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Badminton MN, Anderson KE, Deybach JC, Harper P, Sandberg S, Elder GH. From chemistry to genomics: A concise history of the porphyrias. Liver Int 2024; 44:2144-2155. [PMID: 38767598 DOI: 10.1111/liv.15960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/15/2024] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
We describe developments in understanding of the porphyrias associated with each step in the haem biosynthesis pathway and the role of individuals whose contributions led to major advances over the past 150 years. The first case of erythropoietic porphyria was reported in 1870, and the first with acute porphyria in 1889. Photosensitisation by porphyrin was confirmed by Meyer-Betz, who self-injected haematoporphyrin. Günther classified porphyrias into haematoporphyria acuta, acuta toxica, congenita and chronica. This was revised by Waldenström into porphyria congenita, acuta and cutanea tarda, with the latter describing those with late-onset skin lesions. Waldenström was the first to recognise porphobilinogen's association with acute porphyria, although its structure was not solved until 1953. Hans Fischer was awarded the Nobel prize in 1930 for solving the structure of porphyrins and the synthesis of haemin. After 1945, research by several groups elucidated the pathway of haem biosynthesis and its negative feedback regulation by haem. By 1961, following the work of Watson, Schmid, Rimington, Goldberg, Dean, Magnus and others, aided by the availability of modern techniques of porphyrin separation, six of the porphyrias were identified and classified as erythropoietic or hepatic. The seventh, 5-aminolaevulinate dehydratase deficiency porphyria, was described by Doss in 1979. The discovery of increased hepatic 5-aminolaevulinate synthase activity in acute porphyria led to development of haematin as a treatment for acute attacks. By 2000, all the haem biosynthesis genes were cloned, sequenced and assigned to chromosomes and disease-specific mutations identified in all inherited porphyrias. These advances have allowed definitive family studies and development of new treatments.
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Affiliation(s)
| | - Karl E Anderson
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jean-Charles Deybach
- French Porphyria Reference Center (CRMR Porphyries France), University Paris, Paris, France
| | - Pauline Harper
- Department of Medical Biochemistry and Biophysics, Centre for inherited Metabolic Diseases, Porphyria Centre Sweden, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Sverre Sandberg
- Department of Medical Biochemistry and Biophysics, Centre for inherited Metabolic Diseases, Porphyria Centre Sweden, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Pharmacology, Norwegian Porphyria Centre, Haukeland University Hospital, Bergen, Norway
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
- Institute of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
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Balogun O, Nejak-Bowen K. Understanding Hepatic Porphyrias: Symptoms, Treatments, and Unmet Needs. Semin Liver Dis 2024; 44:209-225. [PMID: 38772406 PMCID: PMC11268267 DOI: 10.1055/s-0044-1787076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Hepatic porphyrias are a group of metabolic disorders that are characterized by overproduction and accumulation of porphyrin precursors in the liver. These porphyrins cause neurologic symptoms as well as cutaneous photosensitivity, and in some cases patients can experience life-threatening acute neurovisceral attacks. This review describes the acute hepatic porphyrias in detail, including acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria, as well as the hepatic porphyrias with cutaneous manifestations such as porphyria cutanea tarda and hepatoerythropoietic porphyria. Each section will cover disease prevalence, clinical manifestations, and current therapies, including strategies to manage symptoms. Finally, we review new and emerging treatment modalities, including gene therapy through use of adeno-associated vectors and chaperone therapies such as lipid nanoparticle and small interfering RNA-based therapeutics.
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Affiliation(s)
- Oluwashanu Balogun
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, PA
| | - Kari Nejak-Bowen
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, PA
- Pittsburgh Liver Institute, University of Pittsburgh, Pittsburgh, PA
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Iron Metabolism in the Disorders of Heme Biosynthesis. Metabolites 2022; 12:metabo12090819. [PMID: 36144223 PMCID: PMC9505951 DOI: 10.3390/metabo12090819] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 01/19/2023] Open
Abstract
Given its remarkable property to easily switch between different oxidative states, iron is essential in countless cellular functions which involve redox reactions. At the same time, uncontrolled interactions between iron and its surrounding milieu may be damaging to cells and tissues. Heme—the iron-chelated form of protoporphyrin IX—is a macrocyclic tetrapyrrole and a coordination complex for diatomic gases, accurately engineered by evolution to exploit the catalytic, oxygen-binding, and oxidoreductive properties of iron while minimizing its damaging effects on tissues. The majority of the body production of heme is ultimately incorporated into hemoglobin within mature erythrocytes; thus, regulation of heme biosynthesis by iron is central in erythropoiesis. Additionally, heme is a cofactor in several metabolic pathways, which can be modulated by iron-dependent signals as well. Impairment in some steps of the pathway of heme biosynthesis is the main pathogenetic mechanism of two groups of diseases collectively known as porphyrias and congenital sideroblastic anemias. In porphyrias, according to the specific enzyme involved, heme precursors accumulate up to the enzyme stop in disease-specific patterns and organs. Therefore, different porphyrias manifest themselves under strikingly different clinical pictures. In congenital sideroblastic anemias, instead, an altered utilization of mitochondrial iron by erythroid precursors leads to mitochondrial iron overload and an accumulation of ring sideroblasts in the bone marrow. In line with the complexity of the processes involved, the role of iron in these conditions is then multifarious. This review aims to summarise the most important lines of evidence concerning the interplay between iron and heme metabolism, as well as the clinical and experimental aspects of the role of iron in inherited conditions of altered heme biosynthesis.
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Papadopoulos AJ, Schwartz RA, Fekete Z, Kihiczak G, Samady JA, Atkin SH, Lambert WC. Pseudoporphyria: An Atypical Variant Resembling Toxic Epidermal Necrolysis. J Cutan Med Surg 2016. [DOI: 10.1177/120347540100500604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background: Pseudoporphyria has been attributed to both medication usage and chronic hemodialysis. Histologically, it is identical to porphyria cutanea tarda. It is most commonly seen as localized bullae on sun-exposed skin, often on the dorsum of the hands and fingers. Objectives: We describe a 31-year-old man with rapidly evolving bullae which became denuded, clinically suggestive of toxic epidermal necrolysis. Pseudoporphyria was proven histologically. However, our patient's eruption was not localized as small bullae but was widespread, with large bullae evolving into large, cutaneous, denuded erosions. Conclusions: We describe a previously unreported, generalized variant of pseudoporphyria that resembles toxic epidermal necrolysis. We provide a review of pseudoporphyria and compare our variant to toxic epidermal necrolysis and mimicking disorders.
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Affiliation(s)
| | - Robert A. Schwartz
- Dermatology, New Jersey Medical School, Newark, New Jersey, USA
- Pathology, New Jersey Medical School, Newark, New Jersey, USA
| | - Zoltan Fekete
- Internal Medicine, New Jersey Medical School, Newark, New Jersey, USA
| | - George Kihiczak
- Pathology, New Jersey Medical School, Newark, New Jersey, USA
| | | | - Suzanne H. Atkin
- Internal Medicine, New Jersey Medical School, Newark, New Jersey, USA
| | - W. Clark Lambert
- Dermatology, New Jersey Medical School, Newark, New Jersey, USA
- Pathology, New Jersey Medical School, Newark, New Jersey, USA
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Abstract
Humans have evolved to retain iron in the body and are exposed to a high risk of iron overload and iron-related toxicity. Excess iron in the blood, in the absence of increased erythropoietic needs, can saturate the buffering capacity of serum transferrin and result in non-transferrin-bound highly reactive forms of iron that can cause damage, as well as promote fibrogenesis and carcinogenesis in the parenchymatous organs. A number of hereditary or acquired diseases are associated with systemic or local iron deposition or iron misdistribution in organs or cells. Two of these, the HFE- and non-HFE hemochromatosis syndromes represent the paradigms of genetic iron overload. They share common clinical features and the same pathogenic basis, in particular, a lack of synthesis or activity of hepcidin, the iron hormone. Before hepcidin was discovered, the liver was simply regarded as the main site of iron storage and, as such, the main target of iron toxicity. Now, as the main source of hepcidin, it appears that the loss of the hepcidin-producing liver mass or genetic and acquired factors that repress hepcidin synthesis in the liver may also lead to iron overload. Usually, there is low-grade excess iron which, through oxidative stress, is sufficient to worsen the course of the underlying liver disease or other chronic diseases that are apparently unrelated to iron, such as chronic metabolic and cardiovascular diseases. In the future, modulation of hepcidin synthesis and activity or hepcidin hormone-replacing strategies may become therapeutic options to cure iron-related disorders.
