Cerebrospinal fluid ATP as a potential biomarker in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke like episodes (MELAS).

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is caused by defective oxidative phosphorylation in the cerebral parenchyma, cerebral blood vessels, and leptomeningeal tissue. Although increased blood and cerebrospinal fluid (CSF) lactate level has been used as a diagnostic biomarker in patients with MELAS, no biomarkers reflecting disease activity exist. Since we have developed a highly sensitive ATP assay system using luciferase luminous reaction, we examined CSF ATP in patients with MELAS and found that it negatively correlates with disease activity and that it reflects the efficacy of the treatment. CSF ATP might be a novel disease monitoring marker for MELAS.