Cerebrospinal Fluid Alzheimer Markers in Depressed Elderly Subjects with and without Alzheimer's Disease

Background

The aim of this study was to explore the relationship between cerebrospinal fluid Alzheimer's disease (AD) markers and depression in elderly people.

Method

We included subjects with AD as well as persons with subjective cognitive impairment and normal cognition. Depression was assessed with the Cornell Scale for Depression in Dementia, and a cut-off score of >6 was used to define depression. Cerebrospinal fluid was analyzed using commercially available assays for β-amyloid 1–42, total tau, and phosphorylated tau 181.

Results

A total of 183 participants (66.7% female) were included (92 with AD and 91 with subjective cognitive impairment), with a mean age (±SD) of 67.6 ± 7.4 years, a Mini-Mental State Examination score of 26.0 ± 4.0, and a median Cornell Scale for Depression in Dementia score of 5 (range 0–19). Depression scores were not associated with higher phosphorylated tau 181 and total tau or reduced β-amyloid 1–42 in AD or non-demented subjects.

Conclusions

These results suggest that AD pathology does not contribute to depression, indicating that other factors may be more important. Further studies of the aetiology of depression in elderly people with and without AD are warranted.

Effects of omega-3 fatty acids on inflammatory markers in cerebrospinal fluid and plasma in Alzheimer's disease: the OmegAD study

BACKGROUND

omega-3 fatty acids (omega-3 FAs) found in dietary fish or fish oils are anti-inflammatory agents that may influence Alzheimer's disease (AD).

OBJECTIVE

To study the effects of dietary omega-3 FA supplementation on inflammatory markers in cerebrospinal fluid (CSF) and plasma from patients with mild to moderate AD.

METHODS

Thirty-five patients (70.3 +/- 8.2 years) were randomized to a daily intake of 2.3 g omega-3 FAs or placebo for 6 months. The inflammatory markers interleukin (IL)-6, tumour necrosis factor-alpha and soluble interleukin-1 receptor type II (sIL-1RII) were analysed in CSF and plasma at baseline and at 6 months. The AD markers tau-protein, hyperphosphorylated tau-protein and beta-amyloid (Abeta(1-42)) were assessed in CSF. High-sensitivity C-reactive protein was assessed in plasma. A possible relation to the APOE genotype was investigated.

RESULTS

There was no significant treatment effect of omega-3 FAs on inflammatory and AD biomarkers in CSF or on inflammatory markers in plasma, nor was there any relation with APOE. A significant correlation was observed at baseline between sIL-1RII and Abeta(1-42) levels in CSF.

CONCLUSIONS

Treatment of AD patients with omega-3 FAs for 6 months did not influence inflammatory or biomarkers in CSF or plasma. The correlation between sIL-1RII and Abeta(1-42) may reflect the reciprocal interactions between IL-1 and Abeta peptides.

CSF biomarkers and incipient Alzheimer disease in patients with mild cognitive impairment

CONTEXT

Small single-center studies have shown that cerebrospinal fluid (CSF) biomarkers may be useful to identify incipient Alzheimer disease (AD) in patients with mild cognitive impairment (MCI), but large-scale multicenter studies have not been conducted.

OBJECTIVE

To determine the diagnostic accuracy of CSF beta-amyloid(1-42) (Abeta42), total tau protein (T-tau), and tau phosphorylated at position threonine 181 (P-tau) for predicting incipient AD in patients with MCI.

DESIGN, SETTING, AND PARTICIPANTS

The study had 2 parts: a cross-sectional study involving patients with AD and controls to identify cut points, followed by a prospective cohort study involving patients with MCI, conducted 1990-2007. A total of 750 individuals with MCI, 529 with AD, and 304 controls were recruited by 12 centers in Europe and the United States. Individuals with MCI were followed up for at least 2 years or until symptoms had progressed to clinical dementia.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative likelihood ratios (LRs) of CSF Abeta42, T-tau, and P-tau for identifying incipient AD.

RESULTS

During follow-up, 271 participants with MCI were diagnosed with AD and 59 with other dementias. The Abeta42 assay in particular had considerable intersite variability. Patients who developed AD had lower median Abeta42 (356; range, 96-1075 ng/L) and higher P-tau (81; range, 15-183 ng/L) and T-tau (582; range, 83-2174 ng/L) levels than MCI patients who did not develop AD during follow-up (579; range, 121-1420 ng/L for Abeta42; 53; range, 15-163 ng/L for P-tau; and 294; range, 31-2483 ng/L for T-tau, P < .001). The area under the receiver operating characteristic curve was 0.78 (95% confidence interval [CI], 0.75-0.82) for Abeta42, 0.76 (95% CI, 0.72-0.80) for P-tau, and 0.79 (95% CI, 0.76-0.83) for T-tau. Cut-offs with sensitivity set to 85% were defined in the AD and control groups and tested in the MCI group, where the combination of Abeta42/P-tau ratio and T-tau identified incipient AD with a sensitivity of 83% (95% CI, 78%-88%), specificity 72% (95% CI, 68%-76%), positive LR, 3.0 (95% CI, 2.5-3.4), and negative LR, 0.24 (95% CI, 0.21-0.28). The positive predictive value was 62% and the negative predictive value was 88%.

