Objective: Non-infectious myelitis in systemic lupus erythematosus (SLE) may be due to SLE myelitis, comorbid multiple sclerosis (MS), or neuromyelitis optica (NMO). We compared characteristics of these three conditions in SLE patients at a large academic institution.
Methods: We searched for neurologic diagnoses of SLE myelitis, NMO myelitis, and MS myelitis among 2297 patients with at least four 1997 American College of Rheumatology revised criteria for SLE between 2000 and 2015. Each subject was reviewed by a neurologist to confirm the underlying neurologic diagnosis. Demographic, clinical, laboratory, and radiographic data were extracted and compared using Fisher's exact test, analysis of variance, and Wilcoxon rank-sum test.
Results: Fifteen of the 2297 subjects with SLE (0.7%) met criteria for a spinal cord syndrome: seven had SLE myelitis, three had AQP4 seropositive NMO, and five had MS. The median SLE Disease Activity Index 2000 score at time of neurologic syndrome presentation was higher in SLE myelitis subjects (8, interquartile range (IQR) 7-16) compared with subjects with NMO (6, IQR 0-14) or MS (2, IQR 0-4), p = 0.02. Subjects with SLE myelitis were also more likely to have elevated anti-dsDNA antibodies at presentation (86%) compared with subjects with NMO (33%) or MS (0%), p = 0.03.
Conclusion: Myelitis occurs rarely among patients with SLE. Compared with subjects with SLE + NMO and subjects with SLE + MS, subjects with SLE myelitis had higher SLE disease activity at presentation.
Keywords: Systemic lupus erythematosus; anti-dsDNA antibodies; neuropsychiatric lupus.