In observational research, a multi-center team of investigators called the “Spanish Pediatric Anti-MOG Study Group” discovered that 85% of children in a study with life-threatening autoimmune conditions had complete or near complete recovery after a specific biomarker was identified and the patients were subsequently given the appropriate treatment. This discovery originating in Spain could accelerate the diagnosis and treatment of children with life threatening diseases. The study represents a milestone in the quest to understand MOG antibody-associated syndromes.

Background

In this observational multi-center study involving 535 children with central nervous system (CNS) demyelinating disorders and encephalitis, the group of life-threatening neurological conditions affecting children were linked to an antibody which points to potential treatment. The study was published in The Lancet Neurology journal.

The findings suggest that the myelin oligodendrocyte glycoprotein (MOG) antibody is associated with a wider range of life-threatening autoimmune conditions than previously thought, including neuromyelitis optica spectrum disorders and encephalitis, which cause severe neurological (brain and nervous system) symptoms such as vision loss, muscle weakness, and loss of coordination and speech.

The Study

The Spanish Pediatric Anti-MOG Study Group, a group of investigators from Spanish universities, conducted the observational, multi-center study including 535 children with CNS demyelinating disorders and encephalitis. 

In a bid to build substantial evidence the research team conducted a prospective study of children (median age 6) with suspected demyelinating syndromes (239 children) and encephalitis other than ADEM (296) attending 40 hospitals across Spain between June 1, 2013 and December 21, 2018. Participants who tested positive for MOG antibodies were assessed for clinical features, response to treatment (i.e. number of relapses) and outcomes over a median follow-up of 42 months.

The study team reported that of the 535 participants, 116 (22%) were found to be positive for MOG antibodies, including 94 (39%) with demyelinating syndromes and 22 (7%) with autoimmune encephalitis. Importantly, 24% (28/116) of these children had syndromes not previously associated with MOG antibodies.

Among the 64 patients with autoimmune encephalitis, MOG antibodies were the most frequent biomarkers—more common than all other neuronal antibodies combined suggesting that MOG antibody testing should be conducted when diagnosing children with suspected encephalitis after excluding infectious causes, particularly as these patients often respond favorably to immunotherapy treatment.

These findings suggest that younger children with MOG-antibody associated syndromes tend to present with clinical features of ADEM (an inflammatory condition that mainly affects the brain), while older children are more likely to have signs of optic neuritis (e.g. loss of vision, pain the eye) or myelitis (e.g. back pain, weakness in both legs).

During follow-up, 33 (28%) of 116 patients positive for MOG antibody disease had relapses. Most of these patients (99/116, 85%) recovered well. However, 17 (15%) experienced disease-related moderate to severe deficits, and one died due to their disease.

Investigator Comment

Dr. Gemma Olive-Cirera, co-author from Sant Joan de Deu Children’s Hospital, University of Barcelona, Spain that “Despite advances in diagnostic testing for encephalitis, up to have of cases have no clear cause. Our findings reveal that the spectrum of MOG antibody disease is broader than previously thought and includes autoimmune encephalitis as well as multiple demyelinating syndromes.” Dr. Olive-Cirera suggested that current classifications and terminology of MOG antibody-associated syndromes need to be updated based on this group’s research findings.

Limitations

The authors note several limitations, including that this was not a registry-based study, and therefore could not assess the incidence or prevalence of MOG antibody-associated syndromes, and that the follow-up was short, which could result in the frequency of relapses being underestimated.

Funding

The study was funded by a number of associations and foundations in Spain.

Lead Research/Investigators

·       Dr Thais Armangue from the Sant Joan de Deu Children’s Hospital, University of Barcelona, Co-study leader

·       Dr. Gemma Olive-Cirera, co-author from Sant Joan de Deu Children’s Hospital, University of Barcelona

·       Professor Josep Dalmau, the University of Barcelona, Co-lead Author

Other members of the Spanish Pediatric Anti-MOG Study Group can be viewed at the source.

Source: EurekAlert!

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