In clinic, some people often suffer from repeated allergies, eczema and other respiratory tract infections or other site infections. In this case, besides routine examinations such as white blood cells, immunoglobulin series, lymphocyte subsets and so on, five tests of immunoglobulin and complement (IgG, IgA, IgM, C3, C4) should also be examined.
However, many people have done this test on the advice of doctors, but do not know or not know its role and clinical significance?

Immunoglobulin G (IgG)

Reference value: Normally, adults are 6-16 g/L.
Increase: IgG multiple myeloma, rheumatoid arthritis, systemic lupus erythematosus, kala-azar, chronic hepatitis and some infectious diseases.
Reduction: nephrotic syndrome, autoimmune disease, primary non-gamma globulinemia, secondary immunodeficiency and some tumors.

Immunoglobulin A (IgA)

Reference value: Under normal conditions, adults are 760-3900 mg/L.
Increase: multiple myeloma IgA, rheumatoid arthritis, systemic lupus erythematosus, cirrhosis, eczema, thrombocytopenia and some infectious diseases.
Reduction: hereditary or acquired antibody deficiency, immunodeficiency, selective IgA deficiency, non-gamma globulinemia, protein loss bowel disease, burns, anti-IgA antibody syndrome, immunosuppressive therapy, late pregnancy, etc.

Immunoglobulin M (IgM)

Reference value: Under normal conditions, adults are 400-3450 mg/L.
Increase: fetal intrauterine infection, neonatal TORCH syndrome, chronic or subacute infection, malaria, infectious mononucleosis, Mycoplasma pneumonia, liver disease, connective tissue disease, macroglobulinemia, asymptomatic monoclonal IgM disease, etc.
Reduction: hereditary or acquired antibody deficiency, mixed immunodeficiency syndrome, selective IgM deficiency, protein loss bowel disease, burns, anti-Ig antibody syndrome (mixed cryoglobulinemia), immunosuppression, etc.

Complement C3, C4

Reference value: Under normal conditions, the content of C3 (beta 1C-globulin) and C4 (beta 1E-globulin) in human blood were 80-1550 mg/L and 130-370 mg/L respectively. The content and activity of blood complement will change under many pathological conditions, so the level of complement should be dynamically observed in clinic.
Increase: various inflammatory diseases, obstructive jaundice, acute myocardial infarction, ulcerative colitis, diabetes mellitus, acute gout, acute thyroiditis, acute rheumatic fever, dermatomyositis, polymyositis, mixed connective tissue disease, nodular periarteritis, etc.
Reduction: Immune impairment or immunodeficiency; in ischemia, coagulative necrosis and toxic necrosis, tissue releases more proteolytic enzymes, resulting in decreased complement hemolysis activity and complement grouping.