The Danish National Epidemiology of Neuromyelitis Optica Spectrum Disorders Based On the 2015 International Panel for NMO Diagnosis (IPND) Criteria (P1.138)

Objective: A retrospective nationwide population-based study in collaboration with all 14 departments of neurology in Denmark to evaluate the epidemiology of NMOSD using 2015 IPND criteria. Background: Few studies estimated the population-based epidemiology of NMOSD, and only one used the recent 2015 IPND criteria. Design/Methods: Target group: (I) patients identified with optic neuritis, transverse myelitis or neuromyelitis optica in the Danish National Patient Register; (II) multiple sclerosis patients with onset of optic neuritis or transverse myelitis registered in The Danish Multiple Sclerosis Registry; (III) patients who were tested for anti-APQ4 antibodies between 01.01.2007 and 31.12.2014 at Danish laboratories were re-evaluated. Final validation of cases with the potential diagnosis of NMOSD was performed by an expert board (FS, TP, ES, JLF, IZ). Results: Out of 4138 patients, who fulfilled the search criteria, 103 patients had at least one positive anti-AQP4 test. The expert board anonymously reviewed all 103 patients, and found that the clinical, neuroimaging and laboratory findings strongly suggested alternative diagnoses in 65 cases. Finally, we recognized 38 seropositive and 17 seronegative NMOSD patients. The prevalence analysis included 49 NMOSD living cases (39 women and 10 men) with onset before 2014. The Danish population comprised 5,585,710 by 01.01.2014, giving a national prevalence of 0.877 per 100,000 persons (95% CI; 0.649 – 1.160). There were 27 cases (20 women and 7 men) with onset between 2007 and 2013 emerging from the entire background population observed for 38,449,668 person years. Hence, the incidence rate was 0.070 per 100,000 person years (95% CI; 0.046 – 0.102). Conclusions: The population-based nationwide Danish prevalence and incidence is similar to the Australian study using the 2015 IPND and comparable with previous studies in other Caucasian populations. Our findings confirm the statement in the 2015 IPND criteria that alternative diagnoses should be excluded, especially in cases with mild or uncertain anti-APQ4 seropositivity. Disclosure: Dr. Papp has nothing to disclose. Dr. Illes has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Novartis, Sanofi-Genzyme, Biogen, Merck-Serono. Dr. Illes has received research support from Biogen and Sanofi-Genzyme. Dr. Magyari has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, Sanofi, Teva, Roche, Novartis, Merck. Dr. Magyari has received research support from received support for congress participation from Biogen, Genzyme, Teva, Roche. Dr. Koch-Henriksen has received research support from Travel expenses, accommodation, and congressional fees from Merck for participation to the 2017 ECTRIMS congress. Dr. Kant has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva, Genzyme. Dr. Gora has nothing to disclose. Dr. Storr has nothing to disclose. Dr. Pfleger has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Genzyme, Biogen, Roche, Novartis, Merck. Dr. Pfleger has received personal compensation in an editorial capacity for Merck, Biogen. Dr. Roemer has nothing to disclose. Dr. Jensen has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with TEVA, Roche, Biogen. Dr. Rosendahl has nothing to disclose. Dr. Locht has nothing to disclose. Dr. Mezei has nothing to disclose. Dr. Christensen ? has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with TEVA, Novartis. Dr. Petersen has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Merck Serono, Roche. Dr. Svendsen has nothing to disclose. Dr. Nielsen has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi-Genzyme, Biogen Denmark, Novartis, Merck. Dr. Frederiksen Battisti has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen Idec, Merck Serono,Santhera, Sanofi-Aventis, Teva, Novartis, Genzyme. Dr. Sellebjerg has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, EMD Serono, Genzyme, Lundbeck, Merck, Novartis and Teva. Dr. Sellebjerg has received research support from Biogen, EMD Serono, Genzyme, Lundbeck, Merck, Novartis and Teva. Dr. Stenager has nothing to disclose. Dr. Petersen has received research support from Biogen Idec, Merck Serono, Novartis, Bayer Schering, Sanofi-Aventis, Roche, Genzyme.