Alzheimer Disease: Quinn JF

Quinn JF, Crane S, Harris C, Wadsworth TL. · Oregon Health and Science University, Portland VA Medical Center, Department of Neurology, Portland, OR 97239, USA. · Expert Rev Neurother. · Pubmed #19402774 No free full text.

Abstract: A considerable amount of literature has accrued examining the role of copper in the pathogenesis of Alzheimer's disease. Remarkably, there is in vitro and animal data to support both copper toxicity and copper deficiency as relevant mechanisms in Alzheimer's disease. These data have prompted preliminary clinical trials of both copper complexing therapy and copper supplementation therapy, which have yielded mixed results. The preclinical and clinical studies are discussed here in an effort to determine how to move forward with rational clinical trials focused on copper modulation.

Sonnen JA, Breitner JC, Lovell MA, Markesbery WR, Quinn JF, Montine TJ. · Department of Pathology and of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA. · Free Radic Biol Med. · Pubmed #18482592 links to  free full text

Abstract: Advances in our understanding of the etiologies and pathogenesis of Alzheimer's disease (AD) highlight a role for free radical-mediated injury to brain regions from early stages of this illness. Here we will review the evidence from transgenic mouse models of AD, autopsy samples, and human biofluids obtained during life paying particular attention to the stage of disease. In addition, we will review the epidemiologic literature that addresses the potential of anti-oxidants to prevent incident dementia from AD, and the clinical trial literature that addresses anti-oxidant preventative or therapeutic strategies for different stage of AD. Future efforts in preclinical models and ultimately clinical trials are needed to define optimally effective agents and combinations, doses, and timing to suppress safely this facet of AD.

Montine TJ, Quinn JF, Montine KS, Kaye JA, Breitner JC. · Department of Pathology, University of Washington, Seattle, WA 98104, USA. · J Alzheimers Dis. · Pubmed #16556967 No free full text.

Abstract: Dementia from Alzheimer's disease (AD) represents a significant and growing public health burden and presents a clear therapeutic imperative. Key to success in this undertaking will be biomarkers for the objective assessment of disease progression and response to therapeutics. Oxidative damage is one facet of AD pathogenesis for which there are experimentally validated quantitative in vivo biomarkers, the F2-isoprostanes (IsoPs). While plasma- or urine-based assays are desirable, consistent and reproducible cross-sectional data for increased F2-IsoPs in AD and mild cognitive impairment have been obtained only for CSF. In addition, measurement of CSF F2-IsoPs can increase the accuracy of laboratory-based classification of geriatric dementias, and have been used to assess objectively the response to anti-oxidant interventions in AD.

Montine TJ, Montine KS, McMahan W, Markesbery WR, Quinn JF, Morrow JD. · Department of Pathology, University of Washington, Seattle, WA 98104, USA. · Antioxid Redox Signal. · Pubmed #15650414 No free full text.

Abstract: Increased free radical-mediated injury to brain is proposed to be an integral component of several neurodegenerative diseases, including Alzheimer's disease (AD). Lipid peroxidation is a major outcome of free radical- mediated injury to brain, where it directly damages membranes and generates a number of oxidized products. F2-Isoprostanes (F2-IsoPs), one group of lipid peroxidation products derived from arachidonic acid, are especially useful as in vivo biomarkers of lipid peroxidation. F2-IsoP concentration is selectively increased in diseased regions of brain from patients who died from advanced AD, where pathologic changes include amyloid beta (Abeta) amyloidogenesis, neurofibrillary tangle formation, and extensive neuron death. Interestingly, cerebral F2-IsoPs are not reproducibly elevated in aged mouse models of cerebral Abeta amyloidogenesis only. There is broad agreement that increased cerebrospinal fluid (CSF) levels of F2-IsoPs also are present in patients with early AD. Demonstrated applications of quantifying CSF F2-IsoPs have improved laboratory diagnostic accuracy of AD and objective assessment of antioxidant therapeutics. In contrast, quantification of F2-IsoPs in plasma and urine of AD patients has produced conflicting data. These results indicate that brain lipid peroxidation is a potential therapeutic target early in the course of AD, and that CSF F2-IsoPs may aid in the assessment of antioxidant experimental therapeutics and laboratory diagnosis of AD.

Montine KS, Quinn JF, Zhang J, Fessel JP, Roberts LJ, Morrow JD, Montine TJ. · Department of Pathology, University of Washington, Harborview Medical Center, Box 359791, 325 9th Ave., Seattle, WA 98104, USA. · Chem Phys Lipids. · Pubmed #15037157 No free full text.

