Association between hepatitis C virus and porphyria cutanea tarda

Porphyria cutanea tarda (PCT) arises from a deficiency of uroporphyrinogen decarboxylase (UROD) in the liver. Several exogenous risk factors are associated with the acquired form of the disease. In Southern Europe, PCT is strongly linked to hepatitis C virus (HCV) infection to the point that a high prevalence of viral infection in some geographic areas generated an increase of PCT cases as a complication. In spite of the association, PCT is a rare complication of HCV infection, thus suggesting the existence of susceptibility factors operating in only some patients. Investigation of liver specimens of PCT patients showed iron accumulation, which albeit moderate, was higher in comparison with HCV-infected patients without PCT. Measurements of hepcidin in serum of HCV-infected patients with and without PCT and calculation of hepcidin/ferritin ratio were compatible with the hypothesis that HCV induced inadequate response of hepcidin to iron accumulation. Administration of direct-acting antivirals (DAA) to HCV-infected patients with active PCT showed that eradication of the virus was followed by resolution of PCT and rapid disappearance of urinary porphyrins. This suggests a direct participation of the virus in the oxidative mechanism leading to UROD inhibition. If clinical evolution of HCV- PCT-patients is placed within a time-frame, rapid PCT resolution by DAA is in striking contrast with a long-delay (in most cases of decades) between viral infection and appearance of overt porphyria. This could be explained if HCV infection (a): enhanced an oxidative environment in the vicinity of UROD and (b): facilitated iron accumulation through hepdicin down-regulation. Thus, only when iron accumulation reached a threshold, inhibition of UROD attained a critical level. However, the enigma is why only a minority of HCV-infected patients develop PCT. If additional risk factors (i.e. alcohol abuse) are not concurring, it should be concluded that modifier genes or epigenetic mechanisms related to iron homeostasis, facilitate iron progressive accumulation in only a minority susceptible patients.

Porphyria cutanea tarda and liver disease. A retrospective analysis of 17 cases from a single centre and review of the literature

BACKGROUND/AIMS

Sporadic Porphyria Cutanea Tarda (sPCT) is associated with liver disease, e.g. HCV infection, haemochromatosis and especially alcoholic liver disease. We conducted a retrospective analysis on the prevalence of liver disorders in association with Porphyria Cutanea Tarda (PCT), in a university referral centre.

METHODS

The PCT cases were retrieved from computerized databases. Patient files lacking information on the presence of concomitant liver disease were excluded from further analysis.

RESULTS

29 PCT patients were retrieved from our databases, of which 17 patients with sPCT were retained for further analysis. Patients were middle aged (mean age: 43 +/- 3) and there was no gender difference (10 males vs. 7 females). Almost all patients had iron overload (14/17). 5 patients had chronic HCV, with type 1b in 3 of them, 7 abused alcohol, 4 patients had hereditary haemochromatosis (3 homozygous C282Y--1 heterozygous H63D/C282Y). In 3 patients sPCT was associated with medication intake and one patient had chronic hepatitis B (HBV). 13 patients were treated with phlebotomies, with success in 11/13. 4 patients were treated with chloroquine, 3 of which also underwent phlebotomies. Of the 5 patients with HCV, 3 were successfully treated with combined antiviral therapy; one of them is planned to be treated; one patient never received therapy and was lost from follow-up. One patient developed hepatocellular carcinoma (HCC) during a median follow-up of 24 years.

CONCLUSIONS

We found a significant association between sPCT and liver disorders, such as chronic HCV infection, alcohol abuse, iron overload and hereditary haemochromatosis. Therefore, patients presenting with PCT should be screened for concomitant liver disease. Iron overload is present in a majority of patients, the majority of patients can be successfully treated with phlebotomies. The risk of developing HCC in our sPCT patients and in literature is low.

The prevalence of HFE C282Y gene mutation is increased in Spanish patients with porphyria cutanea tarda without hepatitis C virus infection

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.

