The S-IgE test checks the levels of antibodies called immunoglobulins in your bloodstream. Antibodies are proteins made by your immune cells to fight off pathogens like bacteria, viruses, and mold but also to food proteins. The immunoglobulin test can show whether there's a problem with your immune system.
IgE antibodies are generally related to allergic reactions. Newer research is also supporting IgE as a biomarker in oncology.
Read more about the S-IgE blood test.