CONCLUSIONS

This multicenter study found that CSF Abeta42, T-tau, and P-tau identify incipient AD with good accuracy, but less accurately than reported from single-center studies. Intersite assay variability highlights a need for standardization of analytical techniques and clinical procedures.

Detection of amyloid in Alzheimer's disease with positron emission tomography using [11C]AZD2184

Purpose

Current positron emission tomography (PET) radioligands for detection of Aβ amyloid in Alzheimer’s disease (AD) are not ideal for quantification. To improve the signal to noise ratio we have developed the radioligand [¹¹C]AZD2184 and report here the first clinical evaluation.

Methods

Eight AD patients and four younger control subjects underwent 93-min PET measurements with [¹¹C]AZD2184. A ratio approach using the cerebellum as reference region was applied to determine binding parameters.

Results

Brain uptake of [¹¹C]AZD2184 peaked within 1 min at 3–4% of injected radioactivity. AD patients had high radioactivity in cortical regions while controls had uniformly low radioactivity uptake. Specific binding peaked within 30 min at which time standardized uptake value ratios (SUVR) ranged between 1.19 and 2.57.

Conclusion

[¹¹C]AZD2184 is a promising radioligand for detailed mapping of Aβ amyloid depositions in Alzheimer’s disease, due to low non-specific binding, high signal to background ratio and reversible binding as evident from early peak equilibrium.

Effects of docosahexaenoic acid-rich n-3 fatty acid supplementation on cytokine release from blood mononuclear leukocytes: the OmegAD study

BACKGROUND

Dietary fish or fish oil rich in n-3 fatty acids (n-3 FAs), eg, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), ameliorate inflammatory reactions by various mechanisms. Whereas most studies have explored the effects of predominantly EPA-based n-3 FAs preparations, few have addressed the effects of n-3 FAs preparations with DHA as the main FA.

OBJECTIVE

The objective was to determine the effects of 6 mo of dietary supplementation with an n-3 FAs preparation rich in DHA on release of cytokines and growth factors from peripheral blood mononuclear cells (PBMCs).

DESIGN

In a randomized, double-blind, placebo-controlled trial, 174 Alzheimer disease (AD) patients received daily either 1.7 g DHA and 0.6 g EPA (n-3 FAs group) or placebo for 6 mo. In the present study blood samples were obtained from the 23 first randomized patients, and PBMCs were isolated before and after 6 mo of treatment.

RESULTS

Plasma concentrations of DHA and EPA were significantly increased at 6 mo in the n-3 FAs group. This group also showed significant decreases of interleukin (IL)-6, IL-1beta, and granulocyte colony-stimulating factor secretion after stimulation of PBMCs with lipopolysaccharide. Changes in the DHA and EPA concentrations were negatively associated with changes in IL-1beta and IL-6 release for all subjects. Reductions of IL-1beta and IL-6 were also significantly correlated with each other. In contrast, this n-3 FA treatment for 6 mo did not decrease tumor necrosis factor-alpha, IotaL-8, IL-10, and granulocyte-macrophage colony-stimulating factor secretion.

CONCLUSION

AD patients treated with DHA-rich n-3 FAs supplementation increased their plasma concentrations of DHA (and EPA), which were associated with reduced release of IL-1beta, IL-6, and granulocyte colony-stimulating factor from PBMCs. This trial was registered at clinicaltrials.gov as NCT00211159.

Pre-operative mild cognitive dysfunction predicts risk for post-operative delirium after elective cardiac surgery

BACKGROUND AND AIMS

To identify pre-operative risk factors for delirium in patients undergoing elective cardiac surgery, using clearly defined diagnostic criteria for delirium, and a thorough clinical assessment.

METHODS

The incidence of post-operative delirium in 107 patients >or=60 years undergoing elective cardiac surgery was calculated. None of the patients included suffered from dementia. Pre-operative cognitive function in all patients was assessed using the Mini Mental State Examination (MMSE) and post-operative delirium was diagnosed using the Confusion Assessment Method (CAM). Post-operative clinical and cognitive assessments were carried out for all patients.

