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Objective: Cerebrospinal fluid (CSF) amyloid β42 (Aβ42), total tau (t-tau) and phosphorylated tau (p-tau) are useful as predictors of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia. However, results are contradictory as to whether these biomarkers reflect the future rate of clinical decline., Methods: This is a retrospective study on 196 patients with AD [mild/moderate AD (n = 72) or AD-MCI (n = 124) at baseline] with a follow-up period of 2-9 years' duration (median 6 years). Lumbar punctures were performed at baseline as a part of the diagnostic procedure., Results: We found an increased risk of rapid cognitive decline defined as a drop in the Mini-Mental State Examination score of ≥ 4 points/year in patients with CSF t-tau concentrations above the median (OR 3.31, 95% CI 1.53-7.16) and CSF p-tau above the median (OR 2.53, 95% CI 1.21-5.26). Patients with CSF t-tau in the highest quartile had a higher risk of dying in severe dementia (HR 4.67, 95% CI 1.16-18.82)., Conclusions: In this large AD cohort, we found an association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease, measured as a rapid cognitive decline and a higher risk of dying in severe dementia.

Objectives: There is an overlap regarding Pittsburgh compound B (PIB) retention in patients clinically diagnosed as Alzheimer's disease (AD) and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [(18)F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)., Methods: Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting., Results: The PIB-positive patients (7 out of 18) had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18) during follow-up., Conclusions: The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.

Background/aims: Amyloid-β (Aβ) protofibrils are neurotoxic soluble intermediates in the Aβ aggregation process eventually forming senile plaques in Alzheimer's disease. This Aβ species is a potential biomarker for Alzheimer's disease and also a promising target for immunotherapy. In this study, we investigated the characteristics of conformation-dependent Aβ antibodies specific for Aβ protofibrils., Methods: Mice were immunized with Aβ protofibrils to generate hybridomas producing Aβ-specific monoclonal antibodies. Binding of antibodies to different Aβ conformations was investigated with inhibition ELISA. The antibodies' complementarity-determining region (CDR) sequences were determined and compared., Results: A majority of the antibodies were of the IgM class, all selectively binding to aggregated Aβ. Two IgG antibodies were generated: one with selective affinity for Aβ protofibrils and the other bound Aβ in all conformations. A high degree of similarity between the heavy-chain CDRs of the conformation-dependent antibodies was found, and all high-affinity Aβ antibodies displayed a high degree of sequence similarity in the light-chain CDRs., Conclusion: Sequence similarity in the heavy-chain CDRs is associated with conformation selectivity of the antibodies, while sequence similarity in the light-chain CDRs correlates with the affinity for Aβ., (Copyright © 2010 S. Karger AG, Basel.)

Aims: Our aim was to evaluate the longitudinal associations of individual and multiple vascular risk factors with the subsequent development of dementia and Alzheimer's disease (AD)., Methods: The Uppsala Longitudinal Study of Adult Men started in 1970 when the 2,268 participants were 50 years old. Baseline investigations included determinations of blood pressure, fasting glucose, cholesterol, BMI and smoking status. Over a maximum follow-up of 40 years, 349 participants were diagnosed with dementia, out of which 127 had AD. Analyses were repeated using a re-examination of the cohort at 70 years of age as a baseline., Results: No associations between vascular risk factors and AD were found. For all-type dementia, the association between high systolic blood pressure and dementia was the most consistent. High fasting glucose was associated with increased risk of all-type dementia only when measured at 70 years. Individuals with both an APOE ε4 allele and vascular risk factors had the greatest dementia risk., Conclusion: Vascular risk factors influence the future risk of dementia, in particular vascular and mixed-type rather than AD. The impact of vascular risk factors on dementia in a longitudinal study depends on the age at baseline and the length of follow-up., (Copyright © 2011 S. Karger AG, Basel.)

