The determination of IgA antibodies in the Vitrotest® Total-IgA immunodiffusion kit is based on the immunoprecipitation reaction. Immunoglobulins of the test serum diffuse in a semi-solid agar gel containing immune polyclonal serum and form a precipitation ring when equivalent concentrations are reached. The diameter of the ring depends on the concentration of IgA. Comparison with the control allows to determine the concentration of immunoglobulins in the tested serum.
○ TK101 – 70 tests
- Immunodiffusion medium – ready-to-use agar gel with wells containing highly specific immune serum to human IgA.
- Control – a mixture of purified polyclonal antibodies of classes G, A, and M of human with known concentrations.
- Sample volume for analysis – 3 µL.
- Analysis time – 24 hours.
Immunoglobulins (antibodies) are a group of glycoproteins found in the blood plasma and tissue fluid of mammals. Five classes of immunoglobulins are found in humans – IgG, IgA, IgM, IgD, and IgE – which differ in molecular size, charge, and carbohydrate content.
IgA presents in two forms – serum and secretory, in serum comprise up 15% of all immunoglobulins, and can be both in monomeric form and as a dimer. Its concentration in normal ranges from 0,8 to 3,0 g/L. Serum immunoglobulin A can activate complement in an alternative pathway and neutralize microbes and toxins circulating in the blood, but its action is weaker than secretory IgA.
Secretory IgA neutralizes bacterial toxins, localizes viruses, and stimulates phagocytosis, providing local resistance to infection. An increased IgA concentration is observed in many inflammatory diseases: acute and chronic bacterial, fungal, parasite infection, chronic liver disease, and cirrhosis. A reduced IgA level is observed at physiologic hypogammaglobulinemia in children (at the age of 3-5 months), congenital hypogammaglobulinemia or agammaglobulinemia, neoplasms of the immune system, treatment with cytostatics and immunosuppressants.
To determine the content of total human IgA in diagnostic laboratories, the radial immunodiffusion (RID) method is widely used, which is considered the standard for measuring of different classes immunoglobulins in human serum and plasma.