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Affiliation(s)
- Antonello Pietrangelo
- Division of Internal Medicine 2 and Center for Hemochromatosis, University Hospital of Modena, Modena, Italy
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Fonseca NA, Marioni J, Brazma A. RNA-Seq gene profiling--a systematic empirical comparison. PLoS One 2014; 9:e107026. [PMID: 25268973 PMCID: PMC4182317 DOI: 10.1371/journal.pone.0107026] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/06/2014] [Indexed: 11/18/2022] Open
Abstract
Accurately quantifying gene expression levels is a key goal of experiments using RNA-sequencing to assay the transcriptome. This typically requires aligning the short reads generated to the genome or transcriptome before quantifying expression of pre-defined sets of genes. Differences in the alignment/quantification tools can have a major effect upon the expression levels found with important consequences for biological interpretation. Here we address two main issues: do different analysis pipelines affect the gene expression levels inferred from RNA-seq data? And, how close are the expression levels inferred to the "true" expression levels? We evaluate fifty gene profiling pipelines in experimental and simulated data sets with different characteristics (e.g, read length and sequencing depth). In the absence of knowledge of the 'ground truth' in real RNAseq data sets, we used simulated data to assess the differences between the "true" expression and those reconstructed by the analysis pipelines. Even though this approach does not take into account all known biases present in RNAseq data, it still allows to estimate the accuracy of the gene expression values inferred by different analysis pipelines. The results show that i) overall there is a high correlation between the expression levels inferred by the best pipelines and the true quantification values; ii) the error in the estimated gene expression values can vary considerably across genes; and iii) a small set of genes have expression estimates with consistently high error (across data sets and methods). Finally, although the mapping software is important, the quantification method makes a greater difference to the results.
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Affiliation(s)
- Nuno A. Fonseca
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, United Kingdom
- * E-mail: (NF); (JM); (AB)
| | - John Marioni
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, United Kingdom
- * E-mail: (NF); (JM); (AB)
| | - Alvis Brazma
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, United Kingdom
- * E-mail: (NF); (JM); (AB)
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Vieira FMJ, Nakhle MC, Abrantes-Lemos CP, Cançado ELR, Reis VMSD. Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients. An Bras Dermatol 2014; 88:530-40. [PMID: 24068123 PMCID: PMC3760927 DOI: 10.1590/abd1806-4841.20132048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Accepted: 09/09/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Porphyria cutanea tarda is the most common form of porphyria, characterized by
the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several
reports associated HFE gene mutations of hereditary hemochromatosis with porphyria
cutanea tarda worldwide, although up to date only one study has been conducted in
Brazil. OBJECTIVES Investigation of porphyria cutanea tarda association with C282Y and H63D
mutations in the HFE gene. Identification of precipitating factors (hepatitis C,
HIV, alcoholism and estrogen) and their link with HFE mutations. METHODS An ambispective study of 60 patients with PCT was conducted during the period
from 2003 to 2012. Serological tests for hepatitis C and HIV were performed and
histories of alcohol abuse and estrogen intake were investigated. HFE mutations
were identified with real-time PCR. RESULTS Porphyria cutanea tarda predominated in males and alcohol abuse was the main
precipitating factor. Estrogen intake was the sole precipitating factor present in
25% of female patients. Hepatitis C was present in 41.7%. All HIV-positive
patients (15.3%) had a history of alcohol abuse. Allele frequency for HFE
mutations, i.e., C282Y (p = 0.0001) and H63D (p = 0.0004), were significantly
higher in porphyria cutanea tarda patients, compared to control group. HFE
mutations had no association with the other precipitating factors. CONCLUSIONS Alcohol abuse, hepatitis C and estrogen intake are prevalent precipitating
factors in our porphyria cutanea tarda population; however, hemochromatosis in
itself can also contribute to the outbreak of porphyria cutanea tarda, which makes
the research for HFE mutations necessary in these patients
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8
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Abstract
Hereditary porphyrias are a group of eight metabolic disorders of the haem biosynthesis pathway that are characterised by acute neurovisceral symptoms, skin lesions, or both. Every porphyria is caused by abnormal function of a separate enzymatic step, resulting in a specific accumulation of haem precursors. Seven porphyrias are the result of a partial enzyme deficiency, and a gain of function mechanism has been characterised in a new porphyria. Acute porphyrias present with acute attacks, typically consisting of severe abdominal pain, nausea, constipation, confusion, and seizure, and can be life-threatening. Cutaneous porphyrias present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe cutaneous photosensitivity and chronic haemolysis or chronic neurological symptoms with or without photosensitivity. Porphyrias are still underdiagnosed, but when they are suspected, and dependent on clinical presentation, simple first-line tests can be used to establish the diagnosis in all symptomatic patients. Diagnosis is essential to enable specific treatments to be started as soon as possible. Screening of families to identify presymptomatic carriers is crucial to decrease risk of overt disease of acute porphyrias through counselling about avoidance of potential precipitants.
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Affiliation(s)
- Hervé Puy
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, Colombes, France
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9
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Phillips JD, Bergonia HA, Reilly CA, Franklin MR, Kushner JP. A porphomethene inhibitor of uroporphyrinogen decarboxylase causes porphyria cutanea tarda. Proc Natl Acad Sci U S A 2007; 104:5079-84. [PMID: 17360334 PMCID: PMC1820519 DOI: 10.1073/pnas.0700547104] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Porphyria cutanea tarda (PCT), the most common form of porphyria in humans, is due to reduced activity of uroporphyrinogen decarboxylase (URO-D) in the liver. Previous studies have demonstrated that protein levels of URO-D do not change when catalytic activity is reduced, suggesting that an inhibitor of URO-D is generated in hepatocytes. Here, we describe the identification and characterization of an inhibitor of URO-D in liver cytosolic extracts from two murine models of PCT: wild-type mice treated with iron, delta-aminolevulinic acid, and polychlorinated biphenyls; and mice with one null allele of Uro-d and two null alleles of the hemochromatosis gene (Uro-d(+/-), Hfe(-/-)) that develop PCT with no treatments. In both models, we identified an inhibitor of recombinant human URO-D (rhURO-D). The inhibitor was characterized by solid-phase extraction, chromatography, UV-visible spectroscopy, and mass spectroscopy and proved to be uroporphomethene, a compound in which one bridge carbon in the uroporphyrinogen macrocycle is oxidized. We synthesized uroporphomethene by photooxidation of enzymatically generated uroporphyrinogen I or III. Both uroporphomethenes inhibited rhURO-D, but the III isomer porphomethene was a more potent inhibitor. Finally, we detected an inhibitor of rhURO-D in cytosolic extracts of liver biopsy samples of patients with PCT. These studies define the mechanism underlying clinical expression of the PCT phenotype, namely oxidation of uroporphyrinogen to uroporphomethene, a competitive inhibitor of URO-D. The oxidation reaction is iron-dependent.
