The prevalence of dual-positive neuromyelitis optica spectrum disorder (NMOSD) is 0.15% in South Asia, according to a new study published in the journal Multiple Sclerosis and Related Disorders. The disease’s clinical phenotype is more similar to neuromyelitis optica rather than myelin oligodendrocyte glycoproteins (MOG)-associated disease, the study also reported.
Patients with NMSOD are either positive for antiaquaporin 4 (AQP4) or antiMOG antibody. However, dual positivity is rare, the researchers noted.
Read more about the types of NMOSD
To assess the prevalence of dual-positive NMOSD in South Asia, a team of researchers from Amrita University in Kochi, Kerala, India, led by Suprabha Panicker, conducted a retrospective cross sectional study at a tertiary healthcare center between August 2018 and November 2021. The researchers tested serum and/or cerebrospinal fluid levels of both antiAQP4 and antiMOG antibodies in 1935 patients with suspected NMOSD.
The results showed that 65 patients (3.35% of all tested cases) were positive for antiAQP-4 antibody, while 217 patients (11.21% of all tested cases) were positive for antiMOG antibody. Only 3 patients (0.15% of all tested cases) were positive for both antibodies.
The proportion of female patients was superior in all 3 groups, with 87.69%, 56.22%, and 66.66%, respectively.
The researchers also reported the clinical features of the 3 patients who were dual positive as well as their medical management.
“Management using methylprednisolone was ineffective for all 3 patients,” the study team wrote.
“However, plasmapheresis and/or periodic rituximab injections produced an excellent response,” they continued.
NMOSD is a rare and chronic inflammatory disease of the central nervous system. In antiAQP-4 antibody-positive disease, autoantibodies mistakenly attack the AQP-4 water channel found on astrocytes and ependymal cells in the central nervous system, while in antiMOG antibody-positive disease, the body makes autoantibodies against MOG.
Lalwani CS, Faisal F, Yadav A, et al. The prevalence and clinical phenotype of dual seropositive neuromyelitis optica spectrum disorders at a national reference center in South Asia. Mult Scler Relat Disord. Published online April 29, 2023. doi:10.1016/j.msard.2023.104736