Abstract: Lipid peroxidation is a major outcome of free radical-mediated injury to brain, where it directly damages membranes and generates a number of oxidized products. Some of the chemically and metabolically stable oxidation products are useful in vivo biomarkers of lipid peroxidation. These include the isoprostanes (IsoPs) and isofurans (IsoFs), derived from arachidonic acid (AA), and neuroprostanes (NeuroPs), derived from docosahexaenoic acid (DHA). We have shown increased levels of IsoPs, NeuroPs, and IsoFs in diseased regions of brain from patients who died from advanced Alzheimer's disease (AD) or Parkinson's disease (PD). Increased cerebrospinal fluid (CSF) levels of IsoPs are present in patients with AD or Huntington's disease (HD) early in the course of their illness, and CSF IsoPs may improve the laboratory diagnostic accuracy for AD. In contrast, quantification of IsoPs in plasma and urine of AD patients has yielded inconsistent results. These results indicate that brain lipid peroxidation is a potential therapeutic target early in the course of AD and HD, that CSF IsoPs may aid in the assessment of anti-oxidant experimental therapeutics and laboratory diagnosis of AD.

Montine TJ, Neely MD, Quinn JF, Beal MF, Markesbery WR, Roberts LJ, Morrow JD. · Department of Pharmacology, Pathology, and Medicine and the Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA. · Free Radic Biol Med. · Pubmed #12208348 No free full text.

Abstract: Lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products, both from fission and endocyclization of oxygenated fatty acids that possess neurotoxic activity. Numerous studies have demonstrated increased lipid peroxidation in brain of patients with Alzheimer's disease (AD) compared with age-matched controls. These data include quantification of fission and endocyclized products such as 4-hydroxy-2-nonenal, acrolein, isoprostanes, and neuroprostanes. Immunohistochemical and biochemical studies have localized the majority of lipid peroxidation products to neurons. A few studies have consistently demonstrated increased cerebrospinal fluid (CSF) levels of isoprostanes in AD patients early in the course of their dementia, and one study has suggested that CSF isoprostanes may improve the laboratory diagnostic accuracy for AD. Similar analyses of control individuals over a wide range of ages indicate that brain lipid peroxidation is not a significant feature of usual aging. Quantification of isoprostanes in plasma and urine of AD patients has yielded inconsistent results. These results indicate that brain lipid peroxidation is a potential therapeutic target in probable AD patients, and that CSF isoprostanes may aid in the assessment of antioxidant experimental therapeutics and the laboratory diagnosis of AD.

Fleisher AS, Raman R, Siemers ER, Becerra L, Clark CM, Dean RA, Farlow MR, Galvin JE, Peskind ER, Quinn JF, Sherzai A, Sowell BB, Aisen PS, Thal LJ. · University of California, San Diego, La Jolla, CA 92037, USA. · Arch Neurol. · Pubmed #18695053 links to  free full text

Abstract: OBJECTIVE: To evaluate the safety, tolerability, and amyloid beta (Abeta) response to the gamma-secretase inhibitor LY450139 in Alzheimer disease. DESIGN: Multicenter, randomized, double-blind, dose-escalation, placebo-controlled trial. SETTING: Community-based clinical research centers. Patients Fifty-one individuals with mild to moderate Alzheimer disease were randomized to receive placebo (n=15) or LY450139 (100 mg [n=22] or 140 mg [n=14]), with 43 completing the treatment phase. Intervention The LY450139 groups received 60 mg/d for 2 weeks, then 100 mg/d for 6 weeks, and then either 100 or 140 mg/d for 6 additional weeks. MAIN OUTCOME MEASURES: Primary outcome measures were adverse events, plasma and cerebrospinal fluid Abeta levels, vital signs, electrocardiographic data, and laboratory safety test results. Secondary outcome measures included the Alzheimer's Disease Assessment Scale cognitive subscale and the Alzheimer's Disease Cooperative Study Activities of Daily Living Scale. RESULTS: Group differences were seen in skin and subcutaneous tissue concerns (P=.05), including 3 possible drug rashes and 3 reports of hair color change in the treatment groups. There were 3 adverse event-related discontinuations, including 1 transient bowel obstruction. The plasma Abeta(40) concentration was reduced by 58.2% for the 100-mg group and 64.6% for the 140-mg group (P<.001). No significant reduction was seen in cerebrospinal fluid Abeta levels. No group differences were seen in cognitive or functional measures. CONCLUSIONS: LY450139 was generally well tolerated at doses of up to 140 mg/d for 14 weeks, with several findings indicating the need for close clinical monitoring in future studies. Decreases in plasma Abeta concentrations were consistent with inhibition of gamma-secretase. Trial Registration clinicaltrials.gov Identifier: NCT00244322.