[Hepatitis C, hemochromatosis and porphyria cutanea tarda]

Porphyria cutanea tarda (PCT) is characterized by decreased activity of the enzyme uroporphyrinogen decarboxylase (URO-D) and the accumulation of uro- and heptaporphyrins in the liver. Apart from increased alcohol exposure and certain drugs, PCT is associated with antibodies to the hepatitis C virus (HCV), with its prevalence increasing from Northern (8-10%) to Southern Europe (71 to 91%). Chronic HCV-infection is thus considered to be a major trigger for PCT and PCT is said to be an important extrahepatic manifestation of HCV-infection in predisposed individuals. Iron overload is common in PCT. Iron is an inhibitory co-factor of URO-D activity in hepatocytes. Accordingly, in support of the critical role of iron, the clinical efficacy of iron removal is coupled to an improvement of hepatic URO-D activities. Up to two thirds of Saxon patients with PCT carry the classical hemochromatosis (HFE) mutations (C282Y and/or H63D). HFE genotyping can help to further classify patients with PCT and associated hemochromatosis. Simple or compound heterozygosity of HFE mutations does not affect the therapeutic response to chloroquine in PCT. Since Patients carrying homozygous mutations (C282Y/C282Y) with hemochromatosis and PCT do not respond to chloroquine, phlebotomy should be first-line treatment to remove toxic iron.

[The combination of carbohydrate and porphyrinic exchange disturbances: is it a chance or regularity?]

The subjects of the study were 399 patients with internal diseases and metabolic disturbances. Carbohydrate exchange parameters (fasting level of capillary blood glucose and glucose tolerance test), and porphyrin fractions in urine (uroporphyrin, coproporphyrin), and feces (protoporphyrin, coproporphyrin) were measured. Hepatic type of porphyrinic dysmetabolism was registered in 201 (50.4%) patients. Out of these patients, 38 had disturbances corresponding to the criteria of symptomatic elevation of fecal porphyrin level, 28 had secondary coproporphyrinuria, 40 had latent, and 95 had manifest late cutaneous porphyria. In patients with normal porphyrinic exchange, the frequency of carbohydrate exchange disturbances did not exceed 6%, while in patients with different variants of porphyrinic dysmetabolism it was almost 40%. The results show that patients with hepatic type of porphyrinic dysmetabolism should be considered to have a higher risk of the development of diabetes mellitus and other carbohydrate disorders.

Porphyria Cutanea Tarda in a Swedish Population: Risk Factors and Complications

There are varying reports on the prevalence of risk factors in porphyria cutanea tarda (PCT). We reviewed 84 patients with PCT in a restricted uptake area in Gothenburg, Sweden and evaluated different potential risk factors for the disease and complications. Besides a thorough medical history, the patients were investigated with urinary porphyrin analyses, transferrin saturation, ferritin and liver tests. Subsamples of patients were tested for antibodies to hepatitis C virus (n = 68), haemochromatosis gene mutations (n = 58) and with the oral glucose tolerance test (n = 31). We found a prevalence of about 1 patient with PCT in 10 000 inhabitants. Nineteen (23%) patients reported heredity for PCT. Identified risk factors were alcohol abuse (38% of male patients), oestrogen treatment (55% of female patients), anti-hepatitis C virus positivity (29% of male patients), diabetes (17%) or impaired glucose tolerance (45% of tested patients) and haemochromatosis gene mutations (57% of tested patients). All patients positive for anti-hepatitis C virus belonged to the non-hereditary group. During follow-up we observed a high incidence of stroke, no case of hepatocellular carcinoma and a normal life expectancy.

The role of inherited and acquired factors in the development of porphyria cutanea tarda in the Argentinean population

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.

The molecular basis of porphyria cutanea tarda in Chile: Identification and functional characterization of mutations in the uroporphyrinogen decarboxylase gene

The porphyrias are heterogeneous disorders arising from predominantly inherited catalytic deficiencies of specific enzymes in heme biosynthesis. Porphyria cutanea tarda (PCT) results from a decreased activity of uroporphyrinogen decarboxylase, the fifth enzyme in heme biosynthesis. The disorder represents the only porphyria that is not exclusively inherited monogenetically. In PCT, at least two different types can be distinguished: acquired/sporadic (type I) PCT, in which the enzymatic deficiency is limited to the liver and inherited/familial (type II) PCT, which is inherited as an autosomal dominant trait with a decrease of enzymatic activity in all tissues. In an effort to characterize the molecular basis of PCT in Chile, we identified eight mutations in 18 previously unclassified PCT families by polymerase chain reaction, heteroduplex analysis, and automated sequencing. To study the role of these mutations in disease causality, in vitro expression of all novel missense mutations was studied. Our results indicate that the frequency of familial PCT in Chile is approximately 50%, thus, to our knowledge, representing the highest incidence of familial PCT reported to date. The data further emphasize the molecular heterogeneity in type II PCT and demonstrate the advantages of molecular genetic techniques as a diagnostic tool and in the detection of clinically asymptomatic mutation carriers.

