Dysregulation of the alternative pathway (AP) of complement cascade has been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the elderly. To further test the hypothesis that defective control of complement activation underlies AMD, parameters of complement activation in blood plasma were determined together with disease-associated gene...

AIM Here we investigated the role of complement activation in phagocytosis and the release of cytokines and chemokines in response to two clinical isolates: Borrelia afzelii K78, which is resistant to complement-mediated lysis, and Borrelia garinii LU59, which is complement-sensitive. METHODS Borrelia spirochetes were incubated in hirudin plasma, or hirudin-anticoagulated whole blood. Complem...

The complement system is a series of serum proteins that perform cell lytic and pro-inflammatory functions as part of the bodies mechanism for removing foreign, dead or damaged cells. The complement system consists of the alternative and classical pathways. During activation the anaphylatoxins C4a and C3a are released and these can be measured using competitive MAS. Abherrant activation of the ...

PURPOSE To determine if the progression of age-related macular degeneration (AMD) is associated with complement activation in the eye. METHODS Immunohistochemistry and ELISAs were used to determine the distribution, concentration, and activation of the alternative pathway complement proteases factor B (FB) and factor D (FD) and the central complement protein C3 in genotyped human postmortem d...

Classic hyperacute rejection is dependent on the activation of the terminal components of complement. Recently, xenoantibodies with limited abilities to activate the classical pathway of complement in vitro have been implicated in the acute vascular rejection of xenografts. It is unclear how these Abs affect their pathogenic activities in vivo. In this study, we demonstrate the ability of an an...

The immune response after brain injury is highly complex and involves both local and systemic events at the cellular and molecular level. It is associated to a dramatic over-activation of enzyme systems, the expression of proinflammatory genes and the activation/recruitment of immune cells. The complement system represents a powerful component of the innate immunity and is highly involved in th...

Sepsis is both a common and, despite present-day therapy, a serious disease. The pathophysiology of the septic response is a complex, multifactorial phenomenon which in part involves the activation of complement by bacterial endotoxin. A monoclonal antibody to human complement factor B, code-named 1H5, which was capable of specifically inhibiting the alternative pathway of complement activation...

INTRODUCTION Uncontrolled HIV infection is known to activate the complement system, leading to an increase in chronic inflammation. Whether or not this activation of complement persists and contributes to chronic inflammation in subjects with HIV infection that is well controlled through use of antiretroviral therapy has not been studied. METHODS We conducted an observational, cross-sectional...

Complement component C4 is a central protein in the classical and lectin pathways within the complement system. During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered self-tissue, where it acts as an opsonin marking the surface for removal. Moreover, C4b provides a platform for assembly of the proteolytically active convertase...

Purpose Genome-wide association studies suggest a role for the complement system in age-related macular degeneration (AMD). We characterized ocular complement activation and evaluated a complement factor D (FD) neutralizing antibody. Methods Mice were treated with toll-like receptor (TLR) ligands, intravitreal injection (IVT), or corneal debridement. Levels of complement proteins and mRNA wer...