Background: The positron emission tomography (PET) radiotracer Pittsburgh Compound-B (PIB) is an in vivo ligand for measuring beta-amyloid (Abeta) load. Associations between PET PIB and cerebrospinal fluid (CSF) Abeta1-42 and apolipoprotein E epsilon4 (APOE epsilon4) have been observed in several studies, but the relations between PIB uptake and other biomarkers of Alzheimer's disease (AD) are less investigated., Method: PET PIB, PET 18Fluoro-2-deoxy-D-glucose and different AD biomarkers were measured twice in CSF, plasma and urine 12 months apart in 10 patients with a clinical diagnosis of mild to moderate AD., Results: PIB retention was constant over 1 year, inversely related to low CSF Abeta1-42 (p = 0.01) and correlated positively to the numbers of the APOE epsilon4 allele (0, 1 or 2) (p = 0.02). There was a relation between mean PIB retention and CSF ApoE protein (r = -0.59, p = 0.07), and plasma cystatin C (r = -0.56, p = 0.09)., Conclusion: PIB retention is strongly related to CSF Abeta1-42, and to the numbers of the APOE epsilon4 allele., (2010 S. Karger AG, Basel.)

Background/aims: Genetic factors influencing common complex conditions have proven difficult to identify, and data from numerous investigations have provided incomplete conclusions as to the identity of these genes. Here we aimed to identify susceptibility genes for late-onset Alzheimer's disease (AD)., Methods: The case-control analysis included samples from 86 AD patients and 404 cognitively healthy controls selected from the Uppsala Longitudinal Study of Adult Men (ULSAM). In the incidence analysis, all 1,088 genotyped ULSAM participants were included. DNA samples from ULSAM participants were analyzed for 2,578 single nucleotide polymorphisms (SNP) within 368 genes. The selection of genes tested for association to AD within this cohort was based on genes previously implicated in conditions with relevance to ULSAM, such as dementia, cardiovascular disease, diabetes and metabolic syndrome, osteoporosis, and cancer., Results/conclusion: Association analysis revealed 82 genes containing at least 1 significant SNP at p < 0.05 with association to AD. Only 20 genes remained significant after a permutation test to correct for multiple comparisons within individual genes. Using publicly available data from 2 genome-wide association (GWA) studies and linkage disequilibrium data from HapMap, we attempted to replicate the AD association identified in ULSAM. In addition to apolipoprotein E, we were able to replicate 5 other genes in both GWA studies at p < 0.05.

Background/objective: The lowering of natively analyzed Abeta42 in cerebrospinal fluid (CSF) is used as a diagnostic tool in Alzheimer's disease (AD). The presence of Abeta oligomers can interfere with such analyses causing underestimation of Abeta levels due to epitope masking. The aim was to investigate if the lowering of CSF Abeta42 seen in AD is caused by oligomerization., Methods: Abeta42 was analyzed under both denaturing and non-denaturing conditions. An Abeta42 oligomer ratio was calculated from these quantifications. The presence of oligomers leads to Abeta42 epitope masking during non-denaturing assays, resulting in a higher ratio., Results: The Abeta42 oligomer ratio was used for the assessment of oligomerized Abeta in human CSF, after being evaluated in transgenic mouse brain homogenates. AD and mild cognitive impairment (MCI) samples displayed the expected decrease in natively measured Abeta42 compared to healthy controls and frontotemporal dementia, but not when analyzing under denaturing conditions. Accordingly, AD and MCI CSF had a higher Abeta42 oligomer ratio in CSF., Conclusion: Combining denaturing and non-denaturing quantifications of Abeta42 into an oligomer ratio enables the assessment of Abeta oligomers in biological samples. The increased Abeta42 oligomer ratio for AD and MCI indicates the presence of oligomers in CSF and that the lowering of natively measured Abeta42 is caused by oligomerization.

