P163 Grey matter myelitis is a severe phenotype of myelitis in systemic lupus erythematosus: experience from a tertiary care hospital in south India over a decade

Abstract

Abstract Background/Aims Myelitis is a severe yet rare manifestation of systemic lupus erythematosus (SLE). Literature on lupus myelitis is limited to case reports and series. Birnbaum et al. reported the largest series (n = 22) with two distinct phenotypes based on clinical and imaging findings with mechanistic and therapeutic implications. Further validation of these two subtypes is not reported to date. The objective of the study was to identify distinct phenotypes in lupus myelitis and compare activity and outcomes with the formulation of a prediction model for survival. Methods This is a retrospective study. Data of 35 lupus myelitis patients with follow-up were extracted from the lupus registry (n = 1550) in the last 15 years (2007-2022). Grey matter myelitis (GMM) (i.e., flaccidity, hyporeflexia) and white matter myelitis (WMM) (i.e., spasticity, hyperreflexia) were two subtypes. Disease activity was assessed by SLEDAI-2K and outcome by death/recurrence/disability - modified Rankin score (MRS). MRS at discharge and SLEDAI at admission were used as predictors for survival outcomes among subtypes. Results Median age at presentation was 24.5 years (12.5-36.5); female-male ratio 32:3. 24 patients presented with GMM and 11 with WMM. GMM had more CNS events (p-0.02), high SLEDAI (p-0.021) and extra CNS involvement (p > 0.05). Anticardiolipin antibodies were increased in WMM (p-0.03). Weibull survival probability plot showed that 25%, 50% & 75% of GMM patients had probability of death within 13, 85, and 376 months from the myelitis episode respectively. The same for WMM was 96, 256, 556 months respectively, implying that GMM has a worse survival outcome. Using linear regression, MRS at discharge and SLEDAI can predict survival status in GMM (R = 0.64, p = 0.04) but not in WMM (R = 0.42, p = 0.46). Conclusion Lupus myelitis has two distinct subtypes. GMM is associated with more active disease, poor survival, and significant disability, and its survival status can be predicted by MRS and SLEDAI scores. Disclosure R. Baisya: None. K. Yerram: None. G. Murthy: None. P.K. Devarasetti: None. L. Rajasekhar: None.