Low prevalence of hepatitis C virus infection in porphyria cutanea tarda in Germany

[Porphyria]

Porphyrien werden durch Enzymdefekte der Hämbiosynthese hervorgerufen und anhand spezifischer biochemischer Muster von Porphyrinen und deren Vorläufern in Urin, Stuhl und Blut diagnostiziert. Das jeweilige Muster der akkumulierten Porphyrine, Vorläufer und Derivate ist verbunden mit der klinischen Ausprägung, die abdominale, neurologische, psychiatrische, endokrine, kardiovaskuläre Symptome, Leberschaden und/oder Lichtempfindlichkeit der Haut umfassen kann. Klinisch werden akute und nichtakute Porphyrien unterschieden. Bei symptomatischen (klinisch aktiven), akuten hepatischen Porphyrien – hierzu gehören akute intermittierende Porphyrie, Porphyria variegata, hereditäre Koproporphyrie und Doss-Porphyrie – kommt es aufgrund einer Regulationsstörung zur Kumulation der Porphyrinvorläufer 5‑Aminolävulinsäure und Porphobilinogen. Bei den nichtakuten Formen – u. a. Porphyria cutanea tarda, erythropoetische und X‑chromosomale Protoporphyrie sowie kongenitale erythropoetische Porphyrie – führen akkumulierte Porphyrine zu Lichtempfindlichkeit (Fotodermatose) und mitunter auch zu schweren Leberschäden. Zur Therapie der Porphyrien stehen sowohl bewährte und sichere als auch innovative Optionen zur Verfügung.

Clinical Guide and Update on Porphyrias

Physicians should be aware of porphyrias, which could be responsible for unexplained gastrointestinal, neurologic, or skin disorders. Despite their relative rarity and complexity, most porphyrias can be easily defined and diagnosed. They are caused by well-characterized enzyme defects in the complex heme biosynthetic pathway and are divided into categories of acute vs non-acute or hepatic vs erythropoietic porphyrias. Acute hepatic porphyrias (acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and aminolevulinic acid dehydratase deficient porphyria) manifest in attacks and are characterized by overproduction of porphyrin precursors, producing often serious abdominal, psychiatric, neurologic, or cardiovascular symptoms. Patients with variegate porphyria and hereditary coproporphyria can present with skin photosensitivity. Diagnosis relies on measurement of increased urinary 5-aminolevulinic acid (in patients with aminolevulinic acid dehydratase deficient porphyria) or increased 5-aminolevulinic acid and porphobilinogen (in patients with other acute porphyrias). Management of attacks requires intensive care, strict avoidance of porphyrinogenic drugs and other precipitating factors, caloric support, and often heme therapy. The non-acute porphyrias are porphyria cutanea tarda, erythropoietic protoporphyria, X-linked protoporphyria, and the rare congenital erythropoietic porphyria. They lead to the accumulation of porphyrins that cause skin photosensitivity and occasionally severe liver damage. Secondary elevated urinary or blood porphyrins can occur in patients without porphyria, for example, in liver diseases, or iron deficiency. Increases in porphyrin precursors and porphyrins are also found in patients with lead intoxication. Patients with porphyria cutanea tarda benefit from iron depletion, hydroxychloroquine therapy, and, if applicable, elimination of the hepatitis C virus. An α-melanocyte-stimulating hormone analogue can reduce sunlight sensitivity in patients with erythropoietic protoporphyria or X-linked protoporphyria. Strategies to address dysregulated or dysfunctional steps within the heme biosynthetic pathway are in development.

Hepatitis C, porphyria cutanea tarda and liver iron: an update

Porphyria cutanea tarda (PCT) is the most common form of porphyria across the world. Unlike other forms of porphyria, which are inborn errors of metabolism, PCT is usually an acquired liver disease caused by exogenous factors, chief among which are excess alcohol intake, iron overload, chronic hepatitis C, oestrogen therapy and cigarette smoking. The pathogenesis of PCT is complex and varied, but hereditary or acquired factors that lead to hepatic iron loading and increased oxidative stress are of central importance. Iron loading is usually only mild or moderate in degree [less than that associated with full-blown haemochromatosis (HFE)] and is usually acquired and/or mutations in HFE. Among acquired factors are excessive alcohol intake and chronic hepatitis C infection, which, like mutations in HFE, decrease hepcidin production by hepatocytes. The decrease in hepcidin leads to increased iron absorption from the gut. In the liver, iron loading and increased oxidative stress leads to the formation of non-porphyrin inhibitor(s) of uroporphyrinogen decarboxylase and to oxidation of porphyrinogens to porphyrins. The treatment of choice of active PCT is iron reduction by phlebotomy and maintenance of a mildly iron-reduced state without anaemia. Low-dose antimalarials (cinchona alkaloids) are also useful as additional therapy or as alternative therapy for active PCT in those without haemochromatosis or chronic hepatitis C. In this review, we provide an update of PCT with special emphasis upon the important role often played by the hepatitis C virus.

