Alteration of oral flora in Mongolian patients with Behçet's disease: a multicentre study.

OBJECTIVES: Behçet's disease (BD) is characterised by repeated acute inflammatory attacks with aphthous ulcers of the oral mucosa, uveitis of the eyes, skin symptoms, and genital ulcers. Although its aetiology is still unknown, there is evidence of the involvement of oral bacteria in systemic diseases. Various types of oral bacteria may be involved in the development and progression of BD. The present study investigated alterations in the oral flora of patients with BD in Mongolia. We collected saliva samples from the Mongolian BD group and healthy control (HC) group, and the oral flora were analysed using next-generation sequencer (NGS). METHODS: DNA was extracted from the unstimulated saliva samples from the 47 BD and 48 HC subjects. The DNA was amplified from the V3-V4 region of 16S rRNA using PCR, and the data were acquired using NGS. Based on the obtained data, we analysed the alpha diversity, beta diversity, and bacterial taxonomy of the salivary flora. RESULTS: Beta diversity differed significantly between the BD and HC flora, but no significant differences were observed in alpha diversity. We found that the proportions of three genera - an S24-7 family unknown species, a mitochondria family unknown species, and Akkermansia species associated with IL-10 production - were significantly lower in the BD than in the HC group. CONCLUSIONS: The reduced proportions of the S24-7 family and symbiotic Akkermansia species may be key phenomena in the oral flora of patients with BD.

Clinical features of Behcet's disease in Mongolia: a multicenter study.

OBJECTIVE: The aim of the present study is to investigate the clinical features of patients with Behcet's disease (BD) in Mongolia. METHODS: Patients were identified and examined from six medical institutions in Mongolia from January 2015 to January 2019. BD was diagnosed according to the diagnostic criteria for BD established by the International Study Group. RESULTS: There were sixty-five patients (22 males and 43 females) recoded, the ratio of 1:1.95, with a marked female predominance. The age of disease onset was 22.2 ± 10.0 (mean ± SD), ranging from 11 to 66 years old. Oral aphthous ulcers, ocular lesions, skin lesions, genital ulcers, pathergy test positivity, articular lesions, superficial vasculitis, deep vein thrombosis, and epididymitis (male only) were observed in 100.0%, 63.1%, 81.5%, 89.2%, 7.7%, 86.2%, 32.3%, 4.6%, and 13.6% of the patients, respectively. The incidence of poor visual prognosis, ≤ 20/200, was significantly higher in males than in females (31.8 vs. 9.3%, incidence rate ratio 4.55 (95% CI 1.16-17.82), p < 0.05). The pathergy test was positive only in 7.7% of cases and only in female subjects. Nasal mucous ulcers were frequently seen in 55.4% of patients that may also be attributed to the environmental conditions of Mongolia. Headache was observed 76.9% of patients in this study. CONCLUSIONS: Clinical manifestations of BD in Mongolia are presented for the first time. The visual prognosis was significantly worse in males. Nasal mucous membrane ulcers and recurrent headaches were frequent among Mongolian patients with BD. Key Points • First results of the examination of the clinical features of Behcet's disease patients in Mongolia. • Nasal ulcerations and recurrent headaches are frequent symptoms in Mongolia Behcet's disease patients, potentially attributed to climate. • Male Behcet's disease patients in Mongolia have a significantly worse prognosis for eye-related complications and vision.