New highly antigenic linear B cell epitope peptides from PvAMA-1 as potential vaccine candidates.

Peptide-based vaccines have demonstrated to be an important way to induce long-lived immune responses and, therefore, a promising strategy in the rational of vaccine development. As to malaria, among the classic vaccine targets, the Apical membrane antigen (AMA-1) was proven to have important B cell epitopes that can induce specific immune response and, hence, became key players for a vaccine approach. The peptides selection was carried out using a bioinformatic approach based on Hidden Markov Models profiles of known antigens and propensity scale methods based on hydrophilicity and secondary structure prediction. The antigenicity of the selected B-cell peptides was assessed by multiple serological assays using sera from acute P.vivax infected subjects. The synthetic peptides were recognized by 45.5%, 48.7% and 32.2% of infected subjects for peptides I, II and III respectively. Moreover, when synthetized together (tripeptide), the reactivity increases up to 62%, which is comparable to the reactivity found against the whole protein PvAMA-1 (57%). Furthermore, IgG reactivity against the tripeptide after depletion was reduced by 42%, indicating that these epitopes may be responsible for a considerable part of the protein immunogenicity. These results represent an excellent perspective regarding future chimeric vaccine constructions that may come to contemplate several targets with the potential to generate the robust and protective immune response that a vivax malaria vaccine needs to succeed.

Irisin levels are correlated with inflammatory markers in frontotemporal dementia.

Irisin is a recently discovered adipomyokine involved in the regulation of glucose and lipid, which also exhibits anti-inflammatory and neuroprotective properties. Here we aimed to compare irisin peripheral levels between individuals with behavioral variant frontotemporal dementia (bvFTD) and cognitively healthy matched controls, in addition to investigating whether there is a correlation between irisin and pro-inflammatory cytokines (IL-6 and TNF) concentrations. Twenty-nine individuals participated in this study, being 18 patients with probable bvFTD and 11 controls. Irisin, IL-6 and TNF levels were measured in EDTA plasma through ELISA. There was no difference of the levels of irisin between the groups (p = 0.964). However, in the bvFTD, but not in control group, the levels of irisin were positively correlated with the concentration of IL-6 (r = 0.637, p = 0.006) and TNF (r = 0.517, p = 0.034). The results suggest that the production of irisin in bvFTD could be related to chronic inflammatory and neurodegenerative states in these patients.

Diagnostic application of sensitive and specific phage-exposed epitopes for visceral leishmaniasis and human immunodeficiency virus coinfection.

The diagnosis of visceral leishmaniasis (VL) has improved with the search of novel antigens; however, their performance is limited when samples from VL/human immunodeficiency virus (HIV)-coinfected patients are tested. In this context, studies conducted to identify more suitable antigens to detect both VL and VL/HIC coinfection cases should be performed. In the current study, phage display was performed using serum samples from healthy subjects and VL, HIV-infected and VL/HIV-coinfected patients; aiming to identify novel phage-exposed epitopes to be evaluated with this diagnostic purpose. Nine non-repetitive and valid sequences were identified, synthetized and tested as peptides in enzyme-linked immunosorbent assay experiments. Results showed that three (Pep2, Pep3 and Pep4) peptides showed excellent performance to diagnose VL and VL/HIV coinfection, with 100% sensitivity and specificity values. The other peptides showed sensitivity varying from 50.9 to 80.0%, as well as specificity ranging from 60.0 to 95.6%. Pep2, Pep3 and Pep4 also showed a potential prognostic effect, since specific serological reactivity was significantly decreased after patient treatment. Bioinformatics assays indicated that Leishmania trypanothione reductase protein was predicted to contain these three conformational epitopes. In conclusion, data suggest that Pep2, Pep3 and Pep4 could be tested for the diagnosis of VL and VL/HIV coinfection.

BsmI polymorphism in the vitamin D receptor gene is associated with 25-hydroxy vitamin D levels in individuals with cognitive decline.

