Complement – Laboratory Test Ranges | Reference

Complement – Laboratory Test Ranges | Reference

Components of the complement system.

Reference range

C3, g/L

C4, g/L

  • 1 months
  • 3 months
  • 0,5
  • 1,0
  • 1 months
  • 3 months
  • 0,12
  • 0,36
  • 4 months
  • 12 months
  • 0,7
  • 1,2
  • 4 months
  • 12 months
  • 0,15
  • 0,44
  • 12 months
  • 24 months
  • 0,6
  • 1,4
  • 12 months
  • 24 months
  • 0,13
  • 0,37
  • 24 months
  • 5 years
  • 0,7
  • 1,1
  • 24 months
  • 5 years
  • 0,19
  • 0,31
  • 6 years
  • 8 years
  • 0,6
  • 1,6
  • 6 years
  • 8 years
  • 0,18
  • 0,38
  • 9 years
  • 11 years
  • 0,6
  • 1,1
  • 9 years
  • 11 years
  • 0,14
  • 0,27
  • 12 years
  • 16 years
  • 0,6
  • 1,1
  • 12 years
  • 16 years
  • 0,14
  • 0,27
Female > 16 years
  • 0,76
  • 1,81
Female > 16years
  • 0,13
  • 0,52
Male > 16 years
  • 0,76
  • 1,64
Male > 16 years
  • 0,12
  • 0,49

Increased C3.

Acute-phase reaction:

  • rheumatoid arthritis, rheumatism;
  • diabetes;
  • myocardial infarction;
  • obstructive jaundice (hepatitis);
  • ulcerative colitis;
  • tumor;
  • goiter;
  • bacterial infection;
  • pneumococcal pneumonia;
  • sarcoidosis;
  • amyloidosis;
  • thyroiditis;
  • inflammatory bowel disease;
  • fever;
  • pneumococcal pneumonia.

Decreased C3:

congenital deficiency of C3 regulatory proteins factors H and I.

acquired deficiency:

  • AIDS;
  • autoimmune hemolytic anemia;
  • acute glomerulonephritis;
  • disseminated intravascular coagulation;
  • systemic lupus erythematosus;
  • malaria;
  • starvation;
  • increased intake of various inflammatory and
    Infectious diseases: subacute bacterial endocarditis,
    viremia, parasitemia and bacterial sepsis;
  • partial lipodystrophy and membranoproliferative proliferative
    glomerulonephritis in the presence of autoantibodies C3 nephritic factor;
  • severe liver damage;
  • drugs: cyclophosphamide (patients with SLE), danazol.

Increased C4:

congenital deficiency:

  • the presence of more than four C4 allele;
  • deficit components C1q, C1r, C1s.

acquired deficiency:

  • rheumatoid arthritis;
  • bacterial infection, bacterial endocarditis;
  • glomerulonephritis;
  • systemic lupus erythematosus;
  • malaria;
  • cryoglobulinemia;
  • sepsis;
  • acute-phase inflammatory response;
  • drugs: cimetidine (in patients with AIDS), cyclophosphamide (patients with SLE), danazol.

Decreased C4:

congenital deficiency:

  • C4 deficiency newborns;
  • hereditary angioedema;

acquired deficiency:

  • rheumatoid arthritis;
  • hereditary and acquired angioedema;
  • complement activation due to immune diseases
    complexes;
  • glomerulonephritis;
  • systemic lupus erythematosus;
  • rheumatoid arthritis;
  • respiratory distress syndrome;
  • autoimmune hemolytic anemia;
  • starvation;
  • sepsis;
  • autoimmune thyroiditis;
  • cryoglobulinemia;
  • kidney transplantation;
  • systemic vasculitis;
  • liver damage.