Sarcoidosis tras tratamiento con interferón y ribavirina. Presentación de un caso y revisión de la bibliografía

Safety, Tolerability, and Immunogenicity of Interferons

Interferons (IFNs) are class II cytokines that are key components of the innate immune response to virus infection. Three IFN sub-families, type I, II, and III IFNs have been identified in man, Recombinant analogues of type I IFNs, in particular IFNα2 and IFNβ1, have found wide application for the treatment of chronic viral hepatitis and remitting relapsing multiple sclerosis respectively. Type II IFN, or IFN gamma, is used principally for the treatment of chronic granulomatous disease, while the recently discovered type III IFNs, also known as IFN lambda or IL-28/29, are currently being evaluated for the treatment of chronic viral hepatitis. IFNs are in general well tolerated and the most common adverse events observed with IFNα or IFNβ therapy are “flu-like” symptoms such as fever, headache, chills, and myalgia. Prolonged treatment is associated with more serious adverse events including leucopenia, thrombocytopenia, increased hepatic transaminases, and neuropsychiatric effects. Type I IFNs bind to high-affinity cell surface receptors, composed of two transmembrane polypeptides IFNAR1 and IFNAR2, resulting in activation of the Janus kinases Jak1 and Tyk2, phosphorylation and activation of the latent cytoplasmic signal transducers and activators of transcription (STAT1) and STAT2, formation of a transcription complex together with IRF9, and activation of a specific set of genes that encode the effector molecules responsible for mediating the biological activities of type I IFNs. Systemic administration of type I IFN results in activation of IFN receptors present on essentially all types of nucleated cells, including neurons and hematopoietic stem cells, in addition to target cells. This may well explain the wide spectrum of IFN associated toxicities. Recent reports suggest that certain polymorphisms in type I IFN signaling molecules are associated with IFN-induced neutropenia and thrombocytopenia in patients with chronic hepatitis C. IFNγ binds to a cell-surface receptor composed of two transmembrane polypeptides IFGR1 and IFGR2 resulting in activation of the Janus kinases Jak1 and Jak2, phosphorylation of STAT1, formation of STAT1 homodimers, and activation of a specific set of genes that encode the effector molecules responsible for mediating its biological activity. In common with type I IFNs, IFNγ receptors are ubiquitous and a number of the genes activated by IFNγ are also activated by type I IFNs that may well account for a spectrum of toxicities similar to that associated with type I IFNs including “flu-like” symptoms, neutropenia, thrombocytopenia, and increased hepatic transaminases. Although type III IFNs share the major components of the signal transduction pathway and activate a similar set of IFN-stimulated genes (ISGs) as type I IFNs, distribution of the IFNλ receptor is restricted to certain cell types suggesting that IFNλ therapy may be associated with a reduced spectrum of toxicities relative to type I or type II IFNs. Repeated administration of recombinant IFNs can cause in a break in immune tolerance to self-antigens in some patients resulting in the production of neutralizing antibodies (NABs) to the recombinant protein homologue. Appearance of NABs is associated with reduced pharmacokinetics, pharmacodynamics, and a reduced clinical response. The lack of cross-neutralization of IFNβ by anti-IFNα NABs and vice versa, undoubtedly accounts for the apparent lack of toxicity associated with the presence of anti-IFN NABs with the exception of relatively mild infusion/injection reactions.

Chronic hepatitis C is a common associated with hepatic granulomas

AIM: To determine the most frequent etiologies of hepatic epithelioid granulomas, and whether there was an association with chronic hepatitis C virus (HCV).

METHODS: Both a retrospective review of the pathology database of liver biopsies at our institution from 1996 through 2006 as well as data from a prospective study of hepatic fibrosis markers and liver biopsies from 2003 to 2006 were reviewed to identify cases of hepatic epithelioid granulomas. Appropriate charts, liver biopsy slides, and laboratory data were reviewed to determine all possible associations. The diagnosis of HCV was based on a positive HCV RNA.

RESULTS: There were 4578 liver biopsies and 36 (0.79%) had at least one epithelioid granuloma. HCV was the most common association. Fourteen patients had HCV, and in nine, there were no concurrent conditions known to be associated with hepatic granulomas. Prior interferon therapy and crystalloid substances from illicit intravenous injections did not account for the finding. There were hepatic epithelioid granulomas in 3 of 241 patients (1.24%) with known chronic HCV enrolled in the prospective study of hepatic fibrosis markers.

