Association of an interleukin 1 alpha polymorphism with Alzheimer's disease.
ABSTRACT Retrospective epidemiologic studies suggest that individuals exposed to anti-inflammatory agents such as nonsteroidal anti-inflammatory drugs have a lower probability of developing AD as well as an older age at onset for the illness. Neuroinflammation may play an important role in the pathogenesis of AD. Interleukin 1 (IL-1), a potent proinflammatory cytokine, is colocalized immunohistochemically to neuritic plaques, a requisite neuropathologic feature for AD. A polymorphism in the 5'-flanking regulatory region at -889 of the IL-1 alpha gene (a C-to-T transition designated as IL-1A[-889] allele 2) may cause an overexpression of IL-1 alpha, a finding shown to be associated with inflammatory diseases. The IL-1A(-889) allele 2 polymorphism may be associated with AD pathogenesis.
A total of 259 patients with AD and 192 nondemented control subjects were included from two different centers (Indianapolis, IN, and Munich, Germany). Genotyping for APOE alleles and IL-1A(-889) allele 2 was performed by PCR-based amplification followed by restrictive endonuclease digestion. Statistical analyses were conducted by center-, gender group-, and age group-stratified Mantel-Haenszel odds ratios, CI, and p values.
The allele frequency of IL-1A(-889) allele 2 was 46% in clinically diagnosed patients with probable AD versus 34% in control subjects from the combined centers.
The authors found an increased risk for AD with an estimated Mantel-Haenszel odds ratio of 1.68 (95% CI 1.1 to 2.6; p = 0.022) for heterozygous carriers and 7.2 (95% CI 2.0 to 24.5; p = 0.003) for individuals homozygous for IL-1A(-889) allele 2. They found no evidence for an interaction between the IL-1A and the apoE epsilon 4 polymorphisms (carriers and homozygotes), age, or gender with regard to conferred risk. The data strongly support an association between the IL-1A(-889) allele 2, especially in homozygotes, and later-onset AD.
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ABSTRACT: Systemic low-grade inflammation is a prognostic risk factor of atrial fibrillation (AF). We hypothesized that genetic polymorphisms, which determine the rate of inflammatory cytokines, are associated with the risk of AF, independently of comorbidity. We included 192 patients with so-called lone AF and age 40 years or below, and 188 healthy controls. All patients were genotyped for single nucleotide polymorphisms (SNPs) in inflammatory genes using fluorescence-based real-time polymerase chain reaction (PCR). A case-control analysis of the C/C, C/T and T/T genotypes on IL1A-889 revealed a significant difference in both the frequency of genotypes (p = 0.03) and in the allelic frequency (p = 0.015). These differences were not significant after Bonferroni corrections. For IL1B-511, IL10-592, IL10-1082, IL18-137, IL18-607 and TNF-308 there were no significant differences, neither in genotype frequency, nor in allelic frequency between the lone AF patients and the controls. Our study failed to show an association between polymorphisms in inflammatory genes and early onset of lone AF. It remains to be established whether polymorphisms in inflammatory genes play a causative role in the pathophysiology of AF.Agents and Actions 11/2010; 59(11):965-9. · 1.59 Impact Factor
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ABSTRACT: Alzheimer’s disease (AD) is a chronic neurodegenerative disease causing progressive impairment of memory and cognitive function. The amyloid cascade hypothesis suggests that mismetabolism of the β-amyloid (Aβ) precursor protein (APP) followed by subsequent formation of non-fibrillar and fibrillar Aβ deposits leads to glial activation and eventually to neurotoxicity, causing cognitive impairment. Several lines of evidence indicate that an inflammatory process contributes to the pathology of AD. First, inflammatory proteins have been identified as being associated with neuritic plaques and in glial cells surrounding these plaques. Second, certain polymorphisms of acute-phase proteins and cytokines associated with AD plaques increase the risk or predispose for earlier onset of developing AD. Third, epidemiological studies indicate that anti-inflammatory drugs can retard the development of AD. Several steps in the pathological cascade of AD have been identified as possible targets for actions of nonsteroidal anti-inflammatory drugs. For instance, microglia are considered a target because this cell type is closely involved in AD pathology through secretion of neurotoxic substances and by modulating a positive feedback loop of the inflammatory mechanism that may be involved in the pathological cascade in AD. On the basis of studies in APP transgenic mice, immunisation with Aβ was recently suggested as a novel immunological approach for the treatment of AD. Immunisation elicits Aβ-specific antibodies that could affect several early steps of the amyloid-driven cascade. Antibodies could prevent Aβ from aggregating into fibrils and accelerate clearance of Aβ by stimulating its removal by microglial cells. This review outlines the pathological and genetic evidence that an inflammatory mechanism is involved in AD and the therapeutic approaches based on inhibition or mediation of inflammation.BioDrugs 15(5). · 2.12 Impact Factor
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ABSTRACT: Alzheimer’s Disease (AD) is the most common type of dementia among the elderly, with devastating consequences for the patient, their relatives, and caregivers. More than 300 genetic polymorphisms have been involved with AD, demonstrating that this condition is polygenic and with a complex pattern of inheritance. This paper aims to report and compare the results of AD genetics studies in case-control and familial analysis performed in Brazil since our first publication, 10years ago. They include the following genes/markers: Apolipoprotein E (APOE), 5-hidroxytryptamine transporter length polymorphic region (5-HTTLPR), brain-derived neurotrophin factor (BDNF), monoamine oxidase A (MAO-A), and two simple-sequence tandem repeat polymorphisms (DXS1047 and D10S1423). Previously unpublished data of the interleukin-1α (IL-1α) and interleukin-1 β (IL-1β) genes are reported here briefly. Results from others Brazilian studies with AD patients are also reported at this short review. Four local families studied with various markers at the chromosome 21, 19, 14, and 1 are briefly reported for the first time. The importance of studying DNA samples from Brazil is highlighted because of the uniqueness of its population, which presents both intense ethnical miscegenation, mainly at the east coast, but also clusters with high inbreeding rates in rural areas at the countryside. We discuss the current stage of extending these studies using high-throughput methods of large-scale genotyping, such as single nucleotide polymorphism microarrays, associated with bioinformatics tools that allow the analysis of such extensive number of genetics variables, with different levels of penetrance. There is still a long way between the huge amount of data gathered so far and the actual application toward the full understanding of AD, but the final goal is to develop precise tools for diagnosis and prognosis, creating new strategies for better treatments based on genetic profile.Journal of Molecular Neuroscience 37(1):74-79. · 2.89 Impact Factor