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Affiliation(s)
- John D Phillips
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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Toll A, Celis R, Ozalla MD, Bruguera M, Herrero C, Ercilla MG. The prevalence of HFE C282Y gene mutation is increased in Spanish patients with porphyria cutanea tarda without hepatitis C virus infection. J Eur Acad Dermatol Venereol 2007; 20:1201-6. [PMID: 17062032 DOI: 10.1111/j.1468-3083.2006.01746.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To investigate the role of C282Y and H63D mutations, and hepatitis C virus (HCV) infection in the pathogenesis of porphyria cutanea tarda (PCT). DESIGN Prospective case-control study. SETTING A large clinical and research institute for the study and treatment of cutaneous diseases in Barcelona, Spain. PATIENTS Ninety-nine consecutive patients with PCT and one hundred and twenty-six control patients (76 healthy subjects and 50 patients chronically infected with HCV), were recruited. MAIN OUTCOME MEASURES The frequency of the C282Y and H63D mutations in patients with PCT vs. controls and the relationship of these mutations with HCV infection, and iron status, as judged by serum iron, liver iron and ferritin levels. RESULTS C282Y mutation was significantly increased in PCT patients. This mutation was more frequent among non-HCV-infected patients. Increased ferritin levels and hepatic iron overload were also observed in PCT patients with heterozygous C282Y state. H63D mutation was only significantly increased among PCT patients with chronic hepatitis C infection. No significant iron overload was observed in patients with H63D mutation. CONCLUSIONS This study confirms the high frequency of C282Y mutation in patients with PCT and its relationship with iron overload. The C282Y mutation has a relevant role in Spanish patients with PCT not associated with HCV chronic infection. On the other hand, the prevalence of the H63D mutation seems not to be increased in patients with PCT. The possibility of an association between HCV infection and H63D mutation in inducing PCT can be hypothesized.
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Affiliation(s)
- A Toll
- Department of Dermatology, Hospital Clinic, University of Barcelona, Spain.
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11
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Abstract
Trata-se de revisão sobre a porfiria cutânea tardia em que são abordados a fisiopatogenia, as características clínicas, as doenças associadas, os fatores desencadeantes, a bioquímica, a histopatologia, a microscopia eletrônica, a microscopia de imunofluorescência e o tratamento da doença.
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12
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Nezamzadeh R, Seubert A, Pohlenz J, Brenig B. Identification of a mutation in the ovine uroporphyrinogen decarboxylase (UROD) gene associated with a type of porphyria. Anim Genet 2005; 36:297-302. [PMID: 16026339 DOI: 10.1111/j.1365-2052.2005.01301.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Porphyria is a group of at least eight diseases caused by abnormalities in the chemical steps that lead to haeme production. The different types of porphyria show different signs and symptoms and can be strongly influenced by environmental factors. Mutations of the uroporphyrinogen decarboxylase (UROD) gene have been shown to be causative for porphyria cutanea tarda (PCT) in humans. Porphyria is a rare disorder in livestock. Although disorders of haeme biosynthesis have been described in cattle, pigs, sheep and cats, PCT has only been reported in pigs. We observed typical signs of porphyria (photosensitivity and porphyrinuria) in a flock of German Blackface sheep and postulated that the porphyria could be caused by a mutation in the UROD gene. To investigate this, we cloned and sequenced the ovine UROD gene. We identified a single point mutation (C --> T) in UROD which leads to an amino acid substitution at Leu 131 Pro, which is located within the active cleft site of the UROD protein.
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Affiliation(s)
- R Nezamzadeh
- Institute of Veterinary Medicine, University of Göttingen,Göttingen, Germany
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13
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Méndez M, Rossetti MV, Del C Batlle AM, Parera VE. The role of inherited and acquired factors in the development of porphyria cutanea tarda in the Argentinean population. J Am Acad Dermatol 2005; 52:417-24. [PMID: 15761419 DOI: 10.1016/j.jaad.2004.09.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Inherited and environmental factors are implicated in the expression of porphyria cutanea tarda (PCT); the contribution of each factor depends on the population. OBJECTIVE To provide a review of PCT cases diagnosed in Argentina over 24 years and evaluate the role of different precipitating factors in its pathogenesis. Methods Plasma and urinary porphyrin levels and erythrocyte uroporphyrinogen decarboxylase (URO-D) activity were determined. Potential precipitating factors were identified in each patient. Additional tests for hepatitis C virus (HCV) and hemochromatosis gene mutations were carried out. RESULTS Several factors (mainly alcohol abuse in men and estrogen ingestion in women), alone or combined were identified in our patients. Prevalence of HCV infection was 35.2%. Inherited URO-D deficiency occurs in 25.0% of cases. H63D was the most common hemochromatosis gene mutation. High incidence of PCT associated with HIV infection was found. CONCLUSIONS PCT is multifactorial. Therefore, knowledge of all risk factors in each patient is important for the management of the disease.
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Affiliation(s)
- Manuel Méndez
- National Research Institute on Porphyrins and Porphyrias (CIPYP), School of Sciences (FCEyN), University of Buenos Aires (UBA), and the Argentine National Research Council (CONICET), Buenos Aires, Argentina
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14
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Gardlo K, Selimovic D, Bolsen K, Ruzicka T, Abel J, Fritsch C. Cytochrome P4501A1 polymorphisms in a Caucasian population with porphyria cutanea tarda. Exp Dermatol 2003; 12:843-8. [PMID: 14714565 DOI: 10.1111/j.0906-6705.2003.00095.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Porphyria cutanea tarda (PCT) is the most frequent porphyria in humans. The familial type is in contrast to the sporadic type due to an inherited defect of the uroporphyrinogen-II-decarboxylase (URO-D) and both types need additional porphyrinogens to lead to the clinical manifestation of the disease. Various factors such as xenobiotics (i.e. polycyclic aromatic hydrocarbons), alcohol, hormones and viral liver infections (hepatitis B and C) are known to induce porphyria. Cytochrome p450 enzymes play a crucial role in the metabolism of porphyrogens and therefore might have an important influence on the pathogenesis of hepatic porphyrias. Association of CYP1A2 polymorphisms with susceptibility to both types of PCT has already been described in Danish patients. We investigated 65 caucasian patients with PCT in comparison to a healthy control group concerning the tpe of PCT and the cytochrome p4501A1 polymorphisms (m1, m2 and m4) using polymerase chain reaction (PCR) and a restriction fragment length polymorphism. We found an increased incidence of the m4 polymorphism in the familial type of PCT (odds ratio 5.5, P-value 0.01), whereas the m1 and m2 mutations, might be provoked by a higher susceptibility to porphyrogens via the cytochrome p4501A1 m4 polymorphism.
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Affiliation(s)
- K Gardlo
- Department of Dermatology, Heinrich-Heine University, Düsseldorf, Germany.
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15
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Affiliation(s)
- Shigeru Sassa
- Laboratory of Biochemical Hematology, The Rockefeller University, New York, NY, USA.
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Phillips JD, Parker TL, Schubert HL, Whitby FG, Hill CP, Kushner JP. Functional consequences of naturally occurring mutations in human uroporphyrinogen decarboxylase. Blood 2001; 98:3179-85. [PMID: 11719352 DOI: 10.1182/blood.v98.12.3179] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Functional consequences of 12 mutations-10 missense, 1 splicing defect, and 1 frameshift mutation-were characterized in the uroporphyrinogen decarboxylase (URO-D) gene found in Utah pedigrees with familial porphyria cutanea tarda (F-PCT). All but one mutation altered a restriction site in the URO-D gene, permitting identification of affected relatives using a combination of polymerase chain reaction and restriction enzyme digestion. In a bacterial expression system, 3 of the missense mutants were found in inclusion bodies, but 7 were expressed as soluble proteins. Enzymatic activity of soluble, recombinant mutant URO-D genes ranged from 29% to 94% of normal. URO-D mRNA levels in Epstein-Barr-virus transformed cells derived from patients were normal (with the exception of the frameshift mutation) even though protein levels were lower than normal, suggesting that missense mutations generally cause unstable URO-Ds in vivo. The crystal structures of 3 mutant URO-Ds were solved, and the structural consequences of the mutations were defined. All missense mutations reported here and by others were mapped to the crystal structure of URO-D, and structural effects were predicted. These studies define structural and functional consequences of URO-D mutations occurring in patients with F-PCT.
