Polymorphisms in Vascular Endothelial Growth Factor Receptor 2 Are Associated with Better Response Rates to Ranibizumab Treatment in Age-related Macular Degeneration
OPHTHALMOLOGY
Authors: Hermann, Manuel M.; van Asten, Freekje; Muether, Philipp S.; Smailhodzic, Dzenita; Lichtner, Peter; Hoyng, Carel B.; Kirchhof, Bernd; Grefkes, Christian; den Hollander, Anneke I.; Fauser, Sascha
Abstract
Purpose: Intravitreal antievascular endothelial growth factor (VEGF) injections are currently the standard treatment for neovascular age-related macular degeneration (AMD), but a broad range of response rates has been observed. We evaluated the association of single nucleotide polymorphisms (SNPs) in VEGF genes and their receptors (VEGFR) with the response rate to ranibizumab in 366 patients with neovascular AMD. Design: Case series study. Participants: A total of 366 eyes of 366 patients with neovascular AMD. Methods: Visual acuity (VA) was determined at baseline, after 3 monthly ranibizumab injections, and after 1 year of treatment. Genotyping of 126 SNPs in the genes encoding VEGF family members VEGFA, VEGFB, VEGFC, VEGFD (FIGF), and placental growth factor (PGF); VEGF receptors VEGFR1 (FLT1), VEGFR2 (KDR), and VEGFR3 (FLT4); and the gene encoding pigment epithelium-derived factor (PEDF) (SERPINF1) was performed. Main Outcome Measures: The changes in VA after 3 injections and after 1 year of treatment and their association with VEGF and VEGFR genotypes. Results: Univariate analyses of variance (ANOVAs) revealed a significant effect of SNP rs4576072 in the VEGFR2 gene on VA change after 12 months (F[1,235] = 14.05; P = 0.02). A stepwise linear regression analysis returned a model (P = 0.01) with SNPs rs4576072 and rs6828477 in the VEGFR2 gene as independent predictors for VA change after 12 months, with a mean increase in VA of 0.26 on the logarithm of the minimum angle of resolution (logMAR) scale in patients with 3 contributing minor alleles compared with a loss of 0.03 logMAR in patients with no minor allele. Conclusions: Polymorphisms in the VEGFR2/KDR gene significantly influence visual outcome in patients receiving ranibizumab treatment for neovascular AMD. This study shows that genetic variation partially explains the wide range of response to ranibizumab treatment, which in the future might help clinicians tailoring medical interventions to individual needs. Ophthalmology 2014;121:905-910 (C) 2014 by the American Academy of Ophthalmology.
Myeloid Wnt ligands are required for normal development of dermal lymphatic vasculature
PLOS ONE
Authors: Muley, Ajit; Odaka, Yoshi; Lewkowich, Ian P.; Vemaraju, Shruti; Yamaguchi, Terry P.; Shawber, Carrie; Dickie, Belinda H.; Lang, Richard A.
Abstract
Resident tissue myeloid cells play a role in many aspects of physiology including development of the vascular systems. In the blood vasculature, myeloid cells use VEGFC to promote angiogenesis and can use Wnt ligands to control vascular branching and to promote vascular regression. Here we show that myeloid cells also regulate development of the dermal lymphatic vasculature using Wnt ligands. Using myeloid-specific deletion of the WNT transporter Wntless we show that myeloid Wnt ligands are active at two distinct stages of development of the dermal lymphatics. As lymphatic progenitors are emigrating from the cardinal vein and intersomitic vessels, myeloid Wnt ligands regulate both their numbers and migration distance. Later in lymphatic development, myeloid Wnt ligands regulate proliferation of lymphatic endothelial cells (LEC) and thus control lymphatic vessel caliber. Myeloid-specific deletion of WNT co-receptor Lrp5 or Wnt5a gain-of-function also produce elevated caliber in dermal lymphatic capillaries. These data thus suggest that myeloid cells produce Wnt ligands to regulate lymphatic development and use Wnt pathway co-receptors to regulate the balance of Wnt ligand activity during the macrophage-LEC interaction.