Therapy of porphyria cutanea tarda

Porphyria cutanea tarda (PCT) is the most common type of porphyria. There is an association of PCT with haemochromatosis, diabetes mellitus and hepatitis C infection. The basis of treatment of PCT consists of three elements: avoidance of triggering factors, iron depletion and porphyrin elimination. Alcohol and certain systemic medical drugs, such as oestrogens (or tuberculostatics), should be considered as triggering factors, and as far as possible, avoided. Other triggering factors, such as chronic haemodialysis in renal insufficiency, need a different approach. The hallmark in iron depletion is phlebotomy. Porphyrin elimination is achieved using low-dose chloroquin therapy. The treatment is safe and effective but has its limits in cases with haemochromatosis (HFE) gene mutations. Here iron depletion needs additional phlebotomy. In patients with chronic haemodialysis-associated PCT, chloroquine is ineffective. Erythropoietin, desferroxamine and small-volume phlebotomy have been employed to control the disease. Childhood PCT is very rare. No controlled studies are available, but published experience suggests that body weight-adapted chloroquine therapy or small volume phlebotomy might be useful.

The prevalence of hepatitis C in patients with porphyria cutanea tarda in Stockholm, Sweden

In many countries hepatitis C virus infection has been considered a major factor triggering overt porphyria cutanea tarda. The prevalence of hepatitis C virus infection was retrospectively studied in 87 patients who during a period of 11 years were diagnosed with porphyria cutanea tarda in Stockholm. Among patients with the sporadic form of porphyria cutanea tarda, the prevalence of hepatitis C virus infection was 36.4%. As hepatitis C virus infection may today be successfully treated and as the infection may be clinically silent and thus unknown to the patient, it is important to screen all patients with porphyria cutanea tarda for hepatitis C virus infection.

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.

Hepatitis C virus-associated extrahepatic manifestations: a review

The hepatitis C virus (HCV) infection is a worldwide disease that is characterized by a preferential chronic evolution with mild to severe liver disease, including cirrhosis and, in lesser proportion, hepatocarcinoma. Out of these complications, HCV is frequently reported to complicate extrahepatic manifestations. Among those associated to HCV infection with a high degree of certainty, mixed cryoglobulinemia and its complications (skin, neurological, renal, rheumatological involvement) are the most prevalent (50%) in HCV-infected patients. The other diseases include noncryoglobulinemic systemic vasculitis, splenic lymphoma with villous lymphocytes, fatigue, porphyria cutanea tarda, sicca syndrome, and autoantibodies production. The extrahepatic manifestations that share mild-degree certainty of association with HCV infection include B-cell non-Hodgkin lymphoma, autoimmune thrombocytopenia, pruritus, and type II diabetes mellitus. The other diseases such as autoimmune thyroiditis, lichen planus are more questionable for their eventual association with HCV and others (pulmonary fibrosis with or without polymyositis, progressive encephalomyelitis, Mooren's corneal ulcers, erythema nodosum, chronic polyradiculonevritis) are mostly case reports. Howerver, even in cases of tight association, the mechanisms through which HCV may promote or induce extrahepatic manifestations remain unclear and merit further investigations.

Hepatitis C virus-related extra-hepatic disease--aetiopathogenesis and management

Summary Hepatitis C virus infection is often associated with extra-hepatic manifestations, secondary to the elicitation of autoimmune reactions, generalized deposition of immune complexes and lymphoproliferative disorders. The most clearly established associations are those linking chronic hepatitis C with mixed cryoglobulinaemia (and the related glomerulonephritis and cutaneous vasculitis), as well as with the presence of autoantibodies. Less well-documented disorders include non-Hodgkin's lymphoma, thrombocytopenia, sialadenitis, thyroid disease, lichen planus, porphyria cutanea tarda, rheumatoid disorders and neurological disorders. Extra-hepatic manifestations are most frequent in patients of female sex, advanced age, long-lasting infection and cirrhosis. Optimal treatment strategies should be based on the predominant manifestation of the disease. In the case of autoimmune disorders not clearly attributable to the viral infection, corticosteroids may be the most effective option. Interferon-alpha alone or in combination with ribavirin may be indicated for those disorders related to immune complex deposition, such as mixed cryoglobulinaemia, although relapses of extra-hepatic signs often occur on discontinuation of treatment. In some cases, interferon-alpha may induce or exacerbate some extra-hepatic manifestations.

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Prevalence of hepatitis C virus infection in porphyria cutanea tarda: systematic review and meta-analysis

BACKGROUND/AIMS

To conduct a systematic review and meta-analysis on the prevalence of hepatitis C virus (HCV) infection in porphyria cutanea tarda (PCT).

METHODS

Studies evaluating prevalence of HCV infection in patients with PCT were considered. Bibliographical searches were conducted in several electronic databases. Studies comparing HCV prevalence in PCT (cases) and in a reference group (controls) were included in the meta-analysis, combining the Odds Ratios (OR) of the individual studies.

RESULTS

Fifty studies including 2,167 patients were identified. Mean HCV prevalence by serology was 47%, and 50% with polymerase chain reaction (PCR). HCV prevalence markedly varied depending on the country and the type of PCT (57% in the sporadic and 26% in the familial form). Eight case-control studies were identified. Seven studies compared HCV prevalence in PCT vs. healthy controls: 40% vs. 0.24%, respectively (OR=275; 95% confidence interval=104-725). Heterogeneity disappeared when only studies evaluating HCV infection by PCR were included.

CONCLUSIONS

HCV prevalence in patients with PCT is approximately 50%, much higher than that reported in general population, suggesting a possible etiopathogenic role of HCV in PCT. The striking geographical variation in this association suggests that genetic and/or environmental factors may also be involved in the pathogenesis of this disorder.