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Affiliation(s)
- J D Phillips
- Department of Medicine, University of Utah School of Medicine, Salt Lake City 84132, USA
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17
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Fracanzani AL, Taioli E, Sampietro M, Fatta E, Bertelli C, Fiorelli G, Fargion S. Liver cancer risk is increased in patients with porphyria cutanea tarda in comparison to matched control patients with chronic liver disease. J Hepatol 2001; 35:498-503. [PMID: 11682034 DOI: 10.1016/s0168-8278(01)00160-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIMS Patients with porphyria and chronic liver disease could be at high risk of developing hepatocellular carcinoma. To define the incidence of primary liver cancer and identify variables associated with the risk of cancer in patients with porphyria cutanea tarda in comparison to control patients. METHODS Fifty-three patients with porphyria cutanea tarda were enrolled in a prospective study (median follow-up 72 +/- 54.1 months; range 12-216) and matched individually to a control case according to age (+/-5 years), sex, duration of follow up (+/- 5 years), severity of liver disease, and hepatitis C virus infection. RESULTS During follow-up hepatocellular carcinoma developed in 18 patients with porphyria and in four control patients. Incidence of primary liver cancer was 4.8 and 1.3 x 100 patients/year in the overall series of patients and of controls, respectively. The cumulative probability of being tumor free was significantly lower in porphyria cutanea tarda than in matched controls (75 vs 95%). Variables independently associated with the risk of liver cancer were the presence of porphyria and cirrhosis at enrollment (Odds ratios: 5.3, 95% CI 1.4-19.3 and 3.0, 95% CI 1.2-7.6, respectively). CONCLUSIONS Patients with porphyria are at higher risk of developing liver cancer than matched control patients.
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Affiliation(s)
- A L Fracanzani
- Dipartimento di Medicina Interna, Università di Milano, Ospedale Maggiore IRCCS, Milan, Italy
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18
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Abstract
Porphyria cutanea tarda (PCT) is a metabolic disorder of haem biosynthesis caused by decreased activity of uroporphyrinogen decarboxylase. Porphyria cutanea tarda is manifest by fragility, erosions, bullae, milia and scars on sun-exposed skin. Excess porphyrins in the skin interact with light of approximately 400 nm-wavelength radiant energy, forming reactive oxygen species. Porphyria cutanea tarda is categorized as familial, acquired or toxic. Factors that may induce clinical expression of PCT in susceptible individuals include alcohol, oestrogen, iron, polyhalogenated compounds and viral infections. Porphyria cutanea tarda is associated with an increased incidence of the haemochromatosis gene. Treatments for PCT include withdrawal of aggravating factors, phlebotomy and oral antimalarial medications.
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Affiliation(s)
- N R Bleasel
- Department of Dermatology, Royal Melbourne Hospital, Victoria, Australia
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19
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Martinelli AL, Villanova MG, Roselino AM, Figueiredo JF, Passos AD, Covas DT, Zucoloto S. Abnormal uroporphyrin levels in chronic hepatitis C virus infection. J Clin Gastroenterol 1999; 29:327-31. [PMID: 10599635 DOI: 10.1097/00004836-199912000-00006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
A strong association between hepatitis C virus (HCV) infection and porphyria cutanea tarda (PCT) has been observed, but the implications of the viral infection in the metabolism of porphyrins in patients without clinical manifestations of PCT are not known. The levels of porphyrin in plasma and uroporphyrin (URO) and coproporphyrin (COPRO) in 24-hour urine were measured in 156 patients with chronic HCV infection showing no clinical evidence of PCT. Levels of URO higher than the upper limit were observed in 35 of 156 patients (22.4%). The range and the mean values +/- standard deviation were 26-1,196 microg/24 hours and 82 +/- 204 microg/24 hours. Increased levels of COPRO and plasma porphyrin were observed in 12 of 156 patients (7.7%) and 2 of 156 patients (1.3%) respectively. There were no differences between patients with increased URO levels and patients with normal URO levels in terms of gender, age, risk factors for HCV infection, alcohol abuse, or hepatitis B viral infection. Transferrin saturation (p = 0.040), gamma glutamyl transpeptidase (p < 0.0001), aspartate aminotransferase (p = 0.006), and alanine aminotransferase (p = 0.040) were significantly higher in patients with abnormal URO than in patients with normal URO. The frequency of cirrhosis was higher, but not significantly different, in patients with increased URO (16.7%) compared with patients with normal URO (3.8%). The authors demonstrated that even without a clinical manifestation of PCT it is possible to detect abnormalities in the metabolism of porphyrins in patients with chronic HCV infection. The implications of these findings deserve additional investigation.
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Affiliation(s)
- A L Martinelli
- Department of Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
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20
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Mendez M, Sorkin L, Rossetti MV, Astrin KH, del C Batlle AM, Parera VE, Aizencang G, Desnick RJ. Familial porphyria cutanea tarda: characterization of seven novel uroporphyrinogen decarboxylase mutations and frequency of common hemochromatosis alleles. Am J Hum Genet 1998; 63:1363-75. [PMID: 9792863 PMCID: PMC1377546 DOI: 10.1086/302119] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Familial porphyria cutanea tarda (f-PCT) results from the half-normal activity of uroporphyrinogen decarboxylase (URO-D). Heterozygotes for this autosomal dominant trait are predisposed to photosensitive cutaneous lesions by various ecogenic factors, including iron overload and alcohol abuse. The 3.6-kb URO-D gene was completely sequenced, and a long-range PCR method was developed to amplify the entire gene for mutation analysis. Four missense mutations (M165R, L195F, N304K, and R332H), a microinsertion (g10insA), a deletion (g645Delta1053), and a novel exonic splicing defect (E314E) were identified. Expression of the L195F, N304K, and R332H polypeptides revealed significant residual activity, whereas reverse transcription-PCR and sequencing demonstrated that the E314E lesion caused abnormal splicing and exon 9 skipping. Haplotyping indicated that three of the four families with the g10insA mutation were unrelated, indicating that these microinsertions resulted from independent mutational events. Screening of nine f-PCT probands revealed that 44% were heterozygous or homozygous for the common hemochromatosis mutations, which suggests that iron overload may predispose to clinical expression. However, there was no clear correlation between f-PCT disease severity and the URO-D and/or hemochromatosis genotypes. These studies doubled the number of known f-PCT mutations, demonstrated that marked genetic heterogeneity underlies f-PCT, and permitted presymptomatic molecular diagnosis and counseling in these families to enable family members to avoid disease-precipitating factors.
