Follow-up study on Chinese children with relapsing MOG-IgG-associated central nervous system demyelination.

BACKGROUND: Some studies have reported clinical features of relapsing MOG-IgG-associated CNS demyelination principally in Caucasians children. It is not clear whether Chinese children share the same phenotype.

OBJECTIVE: To delineate the clinical characteristics in Chinese children with relapsing MOG-IgG-associated demyelination.

METHODS: A follow-up study on 23 Children with relapsing MOG-IgG-associated demyelination from two Chinese tertiary hospitals was performed. Phenotypic features at each demyelinating attacks, neuroimaging characteristics, autoimmune antibodies in CSF/serum, response to disease modifying drugs and functional deficits during the disease course were analyzed.

RESULTS: The median age at disease onset was 5.38 (2.33-12.75) years. The male to female ratio was 1:1.30. The disease duration was 2.33(1.00-8.92) years at the last follow-up. (1) Clinical phenotypes: ADEM was the most common initial presentation (12/23, 52.17%). In 82 attacks during disease course, ADEM was also the most common phenotype (30/82, 36.59%), followed by ON (24/82, 29.27%). (2) Imaging findings: 57/70 (81.43%) brain MRI scans during acute attacks showed new lesions. The most common location of new lesions in brain was the juxtacortical white matter (45/57, 78.95%). In 46 brain MRI scans with supratentorial white matter lesions, ADEM-like patterns were most common (25/46, 54.35%), and 5/46 (10.87%) scans exhibited leukodystrophy-like patterns. (3) Laboratory examinations: Anti-NMDA receptor IgG in CSF was detected in two patients (2/12, 16.67%), with one patient presented with anti-NMDAR encephalitis associated symptoms. (4) Therapeutic responses and outcomes: In 19 patients treated with disease-modifying drugs (including rituximab, mycophenolate mofetil, azathioprine and so on) longer than 6 months, median annualised relapse rates decreased from 1.71 before treatment to 0.44 during treatment (P < 0.05), with eleven patients (11/19, 57.89%) having no relapses. Median EDSS score at the last follow-up was 1.0(0-3.5). Visual dysfunction (12/23, 52.17%) was the most common neurological sequela, with cognitive dysfunction and epilepsy in some of patients.

CONCLUSIONS: The phenotypic features of Chinese children with relapsing MOG-IgG-associated CNS demyelination were similar to that in Caucasian children. ADEM was the most common phenotype in all demyelinating attacks, followed by ON. Cerebral lesions were common and extensive, manifested as ADEM-like or even leukodystrophy-like patterns. Visual dysfunction was the most common neurological sequela. Although some disease-modifying drugs could reduce ARR, optimal treatment needs future study.