Background/aims: Increased cerebrospinal fluid (CSF) tau, decreased CSF amyloid-beta42 (Abeta42) and the apolipoprotein E gene (APOE) epsilon4 allele predict progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD). Here, we investigated these markers to assess their predictive value and influence on the rate of disease progression., Methods: Using ELISA, we measured the CSF biomarkers in 47 AD patients, 58 patients with MCI and 35 healthy control subjects. Twenty-eight MCI patients revisited the clinic and half of them progressed to AD during a period of 3-12 years., Results: The expected changes in CSF total (T)-tau, phosphorylated (P)-tau and Abeta42 levels were found in AD, confirming the diagnostic value of these biomarkers. We were also able to corroborate an increased risk for progression from MCI to AD with elevated CSF T-tau and P-tau and with the presence of the APOE epsilon4/epsilon4 genotype, but not with decreased Abeta42. Finally, for the first time we demonstrated that MCI subjects with high CSF T-tau or P-tau and APOE epsilon4 homozygosity progressed faster from MCI to AD., Conclusions: CSF T-tau and P-tau as well as the APOE epsilon4/epsilon4 genotype are robust predictors of AD and are also associated with a more rapid progression from MCI to AD.

Background/aims: Alterations in gene dosage have recently been associated with neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, and deletions of the progranulin (PGRN) locus were recently described in patients with frontotemporal lobar degeneration (FTLD). FTLD is a genetically complex neurodegenerative disorder with mutations in the PGRN and the microtubule-associated protein tau (MAPT) genes being the most common known causes of familial FTLD. In this study, we investigated 39 patients with FTLD, previously found negative for mutations in PGRN and MAPT, for copy number alterations of these 2 genes., Methods: Gene dosage analysis of PGRN and MAPT was performed using multiplex ligation-dependent probe amplification., Results: We did not identify any PGRN or MAPT gene dosage variations in the 39 FTLD patients investigated., Conclusion: We therefore conclude that alterations in gene copy number of PGRN and MAPT are not a cause of disease in this collection of FTLD patients., (Copyright 2009 S. Karger AG, Basel.)

Background: Memantine is a moderate affinity N-methyl-D-aspartate receptor antagonist approved for treatment of Alzheimer's disease (AD). In AD, tau is abnormally hyperphosphorylated. However, no significant changes of phosphorylated tau levels in CSF are found at follow-up in studies with AD patients. It has been shown in vitro that memantine reverse induced abnormal hyperphosphorylation of tau in hippocampal neurons of rats., Methods: Eleven AD patients were examined with cognitive tests and interviews of relatives. CSF analyses were performed before starting treatment with memantine as well as after 1 year., Results: A statistically significant reduction of CSF phosphorylated tau at the 1-year follow-up was seen, from median 126 (interquartile range 107-153) to 108 (88-133) ng/l (p = 0.018). No statistically significant differences of total tau or Abeta42 were found., Conclusion: The results may reflect effects of memantine on a key pathological feature in AD in line with previous in vitro findings.

Background: Individuals with Down syndrome (DS) invariably develop Alzheimer's disease (AD) during their life span. It is therefore of importance to study young DS patients when trying to elucidate early events in AD pathogenesis., Aim: To investigate how levels of different amyloid-beta (Abeta) peptides, as well as tau and phosphorylated tau, in cerebrospinal fluid (CSF) from children with DS change over time. The first CSF sample was taken at 8 months and the following two samples at 20-40 and 54 months of age., Results: Individual levels of the Abeta peptides, as well as total Abeta levels in CSF increased over time when measured with Western blot. Tau in CSF decreased whereas there was no change in levels of phosphorylated tau over time., Conclusion: The increasing levels of Abeta in CSF during early childhood of DS patients observed in this study are probably due to the trisomy of the Abeta precursor APP, which leads to an overproduction of Abeta. Despite the increased CSF concentrations of Abeta, there were no signs of an AD-indicating tau pattern in CSF, since the levels of total tau decreased and phosphorylated tau remained unchanged. This observation further strengthens the theory of Abeta pathology preceding tau pathology in AD., (Copyright (c) 2007 S. Karger AG, Basel.)