Porphyria cutanea tarda, C282Y, H63D and S65C HFE gene mutations and hepatitis C infection: a study from southern France

BACKGROUND

To evaluate the role of genetic factors in the pathogenesis of porphyria cutanea tarda (PCT) and their association with chronic hepatitis C.

OBJECTIVE

To investigate the relations between hemochromatosis gene (HFE) mutations and PCT in the south of France and their links with chronic hepatitis C virus (HCV) infection.

METHODS

The genotype for the C282Y, H63D and S65C mutations of HFE was determined in 33 patients with PCT, 46 patients with HCV infection but without PCT and 58 controls. Iron status and HCV, HBV and HIV serologies were studied in all patients.

RESULTS

A statistically significant increase in the C282Y mutation was found in PCT patients. No difference was found for H63D or S65C mutations. The prevalence of HCV infection was higher in PCT patients than controls.

CONCLUSIONS

C282Y mutations and HCV infection but not H63D or S65C mutations are PCT-triggering or associated factors in the south of France.

Hemochromatosis (HFE) and transferrin receptor-1 (TFRC1) genes in sporadic porphyria cutanea tarda (sPCT)

Porphyria cutanea tarda (PCT), a disorder characterized by a photosensitive dermatosis and hepatic siderosis, is caused by a decreased activity of the hepatic enzyme uroporphyrinogen decarboxylase (UROD). Two forms of PCT have been described: a familial one (fPCT) with an inherited decrease of UROD activity in all tissues and a sporadic one (sPCT) with a decreased UROD activity restricted to the liver. Iron overload and acquired factors including hepatic viral infections, alcohol, drugs contribute to the expression of PCT. In 65 French sPCT patients and 108 controls we have evaluated the respective role of iron and HCV status, the hemochromatosis (HFE) gene mutations frequencies (H63D. S65C, C282Y), and in a case control study we searched for an association between sPCT and the human transferrin receptor-1 (TFRC1) gene whose product is thought to be in functional association with the HFE protein: three single nucleotide polymorphisms (SNPs) previously characterized and 2 novel ones were studied. The iron-related parameters and transaminases were higher in sPCT patients than those of non-porphyric controls. Of the sPCT patients studied, 28% were HCV positive. In the HFE gene, 17% of sPCT patients carried C282Y mutation compared to 4% in controls, no significant differences were found with H63D and S65C variants. Compound heterozygous genotypes, C282Y/H63D or C282Y/S65C, were not significantly different in sPCT and control groups. Independently from HFE gene mutations, an association was found between the IVS4+198 T allele in the TFRC1 gene and sPCT patients. Analysis of HFE genotypes indicated that C282Y (but not H63D nor S65C) is a susceptibility factor for the development of sPCT in West European continental patients. However, analysis of TFRC1 genotypes suggest that sPCT should be considered as a multifactorial disorder in which other intracellular iron metabolism genes could be involved.

Oxcarbazepine in focal epilepsy and hepatic porphyria: a case report

PURPOSE

Despite the development of new antiepileptic agents (AEDs), the therapy of epilepsies along with hepatic porphyrias remains difficult. Most AEDs such as carbamazepine (CBZ), phenytoin (PHT), valproate (VPA), and lamotrigine (LTG) may precipitate clinically latent porphyria by inducing hepatic metabolism and increasing hepatic heme synthesis. Actually, only gabapentin (GBP), an AED without any hepatic metabolism, is known as a potential therapy for partial seizures in patients having hepatic forms of porphyria.

METHODS

We present the case of a 28-year-old man with porphyria cutanea tarda (PCT) who has had pharmacoresistant epilepsy with complex partial and secondarily generalized seizures since early childhood. Despite having undergone several AED therapies over the years, no seizure-free interval had been observed. Only CBZ could cause a seizure reduction, but this treatment had to be discontinued as an elevation of the transaminases as well as pruritus and erythema were noted. The patient was then started on oxcarbazepine (OCBZ), a ketoanalogue of CBZ similar in its pharmacologic mechanism as well as its clinical use, but which, in contrast to CBZ, has only a low hepatic induction of microsomal enzymes. A final maintenance dose four times higher than that of CBZ was prescribed.

RESULTS

In the follow-up, the patient stopped having seizures, and his liver functions became normal.

