Differences in anti-endothelial and anti-retinal antibody titers: implications for the pathohysiology of acute and chronic central serous chorioretinopathy.

The aim of the study was to evaluate the prevalence of serum anti-retinal (ARAs) and anti-endothelial cell antibodies (ACEAs) in patients with acute and chronic central serous chorioretinopathy (CSC). We enrolled 28 patients with acute CSC, 42 patients with chronic CSC, and 40 healthy controls. The presence of ARAs was determined by indirect immunofluorescence using monkey retina as an antigen substrate, while the presence of AECAs was determined using cultivated human umbilical vein endothelial cells (HUVECs) and primate skeletal muscle according to the manufacturer's instructions (Euroimmun AG). There were no differences in the prevalence of antibodies against rods, cones, cytoplasmic components of retinal nuclear layer cells, and retinal vessels between the acute and chronic CSC groups and the control group (P = 0.27, P = 0.16, P = 0.71, and P = 0.06, respectively). However, AECAs reactive with HUVECs were observed in 46% of patients with acute CSC, 45% of those with chronic CSC, and 22% of controls, whereas AECAs reactive with the skeletal muscle were present in 46%, 45%, and 15%, respectively (difference between groups: P = 0.045 for HUVECs and P = 0.005 for the skeletal muscle). Furthermore, AECA titers were higher in CSC patients than in controls (P = 0.004). This study provides evidence for the possible involvement of an autoimmune process directed against vessel antigens in the pathogenesis of CSC. AECAs may be more important than ARAs in this disease and may be involved in endothelial damage in the choroidal vessels and choriocapillaris, leading to hyperpermeability, which is central to the pathophysiology of CSC.

Involvement of serum anti-retinal antibodies in the pathophysiology of diabetic retinopathy: a pilot study.

The aim of this single-center cross-sectional study was to identify tissue targets for circulating anti-retinal antibodies (ARAs) in the serum of patients with diabetic retinopathy (DR). The study included 61 participants with DR (30 with nonproliferative diabetic retinopathy and 31 with proliferative diabetic retinopathy) and 30 healthy controls. An indirect immunofluorescence (IIF) test was used to detect serum ARAs and identify their targets in the tissue. Four types of ARAs were found in serum samples from DR patients: antibodies against the outer segments of the rods, antibodies against the outer segments of the cones, antibodies against the cytoplasmic components of retinal nuclear layer cells, and antibodies against retinal nerve fibers. A significant difference was noted between groups in the prevalence of antibodies against the outer segments of the rods (NPDR, 40%; PDR, 74.2%; and controls, 40%; P = 0.008) as well as antibodies against the outer segments of the cones (NPDR, 23.3%; PDR, 61.3%; and controls, 30%; P = 0.005). Interestingly, the distribution of immunofluorescence intensity for the outer segments of the rods and cones differed significantly between study groups (P ≢ 0.001 and P = 0.019, respectively). In conclusion, the results of our pilot study showed that in most patients with DR, the outer segments of photoreceptors tend to be the tissue target for serum ARAs. This may indicate their possible involvement in the pathogenesis of DR. However, further research is needed to fully elucidate whether these antibodies participate in photoreceptor damage in the course of DR.