The apolipoprotein E epsilon4 allele and outcome in cerebrovascular disease

BACKGROUND AND PURPOSE: Polymorphism of the apolipoprotein E gene (APOE) may influence outcome after traumatic brain injury and intracerebral hemorrhage, with the epsilon4 allele being associated with poorer prognosis. We investigated APOE allele distribution in acute stroke and the effect of the epsilon4 allele on outcome. METHODS: APOE genotypes were determined in 714 stroke patients: 640 ischemic stroke and 74 intracerebral hemorrhage patients. The survival effect of the epsilon4 allele was assessed with the use of a stratified log-rank test. A Cox proportional hazards regression model was used to estimate the independent effect of epsilon4 dose (0, 1, or 2) on survival, and logistic regression was used to determine the effect on 3-month outcome (good if alive at home, poor if in care or dead). RESULTS: Allele distribution matched the general population with no difference between the ischemic and hemorrhagic groups. Survival in the entire cohort was unaffected by epsilon4 dose. Improved survival with increasing epsilon4 dose was found in the ischemic group (relative hazard=0.76 per allele; P=0.04). If transient ischemic attacks were excluded, a trend for improved survival persisted (P=0.06). With intracerebral hemorrhage, a trend was seen toward reduced survival with epsilon4 (P=0.07, log-rank test). Three-month outcome in the ischemic group was unaffected by epsilon4 dose, and a trend toward poorer outcome with epsilon4 was seen for intracerebral hemorrhage (P=0.10). CONCLUSIONS: The APOE epsilon4 allele had divergent effects on survival and outcome in ischemic and hemorrhagic strokes in this population. The reported adverse effect on patients with intracerebral hemorrhage was supported. The favorable survival effect on ischemic stroke patients requires further study.     

A newly identified polymorphism in the apolipoprotein E enhancer gene region is associated with Alzheimer's disease and strongly with the epsilon 4 allele

Apolipoprotein E allele 4 (apoE epsilon 4) is a major risk factor for late-onset AD. Inheritance of this allele is associated with an earlier age of onset of dementia in individuals with AD. It is unknown whether other polymorphisms in the apoE gene may influence the effect of apoE epsilon 4 on AD. We screened portions of the promoter enhancer element and of the apoE receptor binding domain for other polymorphisms that could affect risk of AD. In particular, a C/G polymorphism at position +113 of the apoE mRNA in the apoE intron 1 enhancer element (IE1) has been recently identified. We found no other polymorphisms. We studied the relationship of the two alleles of the IE1 polymorphism with AD and found an apparent association between IE1 G and AD (n = 94; p = 0.0515). However, the IE1 G allele is also closely associated with apoE epsilon 4 (p < 0.0001). When the presence of apoE epsilon 4 is covaried, the association between the IE1 G allele and AD is no longer statistically significant (odds ratio = 1.29, 95% confidence interval: 0.44, 3.78). In contrast, epsilon 4 is still highly associated with AD when IE1 G is controlled for (odds ratio = 5.91, 95% confidence interval: 3.29, 10.63). Furthermore, there is no significant association between the age of onset of dementia and the inheritance of the G allele. We believe that the apparent association between IE1 G and AD is a consequence of the association between the epsilon 4 and IE1 G alleles.     

Association of apolipoprotein E epsilon 4 allele with bulbar-onset motor neuron disease

BACKGROUND: Variants of the apolipoprotein E (APOE) gene influence the age of onset of Alzheimer's disease. APOE may influence the presentation of other neurological diseases. We investigated the relationship between the allelic variants of apolipoprotein E and clinical presentation in motor neuron disease. METHODS: 123 patients with motor neuron disease and 121 controls were studied. Diagnosis, location of onset and date of onset were recorded prospectively. Genotyping was performed blind to clinical information. FINDINGS: Possession of at least one epsilon 4 allele was significantly more common in patients with bulbar onset motor neuron disease (14/33, 42%) than in limb onset patients (20/90, 22%) and controls (26/121, 21%) (chi 2 = 4.93, p = 0.026 and chi 2 = 5.91, p = 0.015, respectively). INTERPRETATION: These results suggest that the apolipoprotein E epsilon 4 allele may influence the pattern of motor neuron loss in motor neuron disease and that it may affect neuronal function in ways unrelated to the deposition of beta-amyloid or accumulation of neurofibrillary tangles.     