Frontotemporal dementia (FTD) and Alzheimer's disease (AD) are two frequent causes of dementia that share both clinical and neuropathological features. Common to both disorders are the neurofibrillary tangles consisting of aggregations of hyperphosphorylated tau protein. Recently, a number of different pathogenic mutations in the tau gene have been identified in families with FTD and parkinsonism linked to chromosome 17 (FTDP-17). In the present study, a Swedish family with presenile degenerative dementia with bitemporal atrophy was screened for mutations in the tau gene. As a result, the R406W mutation in exon 13 was identified in all affected cases. This mutation has previously been reported in two different FTDP-17 families of Dutch and Midwestern American origin. Common features to these two kindreds and our family are the late age at onset and long duration of the disease. Our pedigree as well as the American one show early memory impairment and pronounced temporal lobar atrophy similar to AD, while the Dutch cases show more FTD features. This further illustrates the large clinical variability among cases with tau mutations and stresses the importance of genetic classification in addition to the traditional clinical classification of neurodegenerative disorders., (Copyright 2004 S. Karger AG, Basel)

This study describes the clinical, neuropsychological, neuroimaging and genetic characteristics in two generations of a Swedish family affected by presenile dementia. The pedigree includes 5 cases (mother and 4 of 5 children) of progressive dementia with onset between 54 and 62 years. The clinical picture is characterized by insidious onset and progressive decline in episodic memory without spatial impairment or dyspraxia, followed by changes in personality and behaviour, with signs of disinhibition, irritability, impulsivity and loss of social awareness. Three siblings, examined after 10 years of duration, showed moderate language deficits but preserved spatial function and praxis. CT and MRI showed progressive bilateral temporal atrophy and moderate frontal white matter changes. Regional cerebral blood flow measurements showed hypoperfusion in temporal areas bilaterally. Quantitative EEG was normal within 5 years after symptom onset and thereafter showed a moderate increase in relative theta power. Sequencing of the tau gene (chromosome 17) revealed the previously described R406W mutation in exon 13 as a likely cause of the disease. This mutation was identified in all affected cases. The clinical picture of this family shows striking similarities not only to frontotemporal dementia but also to Alzheimer's disease., (Copyright 2004 S. Karger AG, Basel)

Frontotemporal dementia (FTD) is a neurodegenerative disease and next to Alzheimer's disease and vascular dementia, the third most common cause of early-onset progressive dementia. FTD leads to neurodegeneration in the frontal and temporal neocortex and usually encompasses both sides of the frontal and anterior temporal lobes. Psychologically, FTD is characterized by personality changes such as lack of insight, inappropriate behaviour, disinhibition, apathy, executive disabilities and a decline in cognitive functions, with large clinical and neuropathological variations among cases. Neuropathological characteristics include gliosis or microvacuolation of cortical nerve cells. Inclusions staining for tau protein and/or ubiquitin are also common findings. Both sporadic and hereditary forms of FTD have been identified and 30-50% of the FTD cases have a familial background. So far, at least three genetic loci for FTD have been identified, at human chromosomes 3, 9 and 17 in familial forms of the disease. A large number of the familial forms have been linked to chromosome 17q21 and referred to as frontotemporal dementia and Parkinsonism linked to chromosome 17. In the majority of these families, pathogenic mutations in the tau gene were identified. However, tau mutations seem to be a rare cause of disease in the general FTD population. Thus, other genes and/or environmental factors are yet to be identified, which will give further clues to this complex and heterogeneous disorder., (Copyright 2004 S. Karger AG, Basel.)

The psychosocial consequences of being at different risk for inheriting Alzheimer's disease (AD) were investigated in a high-risk group (n = 106) and a low-risk group (n = 37). Non-affected individuals from families with AD in two or more generations answered questions about their life situation, quality of life and coping. Their answers were compared with a population sample (n = 408). The high-risk group assessed the quality of their personal relationships and everyday life higher than did the population sample. They also used less emotive and supportive coping strategies compared with the population sample. Nearly 90% in the high-risk group felt anxiety concerning their own risk or the risk of their children and grandchildren of developing AD. About 50% of the respondents complained about a lack of information. The pieces of information they asked for were early signs of the disease, treatment, and practical information on how to handle everyday life with an affected relative., (Copyright 2003 S. Karger AG, Basel)