Extrahepatic manifestations of hepatitis C infection

Hepatitis C virus (HCV) affects 1.8% of the American population, and approximately 38% of patients with HCV will manifest symptoms of at least 1 extrahepatic manifestation during the illness. Renal disease, neuropathy, lymphoma, and Sjögren syndrome with or without mixed cryoglobulinemia are all strongly associated with HCV infection. Porphyria cutanea tarda and diabetes have also been linked to HCV. Most extrahepatic manifestations of chronic HCV infection are immunological, and the chronic infection seems to be necessary for their development. The molecular study of the unique way in which the HCV virus interacts with the human immune system is beginning to provide plausible explanations of the pathogenic role of HCV in some of these syndromes, but many pathogenetic links remain completely obscure.

The cutaneous manifestations of viral hepatitis

Viral hepatitis is a common disease with significant morbidity and mortality that is found throughout the world. It is a known cause of acute and chronic liver disease. Because the disease can be asymptomatic in its acute stages, the diagnosis is often missed. This article reviews the extrahepatic manifestations of the disease, in particular the visible cutaneous lesions, which offer clues to the diagnosis of viral hepatitis. Familiarity with the most common skin lesions associated with each type of hepatitis virus will be useful in identifying previously undiagnosed individuals. This article serves as a review of the most widely published associations between skin diseases and specific subtypes of viral hepatitis.

The management of porphyria cutanea tarda

Porphyria cutanea tarda (PCT), the commonest of all porphyrias, is usually characterized by blisters and fragility of skin in light-exposed areas. It can be clinically indistinguishable from other disorders including variegate porphyria and the diagnosis can only be made by rigorous biochemical analysis. PCT does not cause acute attacks of porphyria. It is usually an acquired condition caused by inhibition of the uroporphyrinogen decarboxylase enzyme in the liver. Hereditary haemochromatosis, hepatitis C virus infection, alcohol, oestrogens and a family history of PCT are the major risk factors for the condition and should be searched for specifically in all patients. Liver disease, including hepatocellular carcinoma, is common in patients with PCT, and should be investigated for at presentation by means of a liver biopsy where possible. Patients with severe hepatic pathology or longstanding untreated PCT need to be monitored for the development of hepatocellular carcinoma in the long term. Low dose twice weekly chloroquine is the mainstay of treatment, but venesection should be used in patients with severe iron overload or hepatitis C-related liver disease. Subsequently, long-term follow-up is needed in all patients to monitor for relapse.

Hepatitis C and D, retroviruses and autoimmune manifestations

Chronic infections with hepatitis C virus (HCV) are associated with various autoimmune manifestations, i.e. mixed cryoglobulinemia, membranoproliferative glomerulonephritis, autoimmune thyroid diseases, sporadic porphyria cutanea tarda and B cell lymphoma. Since exacerbation of hepatitis occurs in 5-10% of HCV patients receiving interferon-alpha treatment and may be successfully treated by immunosuppression afterwards, hepatitis C was also suspected to be associated with autoimmune hepatitis. LKM3 autoantibodies in chronic hepatitis D virus (HDV) infection and epitope recognition are discussed. Lately, endogenous and exogenous retroviruses have been investigated for the induction of autoimmune diseases. Human A type retroviral particles (HIAP), reverse transcriptase activity and anti-HIAP autoantibodies were detected in patients with Sjögren's syndrome. Anti-HIAP and anti-HIV p24 autoantibodies are seen in systemic lupus erythematosus, primary biliary cirrhosis and multiple sclerosis. Multiple sclerosis was even associated with a new human retrovirus called multiple sclerosis associated retrovirus (MSRV). In diabetes long terminal repeats (LTR) were detected in the HLA DQB1 locus, which was shown to associate with an increased risk of diabetes. A second retrovirus called IDDMK(1,2)22 was reported to code for a superantigen, which was implicated as a potential cause of diabetes. This hypothesis, however, was challenged repeatedly. Until now it is unknown whether endogenous retroviruses are aetiological agents of autoimmune diseases or an epiphenomenon, induced by coinfecting viruses (e.g. herpes viruses) and inflammatory processes.

Erythropoietic and hepatic porphyrias

Porphyrias are divided into erythropoietic and hepatic manifestations. Erythropoietic porphyrias are characterized by cutaneous symptoms and appear in early childhood. Erythropoietic protoporphyria is complicated by cholestatic liver cirrhosis and progressive hepatic failure in 10%, of patients. Acute hepatic porphyrias (delta-aminolaevulinic acid dehydratase deficiency porphyria, acute intermittent porphyria, hereditary coproporphyria and variegate porphyria) are characterized by variable extrahepatic gastrointestinal, neurological-psychiatric and cardiovascular manifestations requiring early diagnosis to avoid life-threatening complications. Acute hepatic porphyrias are pharmacogenetic and molecular regulatory diseases (without porphyrin accumulation) mainly induced by drugs, sex hormones, fasting or alcohol. The disease process depends on the derepression of hepatic delta-aminolaevulinic acid synthase following haem depletion. In contrast to the acute porphyrias, nonacute, chronic hepatic porphyrias such as porphyria cutanea tarda are porphyrin accumulation disorders leading to cutaneous symptoms associated with liver disease, especially caused by alcohol or viral hepatitis. Alcohol, oestrogens, haemodialysis, hepatitis C and AIDS are triggering factors. Porphyria cutanea tarda is the most common porphyria, followed by acute intermittent porphyria and erythropoietic protoporphyria. The molecular genetics of the porphyrias is very heterogenous. Nearly every family has its own mutation. The mutations identified account for the corresponding enzymatic deficiencies, which may remain clinically silent throughout life. Thus, the recognition of the overt disorder with extrahepatic manifestations depends on the demonstration of biochemical abnormalities due to these primary defects and compensatory hepatic overexpression of hepatic delta-aminolaevulinic acid synthase in the acute porphyrias. Consequently, haem precursors are synthesized in excess. The increased metabolites upstream of the enzymatic defect are excreted into urine and faeces. The diagnosis is based on their evaluation. Primary enzymatic or molecular analyses are noncontributary and may be misleading. Acute polysymptomatic exacerbations accompany a high excretory constellation of porphyrin precursors delta-aminolaevulinic acid and porphobilinogen. Homozygous or compound heterozygous variants of acute hepatic porphyrias may already manifest in childhood.

