Relationships between activated dendritic cells and dry eye symptoms and signs.

PURPOSE:To examine whether "activated" dendritic cells (aDCs) could serve as a biomarker of systemic immune disorders in individuals with dry eye (DE) symptoms. Secondarily, to examine the impact of a topical anti-inflammatory agent on aDC number. METHODS:Retrospective analysis was conducted to identify individuals with DE symptoms who had in-vivo confocal microscopy (IVCM) imaging between October 2018 and July 2020 at the Miami Veterans Hospital. aDCs were manually quantified based on morphology. Receiver operating curve (ROC) analysis examined relationships between aDC number and systemic immune disease status. Individuals were then grouped by aDC number (≥2 versus <2) and demographics and DE parameters were examined. Paired t-test was performed to evaluated aDC number pre-vs post-initiation of an anti-inflammatory agent. RESULTS:128 individuals were included. Their mean age was 57.1 ± 15.0 years; 71.1% were male, 53.1% self-identified as White and 24.2% as Hispanic. The mean number of aDCs in the central cornea was 1.28 ± 2.16 cells/image. The presence of ≥2 aDCs had a sensitivity of 60% and specificity of 77% for the diagnosis of a systemic immune disorder. Individuals with ≥2 aDCs were more likely to self-identify as Black, have Secondary Sjögren's, and have higher nerve fiber area and fractal dimension. In 12 individuals, aDC number decreased from 2.69 ± 2.36 to 0.58 ± 0.73 cells/image after initiation of an anti-inflammatory agent, p = 0.01. CONCLUSIONS:The presence of ≥2 aDCs in the central cornea suggests a systemic immune disorder in individuals with DE symptoms. Topical anti-inflammatory therapy can reduce the number of aDCs in the central cornea.