Researchers in Korea have found Behçet disease (BD), a rare systemic inflammatory disease, is associated with multiple sclerosis (MS) and rheumatoid arthritis (RA).
Patients with BD were 8.85 times more likely than those in a control group to have MS (95% CI, 2.36-33.17) after adjustments for other comorbid diseases, according to a study published in Dermatology. The association was also strong in RA, with an odds ratio (OR) of 4.62 (95% CI, 3.35-6.35).
In addition, the study determined that BD patients younger than 40 had a higher proportion of RA (OR 23.91; 95% CI) than older patients (OR 3.96; 95% CI 2.83-5.54).
The study is the first to report on the association with MS and RA. Inflammatory bowel disease has previously been suggested as a comorbidity.
The prevalence of BD, which is challenging to differentiate from MS due to similarity in symptoms, is only 0.1 per 100,000 in the United States. A meta-analysis found the global prevalence to be much higher globally at 10.3 per 100,000.
BD is considered an auto-inflammatory disorder due to the absence of pathogenic autoimmune T and B cell responses. BD is characterized by oral and genital canker sores, uveitis, a positive test for a condition where bumps or bruises develop into lesions or ulcers that are often resistant to healing, papulopustular or acne-like lesions, and arthritis. BD is considered a multifactorial or acquired autoimmune disorder. Several genetic factors are suspected, including human leukocyte antigen (HLA)-B51. Altered gene expressions are reported in patients with BD and environmental factors such as microorganisms, vitamin D deficiency, and smoking.
The study reviewed data from 6448 newly diagnosed patients with BD in South Korea from 2012 to 2017 and compared them with patients in a large, national database used as a control group. Both cohorts were analyzed for the presence of MS or RA within a minimum of 5 years prior to their BD diagnosis.
The study found the OR in the BD group was higher in males than females. Also, patients in the BD group without comorbid diseases (type 2 diabetes, hypertension, dyslipidemia) had a higher OR for RA than those with comorbid disease.
Differentiating between neuro-BD and MS is important, the authors said. Both diseases cause cognitive dysfunctions such as memory impairment and diminished frontal-lobe executive function. Also, neuro-BD mimics MS in its high occurrence among young individuals, a relapsing-remitting progression, infiltration by inflammatory cells around the blood vessels, excessively intense lesions on T2-weighted MRI, slower time for the brain to respond to sensory stimulation, and a treatment response to corticosteroids and immunosuppressant drugs.
However, parenchymal involvement is typically seen in the basal ganglia and diencephalon in neuro-BD and in periventricular and white-matter lesions in MS. Also, MS is hypothesized to be frequently observed in developed countries, while neuro-BD is associated with the poor hygiene typically seen in less developed countries.
Jung JH, Han KD, Lee YB, et al. Behçet’s disease is associated with multiple sclerosis and rheumatoid arthritis: A Korean population-based study. Dermatology. Published online March 23, 2021. doi:10.1159/000514634