CONCLUSION: Although uncommon, hepatic granulomas may be part of the histological spectrum of chronic HCV. When epithelioid granulomas are found on the liver biopsy of someone with HCV, other clinically appropriate studies should be done, but if nothing else is found, the clinician can be comfortable with an HCV association.

Sarcoidosis after treatment with interferon-alpha: a case series and review of the literature

Recombinant interferon-alpha (rINF-alpha) is an immunomodulator used in the treatment of various conditions, including viral infections and malignancies. The use of rINF-alpha has been associated with the development of sarcoidosis in recent case reports. In this series, we report the incidence of sarcoidosis in recipients of rINF-alpha for hepatitis C viral (HCV) infection at our institution. We also review the 57 additional cases of sarcoidosis associated with rINF-alpha described in the literature, including clinical presentation, radiographic findings, management, and outcomes, and discuss the potential mechanisms by which rINF-alpha may lead to the development of sarcoidosis.

Sarcoidosis caused by interferon therapy

Interferon alpha (IFN-alpha) is an immunomodulator that is used as an antiviral agent in active chronic viral hepatitis C. IFN therapy can cause an induction or exacerbation of sarcoidosis. Although several reports in the gastroenterology literature have suggested an association between IFN therapy and sarcoidosis, this association has rarely been described elsewhere. A 47-year-old woman developed sarcoidosis after cessation of treatment with IFN and ribavirin for chronic hepatitis C. Her sarcoidosis showed liver, pulmonary and skin involvement. She continues to be monitored regularly in the Department of Pulmonary Diseases without steroid therapy. Her sarcoidosis improved spontaneously. We conclude that patients should be monitored for sarcoidosis during and after IFN therapy.

Sarcoidosis occurring after interferon-alpha therapy for chronic hepatitis C: Report of two cases

We report two patients who were diagnosed with sarcoidosis after receiving interferon (IFN)-alpha therapy for chronic hepatitis C, and conduct a review the relevant literature. The first patient was a 52-year-old female who developed multiple subcutaneous nodules 2 months after finishing IFN-alpha therapy. A skin biopsy from subcutaneous nodules on the right elbow joint revealed sarcoid granulomata. These lesions resolved spontaneously 4 months later. The second patient, a 57-year-old male, developed bilateral hilar and mediastinal lymph node enlargement 2 years after finishing IFN-alpha 2a therapy. A transbronchial lung biopsy demonstrated sarcoid granulomata. In addition, he had uveitis and left ulnar nerve involvement. His eye and nerve involvement gradually improved over 20 months. It is feasible that IFN therapy has been a trigger for sarcoidosis in these patients.

Sarcoidosis in patients with chronic hepatitis C virus infection: analysis of 68 cases

We describe the clinical characteristics, the patterns of association, and the role of antiviral therapies in patients with sarcoidosis associated with chronic hepatitis C virus (HCV) infection. Sixty-eight patients were included in the current study, 56 cases identified in the literature search plus 12 unpublished cases from our department. In 50 HCV patients, sarcoidosis appeared after starting antiviral therapy. Antiviral therapy associated with triggered sarcoidosis consisted of alpha-interferon monotherapy in 20 cases and combined therapy with alpha-interferon and ribavirin in 30. Sarcoidosis appeared during the first 6 months after starting therapy in 66% of patients. The clinical picture of sarcoidosis included predominantly pulmonary disease in 38 (76%) patients and cutaneous sarcoidosis in 30 (60%). Antiviral therapy was discontinued in 60% of patients and continued or adjusted in 14%, while sarcoidosis appeared after completed therapy in the remaining cases. Specific therapy for sarcoidosis was started in only 21 patients, mainly with oral corticosteroids. The outcome of patients was detailed in 46 cases: remission or improvement was observed in 38/46 (83%) patients, stabilization of sarcoidosis in 5/46 (11%), and reactivation of sarcoidosis after an initial improvement in 3/46 (6%). Finally, 18 treatment-naive HCV patients presented sarcoidosis, with 14/18 (87%) patients presenting with pulmonary involvement and 8/18 (44%) with cutaneous involvement. In summary, sarcoidosis may be observed in HCV patients in 2 different situations: triggered by antiviral therapy (in 75% of cases) and unrelated to treatment. Sarcoidosis during antiviral therapy may present mainly as cutaneous or pulmonary disease, with a benign, uncomplicated evolution in more than 85% of cases. However, more complicated cases are observed, especially in HCV patients with preexisting sarcoidosis and/or with previous antiviral treatment. Clinicians should be aware of the possibility that sarcoidosis may initially manifest or be reactivated during or shortly after treatment with antiviral therapy in patients with chronic HCV infection.