Complement deficiencies

2018 ◽  
Author(s):  
Malini Bhole
Keyword(s):  
Immune System ◽  
Complement System ◽  
Bacterial Infections ◽  
Adaptive Immune System ◽  
Classical Pathway ◽  
Adaptive Immune ◽  
Complement Inhibitors ◽  
Inflammatory Damage ◽  
Form Part ◽  
The Complement System

The complement system comprises a group of heat-labile proteins which form part of the innate immune system. The main physiological functions of the complement system include defence against pyogenic bacterial infections, clearance of immune complexes and products of inflammatory damage, and acting as a bridge between the innate and adaptive immune system. The complement system is regulated by various complement inhibitors (regulatory proteins) that are present in both the classical pathway and the alternate pathway and which regulate and prevent spontaneous activation of the complement system, thereby preventing complement-mediated damage to tissues under normal circumstances. This chapter addresses the clinical features, diagnosis, and management of inherited and acquired deficiencies of complement proteins or inhibitors.

Suppressing the CRISPR/Cas adaptive immune system in bacterial infections

2017 ◽  
Vol 36 (11) ◽  
pp. 2043-2051 ◽  
Author(s):  
P. Gholizadeh ◽  
M. Aghazadeh ◽  
M. Asgharzadeh ◽  
H. S. Kafil
Keyword(s):  
Immune System ◽  
Bacterial Infections ◽  
Adaptive Immune System ◽  
Adaptive Immune

scholarly journals C3 AND C4 COMPLEMENT – BIOMARKERS FOR PROGNOSIS OF TREATMENT OF TNF-BLOKERS

2019 ◽  
Vol 32 (2) ◽  
pp. 247-250
Author(s):  
Stanislava Popova ◽  
Mariela Geneva
Keyword(s):  
Immune System ◽  
Complement System ◽  
Inflammatory Diseases ◽  
Adaptive Immune System ◽  
Response Prediction ◽  
The Body ◽  
Control Group ◽  
Phagocytic Cells ◽  
Immune System Activation ◽  
The Complement System

Introduction: The complement system adds antibodies and helps phagocytic cells to destroy pathogens from the body. This is part of a congenital immune system that is not adaptive and does not change over the individual life. However, complement can be "triggered" by the adaptive immune system. The complement system is the main effector of the humoral patr of the immune system. Activation of complement results in opsonization, chemotaxis and cytolysis. Regulation of the complement system can control inflammatory diseases including psoriatic arthritis and vice versa, complement fixation disorders can lead to illness. Treatment with anti-TNF blokers complement activity in patients with inflammatory joint diseases.Objective: To investigate C3, C4 fractions of complement, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complement the response prediction and monitoring of anti-TNF treatment in patients with psoriatic arthritis.Materials and Methods: 36 patients were included sequentially before treatment with TNF-a-blokers. C3, C4, ESR, CRP were assessed at baseline at 6 and 12 months after initiation of treatment with TNF-α blockers. The activity of the disease is measured by the DARSA disease activity scale, the responses being compared with a control group of persons similar in gender and age. Statistical data processing was performed using the SPSS v25.Results and conclusions: According to the results obtained, C3 and C4 were significantly higher than controls at initiation of treatment (C3 111.3 ± 30.8, C4 91.9 ± 12.4 mg / dl, controls 19.1 ± 8.3 mg / dl, 10.2 ± 5.6 mg / dl p = 0.001, p = 0.001). At 6 and 12 months of follow-up, 76.2% of patients had a reduction in the level of C3 and C4 (p = 0.002, 0.001, respectively). It was found that higher baseline levels of C3 were associated with higher DARSA values at 6 and 12 months.Conclusion: The study of the C3 and C4 complement fractions can be used as biomarkers to estimate the prognosis of TNF-blocker therapy.

scholarly journals The Role of Complement System and the Immune Response to Tuberculosis Infection

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 84
Author(s):  
Heena Jagatia ◽  
Anthony G. Tsolaki
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Cell Surface ◽  
Complement System ◽  
Bacterial Cell ◽  
Lectin Binding ◽  
Alternative Pathway ◽  
Classical Pathway ◽  
Bacterial Cell Surface ◽  
The Complement System