Deregulation of amyloid precursor protein (APP) processing with increased production of amyloid beta-peptide (Abeta) is considered to be a key pathogenic event in Alzheimer's disease (AD). It has been suggested that stimulation of the muscarinic M(1) receptor subtype affects APP processing and leads to a change in Abeta concentration. To test the hypothesis that treatment with a cholinesterase inhibitor could change the levels of Abeta in plasma, we measured Abeta42 and Abeta40 plasma levels in AD subjects before tacrine treatment and at weeks 2 and 6 of treatment. Treatment with tacrine had no statistically significant effect on plasma Abeta42 and Abeta40 either at 2 weeks or at 6 weeks of administration compared to baseline levels. Plasma Abeta42 and Abeta40 levels showed large subject-to-subject variation but small variation within the same patient over the 3-sample interval. After 2 weeks of treatment with tacrine, there was a strong negative correlation between tacrine concentration and levels of Abeta42 (r = -0.64; p = 0.01) and Abeta40 (r = -0.55; p = 0.04). However, after 6 weeks there was no correlation between plasma concentrations of tacrine and Abeta42 (r = 0.33; p = 0.34) or Abeta40 (r = -0.22; p = 0.54) levels in plasma. After 2 weeks of treatment with an acetylcholinesterase inhibitor, we found a correlation between higher drug concentrations and lower beta-amyloid levels. This might indicate an effect on APP metabolism with an increased alpha-cleavage. But after 6 weeks of drug treatment, there was no obvious drug effect on beta-amyloid concentrations. This finding may indicate that compensatory mechanisms have started at 6 weeks and that no long-term effect on key pathological features in AD is to be expected by an inhibition of acetylcholinesterase., (Copyright 2002 S. Karger AG, Basel)

To study the role of amyloid precursor protein (APP) in the pathogenesis of Alzheimer's disease (AD), the level of APP was analysed by quantitative immunoblotting in 6 AD patients and 6 age-matched controls in 9 brain regions. These were associative cortices (orbital frontal cortex, inferior temporal cortex, inferior parietal cortex), primary cortex (occipital cortex), limbic structures (anterior cingulate gyrus, hippocampus), subcortical structures (putamen, thalamus) and cerebellum. To assess a potential relationship between APP and presenilin-1 (PS-1) and/or synaptic proteins, the levels of PS-1 and rab3a, a specific synaptic vesicle protein, were also determined in the same tissue samples. The level of APP was almost the same in the association cortical regions, primary cortex, and limbic structures and in the subcortical structures, while the lowest level was found in the cerebellum. There were more marked differences in the level of PS-1 and rab3a between different brain regions. The highest levels of PS-1 and rab3a were found in the association cortical areas, while intermediate levels were found in primary cortex, limbic structures and subcortical structures. As for APP, the lowest level was found in cerebellum. We found significantly reduced levels of all three proteins in the association cortices and in hippocampus in AD. Our data show that the protein levels are reduced in specific areas, restricted to neuronal populations that are known to degenerate in AD. Due to the similarity of the expression of APP, PS-1 and rab3a, it is tempting to speculate whether there is a functional relationship between these proteins., (Copyright 2001 S. Karger AG, Basel)

Cerebrospinal fluid (CSF) tau is a promising biochemical ante-mortem marker for Alzheimer's disease (AD). Levels are increased in AD compared to other dementias, neurological diseases and healthy controls. An age-related decrease in both soluble tau and tau bound to paired helical filaments has been shown in brains from non-demented subjects. To study tau levels in normal ageing, we investigated CSF in 29 healthy individuals aged 45-80 years. A statistically significant increase in CSF tau with increasing age was found which might be caused by neuronal loss during normal ageing and redistribution of soluble tau from the brain into CSF. We could not demonstrate any influence by the APOE genotype, though larger populations have to be investigated to confirm this result. In conclusion, we found an age-dependent increase in CSF tau in healthy individuals. We emphasise the importance of establishing an age-dependent interval of CSF tau in non-demented subjects., (Copyright 2001 S. Karger AG, Basel)