RESULTS

Twenty-five patients (23.4%) developed delirium post-operatively. Clinical parameters, including age, gender, co-morbidities, medications, and peri-operative parameters, were similar in patients with and without post-operative delirium. Patients with pre-operative subjective memory complaints and lower MMSE scores, undergoing valve operation or valve + coronary artery bypass grafting (CABG), exhibited an increased risk of developing post-operative delirium. Additionally, delirious patients had a significant decline in post-operative MMSE score compared with the non-delirious ones.

CONCLUSIONS

The main pre-operative risk factors for post-operative delirium after elective cardiac operations were subjective memory complaints, mild cognitive impairment, and type of cardiac surgery, such as valve procedures. This study suggests that cognitive evaluation should be included in pre-operative assessment.

Patient- and proxy-reported utility in Alzheimer disease using the EuroQoL

This study aims to compare patient- and proxy-rated utilities and health-related quality of life from individuals in different stages of Alzheimer disease (AD). Two hundred seventy-two patients and their primary caregivers were enrolled in a prospective observational study and underwent three consecutive interviews, 6 months apart. Average Mini-Mental State Examination (MMSE) scores were 19.3, 18.0, and 16.4 at the three interviews; scores ranged from 0 to 30. Using the EuroQoL EQ-5D instrument, patient-rated health utilities were on average 0.833 with little variation across MMSE-based severity levels. Proxy-rated health utilities were 0.69 (MMSE >25), 0.64 (MMSE 21-25), 0.50 (MMSE 15-20), 0.49 (MMSE 10-14), and 0.33 (MMSE <10). Proxy-rated utilities, as well as changes in utilities over time, were significantly related to MMSE scores and inversely related to scores on a brief version of the neuropsychiatric inventory (NPI) and institutionalization. Utilities were highly correlated with the disease-specific quality of life instrument QoL-AD. The study shows that the EuroQoL can be used to rate utilities in Alzheimer disease, but there are important differences between patient- and proxy-ratings.

Determinants of costs of care for patients with Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD), the most common cause of dementia, is a major cause of disability and care burden in the elderly. This study aims to estimate the costs of formal and informal care and identity determinants of care costs.

MATERIALS AND METHODS

Two hundred and seventy-two (AD) patients and their caregivers were recruited among patients attending regular visits at six memory clinic in Sweden, Denmark, Norway and Finland. Patients with a diagnosis of AD and with an identifiable primary caregiver were eligible for inclusion. Data was collected by questionnaires at baseline, and at scheduled follow-up visits after 6 months and again after 12 months. Cognitive function was assessed with the Mini Mental State Examination (MMSE) and behavioural disturbances were measured using a brief version of the neuropsychiatric inventory (NPI).

RESULTS

Total annual costs were on average 172,000 SEK, ranging from 60,700 SEK in mild dementia to 375,000 SEK in severe dementia. Costs for community care (special accommodation, home help, etc.) constituted about half of total costs of care and increase sharply with increasing cognitive impairment. Informal care costs, valued at the opportunity cost of the caregiver's time, make up about a third of total costs and also increased significantly with disease severity. Medical care costs (inpatient care, outpatient care, pharmaceuticals), on the other hand, were not significantly related to disease severity. Regression analysis confirmed a strong association between costs and cognitive function, between patients as well as within patients over time. There was also a significant influence on costs from behavioural disturbances. Sensitivity analysis showed that the method chosen to value informal care can have considerable impact on results.

CONCLUSIONS

Costs of care in patient with AD are high and related to dementia severity as well as presence of behavioural disturbances. The cost estimates presented have implications for future economic evaluation of treatments for Alzheimer's disease.

Determination of isoprostanes in urine samples from Alzheimer patients using porous graphitic carbon liquid chromatography–tandem mass spectrometry

F2-isoprostanes (F2-iPs) comprise four classes of isomers produced non-enzymatically by free radical attack on arachidonic acid, a component of the cell membrane. This paper describes a new method for the quantification of F2-isoprostanes in urine samples from thoroughly diagnosed Alzheimer's disease (AD) patients. The sample pretreatment consisted of liquid extraction of 900 microl urine with diethyl ether, its subsequent evaporation, and finally, reconstitution in 50 microl water. Of this, 20 microl was injected into a HPLC system with a 15 mm x 1 mm porous graphitic carbon column coupled to a triple quadrupole mass spectrometer running in negative electrospray ionization mode. The F2-isoprostanes were separated in 15 min using a linear solvent gradient comprising water, methanol, acetonitrile and ammonium hydroxide at a pH of 9.5. The average recovery obtained was approximately 75%. The limit of detection (3S/N) was calculated for iPF2alpha-III to be 0.7 pg injected on column, corresponding to 0.1 nM. The average level of iPF2alpha was 241 +/- 163 pg/mg creatinine in the urine samples from AD patients (average +/- standard deviation). The corresponding control values were 216 +/- 101 pg/mg creatinine, i.e. no statistically significant difference was noticed. No correlation pattern specific to Alzheimer's disease was revealed by principal component analysis of the isoprostane peaks obtained either. The results from this study support earlier findings that levels of peripheral isoprostanes are not increased in patients with Alzheimer's disease.

