[Autoantibodies against islet cell antigens and type 1 diabetes after treatment with interferon-alpha]

Interventions for latent autoimmune diabetes (LADA) in adults

BACKGROUND

Latent autoimmune diabetes in adults (LADA) is a slowly developing type 1 diabetes.

OBJECTIVES

To compare interventions used for LADA.

SEARCH STRATEGY

Studies were obtained from searches of electronic databases, supplemented by handsearches, conference proceedings and consultation with experts. Date of last search was December 2010.

SELECTION CRITERIA

Randomised controlled trials (RCT) and controlled clinical trials (CCT) evaluating interventions for LADA or type 2 diabetes with antibodies were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Studies were summarised using meta-analysis or descriptive methods.

MAIN RESULTS

Searches identified 13,306 citations. Fifteen publications (ten studies) were included, involving 1019 participants who were followed between three months to 10 years (1060 randomised). All studies had a high risk of bias. Sulphonylurea (SU) with insulin did not improve metabolic control significantly more than insulin alone at three months (one study, n = 15) and at 12 months (one study, n = 14) of treatment and follow-up. SU (with or without metformin) gave poorer metabolic control compared to insulin alone (mean difference in glycosylated haemoglobin A1c (HbA1c) from baseline to end of study, for insulin compared to oral therapy: -1.3% (95% confidence interval (CI) -2.4 to -0.1; P = 0.03, 160 participants, four studies, follow-up/duration of therapy: 12, 30, 36 and 60 months; however, heterogeneity was considerable). In addition, there was evidence that SU caused earlier insulin dependence (proportion requiring insulin at two years was 30% in the SU group compared to 5% in conventional care group (P < 0.001); patients classified as insulin dependent was 64% (SU group) and 12.5% (insulin group, P = 0.007). No intervention influenced fasting C-peptide, but insulin maintained stimulated C-peptide better than SU (one study, mean difference 7.7 ng/ml (95% CI 2.9 to 12.5)). In a five year follow-up of GAD65 (glutamic acid decarboxylase formulated with aluminium hydroxide), improvements in fasting and stimulated C-peptide levels (20 μg group) were maintained after five years. Short term (three months) follow-up in one study (n = 74) using Chinese remedies did not demonstrate a significant difference in improving fasting C-peptide levels compared to insulin alone (0.07 µg/L (95% CI -0.05 to 0.19). One study using vitamin D with insulin showed steady fasting C-peptide levels in the vitamin D group but declining fasting C-peptide levels (368 to 179 pmol/L, P = 0.006) in the insulin alone group at 12 months follow-up. Comparing studies was difficult as there was a great deal of heterogeneity in the studies and in their selection criteria. There was no information regarding health-related quality of life, complications of diabetes, cost or health service utilisation, mortality and limited evidence on adverse events (studies on oral agents or insulin reported no adverse events in terms of severe hypoglycaemic episodes).

AUTHORS' CONCLUSIONS

Two studies show SU leading to earlier insulin dependence and a meta-analysis of four studies with considerable heterogeneity showed poorer metabolic control if SU is prescribed for patients with LADA compared to insulin. One study showed that vitamin D with insulin may protect pancreatic beta cells in LADA. Novel treatments such as GAD65 in certain doses (20 μg) have been suggested to maintain fasting and stimulated C-peptide levels. However, there is no significant evidence for or against other lines of treatment of LADA.

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

A 51-year-old man developed type 1 diabetes mellitus following 24 weeks of treatment with recombinant alpha-2b peginterferon plus ribavirin for chronic hepatitis C. Pancreatic autoantibody tests were negative before the start of therapy, but a significant increase in glutamic acid decarboxylase (GAD) antibody titer was seen after 24 weeks of treatment. Six months after the onset of type 1 diabetes mellitus, the patient continues to receive 40 units of insulin daily. The clinical course suggested that recombinant alpha-2b peginterferon plus ribavirin provoked type 1 diabetes mellitus, therefore, in patients who are candidates for interferon therapy the presence of pancreatic autoantibodies and the fasting plasma glucose level should be investigated before and during treatment.

A case of pegylated interferon alpha-related diabetic ketoacidosis: can this complication be avoided?

We report the case of a 42-year-old woman with chronic hepatitis C (genotype 1), who in June 2004 started therapy with pegylated interferon alpha (PEG-IFNalpha) plus ribavirin. Two months later, she discontinued treatment because of polydipsia, polyuria and vomiting leading to a marked dehydration. Biochemical data showed type 1 diabetes mellitus with ketoacidosis, and insulin therapy was started. The patient, who before starting PEG-IFN alpha plus ribavirin therapy tested negative for glutamic acid decarboxylase antibodies (GADAb) and islet cell (ICAb) antibodies, became strongly positive for both autoimmune markers. This case confirms that patients with chronic hepatitis C who do not have baseline markers of pancreatic autoimmunity may develop severe ketoacidosis during treatment with PEG-IFNalpha, as well as with standard IFNalpha. In order to avoid this complication, as no guidelines are available and the pancreatic autoimmunity markers are not routinely analysed, we suggest frequent monitoring (e.g., every one to two weeks) of glycaemic values: e.g., every one to two weeks during the first 3 months (when this complication occurs most frequently) and monthly thereafter so as to identify diabetes at an early stage and before the onset of the appearance of severe ketoacidosis, which is life-threatening.

Simultaneous development of diabetic ketoacidosis and Hashitoxicosis in a patient treated with pegylated interferon-alpha for chronic hepatitis C

Classical interferon-alpha has been shown to be correlated with the development of a variety of autoimmune disorders. A 38 year-old female patient developed simultaneously diabetic ketoacidosis and hyperthyroidism 5 mo following initiation of treatment with pegylated interferon-α and ribavirin for chronic hepatitis C. High titers of glutamic acid decarboxylase, antinuclear and thyroid (thyroid peroxidase and thyroglobulin) antibodies were detected. Antiviral treatment was withdrawn and the patient was treated with insulin for insulin-dependent diabetes mellitus and propranolol for hyperthyroidism. Twelve months after cessation of pegylated interferon-α therapy the patient was euthyroid without any medication but remained insulin-dependent.

Onset of type 1 diabetes mellitus during peginterferon alpha-2b plus ribavirin treatment for chronic hepatitis C

A 61-year-old man was observed to develop type 1 diabetes mellitus following a 3-month treatment with recombinant alpha-2b peginterferon combined with ribavirin for chronic hepatitis C. Serum samples, collected before the start of therapy and 2 months after the diagnosis of diabetes mellitus, revealed islet-cell antibodies at a titer of 20 and 40 JDF-U, respectively, and glutamic acid decarboxylase autoantibodies at a value of 76.5 and 196 IU/ml, respectively. Antibodies to second islet autoantigen were persistently negative. HLA class II typing revealed the presence of DRB1*04/DRB1*14, DQA1*0303-0104 and DQB1*04-0503 alleles. Eight months after the onset of type 1 diabetes mellitus, the patient is still receiving 30 IU insulin daily; the liver function tests are normal and serum hepatitis C virus RNA is negative. These data confirm that, in patients with potential diabetes mellitus, the disease may become manifest as a side-effect during therapy with peginterferon-alpha plus ribavirin. The patient as a candidate for interferon treatment should therefore be investigated, in addition to thyroid autoimmunity, also for pancreatic autoantibodies before starting therapy.