Prevalence of hepatitis-G virus and hepatitis-C virus infection in patients with non-Hodgkin's lymphoma

Several studies have reported that hepatitis-C virus may have a role in the development of non- Hodgkin's lymphoma. Hepatitis-G virus has hepatitis-C virus like characteristics. The possible association between hepatitis-G virus infection and non-Hodgkin's lymphoma is not clear. The aim of this study was to determine the prevalence of hepatitis-G virus and hepatitis-C virus infection in patients with non-Hodgkin's lymphoma without blood transfusion. Forty-four patients with non-Hodgkin's lymphoma were enrolled in the study. Serum samples derived from the patients were tested for antibodies against hepatitis-C virus by ELISA. Hepatitis-G virus and hepatitis-C virus RNA were detected by reverse transcription-polymerase chain reaction. Only two of 44 patients (5%) with non-Hodgkin's lymphoma were positive for Anti- HCV and hepatitis C virus RNA. One patient had low grade non-Hodgkin's lymphoma with follicular mixed histopathology while the other had intermediate grade with diffuse large cell histopathology. Hepatitis-G virus infection was detected in none of the patients. We concluded that hepatitis-G virus does not seem to be in association with non-Hodgkin's lymphoma.

Natural history of HCV infection

Chronic hepatitis C virus (HCV) infection affects 170 million individuals worldwide. These individuals are at risk of developing both hepatological and non-hepatological manifestations. HCV is usually only fatal when it leads to cirrhosis, the final stage of liver fibrosis. Therefore, an estimate of fibrosis progression represents an important surrogate end-point for the evaluation of the vulnerability of an individual patient. In untreated patients, the median expected time to cirrhosis is 30 years; 33% of patients have an expected median time to cirrhosis of less than 20 years and 31% will only progress to cirrhosis after more than 50 years, if ever. Several factors are associated with fibrosis progression rate: duration of infection, age, male gender, consumption of alcohol, HIV co-infection and low CD4 count. Non-hepatological manifestations are frequent with more than 70% of HCV patients experiencing fatigue or at least one extrahepatic clinical manifestation involving primarily the joints, skin and muscles. Several immunological abnormalities are frequently observed, including cryoglobulins (40%),anti-nuclear antibodies (10%) and anti-smooth muscle antibodies (7%). In contrast severe extrahepatic manifestations are rare, with 1% for systemic vasculitis.

Effect of hepatobiliary disease, chronic hepatitis C and hepatitis B virus infections and interferon-alpha on porphyrin profiles in plasma, urine and faeces

BACKGROUND

Documentation of the profiles of porphyrins in hepatobiliary disease is limited. Strong associations of hepatitis B and C virus infections with porphyria cutanea tarda have suggested causal relationships. This study aimed to determine the nature of porphyrin abnormalities in hepatobiliary disease and the effect of interferon-alpha on porphyrin profiles.

METHODS

Total porphyrins were measured in the plasma, urine and faeces of 83 patients with hepatobiliary disease (37 hepatitis C, 20 hepatitis B, 26 other causes) and 12 clinical controls, and porphyrin profiles were determined by high-performance liquid chromatography.

RESULTS

Porphyrins were elevated in the plasma of 11 and urine of 23 patients with hepatobiliary disease, as a result of elevated coproporphyrin I. This was reflected in increased coproporphyrin I:III ratios. Abnormal total porphyrin levels had a significant negative correlation with plasma albumin, and a positive correlation with bilirubin and alkaline phosphatase, but not with aminotransferases. Total urinary porphyrins were elevated in three control patients, but coproporphyrin I:III ratios were normal. Although not seen in plasma or urine, porphyrins that are specific for porphyria cutanea tarda were found in the faeces of six patients, but this occurred with similar frequency in hepatitis B or C infection (four of 50) as in the clinical controls (two of 12). Interferon-alpha had no effect during or after therapy in six patients with hepatitis C.

CONCLUSIONS

Reduced biliary excretion of coproporphyrin I occurs in more severe cholestasis and/or hepatic dysfunction. A causal relationship between viral liver disease and porphyria cutanea tarda which is unlikely to be precipitated by interferon-alpha, is not supported.