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Affiliation(s)
- M Mendez
- Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029, USA
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21
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Abstract
Hereditary hemochromatosis (HH) is a common autosomal recessive disorder that can result in iron overload and a wide range of clinical complications, including hepatic cirrhosis, diabetes mellitus, hypopituitarism, hypogonadism, arthritis, and cardiomyopathy. People with HH can be detected at an asymptomatic stage of the disease by abnormalities in serum iron measures. Early detection is desirable, because periodic phlebotomy provides effective treatment for iron overload and may prevent complications of the disorder. The natural history of HH is poorly understood, however, and the proportion of people detected by screening who will develop serious complications of HH is unknown. The genetics of HH may help to resolve these questions. The gene, HFE, and two mutations, C282Y and H63D, have been identified: the C282Y mutation has a higher penetrance than the H63D mutation, and appears to result in a greater loss of HFE protein function. Most people with HH are C282Y homozygotes, a small proportion are compound heterozygotes or H63D homozygotes, and some have no identifiable HFE mutation or are HFE heterozygotes, suggesting that additional mutations associated with HH are yet to be found. Gender and environmental agents, such as alcohol and dietary iron, influence phenotypic expression of HH. The severity of HH is thus determined by an interaction between genotype and modifying factors. HFE mutations also appear to increase the likelihood of iron overload in inherited anemias and to promote the clinical manifestations of porphyria cutanea tarda. HH is an important paradigm for medical genetics because it offers an opportunity to explore the complexity of gene gene and gene environment interactions.
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Affiliation(s)
- W Burke
- University of Washington, Seattle 98105, USA.
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22
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Whitby FG, Phillips JD, Kushner JP, Hill CP. Crystal structure of human uroporphyrinogen decarboxylase. EMBO J 1998; 17:2463-71. [PMID: 9564029 PMCID: PMC1170588 DOI: 10.1093/emboj/17.9.2463] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Uroporphyrinogen decarboxylase (URO-D) catalyzes the fifth step in the heme biosynthetic pathway, converting uroporphyrinogen to coproporphyrinogen by decarboxylating the four acetate side chains of the substrate. This activity is essential in all organisms, and subnormal activity of URO-D leads to the most common form of porphyria in humans, porphyria cutanea tarda (PCT). We have determined the crystal structure of recombinant human URO-D at 1.60 A resolution. The 40.8 kDa protein is comprised of a single domain containing a (beta/alpha)8-barrel with a deep active site cleft formed by loops at the C-terminal ends of the barrel strands. Many conserved residues cluster at this cleft, including the invariant side chains of Arg37, Arg41 and His339, which probably function in substrate binding, and Asp86, Tyr164 and Ser219, which may function in either binding or catalysis. URO-D is a dimer in solution (Kd = 0.1 microM), and this dimer also appears to be formed in the crystal. Assembly of the dimer juxtaposes the active site clefts of the monomers, suggesting a functionally important interaction between the catalytic centers.
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Affiliation(s)
- F G Whitby
- Department of Biochemistry, University of Utah School of Medicine, 50 N.Medical Drive, Salt Lake City, UT 84132, USA
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23
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Sampietro M, Piperno A, Lupica L, Arosio C, Vergani A, Corbetta N, Malosio I, Mattioli M, Fracanzani AL, Cappellini MD, Fiorelli G, Fargion S. High prevalence of the His63Asp HFE mutation in Italian patients with porphyria cutanea tarda. Hepatology 1998; 27:181-4. [PMID: 9425935 DOI: 10.1002/hep.510270128] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sporadic porphyria cutanea tarda (PCT) is caused by a reduced activity of uroporphyrinogen decarboxylase (URO-D) in the liver. Mild to moderate iron overload is common in PCT, as iron is one of the factors which trigger the clinical manifestations of the disease through the inactivation of URO-D. A role for genetic hemochromatosis in the development of iron overload in sporadic PCT has been hypothesized in the past. The aim of this work was to investigate whether mutations of HFE, which is a candidate gene for hemochromatosis, play the role of genetic susceptibility factors for PCT in Italian patients, who have a high prevalence of acquired triggering factors, such as hepatitis C virus (HCV) chronic infection and alcohol. We determined HFE genotypes of 68 male patients with PCT. Our data do not confirm an association of PCT with the Cys282Tyr HFE mutation, strongly associated with hemochromatosis in Northern European countries. A second mutation of HFE, His63Asp, however, had a significantly increased frequency as it was present in half of the patients. Surprisingly, the presence of the His63Asp mutation was not related to the iron status of patients, suggesting that a subtle abnormality of iron metabolism induced by this mutation could escape detection by the standard parameters of iron status. In PCT patients with liver disease, the presence of the mutation could contribute to the inactivation of URO-D, either directly or through a synergistic action with other factors that cause liver damage.
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Affiliation(s)
- M Sampietro
- Istituto di Medicina Interna e Fisiopatologia Medica, Università di Milano and IRCCS Ospedale Maggiore, Italy
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24
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Fargion S, Fracanzani AL, Romano R, Cappellini MD, Faré M, Mattioli M, Piperno A, Ronchi G, Fiorelli G. Genetic hemochromatosis in Italian patients with porphyria cutanea tarda: possible explanation for iron overload. J Hepatol 1996; 24:564-9. [PMID: 8773911 DOI: 10.1016/s0168-8278(96)80141-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND/AIMS Mild to moderate iron overload is found in most patients with porphyria cutanea tarda. This study aimed to evaluate whether iron overload in patients with porphyria cutanea tarda is related to the presence of a coexistent genetic hemochromatosis gene. METHODS A cohort study of 94 Italian patients with porphyria cutanea tarda (90 men and 4 women) and 20 relatives of five patients with iron overload were studied. Diagnosis of iron overload was assessed by transferrin saturation, serum ferritin and iron removed by phlebotomy to reach depletion. HLA typing by microlymphocytotoxicity test and duodenal ferritin analysis by immunohistochemistry were performed in a smaller number of patients. The chi square test was used to compare means and prevalences. RESULTS Iron overload was present in 62% of the patients. HLA-A3 prevalence was significantly higher (p < 0.01) in subjects with iron overload than in those without. A lack of duodenal ferritin was observed in 14/18 patients with and in 6/12 without iron overload. Family studies showed the presence of iron overload but not of porphyria cutanea tarda in HLA identical or semi-identical relatives of the patients. CONCLUSIONS Italian patients with porphyria cutanea tarda and iron overload appear to have one or even two genes for genetic hemochromatosis.
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Affiliation(s)
- S Fargion
- Institute of Internal Medicine and Medical Physiopathology, Institute G. Pini, Milan
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26
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Gould JW, Mercurio MG, Elmets CA. Cutaneous photosensitivity diseases induced by exogenous agents. J Am Acad Dermatol 1995; 33:551-73; quiz 574-6. [PMID: 7673488 DOI: 10.1016/0190-9622(95)91271-1] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cutaneous photosensitivity diseases may be idiopathic, produced by endogenous photosensitizers, or associated with exogenous photosensitizers. Those caused by exogenous agents include phototoxicity, photoallergy, and the exacerbation or induction of systemic disorders in which photosensitivity is a prominent clinical manifestation. Phototoxic disorders have a high incidence, whereas photoallergic reactions are much less frequent. The action spectra for most phototoxins and photoallergens lie in the UVA range. Phototoxic and photoallergic reactions can be distinguished on the basis of pathogenesis, clinical characteristics, diagnosis, and management. Drugs capable of causing phototoxic reactions include psoralens, porphyrins, coal tar, antibiotics, and nonsteroidal antiinflammatory agents. Drugs capable of causing photoallergic reactions include topical antimicrobial agents, fragrances, sunscreens, nonsteroidal antiinflammatory agents, plants, and psychiatric medications. Drug-induced systemic diseases in which photosensitivity is a prominent component include drug-induced lupus erythematosus, porphyria, and pellagra.