Bowman GL, Dodge H, Frei B, Calabrese C, Oken BS, Kaye JA, Quinn JF. · Department of Neurology, Oregon Health & Science University, Portland, OR, USA. · J Alzheimers Dis. · Pubmed #19158425 No free full text.

Abstract: The brain maintains high levels of ascorbic acid (AA) despite a concentration gradient favoring diffusion from brain to peripheral tissues. Dietary antioxidants, including AA, appear to modify the risk of Alzheimer's disease (AD). The objective of this study was to test the hypothesis that neurodegeneration in AD is modified by brain levels of AA. Thirty-two patients with mild to moderate AD participated in a biomarker study involving standardized clinical assessments over one year. Cerebrospinal fluid (CSF) and serum were collected at baseline for AA and albumin content. Cognitive measures were collected at baseline and one year. CSF and plasma AA failed to predict cognitive decline independently, however, CSF: plasma AA ratio did. After adding CSF Albumin Index (an established marker of blood-brain barrier integrity) to the regression models the effect of CSF: plasma AA ratio as a predictor of cognitive decline was weakened. CSF: plasma AA ratio predicts rate of decline in AD. This relationship may indicate that the CSF: plasma AA ratio is an index of AA availability to the brain or may be an artifact of a relationship between blood-brain barrier impairment and neurodegeneration.

Roher AE, Esh CL, Kokjohn TA, Castaño EM, Van Vickle GD, Kalback WM, Patton RL, Luehrs DC, Daugs ID, Kuo YM, Emmerling MR, Soares H, Quinn JF, Kaye J, Connor DJ, Silverberg NB, Adler CH, Seward JD, Beach TG, Sabbagh MN. · The Longtine Center for Molecular Biology and Genetics, Sun Health Research Institute, Sun City, AZ, USA. · Alzheimers Dement. · Pubmed #19118806 No free full text.

Abstract: BACKGROUND: We evaluated the amounts of amyloid beta (Abeta)) peptides in the central nervous system (CNS) and in reservoirs outside the CNS and their potential impact on Abeta plasma levels and Alzheimer's disease (AD) pathology. METHODS: Amyloid beta levels were measured in (1) the plasma of AD and nondemented (ND) controls in a longitudinal study, (2) the plasma of a cohort of AD patients receiving a cholinesterase inhibitor, and (3) the skeletal muscle, liver, aorta, platelets, leptomeningeal arteries, and in gray and white matter of AD and ND control subjects. RESULTS: Plasma Abeta levels fluctuated over time and among individuals, suggesting continuous contributions from brain and peripheral tissues and associations with reactive circulating proteins. Arteries with atherosclerosis had larger amounts of Abeta40 than disease-free vessels. Inactivated platelets contained more Abeta peptides than activated ones. Substantially more Abeta was present in liver samples from ND patients. Overall, AD brain and skeletal muscle contained increased levels of Abeta. CONCLUSIONS: Efforts to use plasma levels of Abeta peptides as AD biomarkers or disease-staging scales have failed. Peripheral tissues might contribute to both the circulating amyloid pool and AD pathology within the brain and its vasculature. The wide spread of plasma Abeta values is also due in part to the ability of Abeta to bind to a variety of plasma and membrane proteins. Sources outside the CNS must be accounted for because pharmacologic interventions to reduce cerebral amyloid are assessed by monitoring Abeta plasma levels. Furthermore, the long-range impact of Abeta immunotherapy on peripheral Abeta sources should also be considered.

Wadsworth TL, Bishop JA, Pappu AS, Woltjer RL, Quinn JF. · Department of Neurology, Oregon Health & Science University, Portland, OR 97239-3098, USA. · J Alzheimers Dis. · Pubmed #18560133 No free full text.

Abstract: Increasing evidence suggests that Alzheimer's disease (AD) is associated with oxidative damage that is caused in part by mitochondrial dysfunction. Here we investigated the feasibility of modifying Alzheimer pathology with the mitochondrial antioxidant coenzyme Q (CoQ). Exogenous CoQ protected MC65 neuroblastoma cells from amyloid-beta protein precursor C-terminal fragment (APP CTF)-induced neurotoxicity in a concentration dependent manner, with concentrations of 6.25 microM and higher providing near complete protection. Dietary supplementation with CoQ at a dose of 10 g/kg diet to C65/Bl6 mice for one month significantly suppressed brain protein carbonyl levels, which are markers of oxidative damage. Treatment for one month with 2 g lovastatin/kg diet, which interferes with CoQ synthesis, resulted in a significant lowering of brain CoQ10 levels. Mitochondrial energetics (brain ATP levels and mitochondrial membrane potential) were unaffected by either CoQ or lovastatin treatment. Our results suggest that oral CoQ may be a viable antioxidant strategy for neurodegenerative disease. Our data supports a trial of CoQ in an animal model of AD in order to determine whether a clinical trial is warranted.

