CONICET | Buscador de Institutos y Recursos Humanos

In Porphyria Cutanea Tarda (PCT), produced by a partial deficiency of Uroporphyrinogen decarboxylase (URO-D), high carboxylated porphyrins are accumulated in liver and plasma. Porphyrins are photosensitive, light generates free radicals, the ethiological factors of the cutaneous damage characteristic of PCT. In PCT patients a slight to moderate increase in iron deposits has been frequently observed which was associated with the clinical status of the patients; it is not known yet the mechanism underlying the inhibition of URO-D by iron. The aim of this work was to study iron metabolism and oxidative stress in PCT patients to stablish whether there is any relationship between these parameters and the patients clinical status. In 19 healthy subjects (22-75 years old) and in 29 PCTpatients including 6 PCT/HIV (31-89 years old), the levels of plasma iron and transferrin saturation, main iron carrier in blood and tissues, were determined. For these assays, Wiener kits, from Wiener Labs., Argentina were used. We also measured the levels of oxidative stress in whole blood using a kit to determine reactive oxygen species (ROS) (FORT TEST, Italy) based in the spectrophotometric determination of radicals produced from total peroxides. PCT patients showed levels of ferremia and transferrin saturation increased (63% and 59% respectively, p<0,01) compared to healthy subjects. No signficant differences were observed in the levels of oxidative stress between control group and PCT patients. However, in PCT/HIV patients, ROS levels were 32% (120 ± 29 mg hydrogen peroxide/l, p<0,05) enhanced respect to control group (91 ± 21 mg hydrogen peroxide/l). Data here presented, although preliminary; would indicate a possible role of iron in the triggering of PCT through ROS production or alternatively, by oxidation of URO-D substrate, potentiating the clinical signs of PCT.