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Affiliation(s)
- J W Gould
- Department of Dermatology, Case Western Reserve University, Cleveland, OH, USA
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27
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Luo J, Lim CK. Isolation and characterization of new porphyrin metabolites in human porphyria cutanea tarda and in rats treated with hexachlorobenzene by HPTLC, HPLC and liquid secondary ion mass spectrometry. Biomed Chromatogr 1995; 9:113-22. [PMID: 7655298 DOI: 10.1002/bmc.1130090302] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Porphyrin metabolisms in human porphyria cutanea tarda (PCT) and in rats treated with hexachlorobenzene (HCB) have been studied in detail by high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC) and liquid secondary ion mass spectrometry (LSIMS). The analyses of porphyrin metabolites in the urine, faeces and liver biopsies of patients with PCT have shown that apart from uroporphyrin I and III and their expected decarboxylation intermediates and products, a complex mixture of many other porphyrins are present. The new porphyrins identified are: meso-hydroxyuroporphyrin III, beta-hydroxypropionic acid uroporphyrin III, hydroxyacetic acid uroporphyrin III, peroxyacetic acid uroporphyrin III, beta-hydroxyproionic acid heptacarboxylic acid porphyrin III, hydroxyacetic acid hepatocarboxylic porphyrin III and peroxyacetic acid pentacarboxylic porphyrin III.
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Affiliation(s)
- J Luo
- MRC Toxicology Unit, University of Leicester, UK
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28
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29
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Garey JR, Franklin KF, Brown DA, Harrison LM, Metcalf KM, Kushner JP. Analysis of uroporphyrinogen decarboxylase complementary DNAs in sporadic porphyria cutanea tarda. Gastroenterology 1993; 105:165-9. [PMID: 8099886 DOI: 10.1016/0016-5085(93)90022-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Sporadic porphyria cutanea tarda (S-PCT) has been considered an acquired disease because of the generation of liver-specific inhibitors of uroporphyrinogen decarboxylase (URO-D) activity. Several families have been described with S-PCT in multiple generations, raising the possibility of an inherited basis for the disease. To determine if S-PCT is associated with mutant URO-Ds that might be sensitive to liver-specific inhibitors, a molecular analysis of genomic and hepatocellular URO-Ds was undertaken. METHODS Total RNA from lymphoid cell lines from three unrelated patients with S-PCT and poly A+ RNA from liver biopsy samples from two additional patients was used as a template for single-stranded cDNA synthesis, and URO-D sequences were amplified and sequenced. DNA prepared from peripheral blood leukocytes was used as a template to polymerase chain reaction (PCR) amplify the promoter region of the URO-D gene. Sequencing of PCR products was performed completely in both directions by the chain termination method using a variety of custom oligonucleotide primers. RESULTS Ten URO-D alleles were sequenced, and no mutations were found. The promoter region of the URO-D gene was also normal. CONCLUSIONS It is concluded that S-PCT is not due to mutations at the URO-D locus. If inherited factors are involved, other loci must be affected.
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Affiliation(s)
- J R Garey
- Department of Medicine, University of Utah School of Medicine, Salt Lake City
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30
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Kószó F, Morvay M, Dobozy A, Simon N. Erythrocyte uroporphyrinogen decarboxylase activity in 80 unrelated patients with porphyria cutanea tarda. Br J Dermatol 1992; 126:446-9. [PMID: 1610684 DOI: 10.1111/j.1365-2133.1992.tb11816.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To estimate the prevalence of the subgroups of porphyria cutanea tarda (PCT), erythrocyte uroporphyrinogen decarboxylase (UD) activity was measured in 80 unrelated patients with PCT, and in 45 of their relatives by using pentacarboxyl-porphyrinogen III as substrate. The subgroups were differentiated by analysis of the urinary porphyrins of the patients and 119 of their relatives. Of the patients, 77.5% were found to be suffering from the sporadic form of PCT (type I PCT), and 22.5% from the familial form (type II PCT). Every patient with PCT had previously been affected by alcohol, oestrogen or some other liver-damaging factor. The relative frequency of familial PCT was higher in females (nine of 15) than in males (nine of 65), which suggests that inheritance of the gene for type II PCT may predispose to oestrogen-precipitated PCT. The onset of type II PCT occurred at a lower age than that of type I (42.6 vs. 47.0 years). The findings suggest an increased risk of precipitating factors in carriers of an inherited UD deficiency.
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Affiliation(s)
- F Kószó
- Department of Dermatology, Albert Szent-Györgyi Medical University, Szeged, Hungary
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31
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KOSZO F, MORVAY M, DOBOZY A, SIMON N. Erythrocyte uroporphyrinogen decarboxylase activity in 80 unrelated patients with porphyria cutanea tarda. Br J Dermatol 1992. [DOI: 10.1111/j.1365-2133.1992.tb15114.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Affiliation(s)
- J W Young
- Department of Dermatology, Grandview Hospital Medical Center, Centerville, Ohio 45459
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33
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Luo JL, Lim CK. Random decarboxylation of uroporphyrinogen III by human hepatic uroporphyrinogen decarboxylase. JOURNAL OF CHROMATOGRAPHY 1991; 566:409-13. [PMID: 1939452 DOI: 10.1016/0378-4347(91)80257-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The type III heptacarboxylic porphyrinogens derived from enzymic decarboxylation of an acetic acid substituent on uroporphyrinogen III to a methyl group by human hepatic uroporphyrinogen decarboxylase has been analysed by reversed-phase high-performance liquid chromatography with electrochemical detection. The results showed that all four possible heptacarboxylic acid porphyrinogen isomers, with the methyl group attached to rings A, B, C and D of the tetrapyrrole macrocycle, respectively, were formed in almost equal proportions. It was concluded that the normal pathway of uroporphyrinogen III decarboxylation in human liver follows a random mechanism.
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Affiliation(s)
- J L Luo
- Division of Clinical Cell Biology, MRC Clinical Research Centre, Harrow, Middlesex, U.K
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34
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Porphyrias. Dermatology 1991. [DOI: 10.1007/978-3-662-00181-3_44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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35
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Mukerji SK, Pimstone NR. Free radical mechanism of oxidation of uroporphyrinogen in the presence of ferrous iron. Arch Biochem Biophys 1990; 281:177-84. [PMID: 2168153 DOI: 10.1016/0003-9861(90)90429-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Human porphyria cutanea tarda is an unusual consequence of common hepatic disorders such as alcoholic liver disease. Hepatic iron plays a key role in the expression of the metabolic lesions, i.e., defective hepatic decarboxylation of porphyrinogens, catalyzed by uroporphyrinogen decarboxylase. This prompted the present study to determine the in vitro effects of iron on the uroporphyrinogen substrate in the absence and presence of atmospheric oxygen. We observed that (i) unless oxygen is the limiting reactant, autoxidation of ferrous iron and iron-catalyzed oxidation of uroporphyrinogen occurred soon after initiating the reaction at pH 7.4 and 30 degrees C in buffers which are non- or poor chelators of iron; (ii) the rates of uroporphyrinogen oxidation were proportional to the initial concentration of ferrous ion; (iii) about 70% of the oxidations of uroporphyrinogen were accountable due to a free-radical chain reaction pathway involving superoxide radical and hence inhibitable by superoxide dismutase; (iv) uroporphyrinogen could be further oxidized to completion by the hydroxyl radical since the reaction was partially inhibited by both mannitol and catalase which prevent hydroxyl radical production; (v) the oxidizing effects of ferric ion on uroporphyrinogen were none or negligible as compared to those of ferrous ion. Ferric was reduced to ferrous ion in the presence of dithiothreitol. When the ferrous ion thus formed was reoxidized in the presence of atmospheric oxygen, minor but definite oxidations of both uroporphyrinogen and dithiothreitol were observed. The oxidations of Fe2+ and uroporphyrinogen could be blocked by 1,10-phenanthroline, a ferrous iron chelator. The data suggest that ferrous is the reactive form of iron that may contribute to pathogenic development of the disease by irreversibly oxidizing the porphyrinogen substrates to nonmetabolizable porphyrins, which accumulate in porphyric liver.