Lovell MA, Lynn BC, Xiong S, Quinn JF, Kaye J, Markesbery WR. · Department of Chemistry, Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky, Lexington, KY 40536-0230, USA. · Neurology. · Pubmed #18448869 No free full text.

Abstract: OBJECTIVE: To determine if an aberrant protein complex consisting of prostaglandin-d-synthase (PDS) and transthyretin (TTR) in CSF differentiates between subjects with Alzheimer disease (AD) and normal control (NC) subjects. METHODS: Western blot analysis and a unique sandwich ELISA were used to quantify levels of complexed PDS/TTR in ventricular CSF of subjects with autopsy-verified diagnoses and in lumbar CSF of living subjects with mild to moderate probable AD and age-matched NC subjects. Ventricular CSF was obtained from short postmortem interval autopsies of 7 NC subjects (4 men/3 women), 12 diseased control (DC) subjects (7 men/5 women), 4 subjects with mild cognitive impairment (MCI) (2 men/2 women), and 8 subjects with late-stage AD (LAD) (4 men/4 women). Lumbar CSF was obtained from 15 subjects with probable AD (5 men/10 women) and 14 age-matched NC subjects (10 men/4 women) and was analyzed in a double-blind fashion. RESULTS: A significant increase in complexed PDS/TTR in ventricular CSF was found in MCI and LAD subjects but not DC subjects compared with NC subjects. Double-blind analysis of complexed PDS/TTR in lumbar CSF showed a significant sixfold increase in levels of the PDS/TTR complex in living probable AD subjects compared with age-matched NC subjects and a 100% sensitivity and 93% specificity in the identification of subjects with AD. CONCLUSION: After further study of larger numbers of patients, quantifying prostaglandin-d-synthase/transthyretin complex in CSF may be useful in the diagnosis of Alzheimer disease, possibly in the early stages of the disease.

Bekris LM, Millard SP, Galloway NM, Vuletic S, Albers JJ, Li G, Galasko DR, DeCarli C, Farlow MR, Clark CM, Quinn JF, Kaye JA, Schellenberg GD, Tsuang D, Peskind ER, Yu CE. · Geriatric Research, Education, and Clinical Center (GRECC), VA Puget Sound Health Care System, Seattle, WA 98108, USA. · J Alzheimers Dis. · Pubmed #18430993 No free full text.

Abstract: The epsilon4 allele of the apolipoprotein E gene (APOE) is associated with increased risk and earlier age at onset in late onset Alzheimer's disease (AD). Other factors, such as expression level of apolipoprotein E protein (apoE), have been postulated to modify the APOE related risk of developing AD. Multiple loci in and outside of APOE are associated with a high risk of AD. The aim of this exploratory hypothesis generating investigation was to determine if some of these loci predict cerebrospinal fluid (CSF) apoE levels in healthy non-demented subjects. CSF apoE levels were measured from healthy non-demented subjects 21-87 years of age (n=134). Backward regression models were used to evaluate the influence of 21 SNPs, within and surrounding APOE, on CSF apoE levels while taking into account age, gender, APOE epsilon4 and correlation between SNPs (linkage disequilibrium). APOE epsilon4 genotype does not predict CSF apoE levels. Three SNPs within the TOMM40 gene, one APOE promoter SNP and two SNPs within distal APOE enhancer elements (ME1 and BCR) predict CSF apoE levels. Further investigation of the genetic influence of these loci on apoE expression levels in the central nervous system is likely to provide new insight into apoE regulation as well as AD pathogenesis.

