Abstract
Complement has long been recognized as a critical component of the innate immune system. It comprises proteins that play a central role in host defense against infection and in the modulation of antigen-specific immune and inflammatory responses. The complement system can be activated by three proteolytic cascades namely, the classical, the alternative, and the lectin pathways. The activation of complement components by all three pathways leads to the formation of a membrane attack complex (MAC).
There are studies about complement system involvement in different ocular pathologies, like macular degeneration, glaucoma, diabetic retinopathy, and autoimmune uveitis.
Dysregulation of the complement cascade has emerged as a key contributor to the pathophysiology of age-related macular degeneration and there has been a revolution in the treatment of the geographic type. The drug pegcetagoplan, which was approved by the FDA on February 17, 2023, is a C3 inhibitor that binds to C3 or C3b, disrupting further activation of the complement system.
There are studies about the relationship between diabetic retinopathy and dysregulation of the complement system. Some authors found activation of C5a in the vitreous body, other authors found an increase of C9 and factor D in the vitreous body.
Several studies have investigated the role of the complement system in the pathogenesis of glaucoma, especially the role of C3, C1, and complement regulatory proteins.
There are studies about experimental autoimmune uveitis and the role of the complement system in the pathogenesis of ocular autoimmune disease. The studies provided the novel finding that complement activation plays a central role in the pathogenesis of ocular autoimmunity and may serve as a potential target for therapeutic intervention.
Thus, summing up the results of studies conducted by various authors, we conclude that the complement system has its role in the pathogenesis of various eye pathologies. Identification of the complement system activation as a new direction of local ocular immunity in the pathogenesis of autoimmune uveitis will provide an opportunity for the development of targeted treatment regimens.
Publisher
Yerevan State Medical University
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