Hepatitis C and alcohol

A close relationship and possible interaction has been noted between alcohol intake and hepatitis C virus infection, since the discovery of HCV markers. It is not understood whether these are additive or synergistic effects in causing liver injury. Interactions between alcohol and HCV may be studied at several levels, including epidemiology, virology (including viral load), histology (effect on the severity of liver lesions), carcinogenesis (the role of alcohol in the occurrence of hepatocellular carcinoma), and the effect on the extrahepatic manifestations or severity of HCV infection. At the epidemiological level, a high prevalence of HCV infection was noted in patients with alcoholic liver diseases (14-37%), also characterized by a high rate of viral replication as detected by PCR, which was present in over 90% of patients tested. Moreover, the prevalence of anti-HCV antibodies increased proportionally with the severity of liver lesions. Virological analysis based on the determination of HCV RNA levels in the serum showed variations of HCV RNA levels with diet, and a clear relationship between self reported alcohol consumption and the levels of serum HCV RNA (r = .26, p = .001). At the histologic level the role of alcohol may be evaluated either through the development of fibrosis or by determination of the incidence of cirrhosis. A study on the effect of alcohol intake below or over 40 g per day on the histologic progression of liver lesions has confirmed a more rapid increase in fibrosis and a doubling in the incidence of cirrhosis in patients admitting to alcohol consumption >40 g per day. The role of alcohol in the occurrence of hepatocellular carcinoma in patients with cirrhosis due to HCV infection has been extensively studied with controversial results. A recent case control study performed in Italy showed that the relative risk of HCC in patients with HCV infection and heavy alcohol consumption doubled. Finally, alcohol consumption potentially worsens the evolution of dermatological diseases associated with HCV infection such as porphyria cutanea tarda. All of the above are strong arguments which should be used to advise HCV patients against alcohol consumption, regardless of the degree of liver injury. However, the deleterious effect of the occasional intake of small amounts of alcohol has not been demonstrated and therefore an occasional drink may be allowed in some cases.

Autoimmunity and extrahepatic manifestations in hepatitis C virus infection

Hepatitis C virus (HCV) infection is associated with various extrahepatic manifestations: mixed cryoglobulinaemia, membranoproliferative glomerulonephritis and, in southern Europe, to some extent with porphyria cutanea tarda. The association of haplotype HLA B-8 and DR-3 mixed cryoglobulinaemia and HCV infection has recently been demonstrated. Interferon alpha therapy decreases hepatitis C viraemia and improves the clinical signs and biochemical abnormalities of cryoglobulinaemia. There seems to be a south-north gradient in the prevalence of HCV-associated cryoglobulinaemia. The rare combination of hepatitis C and panarteritis nodosa has still not been confirmed. The sicca syndrome also seems to be associated with hepatitis C virus, but this is not the typical Sjögren syndrome. Existing studies have not answered the question of whether HCV plays a pathogenic role in the development of thyroid dysfunction and autoimmune thyroiditis. There seems to be a genetic predisposition for the manifestations of thyroid disease in the case of hepatitis C infection and interferon therapy. This predominantly affects women with haplotype HLA DR-3. Before beginning interferon therapy, these patients often show thyroid autoantibodies against the thyroid peroxidase and/or thyroglobulin. It is still unclear whether the rare combination of hepatitis C with aplastic anaemia and lymphoma has pathogenic aspects. These haematological manifestations are thought to be induced by the infection of haematopoietic cells with the hepatitis C virus. In rare cases, a stimulated HCV-induced interferon gamma synthesis by haematopoietic stem cells has been shown. Although an epidemiological association of hepatitis C with lichen planus, neuropathies and other diseases has been observed, the aetiological role and the pathogenic involvement of the hepatitis C infection remains unclear. Furthermore, the question of whether these extrahepatic diseases are autoimmune has not been clarified. On the other hand, a number of autoantibodies may be observed during the course of hepatitis C. Of particular interest are liver/kidney microsomal antibodies (LKM). Their occurrence in viral hepatitis may indicate an increased risk for treatment with interferons. In the clinical setting, the presence of these diseases should suggest hepatitis C infection and hepatitis C antibodies should be tested and, if positive, hepatitis C-RNA is indicated. If there is any evidence of an aetiological association of replicative hepatitis C infection and the above-mentioned extrahepatic diseases, antiviral treatment should be considered.

Extrahepatic manifestations associated with hepatitis C virus infection. A prospective multicenter study of 321 patients. The GERMIVIC. Groupe d'Etude et de Recherche en Medecine Interne et Maladies Infectieuses sur le Virus de l'Hepatite C