Zhang J, Sokal I, Peskind ER, Quinn JF, Jankovic J, Kenney C, Chung KA, Millard SP, Nutt JG, Montine TJ. · Department of Pathology, University of Washington School of Medicine, Seattle, WA 98104, USA. · Am J Clin Pathol. · Pubmed #18343778 links to  free full text

Abstract: The therapeutic imperative for Alzheimer disease (AD) and Parkinson disease (PD) calls for discovery and validation of biomarkers. Increased cerebrospinal fluid (CSF) tau and decreased amyloid (A) beta42 have been validated as biomarkers of AD. In contrast, there is no validated CSF biomarker for PD. We validated our proteomics-discovered multianalyte profile (MAP) in CSF from 95 control subjects, 48 patients with probable AD, and 40 patients with probable PD. An optimal 8-member MAP agreed with expert diagnosis for 90 control subjects (95%), 36 patients with probable AD (75%), and 38 patients with probable PD (95%). This MAP consisted of the following (in decreasing order of contribution): tau, brain-derived neurotrophic factor, interleukin 8, Abeta42, beta2-microglobulin, vitamin D binding protein, apolipoprotein (apo) AII, and apoE. This first large-scale validation of a proteomic-discovered MAP suggests a panel of 8 CSF proteins that are highly effective at identifying PD and moderately effective at identifying AD.

Wang W, Shinto L, Connor WE, Quinn JF. · Department of Medicine, Oregon Health and Science University, Portland, OR 97239, USA. · J Alzheimers Dis. · Pubmed #18334754 No free full text.

Abstract: Carotenoids are fat-soluble antioxidants that may protect polyunsaturated fatty acids, such as n-3 fatty acids from oxidation, and are potentially important for Alzheimer's disease (AD) prevention and treatment. Fasting plasma carotenoids were measured in 36 AD subjects and 10 control subjects by HPLC. Correlations between plasma carotenoid levels, red blood cell (RBC) n-3 fatty acids, and dementia severity were examined in AD patients.Moderately severe AD patients (MMSE=16-19) had much lower plasma levels of two major carotenoids: lutein and beta-carotene, compared to mild AD patients (MMSE=24-27) or controls. Among AD patients, variables (lutein, beta-carotene, RBC docosahexaenoic acid (DHA) and LDL-cholesterol) were significantly correlated with MMSE. A lower MMSE score was associated with lower lutein, beta-carotene and RBC DHA levels, and a higher LDL-cholesterol level. These variables explained the majority of variation in dementia severity (55% of variance in MMSE). Lutein, beta-carotene and beta-cryptoxanthin were positively correlated with RBC DHA in AD patients. The association between higher carotenoids levels and DHA and higher MMSE scores, supports a protective role of both types of nutrients in AD. These findings suggest targeting multiple specific nutrients, lutein, beta-carotene, and DHA in strategies to slow the rate of cognitive decline.

Carlson NE, Moore MM, Dame A, Howieson D, Silbert LC, Quinn JF, Kaye JA. · Division of Biostatistics, Department of Public Health and Preventive Medicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Mail Code CB669 Portland, OR 97239, USA · Neurology. · Pubmed #18046010 No free full text.

Abstract: BACKGROUND: The use of volumetric MRI as a biomarker for assessing transitions to dementia presumes that more rapid brain loss marks the clinical transition from benign aging to mild cognitive impairment (MCI). The trajectory of this volume loss relative to the timing of the clinical transition to dementia has not been established. METHODS: The authors annually evaluated 79 healthy elderly subjects for up to 15 consecutive years with standardized clinical examinations and volumetric brain MRI assessments of ventricular volume. During the study period, 37 subjects developed MCI. A mixed effects model with a change point modeled the pattern of brain volume loss in healthy aging compared with subjects diagnosed with MCI. RESULTS: The brain loss trajectory of subjects developing MCI during follow-up differed from healthy aging in a two-phase process. First, the annual rate of expansion of ventricular volume decreased with age; however, the annual rates of expansion were greater in those who developed cognitive impairment during follow-up compared with those who did not. Further, subjects who developed MCI had an acceleration of ventricular volume expansion approximately 2.3 years prior to clinical diagnosis of MCI. CONCLUSIONS: Ventricular expansion is faster in those developing mild cognitive impairment years prior to clinical symptoms, and eventually a more rapid expansion occurs approximately 24 months prior to the emergence of clinical symptoms. These differential rates of preclinical atrophy suggest that there are specific windows for optimal timing of introduction of dementia prevention therapies in the future.

Ray S, Britschgi M, Herbert C, Takeda-Uchimura Y, Boxer A, Blennow K, Friedman LF, Galasko DR, Jutel M, Karydas A, Kaye JA, Leszek J, Miller BL, Minthon L, Quinn JF, Rabinovici GD, Robinson WH, Sabbagh MN, So YT, Sparks DL, Tabaton M, Tinklenberg J, Yesavage JA, Tibshirani R, Wyss-Coray T. · Satoris, Inc., 2686 Middlefield Road, Suite E, Redwood City, California 94063, USA. · Nat Med. · Pubmed #17934472 No free full text.

