Browsing by Author "Silva, Berta"
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- Apolipoprotein E isoforms and susceptibility to genetic generalized epilepsiesPublication . Chaves, João; Martins-Ferreira, Ricardo; Carvalho, Cláudia; Bettencourt, Andreia; Brás, Sandra; Chorão, Rui; Freitas, Joel; Samões, Raquel; Lopes, João; Ramalheira, João; Silva, Berta; Costa, Paulo; Martins Da Silva, António; Leal, BárbaraBackground: 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 e4 is an isoform of ApoE with altered function, and was previously associated with early onset epilepsy and refractoriness, both in animal models and in patients with focal epilepsies. There is a limited knowledge on ApoE’s role in Genetic Generalized Epilepsies (GGE). Aim: To determine if ApoE isoforms are risk factors for GGE development. Methods: A group of 337 GGE patients (193 F, 144 M, 33.6 ± 14.2 years) was compared with a group of 342 healthy individuals in a case-control genetic association study. ApoE genotyping was performed using PCR-RFLP. Results: The genotypic frequency of ApoE e3/e2 was lower in GGE patients relative to controls (6.5% in GGE vs. 11.7% in controls, p = 0.019, OR (95% CI) = 0.53 (0.305–0.905). No associations with other clinical data such as photosensitivity or age at disease onset were observed. Conclusion: Our results show that ApoE e3/e2 genotype may be a protective factor for GGE development. There is evidence that this genotype could be neuroprotective, preventing oxidative damage and promoting neuronal survival. Although replication studies are warranted, our data suggest that ApoE isoforms have a role in epileptogenic mechanisms regardless of the specific epileptic manifestations.
- Characteristics of Neuro-Behçet's Disease in a Case-Series from a Single Centre in Northern PortugalPublication . Domingos, Joana; Ferrão, Cláudia; Ramalho, Joana; Rodrigues, Tiago; Moreira, Bruno; Santos, Ernestina; Bettencourt, Andreia; Martins da Silva, Ana; Silva, Berta; Pinho e Costa, Paulo; Vasconcelos, Carlos; Correia, JoãoIntroduction: Behçet's disease (BD) is a multisystem inflammatory disease of unknown etiology that may affect the CNS - Neuro-Behçet (NB). Our aim was to evaluate the frequency of neurological involvement and characterize a cohort of our NB patients. Methods: We retrospectively revised the clinical, laboratory and imaging data of a cohort of BD patients, followed in our hospital outpatient clinic. Results: We identified 138 BD patients. Twenty-five out of 138 had NB (15 female). Four patients presented with neurological symptoms. We identified a total of 37 attacks. Twenty-one attacks were classified as parenchymatous, four non-parenchymatous and 12 as other syndromes. Seventeen patients had CSF analysis performed (20 samples). Five samples were normal, 15 showed CSF pleocytosis. The most frequent finding on MRI performed in the acute phase was extensive lesions involving the brainstem. Two patients died due to the neurological involvement of BD. Conclusion: We found 18.1% prevalence of NB and a higher female-to-male ratio in our group than in other series. Gastrointestinal and vascular involvement was more frequent in the NB group. The fact that neurological involvement may be the first manifestation of BD with therapeutic implications and associated morbidity points out the relevance of an early diagnosis.
- Immunogenetic predisposing factors for mesial temporal lobe epilepsy with hippocampal sclerosisPublication . Leal, Bárbara; Chaves, João; Carvalho, Cláudia; Bettencourt, Andreia; Brito, Cláudia; Boleixa, Daniela; Freitas, Joel; Brás, Sandra; Lopes, João; Ramalheira, João; Costa, Paulo; Silva, Berta; Martins Da Silva, AntónioPurpose: Neuroinflammation appears as an important epileptogenic mechanism. Experimental and clinical studies have demonstrated an upregulation of pro-inflammatory cytokines such as IL-1β and TNF-α, in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Expression of these cytokines can be modulated by polymorphisms such as rs16944 and rs1800629, respectively, both of which have been associated with febrile seizures (FS) and MTLE-HS development. The human leukocyte antigen (HLA) system has also been implicated in diverse epileptic entities, suggesting a variable role of this system in epilepsy. Our aim was to analyse the association between immunogenetic factors and MTLE-HS development. For that rs16944 (-511 T>C, IL-1β), rs1800629 (-308 G>A, TNF-α) polymorphisms and HLA-DRB1 locus were genotyped in a Portuguese Population. Methods: We studied 196 MTLE-HS patients (108 females, 88 males, 44.7 ± 12.0 years, age of onset = 13.6 ± 10.3 years, 104 with FS antecedents) and 282 healthy controls in a case–control study. Results: The frequency of rs16944 TT genotype was higher in MTLE-HS patients compared to controls (14.9% in MTLE-HS vs. 7.7% in controls, p = 0.021, OR [95% CI] = 2.20 [1.13–4.30]). This association was independent of FS antecedents. No association was observed between rs1800629 genotypes or HLA-DRB1 alleles and MTLE-HS susceptibility. Also, no correlation was observed between the studied polymorphisms and disease age of onset. Conclusion: The rs16944 TT genotype is associated with MTLE-HS development what may be explained by the higher IL-1β levels produced by this genotype. High IL-1β levels may have neurotoxic effects or imbalance neurotransmission leading to seizures.
