Candida albicans Antibodies, IgG

Candida albicans Antibodies, IgG (also reported as Anti-Candida albicans IgG or Candida antibodies, IgG) is used as an adjunct when evaluating suspected invasive candidiasis by assessing the organism-specific IgG response. Serial measurement may be used to monitor response to antifungal therapy in deep or disseminated candidiasis. The assay may also aid in assessing immune reactivity to yeast-like fungi within the Candida genus. Results require correlation with microbiology, tissue examination, molecular testing, imaging, and the overall clinical picture.

Candida albicans resides as a commensal organism but can cause disease when local or systemic immune defenses are impaired. Risk factors include immunosuppressive regimens, organ transplantation, corticosteroid exposure, radiation injury, broad-spectrum antimicrobial therapy, malignancy, and prolonged use of hormonal contraceptives. Metabolic and endocrine conditions such as diabetes mellitus and disorders of the thyroid or parathyroid may also contribute. Invasive infection can occur iatrogenically—for example, with intravascular catheterization or during cardiopulmonary bypass—with potential for hematogenous spread. Candidiasis is a common opportunistic infection in HIV, and certain manifestations are AIDS-defining. Serologic assessment is most informative when invasive disease is suspected. In many cases of invasive candidiasis, circulating IgG levels increase within approximately two weeks after onset and decrease with effective antifungal therapy. Absence of detectable antibodies does not rule out infection because humoral responses may be diminished in states of immunodeficiency. Low-level or elevated Candida-specific IgG can be present in healthy individuals due to commensal colonization; therefore, serial testing and integration with other laboratory and clinical data improve interpretation.