CONCLUSIONS

It can be concluded that OCBZ can successfully be administered to patients with hepatic porphyria and focal epilepsy who did not respond to treatment with GBP.

[Role of the hemochromatosis gene in prophyria cutanea tarda. Prospective study of 56 cases]

BACKGROUND

The cause of iron overload in prophyria cutanea tada is unknown. The aim of this work was to determine the frequency of the hemochromatosis gene (HFE) in 56 patients with porphyria cutanea tarda. We analyzed the relationship between HFE mutations and biochemical abnormalities in porphyria cutanea tarda and the interaction with other triggering factors of porphyria cutanea tarda (alcohol abuse, hepatitis C, drugs).

PATIENTS AND METHODS

Hepatitis C, alcohol abuse, drug intake and HFE mutations were determined in 56 patients with porphyria cutanea tarda (44 men and 12 women). Iron status was determined from transferrin saturation, serum iron, and serum ferritin. Liver metabolism was determined from liver chemistries: alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transpeptidase.

RESULTS

Thirty-nine patients (69.4 p. 100) carried HFE mutations, 18 (32.1 p. 100) were H63D heterozygous, 4 (7.1 p. 100) were H63D homozygous, 9 (16 p. 100) C282Y heterozygous, 8 (14.2 p. 100) compound C282Y/H63D heterozygous and none were C282Y homozygous. Comparison between porphyria cutanea tarda with and without mutations showed that compound C282Y/H63D heterozygous status was significantly linked to iron overload: transferrin saturation=0.61 vs 0.39 (p=0.0001) and serum iron=32.9 vs 22.4 (p=0.0046). H63D homozygous status was linked to iron overload but non-significantly: transferrin sturatin=0.53 vs 0.39 (p=0.06). The class with high iron overload (transferrin saturation > 0.45) was not linked with triggering factors of porphyria cutanea tarda. Hepatatic cytolysis was linked to alcohol abuse and hepatitis C but not to HFE mutations.

DISCUSSION

The frequencies of HFE mutations in Lyons France are halfway between Anglo-Saxon and Italian papers, highlighting the Celtic origin of C282Y mutation. Compound heterozygous and to a lesser degree H63D homozygous status explained the highest iron overload in our patients. This favors clinical expression of porphyria cutanea tarda. This iron overload due to HFE mutations is a new triggering factor of porphyria cutanea tarda independent of classical triggering factors: mutation of the erythrocytic uroporpyrinogen decarbocylase gene, alcohol abuse, hepatitis C, and drugs.

Porphyria cutanea tarda in Brazilian patients: association with hemochromatosis C282Y mutation and hepatitis C virus infection

OBJECTIVE

Porphyria cutanea tarda (PCT) is commonly associated with iron overload and hepatitis C virus (HCV) infection. Association between hemochromatosis C282Y or H63D mutations and PCT has been observed, although not uniformly, and iron overload is also commonly found in chronic HCV hepatitis. The aim of the present study was to investigate the frequency of C282Y and H63D mutations and HCV infection in Brazilian patients with PCT and their relationship with iron overload.

METHODS

Twenty-three patients (19 men) aged 39.6 +/- 11.1 yr were studied. All had dermatological lesions of PCT and high levels of urinary uroporphyrin. HCV infection and iron overload were investigated. DNA samples were analyzed for the presence of HFE mutations.

RESULTS

The frequency of C282Y was significantly higher in PCT patients than in 278 healthy individuals (17.4% vs 4%, odds ratio = 5.1, 95% confidence interval 1.5-17.6, p = 0.02), whereas no difference was observed regarding the H63D mutation (30.4% vs 31%, odds ratio = 1, 95% confidence interval 0.4-2.4, p = 1). Biochemical tests in PCT patients showed iron overload with transferrin saturation = 47.3 +/- 20.7% and ferritin = 566.8 +/- 425 ng/ml. Fifteen of 23 (65.2%) patients had HCV infection and alcohol ingestion was observed in 17 of 23 (73.9%).

CONCLUSIONS

PCT patients exhibited evidence of iron overload, a high frequency of HCV, and an association with C282Y mutation. These data further support the notion that both acquired and inherited factors contribute to the occurrence of PCT, and indicate that screening for C282Y may be justified in PCT patients.

