Abstract
Purpose :
The contributory role of the microbiota to the development of autoimmune diseases has emerged in recent years including in mouse models of uveitis. However, less is known regarding the microbiota in uveitis patients. The purpose of this study is to investigate alterations in bacterial diversity and microbiota composition between healthy volunteers and patients with non—infectious uveitis as well as evaluate longitudinal changes in uveitis patients.
Methods :
An observational, prospective single center study was conducted at the National Eye Institute, National Institutes of Health, enrolling patients with non-infectious uveitis and healthy volunteers. Stool samples were collected using a standardized stool sampling kit and samples analyzed using 16S ribosomal RNA sequencing. Participants also completed the Diet History Questionnaire (DHQ). Cross-sectional analyses included age, sex, BMI and diet as covariates.
Results :
A total of 47 healthy volunteers and 55 patients with non-infectious uveitis were enrolled. Of those 55 uveitis patients, 34 patients were treatment naïve and longitudinal sampling was obtained from 12 patients. There were no significant differences in Alpha diversity, phylogenetic diversity, sample richness or bacterial abundances between uveitis patients and healthy volunteers. Similarly, on subgroup analysis, no significant differences in diversity measures were observed between active and quiet uveitis patients at baseline. However, patients with BCR had higher richness, alpha diversity, and phylogenetic diversity compared to other uveitis etiologies although this was not statistically significant. Differential abundance analyses revealed a significantly lower (q< 0.001) abundance of 15 bacterial amplicon sequence variants (ASV) in patients with quiet uveitis compared to active disease. Longitudinal cohort analysis showed that microbiota richness decreased with change in disease activity from active to quiet (coefficient = -56.81, p = 0.038).
Conclusions :
Our preliminary results suggest that there are differences in the microbiota between active and inactive uveitis as well as longitudinal differences as disease activity changes. Further work is required including with metagenomics to validate these observations.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.