title: Prefrontal cortical hypometabolism during low-dose interferon alpha treatment.
abstract: 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.
authors.affiliation: Department of Radiology, University of Freiburg, Germany.
authors.forename: F D
authors.initials: FD
authors.lastname: Juengling
authors.forename: D
authors.initials: D
authors.lastname: Ebert
authors.forename: O
authors.initials: O
authors.lastname: Gut
authors.forename: M A
authors.initials: MA
authors.lastname: Engelbrecht
authors.forename: J
authors.initials: J
authors.lastname: Rasenack
authors.forename: E U
authors.initials: EU
authors.lastname: Nitzsche
authors.forename: J
authors.initials: J
authors.lastname: Bauer
authors.forename: K
authors.initials: K
authors.lastname: Lieb
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006526:Hepatitis C / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D016898:Interferon-alpha / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D011446:Prospective Studies; D014055:Tomography, Emission-Computed
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D019788:Fluorodeoxyglucose F18; D005947:Glucose