Abstract: A molecular test for Alzheimer's disease could lead to better treatment and therapies. We found 18 signaling proteins in blood plasma that can be used to classify blinded samples from Alzheimer's and control subjects with close to 90% accuracy and to identify patients who had mild cognitive impairment that progressed to Alzheimer's disease 2-6 years later. Biological analysis of the 18 proteins points to systemic dysregulation of hematopoiesis, immune responses, apoptosis and neuronal support in presymptomatic Alzheimer's disease.

Li G, Sokal I, Quinn JF, Leverenz JB, Brodey M, Schellenberg GD, Kaye JA, Raskind MA, Zhang J, Peskind ER, Montine TJ. · Mental Illness Research, Education, and Clinical Center and Department of Psychiatry, VA Puget Sound Health Care System, University of Washington, Seattle, WA, USA. · Neurology. · Pubmed #17698783 No free full text.

Abstract: BACKGROUND: Processes of Alzheimer disease (AD) likely begin years prior to the onset of cognitive impairment (latent AD), progress though a prodromal phase of mild cognitive impairment (MCI), and culminate in dementia. While many studies have evaluated CSF tau and Abeta(42) as biomarkers of the dementia or prodromal stages of AD, we are unaware of any study to evaluate these potential CSF biomarkers of latent AD. METHODS: We determined the ratio of CSF tau/Abeta(42) (T/Abeta) using Luminex reagents in 129 control individuals that spanned from 21 to 100 years of age; for comparison we included patients with MCI (n = 12), probable AD (n = 21), or other neurodegenerative diseases (n = 12). RESULTS: We identified 16% of the control group with abnormally elevated CSF T/Abeta; all were 53 years or older. Using age-matched controls with normal CSF T/Abeta we showed that the high CSF T/Abeta subgroup of controls had significantly increased frequency of the epsilon4 allele of the apolipoprotein E gene and significantly increased risk of conversion to MCI during follow-up of up to 42 months suggesting that they had latent AD at the time of lumbar puncture. CONCLUSIONS: These generally applicable methods establish cutoff values to identify control individuals at increased risk of conversion to mild cognitive impairment which may be useful to people weighing the risk-benefit ratio of new preventive therapeutics and to researchers striving to enrich clinical trial populations with people with latent Alzheimer disease.

Bowman GL, Kaye JA, Moore M, Waichunas D, Carlson NE, Quinn JF. · Department of Neurology, Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, OR, USA. · Neurology. · Pubmed #17515542 links to  free full text

Abstract: OBJECTIVE: To determine the stability and functional significance of blood-brain barrier (BBB) integrity in patients with mild to moderate Alzheimer disease (AD). METHODS: Thirty-six patients (mean age 71 +/- 7 years) with mild to moderate AD (Mini-Mental State Examination [MMSE] 19 +/- 5) participated in a biomarker study involving clinical assessments, brain imaging, and CSF and plasma collection over 1 year. BBB integrity was assessed with the CSF-albumin index (CSF-AI). RESULTS: BBB disruption was present in an important subgroup of patients (n = 8/36, 22%) at all time points measured. CSF-AI was highly reproducible over 1 year with an intraclass correlation of 0.96. Age, sex, and APOE status did not correlate with CSF-AI. Vascular factors (blood pressure, Hachinski ischemia score, MR-derived white matter hyperintensity, body mass index) were not strongly associated with CSF-AI levels (p = 0.066). CSF/plasma IgG ratio correlated with CSF-AI in a manner indicating that peripheral IgG has greater access to the CNS in patients with an impaired BBB. Further evidence for the physiologic significance of the CSF-AI was noted in the form of correlations with rates of disease progression, including annual change on MMSE (r(2) = 0.11, p = 0.023), annual Clinical Dementia Rating sum-of-boxes change (r(2) = 0.29, p = 0.001), and annual ventricular volume change (r(2) = 0.17, p = 0.007). CONCLUSIONS: Blood-brain barrier (BBB) impairment is a stable characteristic over 1 year and present in an important subgroup of patients with Alzheimer disease. Age, gender, APOE status, vascular risk factors, and baseline Mini-Mental State Examination score did not explain the variability in BBB integrity. A role for BBB impairment as a modifier of disease progression is suggested by correlations between CSF-albumin index and measures of disease progression over 1 year.

Abdi F, Quinn JF, Jankovic J, McIntosh M, Leverenz JB, Peskind E, Nixon R, Nutt J, Chung K, Zabetian C, Samii A, Lin M, Hattan S, Pan C, Wang Y, Jin J, Zhu D, Li GJ, Liu Y, Waichunas D, Montine TJ, Zhang J. · Applied Biosystems, Framingham, MA, USA. · J Alzheimers Dis. · Pubmed #16914840 No free full text.

