CPT® Code 86363

Myelin oligodendrocyte glycoprotein (MOG-IgG1) antibody; flow cytometry (ie, fluorescence-activated cell sorting [FACS]), each

The CPT® Code 86363 refers to the testing for Myelin oligodendrocyte glycoprotein (MOG-IgG1) antibodies using flow cytometry, specifically fluorescence-activated cell sorting (FACS). MOG-IgG1 antibodies are associated with a condition known as Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD), which is classified as an idiopathic inflammatory demyelinating disease affecting the central nervous system (CNS). This disease is characterized by the presence of antibodies that target the myelin oligodendrocyte glycoprotein, a protein found in the oligodendrocytes of the CNS. The presence of these antibodies can aid in the diagnosis of MOGAD and help differentiate it from other demyelinating diseases such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). MOGAD can present with symptoms similar to those of MS and NMOSD, including optic neuritis and transverse myelitis, but it has distinct features, treatment responses, and generally a better prognosis. The testing process involves collecting a venous blood sample from the patient, which is then analyzed using flow cytometry techniques. FACS is a specialized method that allows for the sorting of individual cells based on their characteristics, particularly their fluorescence. In this procedure, human embryonic kidney (HEK) cells are genetically modified to express a green fluorescent protein (GFP) tagged version of MOG-IgG1. When the patient's serum is introduced, any MOG-IgG1 antibodies present will bind to these modified cells. A secondary anti-human antibody, which is conjugated with fluorescein isothiocyanate, is then added to facilitate the detection of the bound antibodies. As the cells pass through a laser beam, their fluorescence is measured, allowing for the identification and separation of cells that are positive for the MOG-IgG1 antibody. This process may also include further titration studies to determine the dilution factor at which the specific fluorescence remains detectable, providing a semi-quantitative result for the presence of the antibody.