Electrophysiological and neuropsychological functions in patients treated with interferon-beta

Mood disorders associated with interferon treatment: theoretical and practical considerations

OBJECTIVE

To review the theoretical and clinical aspects of mood disorders associated with interferon treatment and discuss their management.

DATA SOURCES

Pertinent and selected laboratory/clinical studies, review articles, letters, abstracts, and book chapters on behavioral and mood-related adverse effects of interferons published in English-language journals in the past two decades were identified by MEDLINE (June 1980-June 2000) and manual searches. DATA SELECTION AND DATA EXTRACTION: All of the publications identified were reviewed, and the relevant data were included. Studies not using criteria for psychiatric diagnosis or instruments for psychiatnc monitoring were excluded.

DATA SYNTHESIS

Clinical observations and limited research data suggest that interferon treatment may be associated with mood disorders. Mood-related symptoms induced by interferons emerge in a few days or weeks and tend to be dose dependent. Their severity may necessitate discontinuation of interferon therapy and/or the use of antidepressant or antimanic agents. The mechanisms responsible for inducing or exacerbating mood disorders in interferon-treated patients have not been elucidated. There is limited evidence implicating alterations in the serotonin system.

CONCLUSIONS

While interferon therapy may trigger or induce mood-related symptoms, preexisting or stable concurrent mood disorders in remission do not necessarily constitute a contraindication to treatment with interferons. Mood disorders associated with interferon treatment can present clinical challenges. However, they may promote our understanding of mood disorders in the context of the current biologic theories of depression and mania.

Psychiatric symptoms related to interferon therapy for chronic hepatitis C: clinical features and prognosis

Psychiatric symptoms during interferon (IFN) therapy for viral hepatitis have been a crucial problem in consultation-liaison psychiatry. However, there have been few studies on psychiatric management for these symptoms and their prognosis. Among 943 patients who were treated with IFN for chronic hepatitis C between 1991 and 1995, 43 patients (4.6%) developed psychiatric symptoms during IFN treatment. Three patients (0.3%), with pre-existing psychiatric disorders showed aggravated symptoms and were excluded from the study. All three patients were able to finish the IFN therapy with psychiatric management. Forty patients (4.2%) manifested psychiatric symptoms induced by IFN. Thirteen patients (1.4%) were diagnosed as anxiety disorder and 21 patients (2.2%) revealed mood disorder with depressive features. There were other psychiatric disorders in six patients (0.6%), including psychotic disorder with delusions/hallucinations in four patients (0.4%), mood disorder with manic features in one patient (0.1%) and delirium in one patient (0.1%). Women developed psychiatric symptoms significantly more than men. Ten of 40 patients (25%) stopped IFN treatment because of manifesting psychiatric symptoms induced by IFN. Twelve patients (30%) required psychiatric treatment for more than 24weeks after ceasing IFN, and seven patients still had anxiety, insomnia and mild hypothymia at the end of the present study. Statistical analysis revealed that IFN-beta therapy and psychiatric manifestations including psychotic symptoms, delirium and manic symptoms were significantly related to long-term psychiatric problems. There are considerable numbers of patients who have required long-term psychiatric management even after cessation of IFN treatment.

Endocrine and neurological adverse effects of the therapeutic interferons

There is experimental evidence that the nervous central and the neuroendocrine systems can influence the immune system, which can in turn influence the brain activity. Endogenous cytokines are known to play a critical role in the pathophysiology of many diseases. The recently acquired experience on the adverse effects of therapeutic cytokines, particularly neurological and endocrine adverse effects, are further illustrative of these interferences. Interferons-alpha have been used in thousands of patients, so that the information accumulated with this group of closely related products is essential to delineate the potential and severity for non-immunological, but largely immune-mediated adverse effects to develop in patients treated with immuno-activating agents.

Clinical toxicity of the interferons

Since their initial description in 1957, the interferons (IFNs) have been increasingly used to treat a wide array of diseases. Acute adverse effects, i.e. 'flu-like' syndromes, hypo- or hypertension, tachycardia, headache, myalgias and gastrointestinal disorders, occur within the first hour or day after starting treatment. They are seldom treatment-limiting and are easily manageable. Sub-acute and chronic effects develop after several days, usually within 2 and 4 weeks of therapy. The most typical is neurological toxicity, including fatigue/asthenia, and behavioural and cognitive changes. Such symptoms may seriously impair quality of life and result in treatment discontinuation. Seizures have seldom been described. Other infrequent central nervous system adverse effects include vertigo, cramp and oculomotor nerve paralysis. Distal paraesthesias and peripheral neuropathy have been reported. IFN-associated autoimmunity is quite rare but a matter of concern. Biological or clinical manifestations usually require several months to become apparent. Autoantibodies have been shown to develop in most patients but have been inconsistently associated with clinical symptoms of systemic lupus erythematosus, rheumatoid-like arthritis and thyroiditis. Both hypo- and hyperthyroidism have been described but are usually reversible. Other infrequent autoimmune reactions include diabetes, pemphigus and worsening of multiple sclerosis. Although several patients present with a pre-existing autoimmune disorder, no predisposing factor has been clearly established. While hypotension and tachycardia are the most frequent acute cardiovascular complications, a few additional cases of cardiac arrhythmias and myocardial ischaemia have been reported after a short course or several weeks of treatment. These latter complications do not appear to be dose-dependent or age-related. Isolated cases of congestive heart failure have also been described. Mild proteinuria has been observed in 15 to 25% of patients, but acute renal toxicity is uncommon. A transient rise in serum aminotransferase levels is frequently noted during the first stage of therapy, especially in patients receiving the highest dosages. Direct hepatotoxicity is extremely rare. Autoimmune hepatitis, which is ill-diagnosed as chronic viral hepatitis, and de novo induction of autoimmune hepatitis, account for the majority of liver diseases. Haematotoxicity is relatively common but mild to moderate, and develops gradually during the first weeks of treatment. Neutropenia is the most common haematological toxicity, but is usually not dose-limiting and resolves rapidly upon drug discontinuation. Myelosuppression, autoimmune and immune allergic haemolytic anaemias and thrombocytopenias have seldom been described. Cutaneous adverse effects comprised nonspecific erythema and hair loss and, less frequently, vasculitis, local ulcerations at the site of injection and exacerbation of psoriasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Addition of IFN-alpha to treatment of malignant brain tumors

Despite many attempts to improve the survival after surgery of patients with malignant astrocytoma the prognosis is poor. We have used natural IFN-alpha in 16 patients with malignant astrocytoma treated between 1987 and 1990; 6 for recurrent tumors. Radiation therapy was given in 2 Gy fractions daily to a total dose of 50 Gy in the tumor area, 5 fractions per week and IFN twice per week, cisplatinum 60 mg/m2 i.v. every second week and vincristine 2 mg every week in 12-h i.v. infusions. Eight patients were reoperated when clinical deterioration suggested recurrent tumor; histological examination showed no residual tumor in 7 of them. Of these 8 patients 3 are alive and well, 2 of them after more than 5 years. The study suggests that malignant astrocytoma can be successfully eradicated with surgery, irradiation, IFN-alpha and chemotherapy. The treatment had, however, unacceptably high neurotoxicity. Earlier removal of the tumor necrosis, before clinical deterioration, could possibly diminish the high complication rate and consequently improve survival.