High frequency of apolipoprotein E epsilon4 allele in young individuals with very mild Alzheimer's disease-related neurofibrillary changes

The pathological process of initial neurofibrillary (NF) changes underlying Alzheimer's disease (AD) represents the early preclinical phase of the disease. In a small percentage of individuals, these initial NF changes (Braaks' stage I of six stages) may develop at a surprisingly young age. The aim of this study was to determine the impact of apolipoprotein E (ApoE) on the development of such initial NF changes in young individuals. To this end, the ApoE genotypes were determined using a seminested polymerase chain reaction assay followed by restriction isotyping in young individuals (n = 44; mean age of 38 years) with initial NF changes (stage I). The results were compared with ApoE genotypes of age-matched controls (n = 70) devoid of such changes (stage 0). Stage I cases exhibited a significantly higher epsilon4 allele frequency compared to controls (0.18 vs 0.09, P = 0.039). Thus, the present study reveals an association of epsilon4 allele with the early onset of AD-related NF changes in young individuals. This finding underlines the relevance of the asymptomatic phase in the course of AD.     

Absence of an apolipoprotein E epsilon4 allele is associated with increased parietal regional cerebral blood flow asymmetry in Alzheimer disease

BACKGROUND: The apolipoprotein E (Apo E) epsilon4 allele has been associated with parietal metabolic abnormalities and asymmetries in asymptomatic subjects at risk for Alzheimer disease (AD). However, previous research has shown minimal effect of the epsilon4 allele on regional cerebral blood flow (rCBF) and metabolism in patients with probable AD. OBJECTIVE: To determine whether the Apo E epsilon4 allele is associated with parietal rCBF abnormalities and asymmetries in patients with probable AD. PATIENTS AND METHODS: Thirty patients with AD with the epsilon4 allele (epsilon4+ AD), 22 patients with AD without the epsilon4 allele (epsilon4- AD), and 14 healthy control subjects underwent single-photon emission computed tomography (SPECT) scanning with 740 MBq technetium Tc 99m hexamethylpropyleneamine oxime. Ratios of parietal-unaffected regions and a left-right parietal asymmetry index were compared between both patient groups. RESULTS: The group with epsilon4- AD was younger (P = .005, Student t test) and had an earlier age of onset (P = .005) than the group with epsilon4+ AD. Analysis of covariance revealed no significant difference in the parietal rCBF ratio, controlling for age of onset and Mini-Mental State Examination score (F(1,48) = 0.06; P = .81). However, contrary to hypothesis, significantly greater parietal rCBF asymmetry was seen in patients with epsilon4- AD (mean +/- SD, 9.7% +/- 5.5%) than those with epsilon4+ AD (6.3% +/- 4.7%; F(1,50) = 5.89; P = .02; analysis of variance). When number of epsilon4 allele copies was considered, this effect appeared to accrue primarily from a difference between patients with 0 and with 2 epsilon4 allele copies. An exploratory analysis of multiple cortical structures suggested that this asymmetry extended to additional regions (superior temporal) and to combined association cortex. CONCLUSIONS: Greater parietal rCBF asymmetry is involved in epsilon4- AD than in epsilon4+ AD. Lack of the epsilon4 allele may be associated with other (as yet undiscovered) genetic or environmental risk factors, which confer greater neuropathological asymmetry.     

Apolipoprotein E epsilon 4 allele distribution in alcoholic dementia and in Alzheimer's disease in Japan

The apolipoprotein E epsilon 4 allele has been associated with both familial and sporadic Alzheimer's disease (AD). Given its possible role in nerve repair and growth, it is plausible that apolipoprotein E may be a common denominator in the pathogenesis of several dementing diseases. Therefore, we investigated epsilon 4 frequencies in demented and nondemented alcoholics, as well as in patients with sporadic AD and controls in Japan. No significant differences in allele frequencies was found between demented and nondemented alcoholics and controls, while a significant association was demonstrated between AD and the epsilon 4 allele. These results support a specific role of epsilon 4 in the pathogenesis of AD, rather than a more general role for epsilon 4 in dementing illnesses.     

Apolipoprotein E epsilon4 allele frequency is increased in Parkinson''s disease only with co-existing Alzheimer pathology

Coronary perforation can be managed with prolonged balloon inflations, covered stents, or embolization of the vessel. We report on a case of a balloon-induced perforation of the distal left anterior descending artery, that was sealed by injecting preclotted autologous blood through the balloon catheter lumen at the site of the perforation. The patency of the distal vessel was maintained.     