The plasma insulin-like growth factor I (IGF-I) level was determined in family members carrying the Swedish amyloid precursor protein (APP) 670/671 mutation with or without Alzheimer's disease (AD) and in age-matched controls from the same family. Plasma growth hormone (GH) and prolactin (PRL) levels were also determined. Measurement of the plasma IGF-I level by radioimmunoassay revealed a significant reduction only in the family members with AD compared to age-matched controls. However, there was no significant difference in the levels of GH and PRL between the mutation carriers with or without AD and their respective age-matched controls. These findings indicate that the mechanism(s) regulating GH and PRL were preserved and those regulating IGF-I levels might be affected in AD patients with the Swedish APP 670/671 mutation. CopyrightCopyright 1999S.KargerAG, Basel

Mutations have been found in more than a hundred early-onset families with Alzheimer's disease (AD) in the genes for the amyloid precursor protein, presenilin 1 and presenilin 2. The object of our investigation was to identify if these mutations or novel ones were operating in a Swiss early-onset AD family (mean age of onset: 53.3 years) with 7 members available, all neuropathologically confirmed. No known or new mutations were detected. Thus, our data support the existence of a yet unknown mutation, or other genes, contributing to familial early-onset AD. CopyrightCopyright 1999S.KargerAG,Basel

Tau proteins are central to the neuropathology of Alzheimer's disease and tau levels in cerebrospinal fluid are elevated in affected individuals. In this study, we investigated the presence of tau in plasma from subjects with Alzheimer's disease (n = 16), frontotemporal dementia (n = 10), vascular dementia (n = 16) and from healthy controls (n = 15). By using an ELISA with monoclonal tau antibodies, tau immunoreactivity was detected in approximately 20% of the subjects. However, no difference between the disease and control groups was seen. After gel filtration of tau immunopositive plasma, the peak reactivity was found in the 160-kD fraction, indicating the source to be tau-like molecules of high-molecular-weight or polymers of low-molecular-weight tau isoforms. We conclude that measurements of tau in plasma cannot be utilized diagnostically for Alzheimer's disease or for the other dementias investigated. Copyrightz1999S.KargerAG,Basel

Objective: To study the progression of Alzheimer's disease (AD) at a very early stage and to evaluate clinical markers of presymptomatic AD., Setting: Longitudinal study at a university hospital., Subjects: A Swedish family harboring a double mutation at codons 670/671 of the APP gene on chromosome 21 was followed longitudinally for 3 years. Both mutation carriers and noncarriers participated., Outcome Measurements: Results from clinical investigations, electroencephalography, neuropsychological and neuroradiological examinations including magnetic resonance imaging, single-photon emission computed tomography and positron emission tomography were assessed and compared on two or more occasions., Main Outcome: During follow-up, 1 initially asymptomatic mutation carrier who was near the expected age of onset for this family, developed cognitive symptoms, and at the end of the follow-up fulfilled the diagnostic criteria for AD. One mutation carrier with cognitive symptoms at the first examination showed clinical deterioration and was diagnosed with AD. One demented mutation carrier died and was shown to have typical AD neuropathology at autopsy. The two remaining asymptomatic mutation carriers, as well as all the noncarriers were asymptomatic. These mutation carriers who were near the expected age of onset of AD but without clinical signs of the disease, did not show changes in either electrophysiological parameters or volumes of the temporal lobes. However, in these 2 individuals the blood flow in the temporal lobe showed intermediate values between the symptomatic mutation carriers and healthy noncarriers. Two neuropsychological tests showed a deterioration that paralleled clinical symptoms in 1 of the mutation carriers who was close to the expected age of onset and who at the end of the follow-up had clinical signs of AD. In the same subject, brain glucose metabolism was pathologically reduced in the temporal lobes before other clinical symptoms were obvious., Conclusion: In this familial form of AD a reduced temporal lobe glucose metabolism was indicative of AD before the expected clinical onset. Reduced glucose metabolism even preceded the development of subjective or objective cognitive dysfunction and might therefore serve as a clinical marker for AD before the onset of clinical symptoms. Reduced cerebral blood flow in the temporal lobes and cognitive deterioration paralleled the clinical decline in the early stage of the disease. Copyrightz1999S.KargerAG,Basel

