Mayo Clinic: Research from Mayo Clinic included in the November issue of JAMA Neurology identifies a new biomarker for brain and spinal cord inflammation, allowing for faster diagnosis and treatment of patients. Vanda Lennon, M.D., Ph.D., and colleagues identified the new biomarker in spinal fluid and blood serum of patients with a neurological disorder called autoimmune meningoencephalomyelitis. The biomarker is an antibody. Antibodies are molecules used by the immune system to fight infections or cancer. When an antibody is directed against healthy tissue by a misguided immune system, as it is in this disorder, it is called an autoantibody.
autoimmune meningoencephalomyelitis, the autoantibody targets a protein
called glial fibrillary acidic protein within cells called astrocytes
that are found in the brain and spinal cord.
“Headache is a prominent symptom reported by the patients,” says Dr.
Lennon, who is senior author on the study. “It is accompanied by
neurological findings of varying severity. Inflammatory cells in the
spinal fluid and MRI images raise suspicion for brain infection, other
inflammatory brain disease or a cancer spreading to the lining of the
Dr. Lennon notes that this disease rapidly reverses with therapy
directed at the immune system, such as prednisone, in contrast to
infections that need antibiotics and cancer that requires aggressive
treatment. A positive test for glial fibrillary acidic protein
autoantibody should bring the correct diagnosis earlier and hasten the
most appropriate treatment.
The glial fibrillary acidic protein antibody biomarker initially was identified in Mayo Clinic’s Neuroimmunology Laboratory,
which is within the Department of Laboratory Medicine and Pathology.
The biomarker was identified using a test developed in the 1960s. The
process involves applying a patient’s serum or spinal fluid to thin
sections of mouse tissues. If an autoantibody is present, it will stick
to the targeted tissue. After the serum or spinal fluid is washed off, a
probe in the form of another antibody is applied to the tissue to
detect any human antibody that remains bound to the tissue. The probe
antibody is tagged with a fluorescent dye. When viewed under a
fluorescence microscope, the tagged antibody shows the location of the
bound human autoantibody, revealing the cells targeted by the immune
system. In this case, the pattern of binding to mouse brain tissue
resembles the pattern of abnormalities seen in MRI images of the
patients’ brain and spinal cord.