OBJECTIVE: Elderly people are at a high risk of developing vitamin D (VitD) deficiency due to both decreased intake and cutaneous synthesis. Most of the biological actions of VitD are mediated by the vitamin D receptor (VDR), which is present in neurons and glial cells of the hippocampus, and in the cortex and subcortical nuclei, essential areas for cognition. It is known that VDR gene polymorphisms may decrease the VDR affinity for VitD. Objective: The present study aimed to investigate the influence of VitD levels on cognitive decline in patients with dementia due to Alzheimer's disease (AD, n = 32) and mild cognitive impairment (MCI, n = 15) compared to cognitively healthy elderly (n = 24). METHODS: We also evaluated the association of VDR gene polymorphisms with cognitive disturbance. Methods: Four polymorphisms on the VDR gene were studied, namely, BsmI, ApaI, FokI and TaqI, by polymerase chain reaction-restriction fragment length polymorphism. Serum levels of 25-hydroxy vitamin D (25(OH)D) were determined by high performance liquid chromatography. RESULTS: Results: No significant difference in 25(OH)D levels or genotypic/allelic frequencies was observed between the groups. Deficiency of 25(OH)D was more frequently observed in women. The AA/AG genotypes of the BsmI polymorphism was associated with sufficient 25(OH)D levels, while the GG genotype of this same polymorphism was associated to insufficient levels in the cognitively-impaired group (individuals with AD or MCI). CONCLUSIONS: Conclusions: The data obtained do not confirm the relationship between reductions of VitD levels, polymorphisms in the VDR gene, and altered cognitive function in this sample. However, the data indicate that BsmI polymorphism in the VDR gene is associated with the VitD levels in individuals with cognitive decline.

BsmI polymorphism in the vitamin D receptor gene is associated with 25-hydroxy vitamin D levels in individuals with cognitive decline / Polimorfismo BsmI no gene do receptor de vitamina D está associado aos níveis de 25-hidroxi vitamina D em indivíduos com declínio cognitivo

ABSTRACT Elderly people are at a high risk of developing vitamin D (VitD) deficiency due to both decreased intake and cutaneous synthesis. Most of the biological actions of VitD are mediated by the vitamin D receptor (VDR), which is present in neurons and glial cells of the hippocampus, and in the cortex and subcortical nuclei, essential areas for cognition. It is known that VDR gene polymorphisms may decrease the VDR affinity for VitD. Objective: The present study aimed to investigate the influence of VitD levels on cognitive decline in patients with dementia due to Alzheimer's disease (AD, n = 32) and mild cognitive impairment (MCI, n = 15) compared to cognitively healthy elderly (n = 24). We also evaluated the association of VDR gene polymorphisms with cognitive disturbance. Methods: Four polymorphisms on the VDR gene were studied, namely, BsmI, ApaI, FokI and TaqI, by polymerase chain reaction-restriction fragment length polymorphism. Serum levels of 25-hydroxy vitamin D (25(OH)D) were determined by high performance liquid chromatography. Results: No significant difference in 25(OH)D levels or genotypic/allelic frequencies was observed between the groups. Deficiency of 25(OH)D was more frequently observed in women. The AA/AG genotypes of the BsmI polymorphism was associated with sufficient 25(OH)D levels, while the GG genotype of this same polymorphism was associated to insufficient levels in the cognitively-impaired group (individuals with AD or MCI). Conclusions: The data obtained do not confirm the relationship between reductions of VitD levels, polymorphisms in the VDR gene, and altered cognitive function in this sample. However, the data indicate that BsmI polymorphism in the VDR gene is associated with the VitD levels in individuals with cognitive decline.

