Abstract
Purpose :
Gut microbial dybiosis is capable of inducing systemic, extra-intestinal and ocular inflammation in murine models. We hypothesise that the translocation of gut microbial endotoxins through the dysfunctional mucous membrane drives disease. We investigated the link between serum lipopolysaccharide (LPS) levels, as a surrogate marker of increased gut permeability, and disease activity in Behçet’s Disease (BD).
Methods :
BD patients attending the multidisciplinary Behçet’s clinic at the Birmingham and Midland Eye Centre, UK, underwent complete clinical assessment for evidence of disease activity using the validated BD Current Activity Form. Active ocular inflammation was defined as at least a 2+ increase in intraocular cells between clinic visits or the presence of a hypopyon as assessed by slit lamp, whilst active oral lesions were defined as the appearance of new ulceration of the oral mucous membrane.
Serum LPS levels were quantified by ELISA with Limulus Amebocyte Lysate chromogenic endpoint assay. Serum LPS levels in patients with BD (n=23) were compared with serum samples from healthy volunteers (n=10) and disease controls (ocular mucous membrane pemphigoid (OcMMP; n=15)). We obtained longitudinal serum samples from BD patients (n=7) to monitor changes in serum LPS with disease phenotype and progression. Non-parametric statistical analyses were analysed by Mann-Whitney U test and Kruskal-Wallis test.
Results :
There was no statistically significant difference in the LPS levels between patients with BD [median: 0.244 EU/ml; interquartile range (IQR): 0.108-0.778], OcMMP [0.175; 0.140-0.202], and healthy controls [0.200; 0.164-0.251] (p=0.504). BD patients with inactive oral lesions had significantly higher levels of LPS (0.462; 0.168-0.856) compared to those with active oral lesions (0.119; 0.057-0.148) and healthy controls (0.200; 0.164-0.251) (p=0.012). There was no difference in the LPS levels of BD patients with active vs. inactive ocular inflammation (p=0.142).
Conclusions :
Serum LPS levels are associated with oral mucous membrane disease activity and indicates a potential role for microbial translocation in the inflammatory pathophysiology of BD.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.