Hemochromatosis genes and other factors contributing to the pathogenesis of porphyria cutanea tarda

Inherited and acquired factors have been implicated in the pathogenesis of porphyria cutanea tarda (PCT), a disorder characterized by a photosensitive dermatosis and hepatic siderosis. This study, comprising 108 patients with PCT, was intended to define the role of hemochromatosis gene (HFE) mutations in the expression of PCT and to determine the contribution of acquired factors including alcohol, hepatitis C virus (HCV), and estrogen. The 2 known HFE mutations, cysteine 282 tyrosine (Cys282Tyr) and histidine 63 asparagine (His63Asp), were detected by polymerase chain reaction, and anti-HCV immunoglobulin G was detected serologically. Liver biopsies were graded for iron content, inflammation, and fibrosis. Estimates of alcohol and estrogen use were based on a questionnaire. Of the PCT patients tested, 19% were homozygous for the Cys282Tyr mutation; controls were equal to 0.5%. The compound heterozygous genotype was detected in 7% of the PCT patients; controls were less than 1%. The transferrin saturation, serum ferritin, and liver iron burden of all PCT patients were higher than those of nonporphyric controls. The highest values were found in PCT patients homozygous for the Cys282Tyr mutation. Of the patients studied, 59% were HCV positive (compared with 1.8% of the population), and 46% consumed more than 70 g of alcohol daily. Of the female patients, 63% were ingesting estrogens. Hepatic damage was most marked in patients with the Cys282Tyr/Cys282Tyr genotype who had HCV and drank heavily. Homozygosity for the Cys282Tyr mutation and HCV are the greatest risk factors for expression of PCT, and in most patients, more than 1 risk factor was identified. It was common for patients with HCV to consume alcohol. Patients with PCT should be screened for HFE mutations and for HCV. (Blood. 2000;95:1565-1571)

Overt and hidden coinfection with hepatitis B and C viruses in chronic liver disease and porphyria cutanea tarda

The aim of this study was to assess the rate of hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection ("the coinfection") in chronic liver disease (CLD) and to reveal overt and hidden HBV infection in patients with antibodies to HCV (anti-HCV). A total of 209 untreated patients (64 with chronic hepatitis B, 79 with chronic hepatitis C and 66 with porphyria cutanea tarda (PCT)) were screened for serological markers of HBV and HCV infection in serum by third generation enzyme-linked immunosorbent assay (ELISA) methods and for HBV DNA and HCV RNA in serum by polymerase chain reaction (PCR). The rate of the overt coinfection in chronic hepatitis B was very low (2/64, 3%). However, in chronic hepatitis C, the rate of the hidden coinfection with HBV was relatively high (19/79, 24%); these patients had higher alanine transaminase (ALT) and asparagine transaminase (AST) levels in serum and a more advanced liver disease. In PCT patients, the rates of HBV and HCV infections were the same, 21% (14/66). In the PCT patients infected with HBV or HCV, the rate of the coinfection was 33% (7/21). The PCT patients with the coinfection had a high serum ALT level and the worst histological picture in the liver. The hidden HBV infection was more frequent than the overt one. The possibility of the overt or hidden coinfection in CLD renders a detailed analysis of all serum samples for both viruses mandatory. Vaccination against HBV infection should be offered to anti-HCV-positive individuals as well as to PCT patients not showing antibodies to HBV (anti-HBV).

Porphyria cutanea tarda and hepatitis C virus: a case-control study and meta-analysis of the literature

BACKGROUND

Porphyria cutanea tarda (PCT) and hepatitis C virus (HCV) infection have been associated in several reports with the prevalence of HCV exhibiting considerable regional variation. However, most reports were confounded by selection bias and a regional prevalence of HCV in the populations studied. In the United States, only a few cases of this association have been reported to date.

OBJECTIVE

We concluded a study to evaluate the association between PCT and HCV in a US population. We used a case-control study design to control the systemic error that may occur during a selecting process or sampling procedure.

METHODS

We reviewed the medical records of Wishard Memorial Hospital, a county hospital serving metropolitan Indianapolis, Indiana, to perform a retrospective case-control study of 26 patients with PCT (as case) against 149,756 regional volunteer blood donors (as control-1) and 51 patients receiving methotrexate for psoriasis (as control-2). HCV antibody titers and other liver abnormalities were our main outcome measures. We then performed a weighted meta-analysis of 17 reports that had at least 17 patients in their study populations.

