Neuronspecific Enolase (NSE)

General Information

Enolase (or phosphopyruvate hydratase) is a glycolytic enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenol pyruvate. With this reaction, glucose is broken down into 2 molecules of pyruvate, the further conversion of which gives a high-energy phosphate substrate (involved in energy production).

Enolase exists in several dimeric isomers, and each of them contains 3 immunologically distinct subunits: α, β, and γ. The alpha subunit of enolase is found in various mammalian tissues. The beta subunit is found in cardiac and skeletal muscle. αγ and γγ isoforms represent neuron-specific or γ-enolase and are found in large amounts in neurons, neuroendocrine cells and tumors arising from these cells.

Therefore, neuron-specific enolase is an important marker in the process of monitoring neuro-endocrine tumors, especially neuroblastomas and small cell lung cancer.

When is the survey conducted?

Research is important for monitoring neuro-endocrine tumors and evaluating the evolution of the disease.

Absolute testimony is: In neuroblastomas and small cell lung cancer

An additional diagnostic method is: In medullary tumors of the thyroid gland.

Lung squamous cell carcinoma In 61-80% of cases, the level of neuron-specific enolase is increased. There is no correlation (correlation) between the marker rate and the presence of metastases in the brain, although the rate correlates with the clinical stage. Lack of response to chemotherapy is associated with robust and persistent elevation of neuron-specific enolase. During periods of remission of the disease, in 80-96% of cases, the normalization of the marker index is observed. Determination of neuron-specific enolase is very informative together with other markers: Pro-gastrin-releasing peptide, Carcinoembryonic antigen CEA,  ცItokeratin fragment19 CYFRA.

Neuron-specific enolase has a positive prognostic value in 92% of cases.

Neuroblastomas In 62% of cases, an increase in the level of neuron-specific enolase was found, which also correlated with the clinical stage of the disease.

Patient preparation - no need

Research material -  Venous blood

Referral norm – <16.3 ng/ml

Interpretation of results

Determination of neuron-specific enolase is not used to screen for cancer in asymptomatic patients. Elevated levels may be found in some meningiomas, gliomas (brain tumors) and kidney carcinomas.

Neuron-specific enolase may be elevated in some benign brain and lung tumors.

With some pathologies and conditions, it is possible that the results of the study are inconclusive:

• Hemolysis - since erythrocytes contain enolase, it is possible to increase its level during hemolysis (eg, in anemia)
• Treatment with high dose biotin (>5 mg/day) - It is recommended that material be collected for the study at least 8 hours after the last dose of biotin.
• High titer of antinuclear auto-antibodies (anti-SSA, anti-RO).
• Administration of monoclonal antibodies into the body for diagnostic or therapeutic purposes.