SEIZURE INDUCED PRODUCTION OF INTERLEUKIN-6 IN HUMAN AND EXPERIMENTAL EPILEPSY
Abstract number :
2.058
Submission category :
Year :
2002
Submission ID :
448
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Kai A. Lehtimäki, Jari Honkaniemi, Tapani Keränen, Jukka Peltola. Medical School, University of Tampere, Tampere, Finland; Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland
RATIONALE: We have previously reported that Interleukin-6 (IL-6) levels are increased in CSF and plasma in patients after single tonic-clonic seizures. Present study was carried out to determine whether the increase in IL-6 levels are correlated to the duration or type of seizures. Also localization and time course of seizure induced IL-6 production was studied in kainic acid injected rats.
METHODS: Here we have determined the levels of IL-6 in cerebrospinal fluid (CSF) and serum samples from healthy controls (n=17) and from patients after a single tonic-clonic seizure (n=16), after prolonged tonic-clonic seizures (n=10) and after prolonged partial seizures (n=7). Also samples after seizures during video-EEG recordings were studied (n=12). To study the time course and localization of seizure induced IL-6 expression, in situ hybridization and Northern blot analysis was performed in rats after kainic acid induced status epilepticus.
RESULTS: After seizures, IL-6 levels were increased in the whole patient group when compared to controls in CSF (median 10.6 pg/ml and 2.5 pg/ml) and serum (median 5.4 pg/ml and 1.2 pg/ml). These changes were more prominent after prolonged tonic-clonic seizures when compared to a single tonic-clonic seizure in CSF (median 58.0 pg/ml and 9.25 pg/ml), as well as in serum (median 19.5 pg/ml and 3.35 pg/ml). In addition, more robust changes in serum IL-6 levels were evident after prolonged tonic-clonic seizures than prolonged partial seizures (median 19.5 pg/ml and 4.0 pg/ml). After seizures during video-EEG recordings, IL-6 levels were increased at 6-12h, especially after generalized seizures. Northern blot analysis revealed increased IL-6 expression at 3-24 h after SE, which was localized in temporal lobe structures and adjacent meninges.
CONCLUSIONS: These results indicate that IL-6 is expressed in the brain parenchyma and meninges after seizures, followed by increased CSF and serum levels of IL-6. This increase in IL-6 levels is dependent on duration and generalization of seizures, indicating that IL-6 production is caused by seizure activity per se. Since IL-6 is also known as neurotrophic factor, IL-6 may therefore contribute to seizure induced neuronal plasticity.
[Supported by: Tampere University Hospital Medical Research Fund]