Increased acetylcholinesterase activity in the CSF of Alzheimer patients carrying apolipoprotein epsilon4 allele

We measured CSF acetylcholinesterase (AChE) activity in 57 Alzheimer's disease (AD) patients with different apolipoprotein E (apoE) genotypes at the early stage of the disease, and in 11 non-demented controls. The AChE activities of the whole AD group did not differ from those of controls. However, analysis of variance over the AD subgroups with two, one or no epsilon4 alleles and controls showed significant differences (p < 0.0001); the AD patients with two epsilon4 alleles had higher AChE activities than controls and AD patients with one or no epsilon4 and also the AD patients carrying one epsilon4 allele had higher AChE activities than the AD patients without the epsilon4 allele. The study suggests that cholinergic metabolism is altered in proportion to the number of apoE epsilon4 alleles. The different degree of AChE activity in relation to the number of epsilon4 alleles might have an impact on AD patients' responses to cholinesterase inhibitors.     

Genetic evidence that the Lewy body variant is indeed a phenotypic variant of Alzheimer''s disease

To investigate the role of cyclic adenosine monophosphate (cAMP) in penile erection in relation to the effect of prostaglandin E1 (PGE1) male adult New Zealand white rabbits were utilized as a model to study intracavernous pressure (ICP) in vivo. After intracavernous injection of PGE1 (0.2-1.6 micrograms/kg) and 8-bromocyclic adenosine monophosphate (8-Br-cAMP, 0.5-1.5 mg/kg), both drugs raised the ICP in a dose-dependent manner. The increased ICPs induced by PGE1 and 8-Br-cAMP were 33.4 +/- 8.12 and 24.1 +/- 4.9 mm Hg, respectively (p < 0.05, paired Student's t test). Administrations of cyclic adenosine monophosphothioate, Rp-isomer (cAMP antagonist, 0.02-0.08 mumol/kg) prior to PGE1 injections inhibited the effect of PGE1 in vivo in a dose-dependent manner. The systemic blood pressures and heart rates in rabbits were unchanged during all the intracavernous injections. The corpus cavernosal tissues isolated from rabbits were studied for the cAMP contents after incubation of different doses of PGE1 in vitro. The cAMP contents were also elevated in a manner parallel with the increases in PGE1 concentrations (3-9 microM). We conclude: (1) the feasibility of intracavernous injection of vasoactive drugs is similar to that in man, thus the rabbit can be used as a suitable alternative for the studies of penile erection, and (2) cAMP is mediated in PGE1-induced relaxation of the rabbit corpus cavernosum, and the cAMP system only participates partially in penile erection.     

Increasing cerebrospinal fluid tau levels in a subgroup of Alzheimer patients with apolipoprotein E allele epsilon 4 during 14 months follow-up

The concentration of tau protein is elevated in the cerebrospinal fluid (CSF) in Alzheimer's disease (AD), suggesting that CSF tau may be a useful biochemical diagnostic marker for this disorder. We investigated CSF tau concentrations on two occasions in AD (n = 18), mild cognitive impairment (MCI, n = 9) and other dementing disease (OD, n = 9) by ELISA (Innotest hTau Antigen, Innogenetics, Belgium). Tau levels were statistically significant higher in the AD group than in MCI and OD groups on both occasions. Twelve of the AD patients showed increasing values of tau at follow-up and six demonstrated diminished values. All AD patients with increasing tau were carriers of one or two epsilon 4 alleles of the apolipoprotein E (APOE, gene. Of those AD cases with decreasing tau levels only three individuals had the epsilon 4 allele, a difference that was statistically significant (P < 0.05). These findings suggest that there may be apolipoprotein E (apoE) isoform-specific differences of tau regulation in AD.     

The epsilon4 allele of the apolipoprotein E gene as a potential protective factor for exudative age-related macular degeneration

Mannan-binding lectin (MBL) is an acute-phase protein which activates complement at the level of C4 and C2. We recently reported that the alternative pathway also is required for haemolysis via this 'lectin pathway' in human serum. CRP is another acute-phase reactant which activates the classical pathway, but CRP also inhibits the alternative pathway on surfaces to which it binds. Since serum levels of both proteins generally increase with inflammation and tissue necrosis, it was of interest to determine the effect of CRP on cytolysis via the lectin pathway. We report here that although CRP increases binding of C4 to MBL-sensitized erythrocytes, which in turn enhances lectin pathway haemolysis, it inhibits MBL-initiated cytolysis by its ability to inhibit the alternative pathway. This inhibition is characterized by increased binding of complement control protein H and decreased binding of C3 and C5 to the indicator cells, which in turn is attributable to the presence of CRP. Immunodepletion of H leads to greatly enhanced cytolysis via the lectin pathway, and this cytolysis is no longer inhibited by CRP. These results indicate that CRP regulates MBL-initiated cytolysis on surfaces to which both proteins bind by modulating alternative pathway recruitment through H, pointing to CRP as a complement regulatory protein, and suggesting a co-ordinated role for these proteins in complement activation in innate immunity and the acute-phase response.     