From January 1996 to January 1997, 321 patients with an average age of 46 +/- 16 years and chronically infected with hepatitis C virus (HCV) were prospectively enrolled in a study designed to determine the prevalence of extrahepatic manifestations associated with HCV infection in a large cohort of HCV patients, to identify associations between clinical and biologic manifestations, and to compare the results obtained in human immunodeficiency virus (HIV)-positive versus HIV-negative subsets. In a cross-sectional study, clinical extrahepatic manifestations, viral coinfections with HIV and/or hepatitis B virus, connective tissue diseases, and a wide panel of autoantibodies were assessed. Thirty-eight percent (122/321) of patients presented at least 1 clinical extrahepatic manifestation including arthralgia (60/321, 19%), skin manifestations (55/321, 17%), xerostomia (40/321, 12%), xerophthalmia (32/321, 10%), and sensory neuropathy (28/321, 9%). Main biologic abnormalities were mixed cryoglobulins (110/196, 56%), thrombocytopenia (50/291, 17%), and the presence of the following autoantibodies: antinuclear (123/302, 41%), rheumatoid factor (107/280, 38%), anticardiolipin (79/298, 27%), antithyroglobulin (36/287, 13%) and antismooth muscle cell (27/288, 9%). At least 1 autoantibody was present in 210/302 (70%) of sera. By multivariate logistic regression analysis, 4 parameters were significantly associated with cryoglobulin positivity: systemic vasculitis (p = 0.01, odds ratio OR[ = 17.3), HIV positivity (p = 0.0006, OR = 10.2), rheumatoid factor positivity (p = 0.01, OR = 2.8), and sicca syndrome (p = 0.03, OR = 0.27). A definite connective tissue disease was noted in 44 patients (14%), mainly symptomatic mixed cryoglobulinemia and systemic vasculitis, HIV coinfection (23%) was associated with 3 parameters: anticardiolipin (p = 0.003, OR = 4.18), thrombocytopenia (p = 0.01, OR = 3.56), and arthralgia or myalgia (p = 0.017, OR = 0.23). HIV-positive patients presented more severe histologic lesions (p = 0.0004). Extrahepatic clinical manifestations in HCV patients involve primarily the skin and joints. The most frequent immunologic abnormalities include mixed cryoglobulins, rheumatoid factor, antinuclear, anticardiolipin, and antithyroglobulin antibodies. Cryoglobulin positivity is associated with systemic vasculitis and rheumatoid factor and HIV positivity. HIV coinfection is associated with arthralgia or myalgia, anticardiolipin antibodies, and thrombocytopenia.

Abnormal uroporphyrin levels in chronic hepatitis C virus infection

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.

Extrahepatic manifestations of chronic hepatitis C. MULTIVIRC Group. Multidepartment Virus C

OBJECTIVE

To assess the prevalence of clinical and biologic extrahepatic manifestations of hepatitis C virus (HCV) infection and to identify associations between clinical and biologic manifestations.

METHODS

To analyze the natural history of extrahepatic manifestations of HCV infection, we reviewed only the data recorded prospectively during the first visit of 1,614 patients with chronic HCV infection, coming from a single monocenter cohort. Exclusion criteria were positivity for hepatitis B surface antigen or human immunodeficiency virus. The prevalence of dermatologic, rheumatologic, neurologic, and nephrologic manifestations; diabetes; arterial hypertension; autoantibodies; and cryoglobulins were assessed. Then, using multivariate analysis, we identified demographic, biochemical, immunologic, virologic, and liver histologic factors associated with the presence of extrahepatic manifestations.

RESULTS

At least 1 clinical extrahepatic manifestation was observed in each of 1,202 patients (74%). Five manifestations had a prevalence >10%: arthralgia (23%), paresthesia (17%), myalgia (15%), pruritus (15%), and sicca syndrome (11%). Four biologic abnormalities had a prevalence >5%: cryoglobulins (40%), antinuclear antibodies (10%), low thyroxine level (10%), and anti-smooth muscle antibodies (7%). Only vasculitis, arterial hypertension, purpura, lichen planus, arthralgia, and low thyroxine level were associated with cryoglobulin positivity. By univariate and multivariate analyses, the most frequent risk factors for the presence of clinical and biologic extrahepatic manifestations were age, female sex, and extensive liver fibrosis.

CONCLUSION

Extrahepatic clinical manifestations are frequently observed in HCV patients and involve primarily the joints, muscles, and skin. The most frequent immunologic abnormalities include mixed cryoglobulins, antinuclear antibodies, and anti-smooth muscle antibodies. The most frequent risk factors for the presence of clinical and biologic extrahepatic manifestations are advanced age, female sex, and extensive liver fibrosis.

Urinary porphyrin excretion in hepatitis C infection

A high prevalence of hepatitis C virus infection in porphyria cutanea tarda in some populations suggests a close link between viral hepatitis and alteration of porphyrin metabolism. Moreover, there is evidence of a role of porphyrinopathies in hepatocarcinogenesis. The aim of our study was to obtain data on the prevalence and patterns of heme metabolism alterations in patients with chronic hepatitis C virus infection. Urinary porphyrin excretion was prospectively studied in 100 consecutive outpatients with chronic hepatitis C infection without signs of photosensitivity, using an ion-pair high-performance liquid chromatography method. Increased total porphyrin excretion was found in 41 patients, with predominant excretion of coproporphyrins (whole study group: mean 146 microg/g creatinine, interquartile range 76-186; normal < 150), in 10 patients excretion exceeded 300 microg/g creatinine. In the majority of all patients studied (75/100) an increased ratio of the relatively hydrophobic coproporphyrin isomer I to isomer III was found. In just one case, urinary porphyrin pattern characteristic for chronic hepatic porphyria was present (uroporphyrin > coproporphyrin, heptacarboxyporphyrin III increased) but the total porphyrin excretion was only slightly elevated in this case. In the whole group, total urinary porphyrin excretion correlated well with serum bilirubin and was inversely correlated with albumin and thrombin time. In conclusion, secondary coproporphyrinuria occurs frequently in heptatitis C infection, whereas in Germany, preclinical porphyria cutanea tarda seems to be rare in these patients.

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.