The complement system orchestrates a multi-faceted immune response to the invading pathogen, Mycobacterium tuberculosis. Macrophages engulf the mycobacterial bacilli through bacterial cell surface proteins or secrete proteins, which activate the complement pathway. The classical pathway is activated by C1q, which binds to antibody antigen complexes. While the alternative pathway is constitutively active and regulated by properdin, the direct interaction of properdin is capable of complement activation. The lectin-binding pathway is activated in response to bacterial cell surface carbohydrates such as mannose, fucose, and N-acetyl-d-glucosamine. All three pathways contribute to mounting an immune response for the clearance of mycobacteria. However, the bacilli can reside, persist, and evade clearance by the immune system once inside the macrophages using a number of mechanisms. The immune system can compartmentalise the infection into a granulomatous structure, which contains heterogenous sub-populations of M. tuberculosis. The granuloma consists of many types of immune cells, which aim to clear and contain the infection whilst sacrificing the affected host tissue. The full extent of the involvement of the complement system during infection with M. tuberculosis is not fully understood. Therefore, we reviewed the available literature on M. tuberculosis and other mycobacterial literature to understand the contribution of the complement system during infection.

scholarly journals Hypoxic Processes Induce Complement Activation via Classical Pathway in Porcine Neuroretinas

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3575
Author(s):  
Ana M. Mueller-Buehl ◽  
Torsten Buehner ◽  
Christiane Pfarrer ◽  
Leonie Deppe ◽  
Laura Peters ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Immune System ◽  
Complement System ◽  
Ganglion Cells ◽  
Age Related Macular Degeneration ◽  
Classical Pathway ◽  
Retinal Diseases ◽  
Multifactorial Diseases ◽  
Age Related ◽  
The Complement System

Considering the fact that many retinal diseases are yet to be cured, the pathomechanisms of these multifactorial diseases need to be investigated in more detail. Among others, oxidative stress and hypoxia are pathomechanisms that take place in retinal diseases, such as glaucoma, age-related macular degeneration, or diabetic retinopathy. In consideration of these diseases, it is also evidenced that the immune system, including the complement system and its activation, plays an important role. Suitable models to investigate neuroretinal diseases are organ cultures of porcine retina. Based on an established model, the role of the complement system was studied after the induction of oxidative stress or hypoxia. Both stressors led to a loss of retinal ganglion cells (RGCs) accompanied by apoptosis. Hypoxia activated the complement system as noted by higher C3+ and MAC+ cell numbers. In this model, activation of the complement cascade occurred via the classical pathway and the number of C1q+ microglia was increased. In oxidative stressed retinas, the complement system had no consideration, but strong inflammation took place, with elevated TNF, IL6, and IL8 mRNA expression levels. Together, this study shows that hypoxia and oxidative stress induce different mechanisms in the porcine retina inducing either the immune response or an inflammation. Our findings support the thesis that the immune system is involved in the development of retinal diseases. Furthermore, this study is evidence that both approaches seem suitable models to investigate undergoing pathomechanisms of several neuroretinal diseases.

Evolution and age characteristics of the innate and adaptive immune system

2016 ◽  
Vol 75 (3) ◽  
pp. 74-84 ◽  
Author(s):  
A.E. Abaturov ◽  
◽  
E.A. Agafonova ◽  
N.I. Abaturova ◽  
V.L. Babich ◽  
...  
Keyword(s):  
Immune System ◽  
Adaptive Immune System ◽  
Adaptive Immune

scholarly journals Halting targeted and collateral damage to red blood cells by the complement system

2021 ◽  
Author(s):  
M. Jalink ◽  
E. C. W. de Boer ◽  
D. Evers ◽  
M. Q. Havinga ◽  
J. M. I. Vos ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Complement System ◽  
Blood Cells ◽  
Defense Mechanism ◽  
Standard Of Care ◽  
Complement Protein ◽  
Complement Inhibition ◽  
Complement Inhibitors ◽  
The Complement System ◽  
Patient Burden

AbstractThe complement system is an important defense mechanism against pathogens; however, in certain pathologies, the system also attacks human cells, such as red blood cells (RBCs). In paroxysmal nocturnal hemoglobinuria (PNH), RBCs lack certain complement regulators which sensitize them to complement-mediated lysis, while in autoimmune hemolytic anemia (AIHA), antibodies against RBCs may initiate complement-mediated hemolysis. In recent years, complement inhibition has improved treatment prospects for these patients, with eculizumab now the standard of care for PNH patients. Current complement inhibitors are however not sufficient for all patients, and they come with high costs, patient burden, and increased infection risk. This review gives an overview of the underlying pathophysiology of complement-mediated hemolysis in PNH and AIHA, the role of therapeutic complement inhibition nowadays, and the high number of complement inhibitors currently under investigation, as for almost every complement protein, an inhibitor is being developed. The focus lies with novel therapeutics that inhibit complement activity specifically in the pathway that causes pathology or those that reduce costs or patient burden through novel administration routes.

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