Direct‐acting antivirals for hepatitis C virus induce a rapid clinical and biochemical remission of porphyria cutanea tarda

Resolution of subclinical porphyria cutanea tarda after hepatitis C eradication with direct-acting anti-virals

BACKGROUND

Hepatitis C virus (HCV) is a risk factor for porphyria cutanea tarda (PCT), a rare disease originating in the liver characterised by overproduction of porphyrins. Although hepatitis C infection is highly prevalent among patients with porphyria, only a minority of hepatitis C patients develop PCT.

AIMS

To explore the presence of porphyrin abnormalities in a cohort of asymptomatic hepatitis C-infected patients and the impact of anti-viral therapy.

METHODS

Eighty-four consecutive patients with HCV infection treated with direct-acting antivirals after 1 January 2018 were longitudinally evaluated for the presence of porphyrin abnormalities. Those patients with biochemical abnormalities at baseline were additionally evaluated at follow-up. Porphyrins in urine were screened by fluorometry and isomer separation was performed by liquid chromatography.

RESULTS

In five patients, all of them asymptomatic, porphyrin profile abnormalities were detected: three presented significant increased urinary porphyrins with a typical PCT profile, and two showed normal levels of urinary porphyrins, but abnormal porphyria-like profiles. Urine evaluation after hepatitis C cure showed complete normalisation of the urinary porphyrins in all patients, confirming the biochemical cure of the disease.

CONCLUSIONS

We document the existence of rare cases of hepatitis C-infected patients with significant uroporphyrinuria in the absence of dermatological manifestations. Anti-viral therapy normalises the biochemical disorder, preventing patients from presenting PCT associated complications.

Porphyria cutanea tarda: Recent update

Porphyria cutanea tarda (PCT) is the most common human porphyria, due to hepatic deficiency of uroporphyrinogen decarboxylase (UROD), which is acquired in the presence of iron overload and various susceptibility factors, such as alcohol abuse, smoking, hepatitis C virus (HCV) infection, HIV infection, iron overload with HFE gene mutations, use of estrogens, and UROD mutation. Patients with familial or type II PCT due to autosomal dominant UROD mutation also require other susceptibility factors, as the disease phenotype requires hepatic UROD deficiency to below 20% of normal. PCT clinically manifests with increased skin fragility and blistering skin lesions on sun exposed areas. The common age of presentation is 5th to 6th decade and occurs slightly more commonly in males. Although mild liver biochemical profile are common, advanced fibrosis and cirrhosis with hepatocellular carcinoma (HCC) can occasionally develop. Screening for HCC using ultrasound examination is recommended in PCT patients, especially with cirrhosis and advanced fibrosis. PCT is effectively and readily treatable with the use of either repeated phlebotomy or use of 100 mg hydroxychloroquine orally twice a week, and both the treatments are equally effective and safe. With the advent of new or direct antiviral agents for HCV infection, treatment of concomitant HCV has become safer and effective. Data are emerging on the benefit of these drugs as monotherapy for both PCT and HCV. After the achievement of remission of PCT, there remains a potential for relapse, especially when the susceptibility factors are not adequately controlled. Scanty data from retrospective and observational studies shows the relapse rate to be somewhat higher after remission with low-dose hydroxychloroquine as compared to phlebotomy induced remission. Future studies are needed on exploring mechanism of action of 4-aminoquinolines, understanding interaction of HCV and PCT, and relapse of PCT on long-term follow-up.

Heme biosynthesis and the porphyrias

Porphyrias, is a general term for a group of metabolic diseases that are genetic in nature. In each specific porphyria the activity of specific enzymes in the heme biosynthetic pathway is defective and leads to accumulation of pathway intermediates. Phenotypically, each disease leads to either neurologic and/or photocutaneous symptoms based on the metabolic intermediate that accumulates. In each porphyria the distinct patterns of these substances in plasma, erythrocytes, urine and feces are the basis for diagnostically defining the metabolic defect underlying the clinical observations. Porphyrias may also be classified as either erythropoietic or hepatic, depending on the principal site of accumulation of pathway intermediates. The erythropoietic porphyrias are congenital erythropoietic porphyria (CEP), and erythropoietic protoporphyria (EPP). The acute hepatic porphyrias include ALA dehydratase deficiency porphyria, acute intermittent porphyria (AIP), hereditary coproporphyria (HCP) and variegate porphyria (VP). Porphyria cutanea tarda (PCT) is the only porphyria that has both genetic and/or environmental factors that lead to reduced activity of uroporphyrinogen decarboxylase in the liver. Each of the 8 enzymes in the heme biosynthetic pathway have been associated with a specific porphyria (Table 1). Mutations affecting the erythroid form of ALA synthase (ALAS2) are most commonly associated with X-linked sideroblastic anemia, however, gain-of-function mutations of ALAS2 have also been associated with a variant form of EPP. This overview does not describe the full clinical spectrum of the porphyrias, but is meant to be an overview of the biochemical steps that are required to make heme in both erythroid and non-erythroid cells.

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.