RESULTS

Sixteen (94%) of 17 PCT patients tested for HCV were antibody positive. Among blood donors, only 255 or 0.17% were HCV antibody positive (P < 10(-5), two-sided chi-square test). Of 5 psoriasis patients tested for HCV, none were HCV antibody positive (P = .0002, two-sided Fisher's exact test). For geographic comparison, meta-analysis of the literature demonstrated a varying regional prevalence of HCV in PCT patients as follows: Northern Europe 17%, Australia/New Zealand 20%, and Southern Europe 65%.

CONCLUSION

Although a marked geographic variation was found in the worldwide prevalence of HCV in PCT patients, a very large percentage of US patients with PCT had HCV infection. Our results emphasize the need for clinicians to actively look for HCV in patients with PCT.

Health effects of chronic high exposure to hexachlorobenzene in a general population sample

Hexachlorobenzene, an organochlorine compound that accumulates in humans, is widespread throughout the environment. In this study, we describe the health status of inhabitants of a rural village that surrounds an electrochemical factory characterized by high levels of hexachlorobenzene in the air. During 1994, we conducted a cross-sectional study of 1 800 inhabitants in the south of Catalonia, Spain, who were older than 14 y of age. We obtained information on lifestyles and occupational and medical histories via questionnaire. Self-reported health outcomes were validated against clinical records and cancer registry data. Serum levels of hexachlorobenzene were very high in males who worked in the electrochemical factory (geometric mean = 54.6 ng/ml in randomized participants). Levels were lower among subjects who had never worked in the electrochemical factory (females, 14.9 ng/ml; males, 9.0 ng/ml). Levels of other organochlorine compounds (i.e., beta-hexachlorocy-clohexane, 2,2-bis[p-chlorophenyl]-1,1-dichloroethylene) were in the same range found in other communities. Perceived health, prevalence of self-reported common chronic conditions, and porphyria cutanea tarda, thyroid pathology, Parkinson's disease, cancer, and reproductive outcomes were within the ranges observed in other studies. Employment in the plant, however, was associated with having any of the a priori selected health outcomes that were potentially related to exposure to hexachlorobenzene (odds ratio for cancer prevalence = 1.9; 95% confidence interval = 0.5, 7.6). Our population of workers and nonworkers had the highest levels of hexachlorobenzene ever described. The results suggest that exposure to hexachlorobenzene did not affect the general health status of the this population, but it was associated with specific health effects of the most highly exposed subjects.

Iron overload in porphyria cutanea tarda

BACKGROUND AND OBJECTIVE

Porphyria cutanea tarda (PCT) is a disorder of porphyrin metabolism associated with decreased activity of uroporphyrinogen decarboxylase (URO-D) in the liver. The relevance of iron in the pathogenesis of PCT is well established: iron overload is one of the factors that trigger the clinical manifestations of the disease and iron depletion remains the cornerstone of therapy for PCT. A role for genetic hemochromatosis in the pathogenesis of iron overload in PCT has been hypothesized in the past but only after the recent identification of the genetic defect causing hemochromatosis has the nature of this association been partially elucidated. This review will outline current concepts of the pathophysiology of iron overload in PCT as well as recent contributions to the molecular epidemiology of hemochromatosis defects in PCT.

EVIDENCE AND INFORMATION SOURCES

The authors of the present review have a long-standing interest in the pathogenesis, etiology and epidemiology of iron overload syndromes. Evidence from journal articles covered by the Science Citation Index(R) and Medline(R) has been reviewed and collated with personal data and experience.

STATE OF THE ART AND PERPECTIVES

Mild to moderate iron overload plays a key role in the pathogenesis of PCT. The recent identification of genetic mutations of the hemochromatosis gene (HFE) in the majority of patients with PCT confirms previous hypotheses on the association between PCT and hemochromatosis, allows a step forward in the understanding of the pathophysiology of the disturbance of iron metabolism in the liver of PCT patients, and provides an easily detectable genetic marker which could have a useful clinical application. Besides the epidemiological relevance of the association between PCT and hemochromatosis, however, it remains to be fully understood how iron overload, and in particular the cellular modifications of the iron status secondary to hemochromatosis mutations, affect the activity of URO-D, and how the altered iron metabolism interacts with the other two common triggers for PCT and etiological agents for the associated liver disease: alcohol and hepatitis viruses. The availability of a genetic marker for hemochromatosis will allow some of these issues to be addressed by studying aspects of porphyrins and iron metabolism in liver samples obtained from patients with PCT, liver disease of different etiology and different HFE genotypes, and by in vitro studies on genotyped cells and tissues.