RESUMO Idosos apresentam risco elevado de desenvolverem deficiência de Vitamina D (VitD) devido à diminuição da ingestão e da síntese na pele. A maioria das ações biológicas da VitD é mediada pelo receptor da vitamina D (VDR), que está presente nos neurônios e células gliais do hipocampo, e no córtex e em núcleos subcorticais, áreas essenciais para a cognição. Sabe-se que polimorfismos do gene VDR podem diminuir a afinidade do VDR pela VitD. Objetivo: O presente estudo teve como objetivo investigar a influência dos níveis de VitD no declínio cognitivo em pacientes com demência devida à doença de Alzheimer (DA, n = 32) e comprometimento cognitivo leve (CCL, n = 15) em comparação a um grupo de idosos cognitivamente saudáveis (n = 24). Nós também avaliamos a associação entre polimorfimos no gene do receptor de VitD e as alterações cognitivas. Métodos: Quatro polimorfismos no gene VDR foram estudados, sendo BsmI, ApaI, FokI e TaqI, por PCR-RFLP. Os níveis séricos de 25-hidroxi vitamina D (25(OH)D) foram determinados por HPLC. Resultados: Não houve diferença significativa nos níveis de 25(OH)D ou nas frequências genotípicas / alélicas entre os grupos. Níveis deficientes de 25(OH)D foram mais frequentes nas mulheres. Os genótipos AA / AG do polimorfismo BsmI foram associados a níveis suficientes de 25(OH)D, enquanto o genótipo GG deste mesmo polimorfismo foi associado a níveis insuficientes no grupo com comprometimento cognitivo (em indivíduos com DA ou CCL). Conclusões: Os resultados obtidos não confirmam a relação entre redução dos níveis de VitD, polimorfismos no gene VDR e função cognitiva alterada nesta amostra. No entanto, os dados indicam que o polimorfismo BsmI no gene VDR está associado aos níveis de VitD em indivíduos com declínio cognitivo.

Leptin, hsCRP, TNF-α and IL-6 levels from normal aging to dementia: Relationship with cognitive and functional status.

Cognitive impairment, including mild cognitive impairment (MCI) and dementia, compromises the patients' cognitive abilities and, to different extents, to carry out daily activities, accompanied by personality and behavioral changes. Studies suggest that leptin, an adipokine, has a neuroprotective role against Alzheimer's disease (AD) and that cytokines are associated with inflammatory processes and dementia. This study aimed to evaluate serum leptin, hsCRP, IL-6 and TNF-α levels in a cognitive continuum group from normal to demential status, and to assess whether they correlates to Mini-Mental State Examination (MMSE) and Functional Assessment Staging (FAST) scores. Forty-three participants were included, of whom 12 with probable AD, 18 with MCI and 13 with no objective cognitive decline. Serum leptin and hsCRP levels were evaluated by immunoturbidimetric method, and IL-6 and TNF-α by ELISA. Higher TNF-α levels were found in individuals with FAST stages 1/2 and normal scores evaluated by MMSE. hsCRP levels were inversely correlated with FAST stages. No association with function or global cognition was observed for leptin and IL-6 levels. However, women presented higher leptin serum levels than men while lower leptin and IL-6 levels were observed in individuals aged ≥59 years. Our results suggest that TNF-α is associated with cognitive and functional decline and that inflammation could be a substrate of cognitive impairment at early clinical stages of dementia.

Polymorphisms in cytokine genes influence cognitive and functional performance in a population aged 75 years and above.

OBJECTIVE: To investigate the frequency of the cytokine single nucleotide polymorphisms (SNPs) tumor necrosis factor (TNF)-α -308G > A, tumor growth factor (TGF)-ß1 codon +10C > T, TGF-ß1 codon +25G > C, interleukin (IL)-10 -1082A > G, IL-10 -819C > T, IL-10 -592C > A, IL-6 -174G > C, and IFN-γ +874T > A in a sample of healthy and cognitively impaired elderlies and to verify the probable association between these SNPs and cognitive and functional performance of subjects aged 75 years and above. METHODS: 259 Brazilian subjects were included, comprising 81 with cognitive impairment no dementia (CIND) and 54 demented seniors (together made up the cognitively impaired group, CI) and 124 age-matched and gender-matched cognitively healthy controls (CHS). The genotyping was performed by multiplex polymerase chain reaction. The cognitive performance was evaluated by Mini-Mental State Examination Brief Cognitive Screening Battery. The functional performance was accessed by Functional Activities Questionnaire. RESULTS: The CClower genotype of TGF-ß1 codon +25G > C was frequent in both patient groups. The TThigher genotype of INF-γ +874T > A was less frequent in the dementia group. IL-10 haplotypes of lower expression were more frequent among CIND and demented patients. In CI, individuals with genetic variants that produce higher expression of TGF-ß1, INF-γ, and IL-10 showed better normalized cognitive performance. Additionally, the Alower allele of INF-γ +874T > A was related to worse functional performance in CI, while the Alower allele of TNF-α -308G > A was associated with better cognitive and functional scores in the CIND group. CONCLUSIONS: Our findings suggest a potential role for certain cytokine SNPs in the development of CIND and dementia, which may influence the functional and cognitive performance of these patients. Copyright © 2016 John Wiley & Sons, Ltd.

