Immunoglobulin A (IgA)

General Information

Immunoglobulin A (IgA) Represents 10-15% of total immunoglobulins. IgA is the primary secretory antibody; It is found in tears, saliva, respiratory, gastrointestinal and urogenital secretions. In its dimeric form (IgA₂), it additionally contains two oligopeptide chains: one binding and one secretory (glycoprotein). IgA₂ is resistant to proteolytic action and participates in agglutination of bacteria, thereby preventing their penetration into mucous membranes.

Elevated IgA levels are found in lymphoproliferative disorders, especially in the case of multiple IgA myeloma and intestinal localization of "Mediterranean" lymphoma. An increase in IgA levels can be observed in many pathologies of the mucosal surface. Decreased IgA levels are observed in patients with chronic sinopulmonary disease, ataxia-teleangiectasia, and congenital deficiency. Some clinically significant IgA deficiency is accompanied by IgG₂ and IgG₄ deficiency.

Patients with congenital IgA deficiency are prone to autoimmune disorders and may develop antibodies to IgA, with the risk of anaphylaxis, even in the case of a single transfusion of IgA-containing blood;

When should I get tested for immunoglobulin A (IgA)?

• Assessment of humoral immunity;
• Monitoring of IgA myeloma treatment.
• Mediterranean lymphoma with intestinal localization.

In case of such symptoms as:

• Prolonged fever with night sweats;
• Bone pain;
• Spontaneous bone fracture;
• Swelling of the lymph nodes and others.

How to prepare for the test?

The test should be performed on an empty stomach.

Research material

Venous blood

Possible interpretation of the results

Concentrations of immunoglobulin A increase:

• IgA myeloma;
• cirrhosis of the liver;
• Obstructive jaundice;
• Alcoholism;
• Subacute and chronic infections;
• Systemic lupus erythematosus (in some patients);
• Sarcoidosis (in some patients);
• Viscot-Aldrich syndrome.

Immunoglobulin A concentration decreases:

• Ataxia-teleangiectasia;
• Chronic sinopulmonary disease;
• Abstinence from alcohol (after 1 year);
• Congenital deficiency;
• Dysgammaglobulinemia;
• Malabsorption (in some patients);
• Cirrhosis of the liver (sometimes);
• Style syndrome (sometimes);
• Recurrent otitis media (sometimes);
• Non-IgA myeloma;
• Waldenström's macroglobulinemia.

Concentrations of immunoglobulin A and other immunoglobulins decrease:

• Acquired and congenital agammaglobulinemia;
• Hereditary thymus aplasia;
• Type I and II dysgammaglobulinemia;
• In infants and early childhood.