| Background |
Enolases are glycolytic enzymes that catalyze the conversion of 2-phosphoglycerate into phosphoenolpyruvate. This catalysis is dependent on two Mg2+ ions bound to the catalytic active site of the enolase. Vertebrates express three different enolase isoforms that consist of three different monomeric units forming either homo- or heterodimers. As NSE is normally expressed in a tissue-specific manner, an increased NSE concentration in serum or cerebrospinal fluid concentration often indicates neuronal damage or malignancies. In clinical diagnostics, NSE is thus a widely used marker for neuroendocrine tumors (NETs), including neuroblastoma and small-cell lung cancer (SCLC). NSE level in bodily fluids has been reported to correlate with extent of disease and response to treatment, allowing the marker to be used as a tool for diagnosis, prognosis, as well as treatment follow-up. Identification of NSE in cord blood allows early postnatal confirmation of neuroblastoma diagnosis in newborn babies. Besides cancer, increased NSE may also reflect the presence other conditions, such as brain damage, cerebral accidents, myocardial infarctions, Guillain-Barré syndrome, or CreutzfeldtJakob disease. Hemolysis can occasionally cause false positive test results, because erythrocytes also contain NSE. |
