Symptomatic myopathy associated with interferon therapy for chronic hepatitis C

A case of polymyositis in a chronic hepatitis C patient treated with peg-interferon-alpha 2b and ribavirin therapy

Hepatitis C virus (HCV) infection may result in progression to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Interferon-based treatment in patients with chronic hepatitis C may achieve viral clearance, and as a consequence improve liver histology and prevent progression to hepatocellular carcinoma. At present, the recommended therapy for chronic hepatitis C is peg-interferon-alpha (PEG-IFN-α) in conjunction with the oral nucleoside analog ribavirin. In the current study, we report a case of polymyositis associated with chronic hepatitis C following PEG-IFN-α and ribavirin therapy. The patient, a 64-year-old female who was treated with combination therapy, demonstrated elevated serum CPK, AST, ALT and LDH levels at 28 weeks after treatment onset. As there was an elevation of the serum HCV-RNA levels, combination treatment was ceased at 24 weeks. The patient had received IFN therapy twice previously (IFN-α 2a and IFN-α 2b with ribavirin therapy); however, no adverse side effects were observed. Further laboratory examination, muscle biopsy and imaging data suggested polymyositis, possibly triggered by the PEG-IFN-α treatment. The patient was subsequently administered prednisolone and the dose tapered over 7 months. As a result the polymyositis has remained in remission. Although many autoimmune diseases have been associated with IFN therapy, the development of polymyositis is extremely rare.

Reversible myopathy during successful treatment with pegylated interferon and ribavirin for acute hepatitis C

There is no standard approved treatment for acute hepatitis C and the combination of pegylated interferon-alpha and ribavirin, currently recognized as the standard of care for chronic hepatitis C, has not been evaluated for acute hepatitis C. Adverse events induced by interferon therapy are numerous but myopathy is rare and has not been described with the use of pegylated interferon-alpha. We report the case of a 33-year-old Caucasian man who was successfully treated for acute hepatitis C with the combination of pegylated interferon-alpha2b and ribavirin, and who during treatment developed myopathy which proved reversible.

[Extrahepatic manifestations of hepatitis C virus infection]

<zakljucak> Hepatitis C virusna infekcija je zaista povezana sa sirokim spektrom ekstrahepatickih sindroma. Neke bolesti su sigurno povezane sa HCV infekcijom (krioglobulinemija, kasna kozna porfirija, membranoproliferativni glomerulo-nefritis), za neke postoji velika verovatnoca (autoimunske bolesti stitaste zlezde, autoimunska trombocitopenija, limfomi, secerna bolest neuropatije, artritis, lihen planus, nodozni poliarteritis, sijaloedenitis sindrom fibromialgije) dok se za neke bolesti ostavlja mogucnost da se radi o slucajnoj udruzenosti za sto su potrebna nova istrazivanja.

[Interferon-alpha and auto-immunity]

PURPOSE

To assess the role of endogenous interferon alpha (IFN) in auto-immune experimental models and human diseases, and to evaluate its iatrogenic potential as a therapeutic agent.

MAIN POINTS

IFN is a cytokine involved in cellular immunity, that promotes both differentiation of dendritic cells and the TH1 pathway. Auto-immune side-effects of recombinant IFN depend on IFN dosage and the pathology concerned. The spectrum extends from occurrence of auto-antibodies in an asymptomatic patient to overt disease such as systemic lupus. Antigenic targets of auto-antibodies are diverse: blood cells coagulation factors, immunoglobulin, hormones, intrinsic factor, intracellular components. Thyroiditis is the most frequently reported auto-immune disease occurring during IFN treatment, including hypothyroidism, hyperthyroidism or a bi-phasic pattern. Currently, true incidence of thyroiditis remains debated. It appears very low (under 1%) in hepatologic series using low-dose IFN. The fact that auto-immunity may be related to the treated disease--before use of IFN--must also be addressed: e.g. antinuclear factors and anti-DNA antibodies in chronic myeloid leukemia or anti-actin and anti-LKM antibodies in chronic C hepatitis.

FUTURE PROSPECTS

Recombinant alpha interferon appears more as a trigger than a de novo inducer of auto-immune disorders. Its use as an immunomodulator agent should be treated with caution.

Hepatitis C Virus Infection, Inflammatory Myopathy, and Pulmonary Fibrosis: Are They Related?

