Clinical Characteristics of MOG and AQP associated Neuromyelitis Optica Spectrum Disorder (NMOSD) in Adults (S13.002)

Objective: To compare clinical characteristics of anti-MOG positive (MOG+) patients to anti-AQP4 positive (AQP4+) NMOSD patients. Background: Anti-MOG antibodies have been associated in a subgroup of NMOSD patients negative to anti-AQP4 antibodies. The clinical spectrum of anti-MOG associated disorders has not been completely elucidated. Design/Methods: Clinical data were obtained by semistructured questionnaires provided with serum samples sent to our laboratory for diagnostic purpose. The semistructured questionnaire contained the 2015 revised NMOSD diagnostic criteria. Samples were tested using a commercial IF-CBA for AQP4-antibodies and by FACS utilizing full-length MOG transfected cell line for MOG-antibodies. Results: 49 patients tested positive for AQP4 or MOG antibodies; no cross-reactivity was detected between MOG and AQP4 antibodies. 16 patients were MOG+ while 28 were AQP4+; 5 patients had MOG antibodies titres across the cut-off of positivity (MOG-borderline). Complete clinical data were available for 15 MOG+ and 15 AQP4+ and 4 MOG-borderline. 14 MOG+ presented with optic neuritis (isolated 6/14, recurrent 5/14). Three of them had associated myelitis, and 2 brainstem involvement; myelitis was present in 7 patients: 4 patients had LETM and 1 had cauda myelitis. Interestingly 1 patient was diagnosed having CLIPPER syndrome. 4 MOG-borderline had optic neuritis. AQP4+ presented with myelitis (LETM 5/8) associated with optic neuritis (4), while only 5 patients had isolated optic neuritis. 1 case presented with area postrema syndrome. Oligoclonal bands were not detected in CSF apart 1 MOG+. Conclusions: In our study population, isolated optic neuritis was the more frequent clinical presentation of MOG+, while myelitis/LETM were more frequent in AQP4+. No clear clinical differences at the time of diagnostic suspect are associated with MOG or AQP4 antibodies even if optic neuritis seems to be more frequent for MOG antibodies. AQP4 and MOG antibodies should be tested in NMOSD diagnosis suspect. MOG antibodies should be considered in future revision of NMOSD diagnostic criteria. Disclosure: Dr. Capobianco has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Almirall, Biogen, Novartis, Merck Serono, Roche, Sanofi Genzyme, TEVA. Dr. Sala has nothing to disclose. Dr. Marnetto has nothing to disclose. Dr. Valentino has nothing to disclose. Dr. Malucchi has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, TEVA, Merck Serono, Roche, Novartis, Sanofi Genzyme. Dr. Malentacchi has nothing to disclose. Dr. Sperli has nothing to disclose. Dr. Lo Re has nothing to disclose. Dr. Bertolotto has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Almirall, Biogen, Roche, Merck Serono, Novartis, Teva, Sanofi Genzyme, Mylan.