<h3>Objectives</h3> Mechanisms underlying burning mouth syndrome (BMS) remain unclear. Evidence of changes in oral mucosal epithelial cells has been found in patients with BMS. This case-control study aimed to investigate whether BMS cases have evidence of impaired mucosal barrier function compared with controls without BMS, focusing on the role of salivary mucins as a first line of defense for oral epithelial cells. <h3>Study Design</h3> A total of 50 women (22 BMS cases and 28 healthy controls) age 50 years or older were included in this study. Participants attended a clinical visit including assessment of BMS symptoms, salivary sample collection, oral examination, swab for candida detection, and DNA collection using the DNA•SAL device. Total protein concentration was measured using the bicinchoninic acid assay. MUC1 protein concentration in saliva samples was quantified by sandwich enzyme-linked immunosorbent assay (Invitrogen). Salivary glycosylation was assessed by protein-normalized dot blot against 3 lectins (Maackia Amurensis Lectin II; WGA: wheat germ agglutinin; UEA: ulex europeus agglutinin (MAL-II), WGA, and UEA). H antigen, the precursor of ABO antigens, secretor status was predicted by performing Sanger DNA sequencing of the FUT2 gene. <h3>Results</h3> The average salivary protein concentration was 1.30 mg/mL in BMS cases vs 0.94 mg/mL in controls (<i>P</i> = .15). Mann-Whitney <i>U</i> test showed a trend toward lower levels of MUC1 in BMS cases (n = 20, sum of ranks = 392.50) compared with controls (n = 24, sum of ranks = 597.50; <i>P</i> = .17). UEA, MALII, and WGA reactivities were each quantitatively lower in cases compared with controls but varied widely (<i>P</i> = NS). The percentage of nonsecretors was 23% among cases vs 38% among controls (<i>P</i> = .28). Genotype-predicted secretors had significantly higher UEA reactivity compared with nonsecretors (<i>P</i> < .001). <h3>Conclusions</h3> Our study overall found trends consistent with higher salivary protein concentration, lower salivary MUC1 levels, and salivary hypoglycosylation in BMS cases compared with controls, although no findings were statistically significant. Study limitations include subject heterogeneity and sample size. As expected, UEA levels were significantly higher in secretors compared with nonsecretors. Other aspects of the oral epithelial barrier, including the quantity of other mucins and glycosylation, remain to be examined.
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