Abstract
Purpose:
Autoimmune retinopathy (AIR), a rare disease, lacks an understood pathophysiology and the standard serological anti-retinal antibody test lacks both specificity and sensitivity. To date, there is no published research on the ability of flow cytometry, a reliably fast and robust technique, to define or diagnose AIR. We characterized the profile of circulating monocytes through flow cytometry due to the established role of macrophages in autoimmune-related disorders, coupled with the fact that many AIR patients respond positively to immunosuppression.
Methods:
Participants were immunosuppression naïve AIR (n=4) or age-matched controls (n=1). Inclusion criteria included age over 40 years, onset of visual symptoms less than six months, no personal or family history of retinal dystrophy, and no illness or surgery in the past two months. Serological samples were prepared for peripheral blood mononuclear cells (PBMC) isolation. Cells were stained for surface CD14 and CD16 antibodies that characterized unique subsets of macrophage populations and were processed through flow cytometry. Finally, these cells were analyzed and compared against controls for relative expression of their respective surface receptors.
Results:
Our findings suggest that AIR patients may contain a subset of PBMC that increasingly express CD14+/CD16+ surface receptors compared to healthy-controls.
Conclusions:
This study is the first to investigate the use of flow cytometry as a method for confirming a clinical diagnosis of AIR. Our findings suggest that, similar to other inflammatory conditions, monocytes may be involved in the pathogenesis of AIR. With an unknown pathophysiology, and a positive response to immunosuppression, it logically follows that an improved diagnostic system will directly target the immune system. This provides an important avenue for investigation, as PBMC and flow cytometry can be used to look at extracellular cytokines along with additional cell types, such as B-cells or T-cells. Further investigation, with additional sampling, is required to achieve statistical significance. Longitudinal studies that track patient disease progression may also shed valuable insight on individuals’ response to immunosuppression.
Keywords: 432 autoimmune disease •
695 retinal degenerations: cell biology •
557 inflammation