Alzheimer's disease and its Lewy body variant: a clinical analysis of postmortem verified cases

OBJECTIVE: The authors compared clinical findings of Alzheimer's disease and the so-called Lewy body variant of Alzheimer's disease. METHOD: Available data were analyzed on the clinical features of 58 patients with Alzheimer's disease and 24 patients with the Lewy body variant of Alzheimer's disease who underwent postmortem examination. RESULTS: The proportion of men was significantly larger in the Lewy body variant group than in the Alzheimer's disease group (66.7% versus 34.5%), and, concordantly, the Lewy body variant group was slightly taller. The prevalence of hallucinations and delusions was significantly higher in Lewy body variant subjects than the Alzheimer's disease subjects, but there were no significant differences between the two groups in educational attainment, family history of dementia, age at onset, duration of illness, cognitive impairment, overall severity of illness, or neuropsychological findings. Patients with the Lewy body variant of Alzheimer's disease tended to experience more frequent extrapyramidal side effects of neuroleptics than did the patients with Alzheimer's disease, but for patients in the two groups who were not exposed to neuroleptics, there was little difference in frequency of extrapyramidal side effects. CSF concentration of homovanillic acid (HVA) was significantly lower in the Lewy body variant patients, even when correction was made for height. CONCLUSIONS: The Lewy body variant of Alzheimer's disease may be suspected in elderly male dementia patients who otherwise meet criteria for Alzheimer's disease but who manifest significant psychiatric symptoms and neuroleptic-induced extrapy-ramidal side effects and have low levels of CSF HVA.     

The apolipoprotein E epsilon 4 allele does not influence the clinical expression of the amyloid precursor protein gene codon 693 or 692 mutations

In 31 symptomatic and 5 asymptomatic carriers of the amyloid precursor protein (APP) gene codon 693 mutation, 10 family members without mutation, and 5 carriers of the APP gene codon 692 mutation (3 with early-onset Alzheimer dementia, 2 with cerebral hemorrhage), a high frequency of the apolipoprotein E epsilon 4 allele was found. Age at onset, age at death, occurrence of dementia, and number of strokes did not differ between APP gene mutation carriers with or without epsilon 4 allele, showing that the clinical expression of these APP mutations is not influenced by the apolipoprotein E gene.     

Distortion of allelic expression of apolipoprotein E in Alzheimer's disease

The APOE epsilon4 allele is a strong genetic susceptibility factor for Alzheimer's disease. Interaction with other biological factors may modulate the effect of the apoE isoforms. However, previous work suggested that other genetic variability within the APOE locus, influencing the effect of the epsilon4 allele, may exist. Such variability could modify the expression of the APOE gene and, in particular, the level of expression of APOE alleles could be an important determinant of disease pathogenesis. To test this hypothesis we examined the levels of expression of APOE in heterozygotes with AD and in controls, using a new method of semi-quantitation. We report that relative epsilon4 mRNA expression is increased in AD compared with controls and suggest that genetic variability in the neural expression of APOE contributes to disease risk.     

Risk of left ventricular dysfunction in patients with probable Alzheimer's disease with APOE*4 allele

OBJECTIVE: To examine the association between the APOE genotype and cardiovascular disease in Alzheimer's disease (AD) patients. DESIGN: Case register study of 100 consecutive referrals to a Memory Clinic where type of dementia and cardiovascular comorbidity were diagnosed and APOE genotype was determined. SETTING: The Memory Clinic, University Hospital Rotterdam Dijkzigt. PARTICIPANTS: One hundred Memory Clinic patients, 59 to 91 years of age, who attended the Memory Clinic in the period between January 1994 and March 1996. MEASUREMENTS: Relative risk of cardiovascular morbidity in probable AD, based on clinical and ECG findings. RESULTS: The diagnosis of probable AD was more frequent in APOE*4 allele-carrying AD patients. When comparing homozygotes for APOE*4 with homozygotes for APOE*3, a nine-fold increase in prevalence of cardiac ischemia on ECG was found in the former. When grouping parameters of left ventricular dysfunction, the prevalence was 7.2 (95% confidence interval 1.2-42.6) times greater in probable Alzheimer patients with APOE4/4. CONCLUSIONS: In patients with probable AD, APOE*4 is associated with cardiac disease indicative of left ventricular dysfunction.     

