The serological test for Candida involves blood testing for the presence of specific antibodies against the yeast Candida. A blood test for antibodies of all classes of IgG, IgA, IgM, and IgE is sometimes needed to confirm the current or even past infections of Candida albicans. In addition, hematological testing of antibodies can be used to monitor therapeutic intervention against the yeast.
What tests does the Candida antibody test include?
IgG antibodies are the predominant antibodies formed during secondary exposure to Candida and reflect past or ongoing infection. IgG antibodies are produced when IgM antibody levels decrease after initial (primary) exposure. IgG antibodies activate the complement and help the phagocytic system to eliminate antigens from the extravascular space. IgG antibodies represent the major class of human immunoglobulins and are evenly distributed in both intravascular (blood serum) and extravascular fluid. Specific IgG antibodies can be detected for many years after the elimination of the infection.
IgA antibodies are found in mucous secretions and are important for local mucosal immunity. Although they represent only 15-20% of human immunoglobulins in serum, they are the predominant class of antibodies in seromucous secretions. High levels of specific serum IgA antibodies against Candida are thought to be associated with Candida infections of the mucous membranes of the gastrointestinal, respiratory, and urogenital tract.
IgM antibodies are the first antibodies to form after the primary exposure to the yeast. IgM immunoglobulin directly activates the complement and helps the phagocytic system to eliminate the antigen from the endovascular space. IgM antibodies are confined to the intravascular space and are considered to be the predominant immunoglobulins in primary infections. Often, during re-infections, IgM antibody levels may not be as high as in primary infections.
IgE antibodies are responsible for the development of allergic reactions to Candida. The yeast Candida, in addition to the human body, is also found in the environment, in the soil, and where there are organic residues as well as in the air from the secretions of other humans or animals. This can cause allergic reactions even from inhaling the yeast.
Predisposing factors that may create favorable conditions for the development of acute and chronic candidiasis include trauma (infection), surgery, the presence of underlying diseases (diabetes, Addison's disease), taking medications (corticosteroids, antibiotics, contraceptives), in cases of immunodeficiency and during pregnancy. It is more common in the elderly and children, while malnutrition and bad food habits are also predisposing factors.