We describe the clinical findings, laboratory and ancillary studies, and histopathologic findings of 2 patients with hepatitis C virus infection who developed inflammatory myopathy and interstitial lung disease. A review of pertinent literature revealed several other patients with a similar cluster of clinical manifestations. The inflammatory myopathy in the cases reported here was atypical and distinct from that found in the anti-synthetase syndrome because it was characterized by mild or intermittent elevation of creatine phosphokinase, absence of anti-JO1 antibodies, and excellent response to oral corticosteroids. Thus, this report supports the hypothesis that hepatitis C virus infection may cause both inflammatory myopathy and pulmonary fibrosis. We suggest that evaluation for hepatitis C virus infection should be pursued in all patients with inflammatory myopathy and pulmonary fibrosis irrespective of anti-JO1 status. We further suggest that hepatitis C should be considered as another cause of myositis and interstitial lung disease in addition to the anti-synthetase syndrome.

Inclusion body myositis associated with hepatitis C virus infection

The case of a 77-year-old woman with hepatitis C virus infection with a 5-year history of muscle weakness and mild disturbance of gait is reported. Steroid therapy did not improve her symptoms. She developed HCV-related liver cirrhosis and hepatocellular carcinoma, and muscle biopsy revealed inclusion body myositis. Immunohistochemistry showed that the nonstructural region of HCV and 8-hydroxy-2'-deoxyguanosine, a marker of DNA damage by reactive oxygen species, were present in striated muscle cells of this patient.

Multinodular polymyositis in a patient with human immunodeficiency and hepatitis C virus coinfection

We report a patient who developed multiple inflammatory muscle masses and generalized polymyositis in the setting of combined human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection. Magnetic resonance imaging (MRI) of muscles showed patchy edema which was particularly intense within the nodular masses. Polymerase chain reaction (PCR) showed no evidence of either virus within muscle. This report reviews earlier literature on muscle nodules associated with myositis and discusses the differential diagnosis of muscle masses in HIV infection.

[Association between polymyositis and hepatitis C infection. Treatment-related difficulties]

INTRODUCTION

Chronic hepatitis C virus infection is often associated with various auto-immune disorders. We report four cases of an association between polymyositis and hepatitis C virus infection. The course and the difficulties of therapy are discussed.

EXEGESIS

Among 510 consecutive patients infected by viral hepatitis C, we report four cases of polymyositis. Corticosteroids increased serum alanine aminotransferase levels in two cases, leading to severe liver injury in one patient. Worsening of polymyositis under interferon-alpha therapy was observed in one case. Clinical and biological stability were reported in another case. Aggravation of polymyositis with severe muscle weakness and dyspnea occurred in two patients after disruption of interferon-alpha treatment. Intravenous gamma globulins subsequently improved their condition, without biological worsening of viral hepatitis.

CONCLUSION

These observations suggest an association between hepatitis C virus infection and polymyositis. Because corticosteroids can induce adverse effects in the liver, intravenous gamma globulins could be used for the treatment of this particular form of polymyositis.

Interferon treatment for dilated cardiomyopathy and striated myopathy associated with hepatitis C virus infection based on serial measurements of serum concentrations of cardiac troponin T

The present authors recently suggested, on the basis of studies using polymerase chain reaction (PCR), that hepatitis C virus (HCV) infection is involved in the etiology or pathogenesis of cardiomyopathic disorders. They have also reported that the serum concentration of cardiac troponin T is an indicator of ongoing myocyte degeneration in patients with dilated cardiomyopathy (DCM) and hypothesized that its serial measurement may be a marker of therapeutic efficacy. This is the first case report of DCM and striated myopathy, associated with HCV infection, treated with interferon therapy guided by monitoring of serial serum concentrations of cardiac troponin T. Positive-plus strands of HCV RNA were found in the patient's myocardium, as well as plus and minus strands in the quadriceps muscle specimens. Serum levels of creatine kinase (CK), CK-MB and cardiac troponin T fell as serum HCV titers decreased during treatment with interferon, whereas conventional treatment of heart failure had no effect. Monitoring of serial serum concentrations of cardiac troponin T may allow the earlier diagnosis and treatment of patients with HCV-associated cardiomyopathy and improve their clinical course.

Hepatitis C-associated autoimmune disorders

Hepatitis C virus (HCV) infection has been associated with multiple autoimmune manifestations. The immune response to HCV infection encompasses the development of autoantibodies, immune complex formation and deposition, and cryoglobulinemia complicated by vasculitis, glomerulonephritis, or neuropathy. HCV infection has been associated with antiphospholipid antibody syndrome, RA, SLE, PM/DM, and thyroid disease. HCV-infected patients also have a high incidence of sicca symptoms with sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. Optimal treatment for HCV-related autoimmune disease remains to be determined, but patients seem to respond to immunosuppression with classic agents or interferon.