Cerebrospinal fluid biomarkers for the differential diagnosis of Alzheimer’s disease / Aplicação de biomarcadores do fluido cerebrospinal no diagnóstico diferencial da doença de Alzheimer

ABSTRACT Introduction: Several studies have been conducted in order to validate cerebrospinal fluid biomarkers for the diagnosis of Alzheimer’s disease (AD), aiming primarily to facilitate the early diagnosis. Objective: To evaluate CSF biomarkers on patients with probable AD and the applicability of the international references values in this population. Methods: 46 individuals were recruited and classified as probable AD (n = 19), mild cognitive impairment (MCI) (n = 5) and other dementias (n = 22). The cerebrospinal fluid (CSF) biomarkers were measured using the INNOTEST kits for enzyme-linked immunosorbent assay (ELISA). Higher Tau protein values and lower Aβand Innotest Amyloid Tau Index (IATI) values were observed in AD group when compared with MCI; higher levels of Tau and phosphorylated Tau (P-Tau), and lower Aβand IATI values were observed in AD group when compared to patients with other dementias. No biomarker or IATI was able to distinguish between MCI and other dementias. The kappa index between biomarkers and the clinical diagnosis was regular to Tau and IATI, and weak to Aβand P-tau. Conclusion: The cut-off values for each biomarker that showed better combined sensibility and specificity differ from the reference values suggested by the manufacturer. The CSF biomarkers represent important resources that can help with the AD diagnosis, although the results interpretation must be made based on the analysis of the three analytes together. The cut-off values must be established to address the specificities and characteristics of each population.

RESUMO Introdução: Estudos têm sido conduzidos no sentido de validar biomarcadores no liquor para o diagnóstico da doença de Alzheimer (DA), objetivando, sobretudo, facilitar o diagnóstico precoce. Objetivo: Avaliar os biomarcadores do liquor em indivíduos com provável DA, bem como a aplicabilidade dos valores de referência internacionais nesta população. Métodos: Foram recrutados 46 indivíduos, sendo classificados como provável DA (n = 19), comprometimento cognitivo leve (CCL) (n = 5) e outras demências (n = 22). Os biomarcadores foram dosados no liquor utilizando-se os kits INNOTEST por ensaio imunossorvente ligado à enzima (ELISA). Maiores valores de proteína Tau e menores valores de Aβ e índice Innotest Amiloide Tau Index (IATI) foram observados no grupo de DA quando comparados com o de CCL; maiores níveis de Tau e Tau fosforilada (Tau-P) e menores valores de Aβ e IATI foram observados no grupo de DA quando comparados com os pacientes que apresentavam outras demências. Nenhum biomarcador ou o IATI foi capaz de discernir entre CCL e outras demências. O índice kappa entre os biomarcadores e o diagnóstico clínico foi regular para a Tau e IATI, e fraco para Aβ e Tau-P. Conclusão: Os valores de cut-off para cada biomarcador que apresentou melhor sensibilidade e especificidade conjugadas diferiram dos valores de referência sugeridos pelo fabricante. Os biomarcadores do liquor representam importantes recursos que podem auxiliar no diagnóstico da DA, mas a interpretação dos resultados deve ser feita com base na análise dos três analitos em conjunto. Os valores de cut-off devem ser estabelecidos de modo a atender as especificidades e as características de cada população.

