Background:TNFi are effective treatments for multiple immune-mediated inflammatory diseases. There are five TNFi’s approved for clinical use. Despite their acceptable safety/efficacy profile, serious side effects have been reported, including central and peripheral nervous system demyelinating diseases (DD).ͥ Causation remains controversial and there is a paucity of data on the long-term outcomes in these patients.Objectives:To assess long term outcomes in patients with DD related to TNFi use.Methods:We conducted a database search and then retrospective chart review to identify patients with potential TNFi related neurologic events at a university medical center between 2006 and 2016. 15 total patients (13 living, 2 deceased) were ultimately identified. Six were able to be contacted by phone to assess their current status. Four of these patients were able to attend a one time-visit to complete a neurologic assessment and musculoskeletal examination. Interviews over the phone or in person were used to complete multiple assessments for disability.Results:15 patients with DD were identified from among 4600 patients on TNFi’s for various indications (0.3%). Mean duration of follow-up was 6.8 years. Neurologic symptoms occurred >12 months after starting a TNFi in 8/15 (53%) patients. 47% of patients had been exposed to two or more TNFi’s. 40% received some form of treatment for their DD, including MS disease modifying therapies, IVIG and immunosuppression. No patients experienced worsening DD after stopping their TNFi except for one patient with MS who experienced a repeat flare. Two of three patients diagnosed with MS after TNFi had a first degree relative with MS. 3/15 (20%) experienced complete resolution of their symptoms. Two patients were deceased; cause of death was thought not directly related to DD on chart review.Conclusion:Prevalence of DD after TNFi exposure was low at our center, consistent with previously published data. Presentations included both central and peripheral demyelinating events. With the exception of one patient who developed MS, withdrawal of TNFi’s appeared to halt further progression or development of new neurologic symptoms. It is unclear if treatment for DD is beneficial after diagnosis and TNFi withdrawal.Patient Data:Table.Baseline characteristics and 6-month outcome of patients who have switched from originator to ABP 501AgeSexIndicationTNFi at time of eventNeurologic Presentation/DiagnosisDuration of follow-up, yearsDD status at last follow-up32FJIAEAtaxia, paresthesias, dysarthria, nystagmus, tetraparesis11Persistent despite tx58MPsAGParesthesias9Improved no tx38FASANumbness and weakness5Resolved, no tx54MPsAEParesthesias, cognitive impairment10Persistent, no tx51FASAIncontinence, paresthesias10Persistent, no tx26FCrohn’sAOptic neuritis11Resolved, no tx49MPsAAMultifocal motor neuropathy3Resolved after tx37MPsAAWeakness, spasticity, paresthesias, optic neuritis9Persistent, on tx33FPsAAOptic neuritis, transverse myelitis (MS)5Flared, no tx59FPsAETransverse myelitis (MS)9Deceased45FASITransverse myelitis7Deceased70MRAACIDP1Received treatment but lost to follow-up34FCrohn’sASmall fiber neuropathy11Persistent, no tx62FRAEOptic neuritis<1Lost to follow-up after initial visit42MUveitis, retinal vasculitisAParesthesias (MS)1Persistent, on txJuvenile idiopathic arthritis (JIA), Psoriatic arthritis (PsA), Ankylosing spondylitis (AS), Rheumatoid Arthritis (RA)Adalimumab (A), Etanercept (E), Golimumab (G), Infliximab (I)Treatment (tx)