Convergence of Lewy bodies and neurofibrillary tangles in amygdala neurons of Alzheimer's disease and Lewy body disorders

Amygdalae of patients with Alzheimer's disease (AD), Parkinson's disease, Down's syndrome, diffuse Lewy body disease or a combination of these diseases were probed with antibodies to neurofilament proteins as well as with Lewy body (LB)- and paired helical filament-specific antibodies. The results indicate that the amygdala is severely affected by the accumulation of both neurofibrillary tangles (NFTs) and LBs in most cases of the diseases mentioned above, and that amygdala LBs have a similar epitope composition to that of LBs in the brain stem and cerebral cortex. While large numbers of both LBs and NFTs were seen in different neurons within the amygdala, these two lesions frequently occurred together in the same neurons of the amygdala. These findings are in contrast to other sites that accumulate LBs and NFTs, but rarely both lesions in the same neuron. Thus, amygdala neurons may be selectively vulnerable to developing both LBs and NFTs, and these inclusions may play a role in the massive degeneration of these neurons in AD and LB disorders of the elderly.     

Apolipoprotein E epsilon 4 allele distribution in Wernicke-Korsakoff syndrome with or without global intellectual deficits

Recent genetic studies show that the apolipoprotein E (ApoE) epsilon 4 allele is a risk factor for Alzheimer's disease (AD). Whether this allele is associated with other dementing diseases is the next important question. The information could provide a clue to the pathogenetic role of ApoE. In the present study, patients with Wernicke-Korsakoff syndrome (WKS) of alcoholic etiology were divided into two groups according to the severity of intellectual deficits, i.e., those of "classical" Korsakoff patients with preserved intellectual function other than amnesia and those with global intellectual deficits. Genotyping showed that the frequency of ApoE epsilon 4 allele was significantly higher in the patients with global deficits, suggesting the involvement of this allele in the intellectual decline of WKS. In contrast, distributions of other two markers, alpha 1-antichymotrypsin and presenilin-1, did not differ between the two groups. These results added further support to the notion that the consequence of acute insult to the brain is influenced by the ApoE genotype, and suggested ApoE's role in the development of a certain group of "alcoholic dementia."     

Bcl-2 and Bax proteins in Lewy bodies from patients with Parkinson's disease and Diffuse Lewy body disease

Double-labelling immunohistochemistry of Bcl-2 and Bax, and ubiquitin (as a marker of Lewy bodies) was examined in the brains of patients with Parkinson's disease and Diffuse Lewy body disease to learn about possible modifications of protein expression and the presence of Lewy bodies. Bcl-2 and Bax immunoreactivities were observed in Lewy body-bearing and non-Lewy body-bearing neurons in patients with parkinsonism. These results show that Bcl-2 and Bax are probably not implicated in Lewy body formation and that the presence of Lewy bodies does not have a direct impact on the expression of Bcl-2 and Bax proteins in individual neurons.     

Utility of the apolipoprotein E genotype in the diagnosis of Alzheimer's disease. Alzheimer's Disease Centers Consortium on Apolipoprotein E and Alzheimer's Disease

BACKGROUND: The epsilon4 allele of the gene encoding apolipoprotein E (APOE) is strongly associated with Alzheimer's disease, but its value in the diagnosis remains uncertain. METHODS: We reviewed clinical diagnoses and diagnoses obtained at autopsy in 2188 patients referred to 1 of 26 Alzheimer's disease centers for evaluation of dementia. The sensitivity and specificity of the clinical diagnosis or the presence of an APOE epsilon4 allele were calculated, with pathologically confirmed Alzheimer's disease used as the standard. The added value of the APOE genotype was estimated with pretest and post-test probabilities from multivariate analyses to generate receiver-operating-characteristic curves plotting sensitivity against the false positive rate. RESULTS: Of the 2188 patients, 1833 were given a clinical diagnosis of Alzheimer's disease, and the diagnosis was confirmed pathologically in 1770 patients at autopsy. Sixty-two percent of patients with clinically diagnosed Alzheimer's disease, as compared with 65 percent of those with pathologically confirmed Alzheimer's disease, had at least one APOE epsilon4 allele. The sensitivity of the clinical diagnosis was 93 percent, and the specificity was 55 percent, whereas the sensitivity and specificity of the APOE epsilon4 allele were 65 and 68 percent, respectively. The addition of information about the APOE genotype increased the overall specificity to 84 percent in patients who met the clinical criteria for Alzheimer's disease, although the sensitivity decreased. The improvement in specificity remained statistically significant in the multivariate analysis after adjustment for differences in age, clinical diagnosis, sex, and center. CONCLUSIONS: APOE genotyping does not provide sufficient sensitivity or specificity to be used alone as a diagnostic test for Alzheimer's disease, but when used in combination with clinical criteria, it improves the specificity of the diagnosis.