Mild cognitive impairment: experience from a memory clinic

Mild cognitive impairment (MCI) is sometimes a transition between normal aging and dementia. We investigated the occurrence of MCI in a population referred to a memory clinic. The criteria used to diagnose the state were similar to those used by Petersen et al. in many previous publications. A clinical evaluation after approximately 3 years was also performed. In a subsample of 43 subjects, we found that, during 1 year, 37% (136/402) of all investigated subjects were patients with MCI. After a mean follow-up time of 3 years, 11% (5/43) showed cognitive improvement, while 53% (23/43) were stable and showed no cognitive decline or improvement. Fifteen out of 42 patients (35%) deteriorated and were diagnosed as demented during the same time. We conclude that MCI is a heterogeneous concept and that the outcome at follow-up is dependent on which population is studied and how MCI has been defined.

Temporary confusion: a fearful experience

Older people admitted to hospital often develop acute temporary confusion. Earlier studies have focused on problems in providing care to the confused, causes of the confusion and the key aspects of caring. The aims of this study were to describe, from a nursing perspective, how older people experienced the phenomenon of temporary confusion and to describe the older peoples' reasoning when they described their experiences. Interviews with five older informants who had recovered from their confusional state were conducted and analysed using the phenomenological method. Two phenomena were studied, 'being temporarily confused' and 'reasoning about experiences of temporary confusion', each was found to be represented by four inter-related constituents. The phenomena can be understood as aspects of suffering and power imbalance between staff and older people.

Solid human embryonic spinal cord xenografts in acute and chronic spinal cord cavities: a morphological and functional study

While therapeutic spinal cord grafting procedures are of interest in the chronic spinal cord injury stage, previous experimental grafting studies, including human spinal cord tissue, have mainly focused on the acute stage. Therefore, solid human embryonic spinal cord grafts were implanted in acute or chronic spinal cord aspiration cavities of immunodeficient rats to compare the morphological and locomotor outcome to that of lesion alone cases. Locomotor function was assessed using the Basso, Beattie, and Bresnahan open-field locomotor rating scale up to 6 months, while the morphological evaluation of graft survival, growth, and integration was performed at 6 weeks or 6 months after implantation. Graft survival was 94% in both lesion models, while graft growth was enhanced in the chronic compared to the acute cavity group. Human specific Thy-1 and neurofilament immunoreactive fibers were observed up to 7 mm into host white matter, while aminergic fibers were observed up to 1 mm into the grafts. Abundant calcitonin gene-related peptide immunoreactive fibers in the grafts in the absence both of immunoreactive cell bodies and colocalized human-specific neurofilament immunoreactivity, suggested host fiber ingrowth. At 6 months, the grafted cases presented less central canal deformation and lower glial fibrillary acidic protein immunoreactivity at the host cavity border compared to that of the nongrafted cases. The strong compensatory regain of locomotor function after unilateral spinal cord lesions was not affected by the human spinal cord grafts. In conclusion, solid human embryonic spinal cord tissue transplanted to a cavity in the adult injured spinal cord results in beneficial morphological effects in both the acute and chronic spinal cord lesion.

Nerve growth factor treatment in dementia

Millions of people are affected by Alzheimer disease. As longevity increases, so will the number of patients with dementia. This has led to an intense search for successful treatment strategies. One area of interest is neurotrophic factors. Brain development and neuronal maintenance, as well as protective efforts, are mediated by a large number of different neurotrophic factors acting on specific receptors. In neurodegenerative disorders, there may be a possibility of rescuing degenerating neurons and stimulating terminal outgrowth with use of neurotrophic factors. The first neurotrophic factor discovered was nerve growth factor (NGF). A wealth of animal studies have shown that cholinergic neurons are NGF sensitive and NGF dependent, which is especially interesting in cognitive disorders, in which central cholinergic projections are important for cognitive function. In Alzheimer disease, cholinergic neurons have been shown to degenerate. This suggests that NGF may be used to pharmacologically counteract cholinergic degeneration and/or induce terminal sprouting in Alzheimer disease. Data from animal studies, as well as from the author's recent clinical trial, in which NGF was infused to the lateral ventricle in patients with Alzheimer disease, will be presented. Effects of NGF on cognition, as well as issues regarding dosage, side effects, and alternative ways of administering NGF, will be discussed.