Frequency of Spinal Cord Involvement and Autoantibody Status in a Large Cohort of Children Presenting with a First Acute Demyelinating Syndrome

Background: Transverse myelitis (TM) can be the presenting manifestation of different autoimmune-mediated diseases such as NMOSD, MS, MOG antibody associated diseases and other rare entities.

Objective: To characterize the clinical phenotype and antibody status (MOG-, AQP4-antibodies (abs)) of children presenting with transverse myelitis as part of their first acute demyelinating syndrome (ADS).

Material and Methods: From our BIOMARKER cohort of 902 children we identified 118 children who had clinical signs, laboratory and radiological evidence of transverse myelitis as part of their first demyelinating attack. 4 children were later diagnosed with GBS, neuroborreliosis or anti-NMDA-receptor encephalitis and were therefore excluded. 99 children had a complete data set including MOG-, AQP4-abs, CSF studies with cell count and/or OCBs and MRI of the entire neuro axis and were finally included in our study.

Results: 99 children (55 females, 44 males, mean age=9.25yrs, SD 5.21, range=8mo-17yrs) showed an involvement of the spinal cord as part of the ADS. We divided these patients into five groups: isolated TM (n = 15), isolated LETM (n = 31), ADEM plus TM/LETM (n = 17), MS plus TM/LETM (n = 20) and TM as part of NMOSD (n = 16). In 32/99 (32%) MOG-abs were tested positive. MOG-abs were predominantly found in children presenting with ADEM plus TM/LETM (n = 14; 82%), NMOSD (n = 6; 38%) and isolated LETM (n = 11; 35%). MOG-abs were found in only 1 child with isolated TM (7%). None of the patients diagnosed with MS presenting with TM/LETM were MOG-abs positive. AQP4-abs were found in 7 children with NMOSD. OCBs were tested positive in 28/99 children (28%). The majority of children fulfilling the McDonald criteria 2017 for MS presenting with TM/LETM were positive for OCBs (17/20; 85%). Children with MOG-abs and involvement of the myelon were only rarely positive for OCBs (4/32; 13%). Average CSF cell count was 67 cells/µl (range=0–1500 cells/µl). The group of children with isolated LETM showed the highest average with 118 cells/µl (range=1–1500 cells/µl). MOG-abs positive children had an average cell count of 85 cells/µl (range=0–331 cells/µl) while MOG-abs negative children had an average of 58 cells/µl with a much broader range (0–1500 cells/µl).

Interpretation: Our results show that a high number of children with a first ADS also presented with an involvement of the spinal cord and that a substantial number of these patients were tested MOG-abs positive. Especially children diagnosed with ADEM in combination with an inflammation of the spinal cord were associated with positive MOG-abs results. Therefore, MOG-abs testing should be considered in every child presenting with a first ADS and may be helpful in distinguishing between different diagnoses.