Greater disease risk for lupus, Sjögren’s found for NMOSD patients
Co-occurring autoimmune disorders more likely for women, African Americans
People with neuromyelitis optica spectrum disorder (NMOSD) are at an increased risk of being diagnosed with another autoimmune disease — specifically lupus or Sjögren’s syndrome — according to a large-scale analysis of inpatient hospitalization data in the U.S.
In fact, NMOSD patients had a 12 times higher disease risk for lupus, or systemic lupus erythematosus (SLE), when compared with the general population, and a more than fivefold greater risk of Sjogren’s.
The co-occurrence of two autoimmune disorders in NMOSD patients was found more often in women and African American individuals — and was linked to both poorer outcomes and an increased healthcare burden for both lupus and Sjögren’s as co-existing diseases.
The researchers noted that people with NMOSD already have “high rates of several complications,” including quadriplegia, blindness, and respiratory failure — “with even higher rates of seizures and paraplegia in those with concomitant [co-occurring] SLE or Sjogren’s.”
The large-scale study, “Nationwide analysis of neuromyelitis optica in systemic lupus erythematosus and Sjogren’s syndrome,” was published in the journal Clinical Rheumatology.
NMOSD, lupus and Sjögren’s have overlapping symptoms
NMOSD is an autoimmune disease caused by a self-targeted immune attack on the spinal cord (myelitis) and/or the optic nerve (optic neuritis), which transmits electrical impulses from the eyes to the brain.
Optic neuritis can result in eye pain and possibly blurry vision or vision loss. Myelitis can lead to a wide range of symptoms, such as paralysis of the arms and legs, loss of sensation, muscle spasticity, breathing difficulties, and a loss of bladder and bowel control.
In case reports, NMOSD has occurred alongside other autoimmune diseases, most frequently Sjögren’s syndrome and lupus, which has raised the question as to whether patients may have an increased disease risk.
In Sjögren’s, the immune system primarily attacks the glands that produce tears and saliva, but also other tissues. In lupus, or more commonly systemic lupus erythematosus, called SLE, any part of the body can be affected, including the skin, kidneys, joints, brain, heart, and lungs.
“Nervous system involvement is common in SLE and Sjogren’s, which can have overlapping features with NMO [NMOSD] making it difficult to distinguish them,” the researchers wrote.
However, a formal relationship between these conditions has not been established, and little is known about the outcomes of those who have both NMOSD and either of these autoimmune diseases.
That led a team led by researchers from two hospitals in Chicago to investigate the occurrence, clinical characteristics, and outcomes of patients hospitalized with NMOSD and lupus or Sjögren’s.
“This is the first study to explore the demographics and hospitalization outcomes of NMOSD patients and compare them with and without overlap of SLE and Sjogren’s,” the team wrote.
Greater disease risk and higher rate of seizures seen for NMOSD patients
Data were collected from the National Inpatient Sample database, the largest all-payer hospitalization database in the U.S. Among the 16,360 NMOSD hospitalizations that occurred between 2016 and 2019, a total of 1,425 (nearly 9%) had a concurrent diagnosis of either lupus or Sjögren’s.
Compared with patients with NMOSD only, the group with NMOSD plus lupus/Sjögren’s had a higher proportion of women (90% vs. 79%), African American individuals (57% vs. 38%), and those of Asia/Pacific Islander race (nearly 6% vs. just more than 3%).
“Strikingly, more than half of NMO patients with SLE or [Sjögren’s] were African Americans,” the researchers wrote.
To explain this finding, the team noted that NMOSD is more prevalent among African American people. There’s also a known higher risk, in that patient population, of frequent and severe neurological involvement from lupus.
Given this, better screening for concurrent autoimmune diseases would be helpful, the scientists noted.
“These findings are especially clinically relevant in African American women with [NMOSD], in whom screening for underlying SLE or [Sjögren’s] and vice versa may be indicated in case of any suspicious features,” the team wrote.
Strikingly, more than half of NMO patients with SLE or [Sjögren’s] were African Americans. … These findings are especially clinically relevant in African American women with [NMOSD], in whom screening for underlying SLE or [Sjögren’s] and vice versa may be indicated in case of any suspicious features.
Overall, people with NMOSD had a 12 times greater risk of being diagnosed with lupus and a 5.6 times higher disease risk of Sjögren’s compared with individuals in the general population.
The Charlson’s comorbidity index, used to assess co-existing medical conditions that may influence mortality risk, was higher in the NMOSD plus lupus/Sjögren’s group. Still, the mortality risk itself was similar between the two groups.
A higher prevalence of seizures (14.73% vs. 6.05%) and paraplegia (21.75% vs. 13.93%) — or paralysis of the lower half of the body — also was found among those with NMOSD associated with lupus/Sjögren’s.
Other outcomes that were not statistically different between the two groups included blindness, optic neuritis, quadriplegia — paralysis below the neck, including both arms and legs — and adult failure to thrive. Lung failure and blood clots known as pulmonary embolisms or deep vein thromboses also were not statistically different between the two groups, and nor was sepsis, or an extreme reaction to an infection.
Finally, the median total hospital charges for individuals with NMOSD plus lupus/Sjögren’s were higher, by more than $15,000 per patient, than for those with NMOSD alone. Specifically, the median charges were $62,906 for someone with two conditions versus $46,816 for a patient with just NMOSD. Patients with concurrent conditions also had a longer time spent hospitalized, at seven days versus five days.
The researchers noted that most patients in both groups had lower incomes and had public insurance (Medicare or Medicaid), “which are known social determinants of poor health outcomes.”
“This study illustrated important features about [NMOSD] in general and associated with SLE/[Sjögren’s],” the researchers concluded, noting that “co-existence of these autoimmune disorders was associated with poor prognosis in terms of higher morbidity for patients and increased health care burden.”
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