Porphyria cutanea tarda, hepatitis C, and HFE gene mutations in North America

In some, but not all countries, porphyria cutanea tarda (PCT) has been associated with chronic infection with the hepatitis C virus (HCV). Recently, PCT has also been associated with mutations in the HFE gene that are associated with HLA-linked hereditary hemochromatosis. Until now, few studies of these associations have been reported from North America. The aims of this study were: 1) to assess the prevalence of HCV infection and HFE mutations in North American patients with PCT; 2) to compare demographic and laboratory features between those who are HCV-positive and HCV-negative; and 3) to study urinary porphyrin excretions in American HCV-positive patients without clinically manifest PCT. Clinical and laboratory data, including tests for HCV and urinary porphyrins, were collected from 70 unselected patients with typical PCT. Urinary porphyrins were also measured in 110 non-PCT patients with chronic hepatitis C. Mutational analyses of the HFE gene were performed in 26 PCT patients. Thirty-nine of 70 (56%) of the PCT patients had evidence of HCV infection. Thirty-two of 39 PCT patients with HCV were men, all of whom used alcohol. In contrast, 22 of 31 PCT patients without HCV infection were women, 12 of whom had taken estrogens. The HCV-positive group was more likely to have used illicit intravenous drugs (45% vs. 0%; P = 0.01), to have had several (>4) sex partners (48% vs. 13%; P = 0.005), and less likely to have no known risk factors for HCV infection (33% vs. 78%; P = 0.004). Total urinary porphyrin excretion was the same in the two groups, but those with HCV infection had a significantly lower percentage of uroporphyrin and higher percentages of hepta-and hexa-carboxy porphyrins in urine. Sixteen of 110 (15%) HCV-positive subjects without PCT had increased urinary porphyrins, but, unlike PCT, these were mainly coproporphyrin. Forty-two percent of PCT patients carried the C282Y mutation of HFE (15% homozygous), and another 31% carried the H63D mutation (8% homozygous). Thus, 73% of PCT patients had one of these mutations. The prevalence of HCV infection (56%) and mutations in the HFE gene (73%) are high among North American patients with PCT. Alcohol and estrogen use are important additional risk factors. All PCT patients should be tested for HCV infection and for HFE gene mutations. Although HCV infection is a trigger for PCT, preclinical PCT is rare in chronic HCV hepatitis C in the United States.

Coexistence of lupus erythematosus and porphyria cutanea tarda in fifteen patients

BACKGROUND

Lupus erythematosus (LE) and porphyria cutanea tarda (PCT) may have similar clinical presentations, and their coexistence presents special problems in diagnosis and management.

OBJECTIVE

The purposes of this study were to describe a patient with discoid LE and PCT and to present a review of 15 patients with coexistent LE (all variants) and PCT.

METHODS

The medical records of all patients with coexistent LE and PCT seen between 1976 and 1995 were retrospectively reviewed.

RESULTS

Of 6179 cases of LE and 676 cases of porphyria (all variants), there were 15 patients, 6 men and 9 women, with coexistent LE and PCT. The mean age at diagnosis of LE was 42.8 years and of PCT was 48 years. Nine patients had discoid LE; five patients had systemic LE, and one patient had subacute cutaneous LE. The initial diagnosis was LE in eight patients, PCT in five patients, and simultaneous LE and PCT in two patients. Precipitating factors for PCT included alcohol in seven patients, iron overload in one patient, and estrogen in one patient. Treatment of LE with hydroxychloroquine 200 mg daily precipitated PCT in two patients. Patients were treated with phlebotomy or low-dose antimalarials for PCT. Patients with systemic LE received systemic glucocorticoid therapy. Patients with discoid LE and subacute cutaneous LE were treated with topical glucocorticoids.

CONCLUSION

The association of LE and PCT poses therapeutic challenges. The preferred treatment for one may exacerbate the other. Use of standard dose antimalarials for LE is inadvisable, and phlebotomy or low-dose antimalarials should be used cautiously in patients with coexistent disease.

High prevalence of hepatitis C virus type 1b in Italian patients with Porphyria cutanea tarda

BACKGROUND

A strong association between sporadic porphyria cutanea tarda and chronic hepatitis C virus infection was recently described in Italy, France and Spain.

