Cognitive impairment in patients with chronic hepatitis treated with interferon alpha (IFNα): results from a prospective study

Background.

Treatment with low-dose interferon alpha (IFN-α) is often associated with neuropsychiatric side effects. In addition to depression and anxiety, IFN-α associated cognitive impairment significantly affects patient’s mental health and quality of life.

Aims of the study.

To measure possible effects of low-dose IFN-α on cognitive functioning and its relationship to the development of depression and anxiety.

Method.

We prospectively followed 38 patients with a chronic hepatitis B or C by neuropsychological tests and psychiatric self-rating scales during 12 weeks of low-dose treatment with IFN-α.

Results.

Before IFN-α treatment, neuropsychological tests as well as self-ratings in the Beck’s Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS) and the Self-Report Symptom Inventory 90 Items-Revised (SCL-90-R) were within the normal range. Following 12 weeks of treatment with IFN-α resulted in a slight, but significant increase in depression scores. Neuropsychological assessment after 12 weeks of IFN-α treatment showed a significant decrease of the immediate recall in the Auditory-Verbal Learning Test (AVLT) and a significant reduction of words recited in the Controlled Oral Word Association Test (COWA). Cognitive impairment did not significantly correlate with depressive symptoms or anxiety.

Conclusion.

Our results indicate that even low-dose IFN-α induces cognitive impairment independent from depressive symptoms, which might be related to functional disturbances in the prefrontal cortex and the hippocampus. We suggest close monitoring of cognitive function during IFN-α treatment of chronic hepatitis.

Interferon alpha (IFNalpha) and psychiatric syndromes: a review

Interferon alpha (IFNalpha) is used for the treatment of several disorders, such as chronic hepatitis or malignant melanoma. During the therapy, IFNalpha may cause severe neuropsychiatric syndromes including depression with suicidal ideation, paranoid psychoses, or confusional states. The reasons and management of these side effects are widely unknown. Our aim is to review research evidence for the contribution of IFNalpha for the etiopathology of psychiatric syndromes. Therefore, research findings of neuropsychiatric syndromes induced by IFNalpha treatment, the putative mechanisms underlying those syndromes, and their treatment are-reviewed. Furthermore, neuropsychiatric syndromes in diseases with high IFNalpha levels such as systemic lupus erythematosus (SLE) are discussed. Finally, the question is addressed whether IFNalpha may contribute to the etiopathology of endogenous psychiatric disorders. IFNalpha may cause psychiatric syndromes in a subset of treated patients. The underlying pathogenetic mechanisms include various effects on neuroendocrine, cytokine, and neurotransmitter systems. Research data on the role of IFNalpha in the pathogenesis of endogenous psychiatric disorders are conflicting. Future research should improve our understanding of the role of IFNalpha for the etiopathology of psychiatric syndromes and has an impact on treatment of IFNalpha-induced psychiatric syndromes.

Prefrontal cortical hypometabolism during low-dose interferon alpha treatment

OBJECTIVE

To evaluate prospectively interferon alpha (IFN-alpha) associated effects on cerebral glucose metabolism and its correlation to neuropsychiatric symptoms during low-dose IFN-alpha-treatment.

METHODS

Eleven patients treated with low-dose IFN-alpha for chronic hepatitis C were prospectively evaluated by neuropsychiatric tests and cerebral [18F]deoxyglucose positron emission tomography (FDG-PET) before and in the 12th week of treatment. PET images were spatially normalized, corrected for variance in global activity and pixel-based t-statistics were calculated for each set of PET scans using SPM96 software. Pixel-cluster with P<0.001 for hypo- or hypermetabolism were displayed in parametric images. Covariance analysis with neuropsychiatric tests was calculated for each cluster.

RESULTS

In week 12 of IFN-alpha treatment, significant hypometabolism with a decrease of local activity ranging from 8 to 12% was found in all patients bilaterally in the prefrontal cortex (BA 9), which correlated in a covariate analysis with changes in depression score as measured by Beck's Depression Inventory. Additionally, hypermetabolism with a maximum increase in local activity of 6-8% was seen in all patients in putamina as well as the left occipital region (BA 18). Before IFN-alpha treatment, only 1/11 patient showed depressive symptomatology. After 3 months of treatment, 6/11 patients were classified as having mild to moderate depressive symptoms (P<0.1; Wilcoxon test).

CONCLUSIONS

Low-dose IFN-alpha therapy is associated with significant prefrontal hypometabolism. This hypometabolism covaried with depression score, but was even found in clinically non-depressed patients. These findings may reflect a possible predisposing factor for IFN-alpha associated neuropsychiatric syndromes and might contribute to a pathophysiological model of affective disorders, as endogenous IFN-alpha levels are elevated in a subset of psychotic patients during acute disease.