Concentration distribution of Interleukin–6 and its soluble receptor in subretinal fluid and plasma

Abstract

Abstract: : Purpose: Interleukin–6 (IL–6) stimulates RPE cell proliferation in retinal detachment (RD) and plays an important role in proliferative vitreoretinopathy. RPE cell produces both IL–6 and its receptor (IL–6R) but not soluble form receptor (sIL–6R). IL–6 and sIL–6R are presented in subretinal fluid (SRF) of RD. The study was designed to clarify the source and biological role of the molecules. Methods: Paired plasma and SRF was collected from the patients with rhegmatogenous RD. Concentrations of IL–6 and sIL–6R molecule were measured by ELISA. Gene and molecule expression of IL–6 and IL–6R on cells within SRF were studied by RT–PCR and immunostaining. Results: sIL–6R levels in plasma is higher than in corresponding SRF while IL–6 levels in SRF is higher than in corresponding plasma, and both were significantly higher than the vitreous fluid from control eyes with macula hole (p<0.05). Cytokeratin–positive RPE–derived cells in SRF expressed genes and molecule of IL–6 and IL–6R as control RPE cells in cell culture. Conclusions: sIL–6R in RD is supplied from blood circulation while IL–6 is produced locally as autocrin manner.

Keywords: retinal detachment • retinal pigment epithelium • cytokines/chemokines