Patients with neuromyelitis optica spectrum disorder (NMOSD) could be particularly at risk for developing certain autoimmune and endocrine disturbances, according to a study recently published in the Journal of Neurological Sciences.
“Patients with NMOSD are likely to have Sjögren’s syndrome (SS), syndrome of inappropriate antidiuretic hormone secretion (SIADH), and central diabetes insipidus (DI). Renal tubular acidosis (RTA) in SS does not facilitate the overlap between NMOSD and SS. SS in NMOSD may predispose patients to DI,” the authors wrote.
Read more about NMOSD comorbidities
This retrospective cross-sectional observational study aimed to understand the overlap between various disorders among the population of Japan. The study period stretched from April 1, 2020, to March 31, 2021, and involved more than 30 million individuals who visited the participating DPC-covered hospitals. The researchers focused on specific conditions, including SS, RTA, and other related electrolyte disorders.
One of the key findings of this study was the substantial overlap between NMOSD and SS. The prevalence of NMOSD was approximately 20 times higher in patients with SS than those without it. Interestingly, this overlap was more prominent among younger age groups, indicating that the linkage between these 2 conditions might not be coincidental but rather driven by shared mechanisms.
However, the presence of RTA alongside SS did not contribute to a higher prevalence of NMOSD, suggesting that electrolyte imbalances or acidosis may not be the common mechanisms underlying these disorders. The study hypothesized that the cross-reactivity of antibodies against different aquaporin proteins might explain the overlap between NMOSD and SS.
Another significant finding is the greater prevalence of SIADH and DI among patients with NMOSD compared to the general population.
“Studies with detailed data regarding the chronological time course of the onset of each condition and the start of medications affecting the serum electrolyte levels are needed to elucidate the relationships between NMOSD, SS, and other conditions related to serum osmotic and electrolytic disturbances,” the authors concluded.
Akaishi T, Tarasawa K, Matsumoto Y, et al. Associations between neuromyelitis optica spectrum disorder, Sjogren’s syndrome, and conditions with electrolyte disturbances. J Neurol Sci. Published online July 24, 2023. doi:10.1016/j.jns.2023.120742