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Affiliation(s)
- S K Mukerji
- Department of Internal Medicine, School of Medicine, University of California, Davis, Sacramento 95817
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36
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Smith AG, De Matteis F. Oxidative injury mediated by the hepatic cytochrome P-450 system in conjunction with cellular iron. Effects on the pathway of haem biosynthesis. Xenobiotica 1990; 20:865-77. [PMID: 2238708 DOI: 10.3109/00498259009046902] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. Some polyhalogenated aromatic chemicals such as 2,3,7,8-tetrachloro-p-dioxin, brominated and chlorinated biphenyls, and hexachlorobenzene cause in humans, animals and hepatocyte systems a partial block in haem biosynthesis leading to accumulation and excretion of uroporphyrin, the oxidation product of the unstable biosynthetic intermediate uroporphyrinogen. 2. The involvement of reactive toxic metabolites of the halogenated chemicals has previously been suggested. The evidence presented in this paper supports a different mechanism involving chronic induction of the microsomal cytochrome P-450 system, mobilization of hepatocellular iron and associated oxidative stress. Besides oxidation of uroporphyrinogen to uroporphyrin, an inhibitor of uroporphyrinogen decarboxylase may also be formed. 3. Studies with iron-loaded mice and chicken embryo hepatocytes show that under appropriate conditions iron alone, or chemicals such as beta-naphthoflavone which induce the same cytochromes P-450 isozymes as do the chlorinated aromatics, will cause a similar uroporphyria. These findings provide an experimental model for the human disease porphyria cutanea tarda, sometimes occurring in patients with liver damage. 4. Experiments with rats and iron-loaded mice indicate that there may also be an association between the induction of uroporphyria and the development of liver tumours after administration of polyhalogenated aromatic chemicals.
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Affiliation(s)
- A G Smith
- MRC Toxicology Unit, Medical Research Council Laboratories, Carshalton, Surrey, UK
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Anderson KE, Goeger DE, Carson RW, Lee SM, Stead RB. Erythropoietin for the treatment of porphyria cutanea tarda in a patient on long-term hemodialysis. N Engl J Med 1990; 322:315-7. [PMID: 2104958 DOI: 10.1056/nejm199002013220507] [Citation(s) in RCA: 313] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- K E Anderson
- Department of Preventive Medicine, University of Texas Medical Branch, Galveston 77550
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38
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Edwards CQ, Griffen LM, Goldgar DE, Skolnick MH, Kushner JP. HLA-linked hemochromatosis alleles in sporadic porphyria cutanea tarda. Gastroenterology 1989; 97:972-81. [PMID: 2789160 DOI: 10.1016/0016-5085(89)91506-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We tested the hypothesis that the hepatic siderosis that characterizes sporadic porphyria cutanea tarda is due to the presence of HLA-linked hemochromatosis alleles. We studied 21 probands with sporadic porphyria cutanea tarda and 135 of their relatives by determining HLA haplotypes and measuring transferrin saturation and serum ferritin concentration. Liver biopsies were performed in all probands and in relatives when appropriate. Seventeen pedigrees were available and were studied by both likelihood analysis and by a gene counting method. We estimated that 10 of the 17 probands with available living relatives possessed at least one hemochromatosis allele. Thirteen of the 21 probands (62%) possessed at least one HLA-A3 alloantigen. Eighteen of 69 relatives who shared an HLA haplotype with a proband (26%) had an elevation of transferrin saturation or serum ferritin concentration. Only one first-degree relative not sharing an HLA haplotype with a proband had an elevated transferrin saturation or serum ferritin concentration. These findings indicate that HLA-linked hemochromatosis alleles are far more common in patients with sporadic porphyria cutanea tarda than in individuals in the general population and may be responsible for the hepatic siderosis associated with most cases of sporadic porphyria cutanea tarda.
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Affiliation(s)
- C Q Edwards
- Department of Internal Medicine, University of Utah College of Medicine, Salt Lake City
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Held JL, Sassa S, Kappas A, Harber LC. Erythrocyte uropophyrinogen decarboxylase activity in porphyria cutanea tarda: A study of 40 consecutive patients. J Invest Dermatol 1989. [DOI: 10.1016/0022-202x(89)90053-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Held JL, Sassa S, Kappas A, Harber LC. Erythrocyte Uropophyrinogen Decarboxylase Activity in Porphyria Cutanea Tarda: A study of 40 Consecutive Patients. J Invest Dermatol 1989. [DOI: 10.1111/1523-1747.ep12280241] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Feldman ES, Bacon BR. Hepatic mitochondrial oxidative metabolism and lipid peroxidation in experimental hexachlorobenzene-induced porphyria with dietary carbonyl iron overload. Hepatology 1989; 9:686-92. [PMID: 2707735 DOI: 10.1002/hep.1840090505] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Both human porphyria cutanea tarda and experimental hexachlorobenzene-induced porphyria are associated with hepatic injury and are potentiated by excess hepatic iron. The mechanisms whereby cellular injury occurs and the synergistic role of iron overload are unknown. In the present experiments, we studied hepatic mitochondrial function and lipid peroxidation in rats with hexachlorobenzene-induced porphyria in which iron loading was achieved by dietary carbonyl iron supplementation. Female rats were treated for 8 weeks, receiving a chow diet supplemented with hexachlorobenzene (0.2%, w/w), carbonyl iron (1.0%, w/w) or hexachlorobenzene + iron. Hepatic total porphyrins were increased 100-fold in rats receiving hexachlorobenzene (hexachlorobenzene alone and hexachlorobenzene + Fe), and total hepatic iron was increased approximately 10-fold in rats receiving iron supplementation (Fe alone and hexachlorobenzene + Fe). There was a significant increase in mitochondrial lipid peroxidation in rats treated with hexachlorobenzene alone and hexachlorobenzene + Fe. A significant reduction in mitochondrial respiratory control ratios and in oxidative phosphorylation (ADP/O ratios) using glutamate and succinate as substrates was demonstrated when rats were treated with hexachlorobenzene + iron. The reductions in respiratory control ratios were due to a combination of an inhibitory defect in electron transport as evidenced by an irreversible decrease in State 3 respiration and an uncoupling effect as evidenced by an increase in State 4 respiration. These findings suggest that lipid peroxidation and mitochondrial dysfunction may contribute to the hepatotoxicity seen in hexachlorobenzene-induced porphyria.
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Affiliation(s)
- E S Feldman
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland Metropolitan General Hospital, Ohio 44109
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Abstract
A previously unrecognized form of dual porphyria has been identified in four patients. One male and one female with acute symptoms were diagnosed as having acute intermittent porphyria (AIP), and two males with cutaneous and acute symptoms were diagnosed as having porphyria cutanea tarda (PCT). Biochemically, the excretion of haem precursors showed a complex constellation, with signs characteristic of both AIP and PCT. In one male, a clinical course with both overt PCT and acute manifestations of AIP was observed. Enzyme studies of haem biosynthesis in erythrocytes revealed a dual deficiency, with decreased activity of both porphobilinogen deaminase, as seen in AIP, and uroporphyrinogen decarboxylase, as seen in PCT. A family study showed that the two disorders do not consistently segregate together. These findings suggest that the dual porphyria reflects a double heterozygous condition of coexistent AIP and PCT genes in the same subject.
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Affiliation(s)
- M O Doss
- Department of Clinical Biochemistry, Faculty of Medicine, Philipp University, Marburg an der Lahn, FRG
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Abstract
The porphyrias are metabolic disorders in which there are excessive accumulation and excretion of porphyrins and porphyrin precursors. Each of the porphyrias has a specific enzyme defect in the pathway of heme biosynthesis that explains the pattern of biochemical abnormalities that occur. However, some patients have the enzyme defect but do not have clinical or biochemical manifestations, indicating that other factors (e.g., demand for increased heme biosynthesis) are also important in causing disease expression. The major clinical manifestations are neurologic dysfunction and photosensitivity. The precise cause of the neurologic dysfunction has not been defined, but the likely possibilities are overproduction of delta-aminolevulinic acid, which may act as a neurotoxin, or a deficiency of heme (or both). The cutaneous lesions in the porphyrias are due to the photo-sensitizing and other effects of porphyrins that are deposited in the skin or are circulating in dermal blood vessels. Therapy is directed to modify the biochemical abnormalities. Most importantly, intravenous administration of hematin is used in the treatment of acute attacks of neurologic dysfunction. Prevention remains a cornerstone in management of patients with porphyria, and those with gene defects should be counseled regarding factors that precipitate acute attacks.
