[Investigation of the complement system in clinical practice]

Véronique Frémeaux-Bacchi1, Marie-Agnès Dragon-Durey, Jacques Blouin

  • 1Service d'Immunologie Biologique, Hôpital Européen Georges-Pompidou, Assistance Publique-Hôpitaux de Paris, 20-40, rue Leblanc, 75908 Paris Cedex 15. veronique.fremeaux-bacchi@hop.egp.ap-hop-paris.fr

Annales De Medecine Interne
|March 24, 2004
PubMed

Insights

The complement system aids host defense and immune complex clearance. Measuring complement proteins like CH50, C3, and C4 is crucial for diagnosing and monitoring autoimmune diseases and deficiencies.

Area of Science:

  • Immunology
  • Clinical Medicine

Background:

  • The complement system is vital for host defense against pathogens and clearing immune complexes.
  • Deficiencies in complement proteins are linked to increased susceptibility to infections and autoimmune diseases.

Purpose of the Study:

  • To provide an overview of complement's medical applications.
  • To emphasize complement's role in disease pathogenesis.
  • To highlight the diagnostic utility of complement protein measurements.

Main Methods:

  • Review of complement system functions in immunity and disease.
  • Discussion of diagnostic assays for complement assessment.
  • Focus on practical applications and underlying disease mechanisms.

Main Results:

  • Complement system defects correlate with infections and autoimmune conditions.
  • CH50, C3, and C4 measurements are key for screening complement abnormalities.
  • Decreased complement levels often indicate consumption, while isolated CH50 absence suggests deficiency.

Conclusions:

  • Complement investigation is essential for diagnosing and managing autoimmune diseases.
  • Specific complement assays aid in identifying deficiencies and monitoring disease progression.
  • Understanding complement's role is critical for effective clinical management.

Related Concept Videos

Humoral Immune Responses01:36

Humoral Immune Responses

Overview
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Complement System01:27

Complement System

The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a membrane...
Urine Studies II: Urine Culture and Sensitivity Test01:26

Urine Studies II: Urine Culture and Sensitivity Test

A urine culture and sensitivity test is a diagnostic procedure used to identify urinary tract bacterial infections and determine the most effective antibiotics for treatment. This test is generally preferred when a patient shows manifestations of a urinary tract infection, such as frequent or painful urination, cloudy or foul-smelling urine, or lower abdominal pain.Purpose of the TestThe primary goals of a urine culture and sensitivity test are to:Determine the specific bacteria causing the...
Rapid Identification of Pathogens01:25

Rapid Identification of Pathogens

MALDI-TOF MS has transformed clinical microbiology by offering a rapid and reliable method for pathogen identification. The traditional approach to microbial identification typically involves time-consuming culture techniques and biochemical tests, which can delay the initiation of appropriate antimicrobial therapy. MALDI-TOF MS avoids these delays by using characteristic ribosomal protein mass patterns of microbial cells, enabling accurate species-level identification within minutes.Principle...
Hypersensitivity Reactions: Immune-Complex Reactions01:19

Hypersensitivity Reactions: Immune-Complex Reactions

Type III hypersensitivity reactions occur when antigen–antibody complexes form and activate the complement system. Normally, these complexes help the clearance of antigens by phagocytes and red blood cells. However, when large numbers of immune complexes are present, they can deposit in tissues—particularly in the walls of blood vessels—leading to inflammation and tissue injury. These deposits trigger complement activation and neutrophil recruitment, resulting in serum sickness, a systemic...