Abstract:

A comparative study has been carried out on the levels of liposoluble vitamins, naturally occurring carotenoids and plasmatic porphyrins in porphyric patients and controls; other biochemical parameters which characterize the pathology were determined, with the aim of evaluating the impairment of the liposoluble antioxidative system in cutaneous and non-cutaneous porphyrias. Blood samples and urine from 68 porphyric patients, 20 with symptomatic porphyria cutanea tarda (PCT), 15 with erythropoietic protoporphyria (EPP), 15 with variegate porphyria (VP) in remission, 18 with latent acute intermittent porphyria (AIP) were collected. Content of retinol, tocoferol, α and β carotens, criptoxantine, zeoxantine and licopene; aminolevulinic acid (ALA), porphobilinogen (PBG), porphyrins and the activity of red blood cells (RBC) deaminase were measured. The retinol content was within normal values in all groups (83.05 ± 19.25 μg/dl). Tocopherol was diminished in PCT (970 ± 12 μg/dl) and EPP (668 ± 10 μg/dl) and normal in AIP and VP (1150 ± 110 μg/dl), zeoxantine was also diminished in PCT (18 ± 2 μg/dl) and EPP (10.3 ± 1.3 μg/dl), and normal in AIP and VP (40.5 ± 1.3 μg/dl). Criptoxantine and licopene carotenoids levels were: AIP = 11.1 ± 21. μg/dl and 13.2 ± 2.1 μg/dl; VP = 10.3 ± 1.1 μg/dl and 2.1 ± 0.9 μg/dl; PCT = 9.1 ± 1.2 μg/dl and 9.2 ± 0.9 μg/dl; EPP = 11.3 ± 1.3 μg/dl and 8.3 ± 1.1 μg/dl, lower than their respective normal values (37.9 ± 1.2 μg/dl and 19.5 ± 0.9 μg/dl). Porphyrin plasma index was elevated in PCT = 4.5 ± 1.0 (λ = 618) EPP = 3.5 ± 0.5 (λ = 635), VP = 4.3 ± 0.5 (λ = 625) and normal in AIP = ≤ 1.3 (λ = 618). α and β carotenoids were reduced in VP = 1.0 ± 1.2 μg/dl and 4.8 ± 0.8 μg/dl; in PCT = 1.2 ± 0.6 μg/dl and 4.0 ± 0.8 μg/dl and in EPP = 2.5 ± 1.0 μg/dl and 8.5 ± 1.0 μg/dl. Normal values were α = 1.9 ± 0.3 μg/dl and β = 9.3 ± 0.5 μg/dl. The content of β carotenoids was diminished in the AIP group (6.1 ± 1.2 μg/dl). These results show that the antioxidant liposoluble system has a reduced capacity in porphyric patients.