Bárbara Leal1,2, João Chaves3, Cláudia Carvalho1,2, Andreia Bettencourt1,2, Joel Freitas3, João Lopes4, João Ramalheira4, Paulo P Costa1,5, Denisa Mendonça6, António M Silva1,4, Berta M Silva1,2. 1. a Unidade Multidisciplinar de Investigação Biomédica , Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto (UMIB/ICBAS-UP) , Porto , Portugal. 2. b Laboratório Imunogenética, Departamento de Patologia e Imunologia Molecular , Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP) , Porto , Portugal. 3. c Departamento de neurociências, Serviço de Neurologia , Hospital de Santo António, Centro Hospitalar do Porto , Porto , Portugal. 4. f Departamento de neurociências, Serviço de Neurofisiologia , Hospital de Santo António, Centro Hospitalar do Porto , Porto , Portugal. 5. d Departamento de Genética , Instituto Nacional de Saúde Dr. Ricardo Jorge , Porto , Portugal. 6. e Departamento do Estudo das Populações , Instituto de Ciências Biomédicas Abel Salazar [ICBAS], Universidade do Porto , Porto , Portugal.
Abstract
PURPOSE: Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is the most frequent pharmaco-resistant epilepsy. It has been associated with febrile seizures (FS) in childhood. Its aetiology remains unclear but genetic factors are involved. Apolipoprotein E (ApoE) is the main lipoprotein secreted in brain. It has a critical immunomodulatory function, influences neurotransmission and it is involved in repairing damaged neurons. ApoE ϵ4 is an isoform of ApoE with altered protein function, previously associated with refractoriness and early onset epilepsy. This study was undertaken to determine if ApoE isoforms are risk factors for MTLE-HS and influence clinical characteristics. METHODS: A group of 188 MTLE-HS patients (101 F, 87 M, mean age = 44.7 ± 11.6 years, 100 with FS antecedents) was studied and compared with a group of 342 healthy individuals in a case-control genetic association study. Data were analysed with Pearson Chi-squared Test or Student's t test, as appropriated. RESULTS: No differences in ApoE ϵ4 allelic frequencies between MTLE-HS patients and controls or between MTLE-HS subgroups were observed. Nevertheless, ApoE ϵ4 carriers had an earlier MTLE-HS onset (11.0 ± 7.9 years in ApoE ϵ4 carriers vs. 14.4 ± 11.2 years in ApoE ϵ4 non-carriers p < 0.05). Additionally, we observed that MTLE-HS patients with FS antecedents had a statistically significant early disease onset (11.5 ± 8.7 years in FS+ vs. 16.0 ± 12.1 years in FS-, p < 0.01). CONCLUSIONS: Our data show that ApoE ϵ4 and FS may not participate directly in etiopathogenic mechanisms of MTLE-HS but could hasten the disease development in predisposed individuals.
PURPOSE:Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is the most frequent pharmaco-resistant epilepsy. It has been associated with febrile seizures (FS) in childhood. Its aetiology remains unclear but genetic factors are involved. Apolipoprotein E (ApoE) is the main lipoprotein secreted in brain. It has a critical immunomodulatory function, influences neurotransmission and it is involved in repairing damaged neurons. ApoE ϵ4 is an isoform of ApoE with altered protein function, previously associated with refractoriness and early onset epilepsy. This study was undertaken to determine if ApoE isoforms are risk factors for MTLE-HS and influence clinical characteristics. METHODS: A group of 188 MTLE-HSpatients (101 F, 87 M, mean age = 44.7 ± 11.6 years, 100 with FS antecedents) was studied and compared with a group of 342 healthy individuals in a case-control genetic association study. Data were analysed with Pearson Chi-squared Test or Student's t test, as appropriated. RESULTS: No differences in ApoE ϵ4 allelic frequencies between MTLE-HSpatients and controls or between MTLE-HS subgroups were observed. Nevertheless, ApoE ϵ4 carriers had an earlier MTLE-HS onset (11.0 ± 7.9 years in ApoE ϵ4 carriers vs. 14.4 ± 11.2 years in ApoE ϵ4 non-carriers p < 0.05). Additionally, we observed that MTLE-HSpatients with FS antecedents had a statistically significant early disease onset (11.5 ± 8.7 years in FS+ vs. 16.0 ± 12.1 years in FS-, p < 0.01). CONCLUSIONS: Our data show that ApoE ϵ4 and FS may not participate directly in etiopathogenic mechanisms of MTLE-HS but could hasten the disease development in predisposed individuals.