We investigated the influence of the apolipoprotein (ApoE) epsilon4 allele on the rate of brain atrophy in patients with clinical dementia and in subjects at risk for dementia. Eighty-one subjects, consecutively referred to a memory clinic due to symptoms of dementia, went through a comprehensive examination, including cerebral magnetic resonance imaging. After an initial investigation these subjects were divided into one of six diagnostic groups; Alzheimer's disease (AD, n = 23), objective cognitive impairment (OCI, n = 27), subjective cognitive impairment (SCI, n = 17), vascular dementia (VaD), frontotemporal dementia (FTD) and unspecified dementia (USD). The last three groups were joined into one diagnostic group designated 'other dementia' (OD, altogether n = 14). In order to study the progression of cognitive impairment as well as the rate of atrophy in different brain regions all subjects were reinvestigated after an average period of 16 months. Interest was focused on investigating if those subjects with one or two epsilon4 alleles differed in either dementia progression or rate of brain atrophy compared to those without the epsilon4 allele. We found that the ApoE epsilon4 carriers had a statistically significantly larger increase in ventricular volume as compared with the ApoE epsilon4 noncarriers. In all diagnostic groups the ApoE epsilon4 carriers showed a greater rate of ventricular volume increase, as compared to the noncarriers. However, this difference was statistically significant only for the OD subjects. No statistical significant changes over time were seen for whole brain volume or volume of the temporal lobes and the medial temporal lobes. The diagnostic groups differed in dementia progression with the AD subjects having the most pronounced reduction in MMSE scores as compared to subjects at risk for AD (OCI and SCI subjects). The presence of ApoE epsilon4 allele did not influence the change in MMSE in any of the diagnostic groups.

To analyse the influence of apolipoprotein E (APOE) genotype on the extent of white matter lesions (WMLs) in Alzheimer's disease (AD), we examined 60 AD patients with magnetic resonance imaging. The WMLs were rated visually in different brain regions. The patients with the APOE genotype sigma4/4 had more extensive WMLs in the deep white matter than patients with genotypes sigma3/3 and sigma3/4. There was a correlation with age for WMLs in the deep white matter in patients with the APOE sigma3/3 genotype. In patients carrying at least one sigma4 allele, the WMLs showed no age correlation. The results could imply that in APOE allele sigma4 carriers, the WMLs represent a pathological process related to the aetiology of the disease.

Apolipoprotein E (APOE) and alpha1-antichymotrypsin (ACT) genotype and allele frequency distribution were investigated in 113 familial Alzheimer's disease (AD) cases. A significantly higher sigma4 frequency was observed in patients with an age of onset between 55-64 and 65-74 years compared to individuals with later or earlier onset. No difference in ACT A allele frequency was seen in any onset group, nor was any influence of ACT genotypes on the age of onset observed. However, the mean age of onset was lowered by the presence of the ACT/AA and ACT/TT genotypes among APOE sigma3/3 bearers. Possible APOE effects on age of onset were evaluated in 78 affected sib pairs. An earlier age of onset was observed in siblings with an sigma4 allele compared to siblings without an sigma4 allele. This supports the notion that the sigma4 allele promotes an earlier age of onset. However, in siblings with the same APOE genotype, a wide range of onset was seen, indicating that unknown genetic or environmental factors affect the expression of AD.

The apolipoprotein E (APOE) gene has in many studies been identified as a susceptibility factor in Alzheimer's disease (AD). The APOE association is rather strong, but other not yet identified genetic factors are assumed to be involved in the pathogenesis of AD. Recently an association between an intronic polymorphism in presenilin-1 (PS-1) gene and late-onset AD was claimed. In order to confirm this observation we studied a sample of Polish patients with sporadic AD. However, our results did not confirm the existence of an association between the intronic polymorphism in the PS-1 gene and late-onset AD.