Abstract: Biomarkers are needed to assist in the diagnosis and medical management of various neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), and dementia with Lewy body (DLB). We have employed a multiplex quantitative proteomics method, iTRAQ (isobaric Tagging for Relative and Absolute protein Quantification), in conjunction with multidimensional chromatography, followed by tandem mass spectrometry (MS/MS), to simultaneously measure relative changes in the proteome of cerebrospinal fluid (CSF) obtained from patients with AD, PD, and DLB compared to healthy controls. The diagnosis of AD and DLB was confirmed by autopsy, whereas the diagnosis of PD was based on clinical criteria. The proteomic findings showed quantitative changes in AD, PD, and DLB as compared to controls; among more than 1,500 identified CSF proteins, 136, 72, and 101 of the proteins displayed quantitative changes unique to AD, PD, and DLB, respectively. Eight unique proteins were confirmed by Western blot analysis, and the sensitivity at 95% specificity was calculated for each marker alone and in combination. Several panels of unique makers were capable of distinguishing AD, PD and DLB patients from each other as well as from controls with high sensitivity at 95% specificity. Although these preliminary findings must be validated in a larger and different population of patients, they suggest that a roster of proteins may be generated and developed into specific biomarkers that could eventually assist in clinical diagnosis and monitoring disease progression of AD, PD and DLB.

Peskind ER, Li G, Shofer J, Quinn JF, Kaye JA, Clark CM, Farlow MR, DeCarli C, Raskind MA, Schellenberg GD, Lee VM, Galasko DR. · VA Puget Sound Health Care System, Mental Illness Research, Education, and Clinical Center, Seattle, WA 98108, USA. · Arch Neurol. · Pubmed #16831961 links to  free full text

Abstract: BACKGROUND: Decreased cerebrospinal fluid (CSF) beta-amyloid 42 (A beta 42) concentration, but not A beta 40 concentration, is a biomarker for Alzheimer disease. This A beta 42 concentration decrease in CSF likely reflects precipitation of A beta 42 in amyloid plaques in brain parenchyma. This pathogenic plaque deposition begins years before the clinical expression of dementia in Alzheimer disease. Normal aging and the presence of the apolipoprotein E (APOE*4) allele are the most important known risk factors for Alzheimer disease. OBJECTIVE: To estimate the interactive effects of normal aging and presence of the APOE*4 allele on CSF A beta 42 concentration in adults with normal cognition across the life span. DESIGN: The CSF was collected in the morning after an overnight fast using Sprotte 24-g atraumatic spinal needles. The CSF A beta 42 and A beta 40 concentrations were measured in the 10th milliliter of CSF collected by sandwich enzyme-linked immunosorbent assay. The APOE genotype was determined by a restriction digest method.Subjects One hundred eighty-four community volunteers with normal cognition aged 21 to 88 years. RESULTS: The CSF A beta 42, but not the A beta 40, concentration decreased significantly with age. There was a sharp decrease in CSF A beta 42 concentration beginning in the sixth decade in subjects with the APOE*4 allele. This age-associated decrease in CSF A beta 42 concentration was significantly and substantially greater in subjects with the APOE*4 allele compared with those without the APOE*4 allele. CONCLUSION: These CSF A beta 42 findings are consistent with acceleration by the APOE*4 allele of pathogenic A beta 42 brain deposition starting in later middle age in persons with normal cognition.

Siemers ER, Quinn JF, Kaye J, Farlow MR, Porsteinsson A, Tariot P, Zoulnouni P, Galvin JE, Holtzman DM, Knopman DS, Satterwhite J, Gonzales C, Dean RA, May PC. · Eli Lilly and Company, Indianapolis, IN 46085, USA. · Neurology. · Pubmed #16505324 No free full text.

Abstract: LY450139 dihydrate, a gamma-secretase inhibitor, was studied in a randomized, controlled trial of 70 patients with Alzheimer disease. Subjects were given 30 mg for 1 week followed by 40 mg for 5 weeks. Treatment was well tolerated. Abeta(1-40) in plasma decreased by 38.2%; in CSF, Abeta(1-40) decreased by 4.42 +/- 9.55% (p = not significant). Higher drug doses may result in additional decreases in plasma Abeta concentrations and a measurable decrease in CSF Abeta.