- Immunogenetic protective factors in Genetic Generalized EpilepsyPublication . Chaves, João; Martins-Ferreira, Ricardo; Ferreira, Ana Marta; Brás, Sandra; Carvalho, Cláudia; Bettencourt, Andreia; Samões, Raquel; Monteiro, Fábio; Freitas, Joel; Chorão, Rui; Lopes, João; Ramalheira, João; Silva, Berta; Costa, Paulo; Martins Da Silva, António; Leal, BárbaraBackground: Genetic Generalized Epilepsies (GGEs) are a heterogeneous group of syndromes characterized by generalized seizure activity that affects both hemispheres, with mainly genetic causes. Neuroinflammation has been established as an important mechanism in epileptogenesis. The ability to develop an appropriated immune response is strongly determined by immunogenetic factors. In this setting, our aim was to evaluate potential associations between GGEs and immunogenetic factors. Methods: The rs16944 (IL-1β -511 T > C) polymorphism and the HLA-DRB1 locus were genotyped in a Portuguese GGE population. Association with two clinicopathological features, photosensitivity and refractoriness, was investigated. This case-control study included 323 GGE patients (187 F, 136 M, 34.0 ± 13.9 years of age), 145 of which with JME diagnosis (88 F, 57 M, 34.1 ± 14.0 years), and 282 healthy controls (174 F, 108 M, 37.7 ± 11.6 years). Results: Decreased frequencies of the HLA-DRB1*09 and DRB1*13 alleles were observed in the GGE population. HLA-DRB1*07 frequency was increased in JME. Rs16944 allelic frequencies were similar between patients and controls. Conclusions: These results, not entirely consistent with previous reports, suggest that HLA molecules may have a complex role in epileptogenesis.
- Serum 25-hydroxyvitamin D levels in multiple sclerosis patients from the north of PortugalPublication . Bettencourt, Andreia; Boleixa, Daniela; Reguengo, Henrique; Samões, Raquel; Santos, Ernestina; Oliveira, José Carlos; Silva, Berta; Costa, Paulo Pinho; da Silva, Ana MartinsIncreasing evidence has shown that individuals with Multiple Sclerosis (MS) have lower 25-hydroxyvitamin D [25(OH)D] levels compared to healthy controls. There is no information regarding 25(OH)D levels and MS in Portugal. Therefore the aim of the current study was to examine the levels of 25(OH)D in a group of patients with MS and in healthy matched controls, as well as the association of 25(OH)D levels with disease course, disability and severity. A group of 244 unrelated Portuguese patients, with a definitive diagnosis of MS, and 198 ethnically matched healthy controls were included in the study. A sub-group of patients with recent disease onset was included. Serum 25(OH)D was measured using an electrochemiluminescence binding assay. The mean serum level of 25(OH)D in patients with MS was 39.9±22.0 nmol/L, which was significantly lower (p<0.0001) than those in healthy controls, 55.4±23.4 nmol/L. There was a negative correlation between 25(OH)D levels and EDSS (r=-0.293, p<0.0001) and MSSS scores (r=-0.293, p<0.0001). In multiple logistic regression analysis adjusted for age, gender, disease form, EDSS, disease duration and MSSS, 25(OH)D levels were independently associated with EDSS (p=0.004) and disease duration (p=0.016), and with MSSS (p=0.001). In accordance with the majority of the literature, low serum 25(OH)D levels were associated with susceptibility and disability in MS patients from Portugal. Lower serum 25(OH)D levels were also found in patients with a recent disease onset, supporting vitamin D levels as a risk factor for MS.
- The vitamin D receptor gene FokI polymorphism and Multiple Sclerosis in a Northern Portuguese populationPublication . Bettencourt, Andreia; Boleixa, Daniela; Guimarães, Ana Luísa; Leal, Bárbara; Carvalho, Cláudia; Brás, Sandra; Samões, Raquel; Santos, Ernestina; Costa, Paulo Pinho; Silva, Berta; da Silva, Ana MartinsThe cause of Multiple Sclerosis (MS) remains poorly understood, but it is widely believed to be an autoimmune disease occurring in genetically susceptible individuals after exposure to as-yet undefined environmental factors. One of these environmental factors is vitamin D, a well-known immune modulator. The biologically active form of vitamin D, 1,25-dihydroxyvitamin D3, has been shown to exert its immune modulatory properties through its nuclear receptor (VDR) namely by inhibiting the proliferation of Th cells. The purpose of this study was to evaluate the influence of FokI VDR polymorphism in MS development and progression.