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Complement Deficiencies Publisher



Shariat M1 ; Heydrzadeh M2 ; Abolhassani H3, 4 ; Bemanian MH5 ; Yazdani R6, 7
Authors
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Authors Affiliations
  1. 1. Department of Immunology and Allergy, Pediatrics Center of Excellence, Children's Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran
  2. 2. Department of Immunology and Allergy, Kashan University of Medical Sciences, Kashan, Iran
  3. 3. Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
  4. 4. Research Center for Immunodeficiencies, Children’s Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran
  5. 5. Department of Allergy & Clinical Immunology, Hazrat Rasoul Hospital, Iran University of Medical Sciences, Tehran, Iran
  6. 6. Research Center for Immunodeficiencies, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran
  7. 7. Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran

Source: Inborn Errors of Immunity: A Practical Guide Published:2021


Abstract

The complement system is important for both innate and adaptive immune system function. A network of at least 30 proteins (in the blood and cell-membrane bound) compose complement system. These proteins play major roles in inflammation, immune complex clearance, induction of a normal humoral immune response, and clearance of apoptotic cells. It is important to mention that several proteins regulate complement-mediated damage. The complement system is activated in three main pathways. This chapter has provided an insight to approach to defects in three main categories of complement deficiency affecting the classical pathway, alternative pathway and lectin pathway. All three pathways have one thing in common which is the activation of the C3 complement component. The clinical features of complement deficiencies are diverse because of the deficiency of any specific component and the pathway associated with autoimmune diseases, predisposition to bacterial infections, angioedema and atypical hemolytic uremic syndrome (aHUS). © 2021 Elsevier Inc. All rights reserved.