Current and innovative emerging therapies for porphyrias with hepatic involvement

Porphyrias are rare inherited disorders caused by specific enzyme dysfunctions in the haem synthesis pathway, which result in abnormal accumulation of specific pathway intermediates. The symptoms depend upon the chemical characteristics of these substances. Porphyrins are photoreactive and cause photocutaneous lesions on sunlight-exposed areas, whereas accumulation of porphyrin precursors is related to acute neurovisceral attacks. Current therapies are suboptimal and mostly address symptoms rather than underlying disease mechanisms. Advances in the understanding of the molecular bases and pathogenesis of porphyrias have paved the way for the development of new therapeutic strategies. In this Clinical Trial Watch we summarise the basic principles of these emerging approaches and what is currently known about their application to porphyrias of hepatic origin or with hepatic involvement.

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.

Experience in management of porphyria cutanea tarda in a tertiary referral Brazilian hospital from 2002 to 2017

BACKGROUND

Porphyria cutanea tarda (PCT) is the most common porphyria worldwide. The known acquired precipitating factors that induce PCT include alcoholism, hepatitis C virus infection, human immunodeficiency virus infection, and estrogen intake. Hereditary hemochromatosis is considered an inherited risk factor. The aim of this study was to describe and analyze precipitating factors and family history, with emphasis on PCT management.

METHODS

A retrospective study of 87 patients with PCT was conducted between January 2002 and December 2017.

RESULTS

A male predominance of 1.8 : 1 was found. The median age at diagnosis was 49 years (range 18-71). Family history of PCT was observed in 19.5% of patients. Two or more acquired precipitating factors were present in 42.5%. Patients were treated with antimalarial monotherapy (72.4%), antimalarial combined with phlebotomy (22.9%), and only with phlebotomy (4.6%). Acquired precipitating factors and inherited factors were not associated with treatment group. There was a difference in 24 h-UP normalization rate between treatment groups; combined therapy takes longer than antimalarial monotherapy, 38 months versus 15 months, respectively (CI 95%, 6.5-63.5 vs. 12.9-17) (log-rank test, P = 0.004).

CONCLUSION

Precipitating factors did not seem to be associated with treatment choice; however, all acquired and inherited precipitating factors should be investigated, and the choice between phlebotomy and/or antimalarials should be individualized. All dermatologists treating PCT patients should observe transferrin saturation and ferritin levels to search for underlying hereditary hemochromatosis.

Human oncoviruses: Mucocutaneous manifestations, pathogenesis, therapeutics, and prevention: Hepatitis viruses, human T-cell leukemia viruses, herpesviruses, and Epstein-Barr virus

In 1964, the first human oncovirus, Epstein-Barr virus, was identified in Burkitt lymphoma cells. Since then, 6 other human oncoviruses have been identified: human papillomavirus, Merkel cell polyomavirus, hepatitis B and C viruses, human T-cell lymphotropic virus-1, and human herpesvirus-8. These viruses are causally linked to 12% of all cancers, many of which have mucocutaneous manifestations. In addition, oncoviruses are associated with multiple benign mucocutaneous diseases. Research regarding the pathogenic mechanisms of oncoviruses and virus-specific treatment and prevention is rapidly evolving. Preventative vaccines for human papillomavirus and hepatitis B virus are already available. This review discusses the mucocutaneous manifestations, pathogenesis, diagnosis, treatment, and prevention of oncovirus-related diseases. The first article in this continuing medical education series focuses on diseases associated with human papillomavirus and Merkel cell polyomavirus, while the second article in the series focuses on diseases associated with hepatitis B and C viruses, human T-cell lymphotropic virus-1, human herpesvirus-8, and Epstein-Barr virus.

Disappearance of multiple hyperechoic liver nodules in sporadic porphyria cutanea tarda after treatment with ledipasvir/sofosbuvir for hepatitis C

Ultrasonography in a 60-year-old man with chronic hepatitis C (CHC) demonstrated multiple hyperechoic nodules. Radiological investigations did not reveal any signs of malignancy. However, magnetic resonance chemical shift imaging showed multiple focal fatty changes in the liver. Urinary levels of uroporphyrin and coproporphyrin were elevated, and we made a diagnosis of porphyria cutanea tarda. Direct-acting antivirals, ledipasvir/sofosbuvir, were initiated for CHC, which led to sustained viral response, resolution of the liver nodules, and normalization of urinary porphyrin. Hepatitis C virus infection can cause porphyria cutanea tarda with multiple hyperechoic liver nodules, which might be cured by direct-acting antivirals.

Extrahepatic manifestations of HCV: the role of direct acting antivirals

INTRODUCTION

Hepatitis C virus (HCV) represents a major health concern, as nearly 3 million people become newly infected by this pathogen annually. The majority of infected individuals fail to clear the virus, and chronicity is established. Chronic HCV patients are at high risk for liver disease, ranging from mild fibrosis to cirrhosis and severe hepatocellular carcinoma. Over the last few years, the development of multiple direct acting antivirals (DAA) have revolutionized the HCV infection treatment, demonstrating cure rates higher than 90%, and showing less side effects than previous interferon-based regimens. Areas covered: Besides liver, HCV infection affects a variety of organs, therefore inducing diverse extrahepatic manifestations. This review covers clinical, experimental, and epidemiological publications regarding systemic manifestations of HCV, as well as recent studies focused on the effect of DAA in such conditions. Expert commentary: Though further research is needed; available data suggest that HCV eradication is often associated with the improvement of extrahepatic symptoms. Therefore, the emergence of DAA would offer the opportunity to treat both HCV infection and its systemic manifestations, requiring shorter treatment duration and driving minor adverse effects.