Genetic predisposition to higher production of interleukin-6 through -174 G > C polymorphism predicts global cognitive decline in oldest-old with cognitive impairment no dementia / Predisposição genética à maior produção de interleucina-6 por meio do polimorfismo -174 G > C prediz declínio cognitivo global em idosos muito idosos com comprometimento cognitivo não demência

Interleukin 6 (IL-6) is a pro-inflammatory cytokine upregulated in neurodegenerative contexts. The polymorphism IL-6 -174 G > C influences release levels of this cytokine. We aimed to evaluate the influence of IL-6 -174 G > C on global cognitive score of a group with cognitive impairment no dementia in one year of follow-up.Methods The subjects were categorized in two groups: short-term decline in global cognitive score and those with short-term stability or improvement. IL-6 174 G > C information were compared among these groups.Results We observed that individuals with cognitive impairment no dementia with GGlowergenotype were more frequent among global cognitive score non-decliners while carriers of at least one Chigherallele were more frequent in the group with global cognitive score decliners (p = 0.012; RR = 3.095 IC95%= 1.087-8.812).Conclusion These results suggest that the higher expression of IL-6 gene may be an independent risk factor for cognitive decline among individuals with cognitive impairment no dementia.

Interleucina 6 (IL-6) é uma citocina pró-inflamatória cuja produção acentua-se em contextos neurodegenerativos. O polimorfismo IL-6 -174 G > C influencia os níveis secretados deste mediador inflamatório. Nós objetivamos avaliar a influência de IL-6 -174 G > C sobre o escore cognitivo global de um grupo com comprometimento cognitivo não demência em um ano de seguimento.Métodos Os participantes foram categorizados em dois grupos: com declínio em escore cognitivo global em curto prazo e aqueles com melhora ou estabilidade do escore cognitivo global.Resultados Nós observamos que indivíduos com comprometimento cognitivo não demência carreadores do genótipo GGbaixa foram mais frequentes entre pacientes com escore cognitivo global não declinante, enquanto carreadores de no mínimo um alelo Caltaforam mais frequentes no grupo que apresentou declínio no escore cognitivo global (p = 0,012; RR = 3,095 IC95%= 1,087-8,812).Conclusão Estes resultados sugerem que a alta expressão do gene IL-6 pode ser um fator de risco independente para declínio cognitivo entre pacientes com comprometimento cognitivo não demência.

Genetic predisposition to higher production of interleukin-6 through -174 G > C polymorphism predicts global cognitive decline in oldest-old with cognitive impairment no dementia.

Interleukin 6 (IL-6) is a pro-inflammatory cytokine upregulated in neurodegenerative contexts. The polymorphism IL-6 -174 G > C influences release levels of this cytokine. We aimed to evaluate the influence of IL-6 -174 G > C on global cognitive score of a group with cognitive impairment no dementia in one year of follow-up.Methods The subjects were categorized in two groups: short-term decline in global cognitive score and those with short-term stability or improvement. IL-6 174 G > C information were compared among these groups.Results We observed that individuals with cognitive impairment no dementia with GGlowergenotype were more frequent among global cognitive score non-decliners while carriers of at least one Chigherallele were more frequent in the group with global cognitive score decliners (p = 0.012; RR = 3.095 IC95%= 1.087-8.812).Conclusion These results suggest that the higher expression of IL-6 gene may be an independent risk factor for cognitive decline among individuals with cognitive impairment no dementia.

TGF-ß1 Codon 10 T>C Polymorphism Influences Short-Term Functional and Cognitive Decline in Healthy Oldest-Old Individuals: The Pietà Study.

BACKGROUND: Inflammation and cytokine production are a common finding in aging, which probably exert influence on cognitive and functional abilities in elderly people. Transforming-growth-factor beta 1 (TGF-ß1) is an important multifunctional anti-inflammatory cytokine that displays immunomodulatory activities. OBJECTIVE: This prospective investigation aimed to evaluate the TGF-ß1 codon 10 T>C on functional and cognitive decline in subjects aged 75+ years. METHODS: The Functional Activities Questionnaire evaluated the functional performance and the cognitive assessment was evaluated through brief cognitive tests, consisting of: the Mini-Mental State Examination, animal category fluency test, and picture drawings memory test. All tests were administered twice, with a one-year interval. RESULTS: Carriers of Tlower allele showed significant short-term decline in cognitive and functional performance, while individuals with CChigher genotype of TGF-ß1 codon 10 T>C remained stable or showed improvement. CONCLUSION: Our findings indicate that the lower production of TGF-ß1 could predict a longitudinal functional and cognitive decline in oldest-old individuals.