Introduction: MOG-Abs are found in children with ADS but their significance is not clear.

Method: Acute serum samples from 66 children with first episode ADS (12 ADEM, 24 optic neuritis, 18 transverse myelitis, 12 other CIS) were tested for MOG-Abs by cell-based assay. MOG-Abs and oligoclonal bands (OCBs) were used in a classification and regression decision tree analysis (RDTA) to predict progression to MS at one year.

Results: 24/66 (36%) children had MOG-Abs. When compared to the MOG-Abs negative group (n=32), the positive patients presented with ON (50% vs 29%), TM (17% vs 33%), ADEM (17% vs 19%) or other CIS (17% vs 19%). CSF OCB positivity at onset was higher in the MOG-Abs negative group (14/35 vs 1/17, p=0.011).  Subsequently 16 MOG-Ab negative patients were diagnosed with MS (15 clinical, 1 radiological) compared to 3 positive patients (2 clinical, 1 radiological) (p=0.046).  In the RDTA model, a positive test result (negative MOG-Ab with positive OCB) resulted in positive likelihood ratio of 11.0 (95% CI 2.7-45) for development of MS, whereas a negative test result (positive MOG-Ab, or negative MOG-Ab with negative OCB) resulted in a negative likelihood ratio of 0.44 (95% CI 0.26 to 0.76).

Conclusions: MOG-Abs are found at presentation in 36% of patients with childhood ADS, across a range of demyelinating disorders.  When combined with negative OCB results they help to distinguish those children who will not develop MS from those who have negative MOG-Abs and positive OCBs and are at high risk.