Immunological Adverse Effects of Interferon Treatment

Elevated serum ALT levels during pegylated interferon monotherapy may be caused by hepatic iron overload

OBJECTIVE

Persistently elevated serum alanine aminotransferase (ALT) levels have been observed in chronic hepatitis C (CHC) patients during pegylated interferon (PEG-IFN) therapy. We investigated whether elevated serum ALT levels during PEG-IFN therapy are associated with iron overload.

METHODS

Sixty-three CHC patients treated with PEG-IFNalpha-2a monotherapy were evaluated. The associations between elevated serum ALT levels (> or =70 IU/l) were investigated before and 24 weeks after therapy. We classified patients as follows: patients with no elevated serum ALT levels (group NE: n = 35), patients with elevated serum ALT levels (group E: n = 28), and patients with no elevated serum ALT level and negative HCV RNA (group NE-: n = 24), and patients with elevated serum ALT level and negative HCV RNA (group E-: n = 19). We also compared total iron score (TIS) and fibrosis stage in liver specimens obtained before and during therapy from 3 patients with elevated serum ALT levels.

RESULTS

Serum ferritin levels were significantly increased after 24 weeks compared to baseline levels in group E (218 +/- 273 vs. 438 +/- 308 ng/ml; p < 0.0001) and group E- (146 +/- 152 vs. 410 +/- 291 ng/ml; p < 0.0001). Serum ALT and ferritin levels were significantly correlated after 24 weeks. The liver specimens revealed that TIS and fibrosis progressed during therapy.

CONCLUSION

Our findings suggest that the elevation in serum ALT levels during therapy is caused by iron overload which may be induced by PEG-IFNalpha-2a.

[Beta interferon and thyroid]

We report the case of a thyroiditis in a 44-year-old woman with relapsing-remitting multiple sclerosis treated with interferon beta. Before treatment, thyroid function tests were normal and anti-thyroid (anti-thyroglobulin and anti-thyroid peroxidase) antibodies were negative. After 18 months of treatment, the patient presented clinical features of thyroiditis. We noted a rise in TSH values and anti-thyroid antibodies were found positive. Treatment was not discontinued and further surveillance showed an improvement in clinical and biological features. We conclude that thyroid function should be monitored during INF beta treatment. Laboratory tests must be carried out before therapy. Clinical follow-up is indicated before undertaking biological tests.

Autoantibodies in multiple sclerosis patients before and during IFN-beta 1b treatment: are they correlated with the occurrence of autoimmune diseases?

Autoimmune side effects, namely autoantibody (autoAb) occurrence and thyroid function alteration, have been described during interferon-beta (IFN-beta) treatment for multiple sclerosis (MS). AutoAb occurrence and autoimmune thyroid diseases are also frequently detected in MS patients free of any treatment. The aim of this study was to evaluate the relationship between IFN-beta 1b treatment, autoAb occurrence, and autoimmune diseases in MS. Thyroid and liver function and serum autoAb (antithyroid, antinuclear, anti-liver, anti-kidney microsomes, anti-smooth muscle and parietal cell antigens) occurrence were evaluated in 156 relapsing-remitting MS (RRMS) patients before and every 3 months after starting IFN-beta 1b treatment (8 MIU subcutaneously [s.c.] on alternate days). The probability of having liver or thyroid function alteration or autoAb occurrence was analyzed longitudinally with the generalized estimating equations (GEE) approach. At baseline, 16.1% of patients had autoAb. During treatment, autoAb occurred de novo in 7.2% of patients. GEE analysis showed that the probability of having autoAb at any time during IFN-beta 1b treatment did not change significantly compared with baseline. AutoAb occurring de novo rarely persisted during treatment and significantly less than those already present at baseline. Positivity for autoAb at baseline or during treatment was not correlated with the development of thyroid or liver function alteration during IFN-beta 1b treatment. Our study indicates that IFN-beta treatment is a safe treatment for MS patients, free of risk of autoimmunity and of associated liver or thyroid function alteration.

Thyroid function and anti-thyroid antibodies in MS patients screened for interferon treatment. A multicenter study

Interferon beta (IFNB) treatment for multiple sclerosis (MS) has been associated with thyroid disorders (TD), in particular in patients with subclinical TD or anti-thyroid (AT) autoantibodies (autoAb) before starting treatment. TD and AT autoAb frequency was reported increased in MS. To determine whether MS patients have subclinical thyroid function abnormalities or anti-thyroid autoimmunity predisposing to develop TD, we performed a prospective multicenter screening of thyroid function and autoimmunity in 152 relapsing-remitting (RR) MS patients selected to receive IFNB treatment and in 437 healthy normothyroidal controls. Thyroid-related hormones and anti-thyroid microsomal antigen (anti-TMA) autoAb were tested with sensitive immunoradiometric or chromatographic assays. Cases were stratified for different progressively decreasing or increasing cutoff values of thyroid-stimulating hormone (TSH) (0.3, 0.2, 0.1, 3 and 5 mIU/l), and odds ratios (OR) with 95% confidence intervals (CI) calculated using logistic regression adjusted for gender, age, and anti-TMA autoAb positivity. The frequency of cases below or above the TSH cutoff values was not significantly different in MS patients and controls, and the risk to have an abnormal TSH level was not significantly increased in MS patients (OR ranging 0.37-0.84; CI, 0.05-3.01), even if anti-TMA autoAb positive (OR ranging 0.35-0.85; CI, 0.04-3.00). Frequencies of subclinical hypothyroidism and of anti-TMA autoAb positivity were, however, trending higher in MS men (ranging 5-7%) than in controls (3%). MS patients do not have an increased risk of subtle thyroid function abnormalities, subclinical TD, or anti-TMA autoAb positivity that may predispose to develop thyroid dysfunction during IFNB treatment. The positive trend for subclinical hypothyroidism and anti-TMA autoAb positivity, however, advises a longitudinal study of thyroid function and autoimmunity during IFNB treatment to see whether patients with baseline subclinical thyroid dysfunction develop clinically significant alteration during treatment.

Autoimmune events during interferon beta-1b treatment for multiple sclerosis

Autoimmune events, although rarely reported during interferon beta-1b (IFNB) treatment of relapsing-remitting (RR) multiple sclerosis (MS), may be more frequent than expected due to the many immunologic abnormalities associated with this disease. We report the prospective two-year follow-up of autoimmune events in 40 RR MS patients treated with IFNB and in 21 untreated MS controls. Thyroid and liver function and serum level of 12 autoantibodies (autoAbs) against organ- (thyroid, gastric, pancreatic) and non-organ-specific antigens were serially monitored. In contrast to control patients, autoAbs (anti-nuclear, -smooth muscle or -thyroid antigens) were detected in 13 IFNB-treated patients, and these were associated with thyroid or liver function alteration in many cases. Persistent autoimmune thyroid dysfunction occurred in three IFNB-treated patients, all of whom were women with a familial history of thyroid disease or baseline anti-thyroid autoAb positivity. For improvement of the MS relapse rate, thyroid dysfunction was adequately treated without stopping IFNB. Liver function alteration (17 IFNB-treated patients, associated with non-organ-specific autoAbs in four) was transient and did not require IFNB treatment to be stopped, with the exception of one patient who was already suffering from a drug-induced hepatopathy at baseline. During the IFNB treatment of MS, several autoimmune events may occur, indicating that thyroid and liver function and autoAbs must be carefully monitored.