study suggests that the presence of subretinal fibrosis in patients belonging to CARMS 5 may be associated with a poor vitamin D status. Our observations warrant further investigation into the role of vitamin D in the development of subretinal fibrosis

Blood expression levels of chemokine receptor CCR3 and chemokine CCL11 in age-related macular degeneration:a case-control study

BACKGROUND: Dysregulation of the CCR3/CCL11 pathway has been implicated in the pathogenesis of choroidal neovascularisation, a common feature of late age-related macular degeneration (AMD). The aim of this study was to investigate the expression of CCR3 and its ligand CCL11 in peripheral blood in patients with neovascular AMD. METHODS: Patients with neovascular AMD and healthy controls were included. Blood samples were obtained and prepared for flow cytometry to investigate the expression of CCR3. Levels of CCL11 were measured in plasma using Cytometric Bead Array. Differences between the groups were tested using Kruskal-Wallis test and Mann–Whitney U test. RESULTS: Patients (n = 83) with neovascular AMD and healthy control persons (n = 114) were included in the study. No significant difference in the expression of CCR3 was found on CD9+ granulocytes when comparing patients suffering from neovascular AMD with any of the control groups. We did not find any alteration in CCL11 levels in patients among the age matched groups. There was no correlation between expression of CCR3/CCL11 and clinical response to treatment with anti-vascular endothelial growth factor (VEGF). CONCLUSION: Our results do not suggest a systemic alteration of the CCR3/CCL11 receptor/ligand complex in patients with neovascular AMD

CX3CL1/CX3CR1 and CCL2/CCR2 Chemokine/Chemokine Receptor Complex in Patients with AMD

PURPOSE: The chemokine receptors CX3CR1 and CCR2 have been implicated in the development of age-related macular degeneration (AMD). The evidence is mainly derived from experimental cell studies and murine models of AMD. The purpose of this study was to investigate the association between expression of CX3CR1 and CCR2 on different leukocyte subsets and AMD. Furthermore we measured the plasma levels of ligands CX3CL1 and CCL2.METHODS: Patients attending our department were asked to participate in the study. The diagnosis of AMD was based on clinical examination and multimodal imaging techniques. Chemokine plasma level and chemokine receptor expression were measured by flow-cytometry.RESULTS: A total of 150 participants were included. We found a significantly lower expression of CX3CR1 on CD8+ T cells in the neovascular AMD group compared to the control group (p = 0.04). We found a significant positive correlation between CCR2 and CX3CR1 expression on CD8+ cells (r = 0.727, p = 0.0001). We found no difference in plasma levels of CX3CL1 and CCL2 among the groups.CONCLUSIONS: Our results show a down regulation of CX3CR1 on CD8+ cells; this correlated to a low expression of CCR2 on CD8+ cells. Further studies are needed to elucidate the possible role of this cell type in AMD development

Dysregulation of CXCR3 expression on peripheral blood leukocytes in patients with neovascular age-related macular degeneration

PURPOSE: The chemokine receptor CXCR3 has been strongly related to inhibition of angiogenesis. The purpose of this study was to investigate the association between expression of CXCR3 on peripheral blood leukocytes and age-related wet macular degeneration. Furthermore, we measured the plasma concentration of chemokines CXCL9 to -11.METHODS: The study group consisted of patients with age-related macular degeneration (AMD) attending our department. Patients referred for reasons other than AMD were enrolled as control subjects. The expression of CXCR3 on T cells and the plasma concentration of CXCL9 to -11 were measured using flow cytometry.RESULTS: We looked at all CD8(+) T cells expressing CXCR3 and found a significantly lower percentage of these cells in the neovascular AMD group compared to the age-matched control group (P = 0.05). When dividing the CD8(+) cells into functional groups according to their expression of CXCR3, we found a significantly lower percentage of CD8(+) CXCR3(high) cells in the group with neovascular AMD compared to the control group (P = 0.038). We found a lower percentage of CD4(+)CD69(+)CXCR3(+) T cells in the group of patients with neovascular AMD when compared to the age-matched control group (P = 0.052).CONCLUSIONS: Our results point toward a systemic dysregulation of CXCR3 in patients with neovascular AMD. Since there is evidence to suggest that CXCR3 is able to alter the response of VEGF, the primary driver of choroidal neovascularization (CNV) formation, low levels of CXCR3 could potentially drive some patients toward a more angiogenic profile leading to CNV formation and growth. CXCR3-enhancing molecules could therefore be a possible target for treatment of AMD