[Hepatic porphyrias and alcohol]

Alcohol has an porphyrinogenic action and can cause a disturbance of porphyrin metabolism in healthy people as well as lead to a biochemical and clinical manifestation of acute and chronic hepatic porphyrias, especially acute intermittent porphyria and porphyria cutanea tarda. After excessive consumption of alcohol a temporary, clinically asymptomatic secondary hepatic coproporphyrinuria in man can be observed, which can become persistent in cases of alcohol-induced liver damage. Nowadays alcohol-liver-porphyrinuria syndrome is the first to be mentioned in secondary hepatic disturbances of porphyrin metabolism. In people with a genetic lack of uroporphyrinogen-decarboxylase alcohol is able to transform an asymptomatic coproporphyrinuria into a chronic hepatic porphyria or porphyria cutanea tarda. From experimental and clinical studies the conclusion can be drawn that alcohol inhibits the enzymes delta-aminolevulinic-acid-dehydratase (synonym: porphobilinogen-synthase), uroporphyrinogen-decarboxylase and coproporphyrinogen-oxidase and induces delta-aminolevulinic-acid-synthase in the liver. Abstinence of alcohol is a therapeutically and prophylactically important measurement in all types of hepatic porphyrias. For clinical experience follows that in cases with chronic consumption of alcohol, fatty liver, alcohol induced hepatitis and liver cirrhosis porphyrin studies in urine should be made to notice a hepatic porphyria in the latent phase very early. When dealing with abdominal and cutaneous symptoms in clinical context with consumption of alcohol one has to exclude hepatic porphyria differential diagnostically.

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.

The C282Y mutation in the haemochromatosis gene (HFE) and hepatitis C virus infection are independent cofactors for porphyria cutanea tarda in Australian patients

BACKGROUND/AIM

Whether mutations in the putative haemochromatosis gene (HFE) and hepatitis C virus act independently to precipitate porphyria cutanea tarda is unknown. The aim of the study was to investigate the relationship between mutations in HFE, hepatitis C and porphyria cutanea tarda.

METHODS

The frequencies of the C282Y and H63D mutations in HFE were determined in 27 patients with porphyria cutanea tarda and compared with the reported control frequencies. In addition, the presence of hepatitis C virus infection was identified and related to the patients' HFE status.

RESULTS

The C282Y mutation was found in 44.4% of patients compared with the control frequency of 12% (p<0.001). Three patients were homozygous for the C282Y mutation, two of whom did not meet current clinical diagnostic criteria for expressed haemochromatosis. The proportion of patients with the H63D mutation did not differ from the reported control frequency. The mean transferrin saturation and serum ferritin concentration were similar in porphyria cutanea tarda patients who were homozygous normal and heterozygous for the C282Y mutation, but greater in both groups than previously reported in healthy controls. Seven (25.9%) patients were anti-HCV IgG positive. None of these patients carried the C282Y mutation. Porphyria cutanea tarda patients heterozygous for the C282Y mutation and patients with anti-HCV antibodies had elevated transferrin saturations and serum ferritin concentrations.

CONCLUSIONS

The raised frequency of the C282Y mutation in porphyria cutanea tarda indicates that this mutation is likely to be a predisposing factor. However, abnormalities of iron indices also exist in porphyria cutanea tarda patients without mutations in HFE. Hepatitis C virus infection is likely to be another common precipitating factor for porphyria cutanea tarda which acts independently of the C282Y mutation.

Epidemiology of hepatitis C and G in sporadic and familial porphyria cutanea tarda

From 1995 to 1997, we prospectively evaluated the prevalence of hepatitis C virus (HCV) RNA in 124 patients with porphyria cutanea tarda (PCT) from Northern France (83 sporadic and 41 familial PCT). Serum samples were analyzed for ferritin, transaminases, HCV antibodies, and HCV RNA. In addition, genotyping of HCV and searches for HCV infection risk factors (blood transfusion, iv drug abuse, and surgical intervention) were performed. Twenty-six of 124 patients (21%; 95% CI: 13.9-28) were positive for serum HCV antibodies. All of them were also positive for HCV RNA. The prevalence of HCV infection was higher in the sporadic PCT group (26.5%, 22 out of 83) than in the familial PCT group (9.7%, 4 out of 41). Risk factors for hepatitis C infection were found to be significantly increased in the HCV-positive group when compared with the HCV-negative PCT group. In all HCV-positive patients with a risk factor, the suspected date of exposure to the virus always preceded the clinical onset of PCT. The HCV genotype pattern in PCT patients was similar to that observed in nonporphyric HCV patients in western European countries. Serum ferritin level was increased in both HCV-positive and HCV-negative porphyric patients. Transaminase levels were significantly higher in HCV-infected PCT patients. Sixty-seven out of 124 patients were retrospectively studied for hepatitis G virus (HGV) infection. Six of these 67 patients (8.9%; 95% CI: 2.1-15.8) were positive for HGV RNA. None of the six HGV-infected patients were positive for HCV RNA. The HGV-infected patients did not differ statistically from those without HGV infection with regard to age, ferritin, transaminase levels, and PCT treatment. These results support the view that sporadic cases of HGV infection may occur frequently. This study of a large cohort of HCV and PCT patients further documents an increasing gradient in HCV prevalence from northern to southern Europe, and shows that HCV infection acts as a triggering factor of PCT. Finally, the HGV prevalence found in the PCT patients was comparable with that found in French blood donors, suggesting that HGV is not a PCT triggering factor.