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Affiliation(s)
- J R Bloomer
- Division of Gastroenterology and Hepatology, University of Minnesota, Minneapolis
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Adjarov DG, Elder GH. A simplified method for determination of uroporphyrinogen decarboxylase activity in human blood. Clin Chim Acta 1988; 177:123-30. [PMID: 3233762 DOI: 10.1016/0009-8981(88)90133-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The determination of erythrocyte uroporphyrinogen decarboxylase activity is essential for differentiating familial (type II) porphyria cutanea tarda from the sporadic (type I) form of the disease. A new technique for the determination of uroporphyrinogen decarboxylase activity in human blood is described. Haemolysate is incubated with uroporphyrinogen III as substrate. Uroporphyrinogen unconverted during the reaction is oxidised to uroporphyrin and measured directly as free acid by HPLC. The enzyme activity is then calculated from the amount of substrate consumed. The technique is simple, rapid and highly reproducible. It is recommended as a clinical assay.
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Affiliation(s)
- D G Adjarov
- Department of Biochemistry, Institute of Gastroenterology and Nutrition, Medical Academy, Sofia, Bulgaria
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Edwards CQ, Griffen LM, Skolnick MH, Kushner JP. Sporadic porphyria cutanea tarda in individuals with HLA-linked hemochromatosis allele(s). Preliminary report. Ann N Y Acad Sci 1988; 526:47-53. [PMID: 3164603 DOI: 10.1111/j.1749-6632.1988.tb55491.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- C Q Edwards
- Department of Internal Medicine, University of Utah College of Medicine, Salt Lake City 84132
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Cantoni L, Rizzardini M, Graziani A, Carugo C, Garattini S. Effects of chlorinated organics on intermediates in the heme pathway and on uroporphyrinogen decarboxylase. Ann N Y Acad Sci 1987; 514:128-40. [PMID: 3442377 DOI: 10.1111/j.1749-6632.1987.tb48767.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Experimental porphyria induced by PHAHs is characterized by a progressive reduction in the activity of UROD. After intoxication with TCDD, the most porphyrogenic compound known to date, the liver was the principal site of action, as regards both porphyrin accumulation (mostly uroporphyrin) and the degree of enzyme impairment; the kidney was the site of the second greatest accumulation; the brain and erythrocytes were unaffected. Additional modifications of the heme pathway involved induction of the activity of ALAS and, at least in HCB-induced porphyria after iron pretreatment, may have involved reduced activity of uroporphyrinogen III cosynthetase. These changes can alter the amount and the isomeric composition of uroporphyrinogens and uroporphyrins present in the liver in a way that is likely to help reduce formation of coproporphyrinogen III in porphyric animals. As in the human syndrome porphyria cutanea tarda, iron administration increased porphyrin accumulation and the degree of reduction of UROD activity in mice fed HCB. Mice fed HCB also presented an activation of the type O form of XO. This activation was independent of tissue injury derived from the lipid peroxidation that was concomitant with iron administration. The increase in activity of the type O form of XO may be a characteristic feature of the liver damage found in PHAH intoxication and, in intoxicated animals, could be a source in the liver of oxidant species involved in the mechanism of UROD inactivation--if this inactivation is in fact due to an oxidative reaction.
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Affiliation(s)
- L Cantoni
- Istituto di Ricerche Farmacologiche, Mario Negri, Milan, Italy
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Beaumont C, Fauchet R, Phung LN, De Verneuil H, Gueguen M, Nordmann Y. Porphyria cutanea tarda and HLA-linked hemochromatosis. Evidence against a systematic association. Gastroenterology 1987; 92:1833-8. [PMID: 3569756 DOI: 10.1016/0016-5085(87)90612-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This study was designed to test the hypothesis that a hemochromatosis allele is implicated in the expression of porphyria cutanea tarda. HLA phenotypes were determined in 69 porphyria cutanea tarda patients, 42 of which had the sporadic type (normal erythrocyte uroporphyrinogen decarboxylase activity) and 27 unrelated patients who had the familial type (diminished erythrocyte uroporphyrinogen decarboxylase activity). The incidence of HLA antigen A3, a marker of the hemochromatosis allele, was identical in the sporadic patients (23.8%), in the familial patients (22.2%), and in the controls (24.5%). Furthermore, no clinical difference could be found between A3 and non-A3 patients. These results demonstrate no systematic association between hemochromatosis and porphyria cutanea tarda in the population studied. Another HLA-linked gene, however, could be implicated in the expression of the disease as HLA antigen DR7 presented an incidence statistically different (p less than 0.05) between sporadic (16.6%) and familial patients (43%).
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Toback AC, Sassa S, Poh-Fitzpatrick MB, Schechter J, Zaider E, Harber LC, Kappas A. Hepatoerythropoietic porphyria: clinical, biochemical, and enzymatic studies in a three-generation family lineage. N Engl J Med 1987; 316:645-50. [PMID: 3821794 DOI: 10.1056/nejm198703123161101] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Hepatoerythropoietic porphyria is caused by a marked deficiency in the activity of uroporphyrinogen decarboxylase, an enzyme that is essential for heme biosynthesis. It has been hypothesized that uroporphyrinogen decarboxylase deficiency is inherited as a homozygous defect in the disease. This suggestion has been supported by reports of a deficiency of the enzyme in parents of patients with the disorder. Further confirmation would be provided by demonstrating a similar uroporphyrinogen decarboxylase deficiency in the offspring of such patients. This study follows the enzymatic defect throughout three generations of a family in which a second-generation male was shown to have hepatoerythropoietic porphyria. Detailed biochemical and enzymatic analyses revealed a moderate deficiency of uroporphyrinogen decarboxylase in both the proband's parents and in his three children, all of whom were asymptomatic. The mildness of the clinical symptoms in the proband correlated with a higher level of residual enzyme activity than that in previously described patients. We conclude that clinically manifested hepatoerythropoietic porphyria results from the homozygous inheritance of a defect in the uroporphyrinogen decarboxylase gene, that the severity of clinical symptoms is probably related to the level of residual enzyme activity, and that the genetic defect of uroporphyrinogen decarboxylase in hepatoerythropoietic porphyria can be heterogeneous.
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Ríos de Molina MC, Wainstok de Calmanovici R, San Martín de Viale LC. Liver porphyrinogen carboxylase in hexachlorobenzene porphyric rats. Studies with intermediate porphyrinogens of series III and with uroporphyrinogen I. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1987; 19:365-72. [PMID: 3595984 DOI: 10.1016/0020-711x(87)90010-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The present work studies the action of hexachlorobenzene (HCB) on the decarboxylation of uroporphyrinogen (Urogen) I and III and also on the decarboxylation of intermediate porphyrinogens of series III under different conditions using liver of normal and porphyric rats as enzyme source. The same enzyme is involved in the Urogen decarboxylation of both isomeric series I and III and catalyses the four steps in both cases. HCB affects all of them. HCB blocks the four steps of Urogen III decarboxylation to the same degree, as a function of intoxication time. HCB leads, in general, to an increase in the efficiency (Km/Vmax) of the porphyric system. These data can be interpreted as a reaction of the organism to overcome the enzymatic blockade.
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