Serum neuronal, glial, and mitochondrial markers in autosomal dominant optic atrophy and Leber’s hereditary optic neuropathy

In this study, we investigated neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP), two biomarkers of neurodegeneration that have recently become easily measurable in serum due to the development of ultrasensitive digital immunoassay methods. Additionally, we analyzed growth/differentiation factor 15 (GDF-15), a well-established biomarker for primary mitochondrial diseases caused by defects in mitochondrial translation mechanisms and mitochondrial DNA integrity. Specifically, this study conducted a clinical and laboratory investigation to explore the hypothesis that individuals with Leber's Hereditary Optic Neuropathy (LHON) and Autosomal Dominant Optic Atrophy (ADOA) might exhibit differences in their pathogenic mechanisms. Serum levels of NfL, GFAP, and GDF-15 were assessed in a cohort of patients diagnosed with ADOA and LHON, and the clinical significance of these biomarkers was examined in relation to clinical impairment and optical coherence tomography (OCT) data. Serum NfL levels were found to be elevated in both ADOA and LHON patients compared to the control group. In contrast, serum GFAP levels showed a significant elevation only in ADOA patients. Conversely, GDF-15 levels were increased exclusively in LHON patients. Finally, no significant differences were observed when comparing the levels of the three biomarkers with OCT parameters and visual acuity data.