Adrenomedullin plasma concentrations in patients with retinitis pigmentosa

Purpose: To evaluate the relationship between retinitis pigmentosa (RP) and plasma adrenomedullin (ADM) levels. 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 ophtalmological examination. The study group included 26 patients with RP and 14 patients with syndromic RP. Plasma ADM levels were determined in duplicate with a specific radioimmunoassay method. Results: In the HS plasma ADM levels were 13.7 ± 6.1 pg/mL. The mean of plasma ADM concentrations in all patients with RP (23.4 ± 10.7 pg/mL) was significantly (P < 0.0001) higher than that of HS. Moreover, in the syndromic RP patients, plasma ADM levels (28.6 ± 14.35 pg/ml) were higher than those of HS and RP patients (P < 0.0017). Conclusion: The increase of plasma ADM levels in RP patients may be a response to photoreceptor damage.