Nationwide analysis of neuromyelitis optica in systemic lupus erythematosus and Sjogren's syndrome.

OBJECTIVE: Neuromyelitis optica (NMO), also known as Devic's disease, is a rare inflammatory demyelinating disorder causing myelitis and optic neuritis. While there have been reports of systemic lupus erythematosus (SLE) and primary Sjogren's syndrome (SS) occurring with NMO, a formal association is not established. We aimed to investigate the occurrence of NMO in SLE and SS patients and study the clinical characteristics and outcomes of NMO and SLE/SS hospitalizations utilizing the national inpatient sample (NIS) database.

METHODS: The NIS database from 2016 to 2019 was used to extract data. Adult hospitalizations with the principal or secondary diagnosis of NMO were included. We classified NMO patients with and without concomitant diagnosis of SLE or Sjogren's syndrome. We evaluated and compared the clinical characteristics and outcomes of NMO hospitalizations with and without SLE or Sjogren's syndrome. STATA17 was used for data analysis. We also calculated the odds ratio of NMO in SLE and Sjogren's syndrome.

RESULTS: There were a total of 16,360 adult hospitalizations with the principal or secondary discharge diagnosis of NMO. Among all NMO hospitalizations, 1425 (8.71%) had the primary or secondary diagnosis of SLE or SS. The odds of NMO in SLE and Sjogren's syndrome were noted to be 12.29 and 5.56, respectively. NMO with SLE/SS group had higher proportion of females (89.82% vs 79%, P value < 0.001), African Americans (56.63% vs 38.28, P value < 0.001), and Asians (5.73% vs 3.25, P value 0.04). The Charlson comorbidity index was higher for NMO-SLE/SS overlap (2.44 vs 1.28, P value < 0.001). There was no significant difference in overall mortality rates of both groups (2.11% vs 1.2%, P value 0.197). There were significantly higher reported seizures (14.73% vs 6.05, P value < 0.001) and paraplegia (21.75% vs 13.93%, P value < 0.001) in NMO-SLE/SS patients. These patients also had a longer length of stay in comparison to the reference group (7 vs 5 days, P value < 0.001) as well as higher total charges.

CONCLUSIONS: NMO patients had a 12-fold higher risk of SLE and 5-fold higher risk of Sjogren's disease when compared to general population. Patients with overlap of NMO and SLE or Sjogren's were predominantly women and were more likely to be African-American. Co-existence of these autoimmune disorders was associated with poor prognosis in terms of higher morbidity for patients and increased health care burden. Key Points • NMO is a rare autoimmune disease seen predominantly in women in the middle age group with low overall mortality. • SLE and Sjogren's have increased odds of NMO in comparison to general population. • NMO patients have high rates of several complications such as paraplegia, quadriplegia, seizures, blindness, sepsis, and respiratory failure with even higher rates of seizures and paraplegia in those with concomitant SLE or Sjogren's.