Abstract
Purpose :
Patients with Sjögren Syndrome (SS) have conjunctival alterations. This study investigated immune-related molecular pathways activated in the conjunctiva of aqueous-tear deficiency (ATD) in patients with and without SS.
Methods :
Patients with ATD (n=12; 7 SS and 5 non-SS ATD) and healthy controls (HC, n=19) completed a series of oral and ocular surface exams. Ocular symptom severity scores were evaluated using validated questionnaires. All SS patients fulfilled the ACR/EULAR criteria. Impression cytology of the temporal bulbar conjunctiva was performed to collect cells, which were lysed and subjected to RNA extraction and gene expression studies using the NanoString Immunology Panel. Statistical analysis was performed using ROSALIND software to identify differentially expressed genes (DEGs) that passed the FDR. We performed several analyses: 1) HC/ATD subjects, 2) SS/non-SS ATD, and 3) a Venn Diagram to compare our published HC/SS study to the HC/ATD analysis.
Results :
Only age-matched female subjects were enrolled. ATD subjects showed significantly increased signs and symptoms of dry eye. Unsupervised clustering showed that almost all non-SS ATD subjects (4/5) clustered within SS subjects. NanoString analysis demonstrated 50/594 DEGs in the HC/ATD comparison: 42 DEGs were upregulated, and 8 were downregulated (ZBTB16, TGFBI, CLU, TRAF1, C1S, IL11RA, TRAF5, IL18 [-2.65 to -1.5 fold decrease]). The top 5 most upregulated DEGs in descending order were BST2, IFITM1, IL19, CXCL1, and LAMP3 (5 to 2.81-fold increase). Twenty-two pathways had a global significance score ≥2. The top 5 upregulated pathways were Type I Interferon, MHC I Class Presentation, Type II Interferon, B cell Receptor Signaling, and MHC Class II Presentation. In the SS/non-SS ATD subjects comparison, 7/594 DEGs were upregulated (BST2, LAMP3, IFITM1, CA4/B, MX1, IRF7, IFI35) and the only pathway with a global significance score ≥2 was Type I Interferon. Venn diagram showed that 40 DEGs were common between HC/ATD and HC/SS comparisons.
Conclusions :
These results indicate that the conjunctiva of ATD patients exhibits a phenotype of immune activation, including Type I and II interferons, B cell activation and MHC Class I presentation. Furthermore, 80% of the DEGs were present in ATD and SS, indicating that regardless of the diagnosis of SS or not, the conjunctiva of these two groups has a similar transcriptome.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.