CPT® Code 83516

Immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semiquantitative, multiple step method

An immunoassay is a laboratory technique used to detect the presence of a specific chemical substance, known as an analyte, in a sample. This particular procedure, identified by CPT® Code 83516, is designed for the qualitative or semiquantitative assessment of analytes that are not related to infectious agents, meaning it does not focus on antibodies or antigens produced in response to infections. Instead, it targets various non-infectious substances that may indicate underlying health conditions. The immunoassay can be performed using a multiple-step method, which often enhances the accuracy and reliability of the test results. The range of conditions that can be evaluated through this testing includes, but is not limited to, celiac disease, which is an autoimmune disorder triggered by gluten; motor and sensory neuropathy, which affects the peripheral nervous system; Crohn's disease and other forms of inflammatory bowel disease, which cause chronic inflammation of the gastrointestinal tract; liver disease, which encompasses a variety of liver dysfunctions; and thyroid disease, which involves disorders of the thyroid gland. Specific examples of analytes that may be tested using this code include Asialo IgG and IgM, ganglioside IgG and IgM, and gliadin IgA and IgG. It is important to note that when multiple immunoglobulin classes or subclasses are tested, each one is reported separately. For instance, if both gliadin IgA and IgG are assessed, the code 83516 would be reported twice to reflect the testing of both substances. The qualitative aspect of the test indicates whether the analyte is present or absent, while the semiquantitative aspect provides an approximate measure of the analyte's concentration. This code is specifically utilized for tests employing a multistep method, distinguishing it from CPT® Code 83518, which is reserved for single-step methods like reagent strip tests.