Hepatitis C virus infection and autoimmunity

Hepatitis C virus (HCV) infection has been associated with a plethora of immune and autoimmune perturbations. We review serological and clinical autoimmune manifestations associated with HCV infection, discuss treatment regimens for HCV-related autoimmune diseases, and present a framework for understanding HCV-associated autoimmune disease by performing a computerized literature search from which representative articles were used and referenced. The immune response to HCV may include the development of cryoglobulins, rheumatoid factor, antinuclear antibodies (ANA), anticardiolipin, antithyroid, anti-liver/kidney/microsomal antibodies (anti-LKM), as well as HCV/anti-HCV immune complex formation and deposition. HCV infection is a significant cause of mixed essential cryoglobulinemia, which may then be complicated by cryoglobulinemic glomerulonephritis, vasculitis, or neuropathy. It has also been associated with membranous and membranoproliferative glomerulonephritis. Subsets of autoimmune hepatitis patients are infected with HCV and evidence suggests that HCV is a causative agent of antithyroid antibodies and autoimmune thyroid disease. Although cause-and-effect remain to be proved, there are reports of HCV infection preceding or coincident with polyarthritis, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and polymyositis/dermatomyositis (PM/DM). HCV-infected patients also have a high incidence of sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. However, HCV is not a major causative factor for most autoimmune diseases. Optimal treatment for HCV-related autoimmune disease remains to be determined. Interferon alpha (IFN alpha) has successfully reduced viremia/transaminitis, cryoglobulins, proteinuria, and nephritis, but recurrent disease manifestations are frequent after discontinuation of therapy. Moreover, IFN alpha may precipitate or exacerbate autoimmune disease symptoms. HCV-related autoimmune disease also has been treated successfully with corticosteroids, azathioprine, and cyclophosphamide, although HCV viremia persists and may worsen.

Nonhepatic manifestations and combined diseases in HCV infection

Infection with hepatitis C virus (HCV) may affect not only the liver but also various nonhepatic tissues and organs and may combine with many etiologically unrelated diseases and morbid conditions. Numerous nonhepatic manifestations in HCV infection have been previously reported. For some (eg, cryoglobulinemia), the association is well established. For others, such as sialadenitis and lichen planus, the association is probable (but not completely documented) and, for the remainder, the associations are weak. Extrahepatic manifestations may result from immunological mechanisms as well as virus invasion and replication in the affected extrahepatic tissues and organs. Thyroid abnormalities, primarily Hashimoto's disease, and isolated increases of anti-thyroid antibodies (ATPO) appear to be more frequent in chronic hepatitis C than B or D, with high ATPO titers clustering mainly among females. Interferon-alpha (IFN-alpha) therapy is associated with development of thyroid dysfunction in 5.5-12.9% of patients, usually exposing preexisting subclinical thyroid abnormalities. Mixed cryoglobulinemia (MC) is commonly found (36-45%) in patients with chronic HCV infection; however, only in a minority of cases does it become clinically manifested as systemic vasculitis with purpura, neuropathy, or Raynaud's phenomenon. In a number of patients, MC may terminate in non-Hodgkin's B-cell lymphoma. Treatment of these lymphoproliferative disorders with IFN-alpha is advocated. Idiopathic thrombocytopenia is now recognized more frequently in association with chronic HCV infection and is usually aggravated by IFN-alpha therapy. Patients with porphyria cutanea tarda (PCT) have demonstrated serological markers of HCV infection in 62-82% of cases. The usefulness of IFN-alpha in PCT remains to be demonstrated. Lichen planus has also been found in association with chronic HCV infection, particularly when severe or affecting the oral cavity. Other nonhepatic manifestations have also been reported in HCV infection such as diabetes, corneal ulceration, uveitis, and sialadenitis. These manifestations deserve further study and documentation. Finally, markers of autoimmunity occur with high frequency in chronic HCV infection; however, combination with the classical syndrome of autoimmune hepatitis is rare. In the presence of various autoantibodies, the clinical features of chronic hepatitis C do not appear to be modified and, contrary to general perception, IFN-alpha therapy within randomized controlled trials should not be withheld since the response rate to IFN-alpha does not appear to differ in the presence or absence of low titers of these markers.