Abstract
Abstract: :
Purpose: Intravenous 7 S immunoglobulin (IG) was used in a first clinical trial for treatment of idiopathic choroidal neovascularisation in patients with promising results. However, the outcome of IG interaction with endothelial cells of the vascular bed is not clear as yet. Methods:CEC were obtained from human donors and were strongly positive for factor VIII-related antigen. Vascular endothelial growth factor (VEGF) was used as an angiogenic stimulant. Proliferation assay. VEGF-stimulated CEC were exposed to IG at concentrations varying from 5-40 mg/ml. The proliferation rate was tested by counting the cells in a Thomae chamber. Migration assay was performed using FluoroBlock inserts. Chemotaxis was measured by detecting the fluorescence of CEC migrating through the pores to the lower chambre of the membranes toward angiogenic VEGF. Tube-formation assay was performed with ECM gel coated 96-well plates (104 cells/well). The gel proteins allow cell alignment and capillary-like formation. For statistical analysis student´s t-test was used. Results:The stimulatory effect of VEGF (50 ng/ml) on CEC proliferation was significantly blocked in a concentration dependent manner by exposure of the cells to 20 or 40 mg IG/ml (n = 4) by 33 % (p = 0.004) or 45 % (p = 0.00004) respectively. Treatment with 40 mg/ml IG resulted in a 56 % inhibition of endothelial cell migration toward VEGF. Tube formation by CEC was apparent in all experimental groups but was less prominent in the presence of 40 mg/ml IG. Conclusion:Thus, blockade of cellular proliferation, migration and tube formation may explain the therapeutic effect of inhibition of choroidal neovascularuisation and vascular disorders by IG.
Keywords: 346 choroid: neovascularization • 514 pharmacology • 505 pathobiology