title: An explorative study of non-invasive ultra-weak photon emission and the anti-oxidative influence of oral zinc sulphate in light-sensitive patients with erythropoietic protoporphyria.
abstract: BACKGROUND
  Erythropoietic protoporphyria (EPP) is a rare, inherited disorder of haem biosynthesis owing to deficient ferrochelatase (FECH) and accumulation of protoporphyrin IX (PPIX). This results in acute cutaneous photosensitivity upon light exposure with production of reactive oxygen species (ROS) and ultra-weak photon emission (UPE) as a by-product. We investigated if UPE evaluated the light sensitivity in EPP patients and influence of zinc treatment.
  
  
  METHODS
  Fourteen EPP patients took zinc sulphate (3 × 200 mg/day) during spring and summer. Using a photomultiplier (PM), UPE was measured from the buttock skin and dorsal hand before and after solar-simulated light (SUN) exposure. Blood samples were analysed routinely for plasma zinc, iron, ferritin, transferrin, haemoglobin, erythrocyte PPIX and Zn-PPIX.
  
  
  RESULTS
  UPE in EPP patients resembled that seen in healthy individuals. Without treatment, a seasonal decrease was seen from spring to summer in four control patients. However, oral zinc treatment reduced ROS formation significantly regardless of SUN exposure. After SUN exposure, the initial burst was correlated to plasma iron and erythrocyte PPIX. During treatment, an inverse correlation was found between plasma zinc concentration and the initial burst.
  
  
  CONCLUSIONS
  Measurements of UPE can be used for monitoring UVA-induced oxidative processes in vivo in the skin of EPP patients.
authors.affiliation: Department of Dermatology, Copenhagen University Hospital, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: Anita Birgit
authors.initials: AB
authors.lastname: Petersen
authors.forename: Peter Alshede
authors.initials: PA
authors.lastname: Philipsen
authors.forename: Hans Christian
authors.initials: HC
authors.lastname: Wulf
mesh_terms: D000284:Administration, Oral; D000975:Antioxidants / Q000008:administration & dosage; D001252:Astringents / Q000008:administration & dosage; D003879:Dermatologic Agents / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D010783:Photometry / Q000379:methods*; D017785:Photons; D010787:Photosensitivity Disorders / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D010865:Pilot Projects; D017092:Porphyria, Erythropoietic / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D019287:Zinc Sulfate / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D001252:Astringents; D003879:Dermatologic Agents; D017382:Reactive Oxygen Species; D019287:Zinc Sulfate