【Precision Medicine】Neuromyelitis Optica NMOSD blood test is a two-pronged approach to strengthen the basis for treatment

What is Neuromyelitis Optica Spectrum Disorder?

Neuromyelitis generalis NMOSD was published in 1884 by Eugène Devic in 17 cases (one of which was Devic himself) with fatal optic neuritis and myelitis comorbidities, so it is also known as Devic’s syndrome, which is a rare and severe autoimmune central nervous system inflammatory disease. Due to the imbalance of the immune system, patients produce autoimmune antibodies to attack the central nervous system cells in the body, mainly invading the optic nerve, spinal cord and brain.

If NMOSD invades the optic nerve, patients often develop color blindness, deterioration of vision, visual field defects, and eye pain in a short period of time. If it invades the spinal cord, it will cause mobility disorders, sensory disorders, bladder dysfunction, mild limb paralysis, pain, severe incontinence, and even paralysis or loss of self-care ability.^[1]

epidemiology

The global incidence rate is approximately 0.039-0.73 per 100,000 person-years per year, and the incidence rate for those under 18 years of age is about 0.01-0.06 per 100,000 person-years per year.^[2]
Previous studies have shown that the prevalence rate in Japan is about 3.42 per 100,000 people, Malaysia is 1.94 per 100,000 people, and South Korea is 2.56 per 100,000 people^[3], while another study has shown that the average prevalence rate in East Asia such as Japan, South Korea, and China is about 3.5 per 100,000 people^[4].

In recent years, the number of people suffering from the disease in Taiwan has also increased, but due to the fact that it is a rare disease, the prevalence rate in the 2011-2015 survey was about 1.47 per 100,000 people ^[5].

It is more common in women, and four studies conducted in different countries have found that the incidence in women is about 2.27 to 9.8 times that of men ^[6].
The average age of onset ranges from 35 to 45 years ^[6], although studies have suggested that there is still a risk in those over 60 years and under 18 years of age.

Core clinical features

Because the disease occurs in the central nervous system and does not necessarily target a specific part of the disease, the following symptoms are common:

Optic neuritis: vision loss in one or both eyes at the same time in a short period of time, eye pain
Acute myelitis: weakness of the limbs, bladder dysfunction, incontinence
Acute brainstem syndrome: unexplained hiccups, nausea, or vomiting
Symptomatic narcolepsy, acute diencephaly clinical syndrome, and typical NMOSD diencephaly lesions
Symptomatic cerebral syndrome with typical NMOSD brain lesions

The symptoms of NMOSD are usually severe, the recovery period is long, and the recurrence rate is very high, and in severe cases, it is easy to lead to permanent disability or neurorespiratory failure and death.

Irreversible, highly recurrent! Early detection is the key to proper treatment

NMOSD is easily confused with multiple sclerosis, but the two are completely different diseases, with different pathogenic mechanisms and different treatments, and if the wrong treatment is used, it may not only be ineffective but may increase the number of acute attacks.

It is important to show an accurate diagnosis.

Clinical Standard Diagnostic Procedures:

Core clinical features
Serological test results of AQP-4 antibody
MRI imaging features and observation of neuropathy can be used to make a correct diagnosis

The two-stage serological test greatly improves the accuracy of disease diagnosis
Give out-of-pocket patients an option to ease their burden

Because the clinical features may be confused with multiple sclerosis (MS), serologic testing for AQP-4 antibodies is added clinically.

However, there is a possibility of false negatives due to serologic test results.

Clinically, it will enter the third step, allowing patients to use MRI testing at their own expense, but the high cost and the need for part-by-site testing may make some patients hesitate and cause a delay in the timing of treatment.

At present, the second test option for patients is to use a second serological test for MOG antibodies, if the AQP-4 antibody is negative but the MOG antibody is positive, it can also help the doctor to confirm the diagnosis and provide accurate treatment in the future.

Compared with MRI testing, the two-pronged testing of AOP-4 antibody and MOG antibody can improve the accuracy of the disease at a more affordable cost for patients.

The earlier the treatment of NMOSD, the more it can not only reduce the damage to the organs, but also greatly reduce the risk of disease progression, which has a positive impact on the prognosis and quality of life. Therefore, early symptom detection and double serological testing procedures are essential, and the financial burden is relatively easy for patients.

This article cites information:

[1] Taiwan Neuroimmunological Medical Association. September 2022. Panoptic neuromyelitis. Published by Taiwan Neuroimmunology Association.

[2] Papp V, et al. Neurology. 2021; 96:59-77.

[3] Tian DC, et al. Lancet Reg Health West Pac. 2020; 2:100021.

[4] Hor JY, et al. Front Neurol. 2020; 11:501.

[5] Fang CW, et al. Mult Scler Relat Disord. 2020; 45:102425.

[6] Etemadifar M, et al. Mult Scler Int. 2015; 2015:1-8.