Endothelin-1 plasma concentrations in patients with retinitis pigmentosa

Purpose: The aim of this study was to investigate the behaviour of plasma endothelin-1 (ET-1) levels in patients affected by retinitis pigmentosa (RP) and syndromic RP.

Methods: Blood samples were obtained from a group of 40 consecutive patients with RP matched with 35 healthy subjects (HS) as control. We carried out a complete ophthalmological examination. The study group included 26 patients with RP and 14 patients with syndromic RP. Plasma ET-1 levels were determined in duplicate with a specific radioimmunoassay method.

Results: In the HS plasma ET-1 levels were 7.48+/-2.58 pg/mL. The mean of plasma ET-1 concentrations in all patients with RP ( 16.2+/-5.6 pg/mL) was significantly (P<0.01) higher than that of HS. Moreover, in the syndromic RP patients, plasma ET-1 levels (18.9+/-6.8 pg/mL) were higher than those of HS and RP patients (P<0.01).

Conclusion: The increase of plasma ET-1 levels in RP patients suggests that ET-1 may play a role in the pathophysiology of the diseases involving retinal pigment epithelial cells and the retinal vascular system such as RP.