Type 1 diabetes mellitus provoked by peginterferon alpha-2b plus ribavirin treatment for chronic hepatitis C

Septin-3 autoimmunity in patients with paraneoplastic cerebellar ataxia

BACKGROUND

Septins are cytoskeletal proteins with filament forming capabilities, which have multiple roles during cell division, cellular polarization, morphogenesis, and membrane trafficking. Autoantibodies against septin-5 are associated with non-paraneoplastic cerebellar ataxia, and autoantibodies against septin-7 with encephalopathy with prominent neuropsychiatric features. Here, we report on newly identified autoantibodies against septin-3 in patients with paraneoplastic cerebellar ataxia. We also propose a strategy for anti-septin autoantibody determination.

METHODS

Sera from three patients producing similar immunofluorescence staining patterns on cerebellar and hippocampal sections were subjected to immunoprecipitation followed by mass spectrometry. The identified candidate antigens, all of which were septins, were expressed recombinantly in HEK293 cells either individually, as complexes, or combinations missing individual septins, for use in recombinant cell-based indirect immunofluorescence assays (RC-IIFA). Specificity for septin-3 was further confirmed by tissue IIFA neutralization experiments. Finally, tumor tissue sections were analyzed immunohistochemically for septin-3 expression.

RESULTS

Immunoprecipitation with rat cerebellum lysate revealed septin-3, -5, -6, -7, and -11 as candidate target antigens. Sera of all three patients reacted with recombinant cells co-expressing septin-3/5/6/7/11, while none of 149 healthy control sera was similarly reactive. In RC-IIFAs the patient sera recognized only cells expressing septin-3, individually and in complexes. Incubation of patient sera with five different septin combinations, each missing one of the five septins, confirmed the autoantibodies' specificity for septin-3. The tissue IIFA reactivity of patient serum was abolished by pre-incubation with HEK293 cell lysates overexpressing the septin-3/5/6/7/11 complex or septin-3 alone, but not with HEK293 cell lysates overexpressing septin-5 as control. All three patients had cancers (2 × melanoma, 1 × small cell lung cancer), presented with progressive cerebellar syndromes, and responded poorly to immunotherapy. Expression of septin-3 was demonstrated in resected tumor tissue available from one patient.

CONCLUSIONS

Septin-3 is a novel autoantibody target in patients with paraneoplastic cerebellar syndromes. Based on our findings, RC-IIFA with HEK293 cells expressing the septin-3/5/6/7/11 complex may serve as a screening tool to investigate anti-septin autoantibodies in serological samples with a characteristic staining pattern on neuronal tissue sections. Autoantibodies against individual septins can then be confirmed by RC-IIFA expressing single septins.

Hepatitis C virus infection and type 1 and type 2 diabetes mellitus

Hepatitis C virus (HCV) infection and diabetes mellitus are two major public health problems that cause devastating health and financial burdens worldwide. Diabetes can be classified into two major types: type 1 diabetes mellitus (T1DM) and T2DM. T2DM is a common endocrine disorder that encompasses multifactorial mechanisms, and T1DM is an immunologically mediated disease. Many epidemiological studies have shown an association between T2DM and chronic hepatitis C (CHC) infection. The processes through which CHC is associated with T2DM seem to involve direct viral effects, insulin resistance, proinflammatory cytokines, chemokines, and other immune-mediated mechanisms. Few data have been reported on the association of CHC and T1DM and reports on the potential association between T1DM and acute HCV infection are even rarer. A small number of studies indicate that interferon-α therapy can stimulate pancreatic autoimmunity and in certain cases lead to the development of T1DM. Diabetes and CHC have important interactions. Diabetic CHC patients have an increased risk of developing cirrhosis and hepatocellular carcinoma compared with non-diabetic CHC subjects. However, clinical trials on HCV-positive patients have reported improvements in glucose metabolism after antiviral treatment. Further studies are needed to improve prevention policies and to foster adequate and cost-effective programmes for the surveillance and treatment of diabetic CHC patients.

GABAB receptor antibodies in paraneoplastic cerebellar ataxia

Autoantibodies to the gamma-aminobutyric acid-B (GABAB) receptor were recently described in patients with limbic encephalitis presenting with early or prominent seizures. We report on a 64-year-old man with malignant melanoma who during adjuvant therapy with interferon (IFN)-alpha developed cerebellar ataxia. Indirect immunofluorescence on brain tissue sections revealed high-titer (1:20,000) IgG1 serum autoantibodies to the cerebellar molecular and granular layer, which were confirmed to be directed against GABAB receptor in a cell-based assay. This case highlights cerebellar ataxia in the absence of seizures as a clinical manifestation of GABAB receptor autoimmunity and extends the spectrum of tumors underlying this condition to malignant melanoma. IFN-alpha therapy may have contributed to the development of autoimmunity in this patient.

