Some patients with neuromyelitis optica spectrum disorder (NMOSD) have antiargonaute antibodies in their blood, a new study published in the Journal of Neurology, Neurosurgery & Psychiatry found. In some cases, these are the only autoantibodies present in the blood and could potentially be a novel biomarker for the disease.
“Their presence is associated with a myelitis phenotype and a severe disease course,” the researchers wrote.
The most common autoantibodies present in the blood of patients with NMOSD are antiaquaporin-4 (AQP-4) antibodies. This is followed by antimyelin oligodendrocyte glycoprotein (MOG) antibodies. Antiargonaute antibodies were only recently reported as a potential biomarker in patients with neurological disorders.
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Read more about the etiology of NMOSD
In the present study, a team of researchers from France investigated whether antiargonaute antibodies could be detected in the blood of patients with NMOSD and if they could have any clinical use.
The team prospectively analyzed 104 patients who were referred to their center with suspected NMOSD. They tested anti-AQP-4, anti-MOG, and anti-argonaute antibodies using cell-based assays.
The results showed that 43 patients were positive for anti-AQP-4 antibodies, 34 were positive for antiMOG antibodies, and 27 were negative for both antibodies.
A small percentage of the patients (6.7%) were positive for anti-argonaute antibodies, and most of them were also positive for anti-AQP-4 antibodies.
The median age at which symptoms of the disease appeared in these antiargonaute-positive patients was 37.5 years. Most of these patients exhibited transverse myelitis at the onset of the disease.
One patient experienced diencephalic syndrome at onset and transverse myelitis at follow-up. One patient also had polyradiculopathy.
The median Expanded Disability Status Scale (EDSS) scores of these patients were 7.5 at disease onset and 4.25 at the last evaluation, with a median follow-up of 40.3 months.
The researchers concluded that anti-argonaute antibodies could be a potential biomarker in NMOSD and may indicate a severe disease course.
Argonaute is a protein that plays a crucial role in gene silencing following translation and small RNA biogenesis.
Reference
Carta S, Le Duy D, Rogemond V, et al. Anti-argonaute antibodies as a potential biomarker in NMOSD. J Neurol Neurosurg Psychiatry. Published online February 21, 2023. doi:10.1136/jnnp-2022-33070
