Complement is activated through the three different pathways, which are the classical (CP), lectin (LP), and alternative pathways (AP). Complement activation functions to eliminate invading pathogens, whereas dysregulation of complement activation can induce inflammatory disorders such as age-related macular degeneration (AMD). In retinal degeneration induced by sodium iodate (NaIO), a murine model of dry AMD (also called atrophic AMD), it has been suggested that the AP and CP are involved in the disease development.
View Article and Find Full Text PDFJpn J Ophthalmol
May 2025
Purpose: To investigate the relationship between high temperature requirement A (HTRA1) and the local complement system, we measured HTRA1 and complement activation products in the aqueous humor of patients with neovascular age-related macular degeneration (nAMD).
Study Design: Surveys (cross-sectional studies).
Methods: One hundred twenty-one eyes of 121 patients with nAMD and 55 control eyes were enrolled.
BMC Ophthalmol
July 2023
Purpose: Due to technological advancements, surgical invasiveness has been reduced. However, cataract surgery has been implicated in causing postoperative inflammation, including dry eye syndrome. The innate immune system may be involved in postoperative inflammation, and complement activation could potentially play a crucial role in defense against pathogens, homeostasis, and wound healing.
View Article and Find Full Text PDFPurpose: To investigate the association of risk alleles in complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) with complement activation products in the aqueous humor in eyes with neovascular age-related macular degeneration (nAMD) including polypoidal choroidal vasculopathy (PCV), retinal angiomatous proliferation (RAP), and pachychoroid neovasculopathy (PNV).
Design: Prospective, comparative, observational study.
Participants: Treatment-naïve patients with nAMD and cataract patients as controls.
The complement system plays an important role in host defense and is activated three different activation pathways. We have previously reported that mannose-binding lectin-associated serine protease (MASP)-3, unlike its splicing variant MASP-1, circulates in an active form and is essential for the activation of the alternative pathway (AP) the activation of complement factor D (FD). On the other hand, like MASP-1 and MASP-2 of the lectin pathway (LP), MASP-3 forms a complex with the pattern recognition molecules (PRMs) of the LP (LP-PRMs).
View Article and Find Full Text PDFWe evaluated changes in the complement system resulting from anti-vascular endothelial growth factor (VEGF) in eyes with age-related choroidal neovascularization (CNV) including neovascular age-related macular degeneration, pachychoroid neovasculopathy, and polypoidal choroidal neovasculopathy. We measured the concentrations of the complement activation products (C3a, C4a), VEGF, and monocyte chemotactic protein-1 in the aqueous humor during intravitreal anti-VEGF injections for CNV. The VEGF level decreased significantly (P < 0.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
November 2020
Purpose: To investigate the characteristics of complement activation products and angiogenic cytokines in the aqueous humor in eyes with pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD).
Methods: This was a prospective, comparative, observational study. All patients with choroidal neovascularization were classified as PNV without polyps, PNV with polyps (polypoidal choroidal vasculopathy [PCV]), or drusen-associated nAMD according to the presence or absence of pachychoroid features and soft drusen.
The complement system may be activated in the posterior segment of the eye with chorioretinal disease, which may be reflected to the concentration of anaphylatoxins in the aqueous humor. Little is known about the distribution of anaphylatoxins in the aqueous and vitreous humor. The aim of the present study was to investigate the distribution of anaphylatoxin concentration in the aqueous and vitreous humor of the eyes with idiopathic epiretinal membrane or idiopathic macular hole.
View Article and Find Full Text PDFPurpose: The complement system is activated via 3 different pathways; the lectin pathway (LP), classical pathway (CP), and alternative pathway. To investigate the possible roles for the LP or CP in the development of neovascular age-related macular degeneration (nAMD), we compared aqueous humor levels of complement proteins of the LP and CP between eyes with nAMD and those with cataract as controls.
Methods: Seventeen eyes from 17 patients with treatment-naïve nAMD and 9 eyes from 9 patients with cataract were studied.
Background: Onset of Henoch-Schönlein purpura (HSP) in middle age is uncommon, and adults with renal or gastrointestinal involvement present with more severe disease than do similar pediatric patients.
Case Presentation: We present the case of a 69-year-old male with HSP who, after treatment with steroids, cyclophosphamide, and continuous intravenous prostaglandin E1 (PGE1), died as a result of severe gastrointestinal involvement with non-occlusive mesenteric ischemia (NOMI). Vascular narrowing associated with the NOMI improved after catheter injection of PGE1 and prednisolone, but the patient died of bleeding from an exposed small vessel.