Type 1 Diabetes Mellitus Associated with Pegylated Interferon-α Plus Ribavirin Treatment for Chronic Hepatitis C: Case Report and Literature Review

Combined pegylated interferon (PEG-IFN)+ribavirin (RBV) therapy has been used as a primary treatment for chronic hepatitis C. However, IFN-induced autoimmune disease, including type 1 diabetes mellitus, has been highlighted as one of the problems with this therapy. Here we report the case of a patient who developed type 1 diabetes mellitus during combined PEG-IFN+RBV therapy for hepatitis C but who showed no exacerbation of diabetes despite continued use of IFN. A 63-year-old man with chronic hepatitis C and a nonresponder to previous IFNα treatments, was admitted to our hospital because of excessive thirst, polydipsia, and polyuria 24 weeks after the start of PEG-IFNα+RBV therapy. High levels of blood glucose and glycosylated hemoglobin and low levels of C-peptide and immunoreactive insulin were observed. The serum antiglutamic acid decarboxylase antibody titer was 27,700 U/mL. We diagnosed IFN-induced type 1 diabetes mellitus; however PEG-IFNα+RBV therapy was continued for 48 weeks. Serum HCV remains negative five years after this treatment. Intensive insulin therapy was started immediately after the diagnosis of type 1 diabetes. Although the patient initially required 22 U/day of insulin, the dosage could be gradually reduced after completion of PEG-IFNα+RBV therapy and blood glucose remained well controlled. Prediction of onset of type 1 diabetes mellitus on the basis of baseline measurement of pancreas-associated autoantibodies is difficult. Therefore, it would be advisable to consider the possibility of onset of type 1 diabetes mellitus in all patients receiving IFN+RBV therapy.

Trajectories of anti-islet autoantibodies before development of type 1 diabetes in interferon-treated hepatitis C patients. Case reports and a literature review

Interferon-alpha (IFN-α) is widely used in the treatment of viral hepatitis, however, it is known that IFN-α therapy may induce type 1 diabetes. We report here on two cases of chronic viral hepatitis C who developed autoimmune type 1 diabetes during Peg-IFN-α plus ribavirin (RBV) therapy. Case 1: a 48-year-old male with chronic hepatitis C with chronic thyroiditis. The patient's plasma glucose level was normal and anti-islet autoantibody tests were negative before Peg-IFN-α+RBV therapy. The emergence of glutamic acid decarboxylase 65 autoantibody (GAD65Ab) was observed after five months of treatment. Autoantibodies to insulin and insulinoma-associated antigen-2 (IA-2) also became positive. Eleven months later, thirst and polydipsia occurred with increased fasting plasma glucose level and the patient was diagnosed with type 1A diabetes. Zinc transporter-8 autoantibody (ZnT8Ab) was not detectable at any point. The patient has type 1 diabetes-susceptible HLA-DRB1-DQB1 haplotypes *0405-*0401 and *0901-*0303. Case 2: a 65-year-old male with chronic hepatitis C with type 2 diabetes on insulin treatment. GAD65Ab and IA-2Ab were negative before Peg-IFN-α+RBV therapy, however, nine months later, a single appearance of GAD65Ab was observed. After twelve months, his plasma glucose control worsened rapidly, and he was diagnosed with type 1A diabetes. IA-2Ab and ZnT8Ab were negative throughout the clinical course. His HLA-DRB1-DQB1 haplotypes were *0410-*0402 and *1407-*0503. Both cases showed a unique GAD65Ab epitope (amino acids 360-442). These clinical courses suggest that IFN-α therapy provoked acute islet autoimmunity and onset of type 1 diabetes. Therefore, during IFN-α therapy, patients should be closely monitored for the occurrence of type 1 diabetes.

Effect of ingested interferon-alpha on beta-cell function in children with new-onset type 1 diabetes

OBJECTIVE

To evaluate the safety and efficacy of ingested human recombinant interferon-alpha (hrIFN-alpha) for preservation of beta-cell function in young patients with recent-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

Subjects aged 3-25 years in whom type 1 diabetes was diagnosed within 6 weeks of enrollment were randomly assigned to receive ingested hrIFN-alpha at 5,000 or 30,000 units or placebo once daily for 1 year. The primary outcome was change in C-peptide secretion after a mixed meal.

RESULTS

Individuals in the placebo group (n = 30) lost 56 +/- 29% of their C-peptide secretion from 0 to 12 months, expressed as area under the curve (AUC) in response to a mixed meal. In contrast, children treated with hrIFN-alpha lost 29 +/- 54 and 48 +/- 35% (for 5,000 [n = 27] and 30,000 units [n = 31], respectively, P = 0.028, ANOVA adjusted for age, baseline C-peptide AUC, and study site). Bonferroni post hoc analyses for placebo versus 5,000 units and placebo versus 30,000 units demonstrated that the overall trend was determined by the 5,000-unit treatment group. Adverse events occurred at similar rates in all treatment groups.

CONCLUSIONS

Ingested hrIFN-alpha was safe at the doses used. Patients in the 5,000-unit hrIFN-alpha treatment group maintained more beta-cell function 1 year after study enrollment than individuals in the placebo group, whereas this effect was not observed in patients who received 30,000 units hrIFN-alpha. Further studies of low-dose ingested hrIFN-alpha in new-onset type 1 diabetes are needed to confirm this effect.

Peginterferon (PEG-IFN) plus ribavirin combination therapy, but neither interferon nor PGE-IFN alone, induced type 1 diabetes in a patient with chronic hepatitis C

Interferon (IFN) therapies, including IFN, peginterferon (PEG-IFN) and ribavirin (RBV) plus PEG-IFN combination, are widely used for patients with chronic hepatitis C. We encountered a patient with chronic hepatitis C in whom previous IFN or PEG-IFN alone had not induced type 1 diabetes (T1D), while the addition of RBV to PEG-IFN did induce T1D. The patient had HLA types conferring highly susceptibility to T1D. Thus, adding RBV to PEG-IFN may render chronic hepatitis C patients, with T1D-susceptible HLA types, more prone to developing T1D than IFN or PEG-IFN alone. To prevent T1D development, we recommend HLA typing prior to initiating RBV plus PEG-IFN administration.