AIMS

To explore whether hepatitis C virus genotype plays a role in porphyria cutanea tarda complicating chronic hepatitis C.

PATIENTS

Forty-seven hepatitis C virus-positive porphyria cutanea tarda patients and a control group of 45 patients of similar age with hepatitis C virus-associated chronic liver disease.

METHODS

Comparison of frequency of hepatitis C virus genotypes in the two groups and in relation to the age of patients, hepatic histopathology and with the presence of other factors potentially able to trigger porphyria cutanea tarda.

RESULTS

A single genotype, hepatitis C virus 1b, was found to be present in nearly 90% of porphyria cutanea tarda-associated chronic liver disease, significantly exceeding the frequency of the same genotype in the control group (p = 0.0001). The presence of hepatitis C virus 1b was not related to the age of patients or disease severity as evaluated by hepatic histopathology.

CONCLUSIONS

Hepatitis C virus-associated chronic hepatitis found in the majority of Italian patients with porphyria cutanea tarda is usually sustained by hepatitis C virus genotype 1b. This viral strain might have a direct pathogenic role in inducing porphyria cutanea tarda or could increase the susceptibility of patients of other triggering factors such as iron overload or alcohol abuse.

[Prevalence of porphyria cutanea tarda in Madrid and relationship between urine porphyrin and ethanol intake in a multiple linear regression model]

BACKGROUND

The application of a simple fluorometric analytical method enabled us to quantify the urinary porphyrin excretion and to establish the prevalence of porphyria cutanea tarda (PCT) in the town of Madrid, Spain, in a cross-sectional study.

PATIENTS AND METHODS

The study assessed 1,613 subjects from three districts in Madrid, in whom further variables potentially related to porphyrinuria such as ethanol intake or -in women-oral contraceptive use were measured and recorded.

RESULTS

The estimated prevalence of the disease was 1.24 cases per 1,000 inhabitants (95% confidence interval 0.15-4.47 per thousand). After excluding from the study sample all cases with existent disease, an analysis was performed to ascertain an unilateral tolerance interval for urinary porphyrin concentration in the adult population; this level was established at 181.2 micrograms/l. The effect of ethanol intake on porphyrinuria was considered significant using a multiple linear regression model adjusted for the control variables gender, age and body mass index. In fertile women, contraceptive use did not attain statistical significance when that variable was included in a multiple regression model.

CONCLUSIONS

A high prevalence has been estimated for PCT in the Madrid population. A significant association was further found between alcohol intake and porphyrinuria in non-porphyric adults.

Lack of association between porphyria cutanea tarda and alpha 1-antitrypsin deficiency

OBJECTIVE

To determine whether alpha 1-antitrypsin deficiency is involved in the pathogenesis of chronic liver disease in patients with porphyria cutanea tarda and in their recently described high prevalence of hepatitis C virus infection.

DESIGN

Consecutive patients diagnosed as having porphyria cutanea tarda and chronic liver disease.

SETTING

A northern Italian hospital.

METHODS

alpha 1-antitrypsin phenotypes were characterized by isoelectric focusing and the results confirmed by DNA analysis in 63 Italian patients with porphyria cutanea tarda.

RESULTS

alpha 1-antitrypsin phenotypes different from the normal one were found in 13% of the patients. This prevalence did not differ from that in control subjects (9%). Clinical characteristics of patients with porphyria cutanea tarda with normal or altered alpha 1-antitrypsin phenotype, including age of presentation of the disease, prevalence of hepatitis C virus infection, liver histology, prevalence of iron overload and hepatocellular carcinoma occurrence, did not differ significantly.

CONCLUSION

alpha 1-antitrypsin does not seem to play a role in the pathogenesis of chronic liver disease and hepatitis C virus infection in patients with porphyria cutanea tarda. Patients in whom the two defects coexist do not have a more severe disease.

Incidence of hereditary porphyria cutanea tarda (PCT) in a sample of the Italian population

The determination of the enzymatic activity of URO-D in erythrocytes is the screening method used for differentiation between hereditary and non-hereditary forms of porphyria cutanea tarda (PCT). The aim of the present work was to establish the relative frequencies of the symptomatic and hereditary forms by the determination of the URO-D enzyme in the PCT patients who were regularly treated at the Centre for Porphyrins in our Institute. In the course of this work we also examined the statistical properties of the distributions of both normal and porphyric subjects, so as to be able to suggest values for discriminating between normal subjects and the various types of porphyric subjects.