Objective: This study sought to identify factors that increased the risk of recurrence after an initial transverse myelitis (TM) presentation.
Methods: Retrospective cohort study of 192 patients initially presenting with TM of unknown etiology. Patients diagnosed with multiple sclerosis during the first myelitis episode were excluded. Demographic and laboratory data were analyzed for associations with recurrence.
Results: One hundred ten of 192 patients (57%) eventually developed recurrent symptoms: 69 (63%) neuromyelitis optica (NMO) or NMO spectrum disorder, 34 (31%) non-NMO recurrent TM, and 7 (6%) systemic autoimmune disease. Multiple independent risk factors for recurrence were identified: African American race (risk ratio 1.60, p < 0.001, 95% confidence interval 1.26-2.03; similarly noted hereafter), female sex (1.88, p = 0.007, 1.19-2.98), longitudinally extensive myelitis at onset (1.34, p = 0.036, 1.01-1.78), Sjogren syndrome antigen A (1.89, p = 0.003, 1.44-2.48), vitamin D insufficiency (4.00, p < 0.001, 1.60-10.0), antinuclear antibody titer ≥1:160 (1.69, p = 0.006, 1.23-2.32), and the presence of inflammatory markers (e.g., immunoglobulin G index) in the CSF (2.14, p < 0.001, 1.44-3.17).
Conclusions: Sex, race, and serologic biomarkers warrant consideration when assessing risk of TM recurrence. Male sex and Caucasian American race were independently associated with risk of monophasic idiopathic TM. Recurrence risk in female and African American patients appears driven by a greater likelihood of developing NMO or NMO spectrum disorder.