Hepatic uroporphyrinogen decarboxylase activity in porphyria cutanea tarda patients: the influence of virus C infection

Porphyria cutanea tarda (PCT) is caused by a decreased activity of the hepatic enzyme uroporphyrinogen decarboxylase (URO-D). This deficiency causes overproduction, hepatic deposition, and increased excretion of uroporphyrin. Iron overload and hepatic viral infections are considered aggravating factors of the disease. Two forms of PCT have been described, as follows: a familial one with an inherited decrease of URO-D activity in all tissues and a sporadic one with a decreased activity of URO-D restricted to the liver. To assess whether the hepatic URO-D returns to normal during a remission of the disease, this activity was measured in liver biopsy samples in 24 sporadic PCT patients. The hepatic and urinary porphyrin concentrations were also measured. Viral status and histopathological findings were analyzed to assess their involvement in PCT. Six patients treated by phlebotomy to reduce hepatic iron and who were considered to be in clinical remission, characterized by a disappearance of cutaneous lesions, showed higher hepatic URO-D activities and lower hepatic porphyrin concentrations than did patients with overt PCT. The medians of these variables, however, did not achieve normal values. The hepatic URO-D activity showed a significant inverse relationship with both hepatic porphyrins and urinary uroporphyrin excretion. Hepatic URO-D activity was not reduced by hepatitis C virus (HCV) infection and liver damage. We conclude that the achievement of remission in PCT largely depends on the transient normalization of hepatic URO-D activity. A small increase in hepatic coproporphyrin in nonporphyric patients could reflect hepatic injury/iron/alcohol-induced oxidative stress oxidizing the accumulated heme precursors rather than a direct effect on hepatic URO-D enzyme.

HCV and HGV in B-cell non-Hodgkin's lymphoma

BACKGROUND/AIMS

A causative role of hepatitis C virus infection (HCV) has been discussed in the pathogenesis of mixed cryoglobulinaemia and in B-cell non-Hodgkin's lymphoma. No data are available concerning the newly discovered hepatitis G virus (HGV) and extrahepatic manifestations such as haematological malignancies. But, HCV and HGV most probably belong to the same family of Flavivirus. Consequently, we looked for the prevalence of HCV, HGV and cryoglobulins in patients with B-cell non-Hodgkin's lymphoma.

METHODS

Serum samples from 69 patients with non-Hodgkin's lymphoma were studied. Diagnosis of non-Hodgkin's lymphoma was established according to the Kiel classification. Active HCV- and HGV infections were investigated using polymerase chain reaction for detection of viral RNA. Cryoglobulins were detected from serum and monoclonal immunoglobulin components were analysed with immunofixation electrophoresis. In addition, we assessed the clinical course of HCV- and HGV-infected patients under chemotherapy.

RESULTS

Three of 69 (4.3%) patients with B-cell non-Hodgkin's lymphoma were HCV-infected and nine non-Hodgkin's lymphoma patients (13.0%) were positive for hepatitis G virus RNA. All HGV infected patients were suffering from low-grade non-Hodgkin's lymphoma. No HGV-infected patient was co-infected by HCV and neither HCV- nor HGV-infected patients showed clinical signs of chronic liver disease before, during or after chemotherapy. Serum samples from all patients were devoid of cryoglobulins.

CONCLUSIONS

HCV seems to have no significance for the pathogenesis of non-Hodgkin's lymphoma in Germany. The increased prevalence of hepatitis G (16.3%) in patients with low-grade non-Hodgkin's lymphoma could suggest a pathological consequence of HGV infection outside of the liver. Evidence of clinically relevant hepatic disease in HGV infected patients was not obtained. Further, chemotherapy does not seem to affect the subsequent clinical course of HGV infection.

High prevalence of the His63Asp HFE mutation in Italian patients with porphyria cutanea tarda

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.

Clinical manifestations of hepatitis C

Hepatitis C is a common cause of viral hepatitis that progresses to chronic infection in the majority of patients. Clinically, the infection is generally asymptomatic, but it may present with a wide variety of symptoms. Cirrhosis, hepatocellular carcinoma, cryoglobulinemia, auto-antibodies, and glomerulonephritis have been strongly associated with HCV. There is a probable association with autoimmune disease and NHL. More information is needed to determine whether lichen planus, PCT, and other disorders are part of the growing clinical spectrum or just coincidental associations with chronic liver disease.

Mode of hepatitis C virus infection, epidemiology, and chronicity rate in the general population and risk groups

Since the discovery of the hepatitis C virus (HCV), it has become evident that this infectious agent is a primary cause of posttransfusion and sporadic non-A, non-B hepatitis. Identification and introduction of surrogate markers for posttransfusion hepatitis and later introduction of anti-HCV screening has decreased the incidence of posttransfusion hepatitis. Community-acquired HCV infection is less common than posttransfusion HCV hepatitis. HCV infection may lead to liver cirrhosis without prior evidence of laboratory or histologic infection. Populations at risk for HCV infection include patients receiving organ transplants, health care workers, infants born to HCV-infected mothers, and hemodialysis patients. Intravenous drug abusers and their sexual partners also demonstrate a high rate of HCV infection. Nosocomial HCV transmission may occur despite the observance of universal precautions. Dental or surgical intervention, salivary inoculation, family members infected with HCV, cocaine abuse, HIV infection, and lower socioeconomic status also each correlate with an increased risk of infection. HCV infection is associated with many immune-mediated diseases. There may also be some relationship between human leukocyte antigens and HCV infection. Since there currently is no HCV vaccine, prevention of exposure remains the only possibility for reducing HCV transmission and prevalence.