title: Levels of uroporphyrinogen decarboxylase (URO-D) in erythrocytes of Italian porphyria cutanea tarda patients.
abstract: Porphyria cutanea tarda (PCT) is a human metabolic disorder due to the acquired or genetic impairment of uroporphyrinogen decarboxylase (URO-D) activity, the fifth enzyme of the heme biosynthetic pathway. A classification of inherited and non-inherited forms is based on the enzyme activity levels in red blood cells (RBC). Clinical manifestations of PCT are often precipitated by triggering factors such as alcohol, drug abuse, estrogens, virus infections, hepatotoxic chemicals and hepatic siderosis. We measured URO-D activity in RBC from a large sample of Italian PCT patients in order to define the enzyme activity distribution and to attempt a correlation among activity, risk factors and clinical outcome. Three classes of patients with low, normal and over-normal URO-D activity were defined according to control values. Low URO-D levels were present in 25.8% of patients, suggesting the familial form of PCT (type II). In this group, the outcome of PCT seems to be less influenced by risk factors. Patients with over-normal URO-D activity in RBC deserve further investigation.
authors.affiliation: Centro Anemie Congenite, IRCCS Ospedale Maggiore Policlinico, Padiglione Granelli, Dipartimento di Medicina Intema, Università degli Studi di Milano, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Tavazzi
authors.forename: Franco
authors.initials: F
authors.lastname: Martinez di Montemuros
authors.forename: Silvia
authors.initials: S
authors.lastname: Fargion
authors.forename: Anna Ludovica
authors.initials: AL
authors.lastname: Fracanzani
authors.forename: Gemino
authors.initials: G
authors.lastname: Fiorelli
authors.forename: Maria Domenica
authors.initials: MD
authors.lastname: Cappellini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D017119:Porphyria Cutanea Tarda / Q000201:enzymology* / Q000209:etiology; D011166:Porphyrins / Q000652:urine; D011379:Prognosis; D012307:Risk Factors; D014575:Uroporphyrinogen Decarboxylase / Q000097:blood*
chemical_list: C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D011166:Porphyrins; D014575:Uroporphyrinogen Decarboxylase