Quinn JF, Bussiere JR, Hammond RS, Montine TJ, Henson E, Jones RE, Stackman RW. · Portland Veterans Affairs Medical Center, P3 R&D Portland, OR, United States. · Neurobiol Aging. · Pubmed #16448723 No free full text.

Abstract: Oxidative stress may play a key role in Alzheimer's disease (AD) neuropathology. Here, the effects of the antioxidant, alpha-lipoic acid (ALA) were tested on the Tg2576 mouse, a transgenic model of cerebral amyloidosis associated with AD. Ten-month old Tg2576 and wild type mice were fed an ALA-containing diet (0.1%) or control diet for 6 months and then assessed for the influence of diet on memory and neuropathology. ALA-treated Tg2576 mice exhibited significantly improved learning, and memory retention in the Morris water maze task compared to untreated Tg2576 mice. Twenty-four hours after contextual fear conditioning, untreated Tg2576 mice exhibited significantly impaired context-dependent freezing. ALA-treated Tg2576 mice exhibited significantly more context freezing than the untreated Tg2576 mice. Assessment of brain soluble and insoluble beta-amyloid levels revealed no differences between ALA-treated and untreated Tg2576 mice. Brain levels of nitrotyrosine, a marker of nitrative stress, were elevated in Tg2576 mice, while F2 isoprostanes and neuroprostanes, oxidative stress markers, were not elevated in the Tg2576 mice relative to wild type. These data indicate that chronic dietary ALA can reduce hippocampal-dependent memory deficits of Tg2576 mice without affecting beta-amyloid levels or plaque deposition.

Peskind ER, Riekse R, Quinn JF, Kaye J, Clark CM, Farlow MR, Decarli C, Chabal C, Vavrek D, Raskind MA, Galasko D. · VA Puget Sound Health Care System, Mental Illness Research, Education and Clinical Center (MIRECC), University of Washington School of Medicine, Seattle, WA 98108, USA. · Alzheimer Dis Assoc Disord. · Pubmed #16327349 No free full text.

Abstract: Three hundred forty-two subjects underwent 428 research lumbar punctures for studies of cerebrospinal fluid (CSF) biomarkers. Subjects were 67 Alzheimer disease or mild cognitive impairment (AD/MCI) patients and 275 cognitively normal adults aged 21 to 88. Lumbar puncture was performed in the lateral decubitus or sitting position using the Sprotte 24 g atraumatic spinal needle. Up to 34 ml of cerebrospinal fluid were collected. Anxiety and pain experienced during lumbar puncture were rated on a visual analog scale. The frequency of any adverse event (11.7%), clinically significant adverse events (3.97%), and typical post-lumbar puncture headache (PLPHA) (0.93%) was low. Risk of post-lumbar puncture headache was unrelated to age, gender, position during lumbar puncture, ml of cerebrospinal fluid collected, or minutes of recumbent rest following lumbar puncture. The frequency of post-lumbar puncture headache was lower in AD/MCI (P = 0.03) than any other subject group. Anxiety and pain ratings were low. Younger subjects reported more anxiety than old (P = 0.001) and AD/MCI subjects (P = 0.008) and more pain than older normal subjects (P = 0.013). Pain ratings for women were higher than those for men (P = 0.006). Using the Sprotte 24 g spinal needle, research lumbar puncture can be performed with a very low rate of clinically significant adverse events and with good acceptability in cognitively impaired persons and cognitively normal adults of all ages.

Woltjer RL, Cimino PJ, Boutté AM, Schantz AM, Montine KS, Larson EB, Bird T, Quinn JF, Zhang J, Montine TJ. · Department of Pathology, Division of Neuropathology, University of Washington, Seattle, WA, USA. · FASEB J. · Pubmed #16129700 links to  free full text

Abstract: Biochemical characterization of the major detergent-insoluble proteins that comprise hallmark histopathologic lesions initiated the molecular era of Alzheimer's disease (AD) research. Here, we reinvestigated detergent-insoluble proteins in AD using modern proteomic techniques. Using liquid chromatography (LC)-mass spectrometry (MS)-MS-based proteomics, we robustly identified 125 proteins in the detergent-insoluble fraction of late-onset AD (LOAD) temporal cortex that included several proteins critical to Abeta production, components of synaptic scaffolding, and products of genes linked to an increased risk of LOAD; we verified 15 of 15 of these proteins by Western blot. Following multiple analyses, we estimated that these represent ~80% of detergent-insoluble proteins in LOAD detectable by our method. Abeta, tau, and 7 of 8 other newly identified detergent-insoluble proteins were disproportionately increased in temporal cortex from patients with LOAD and AD derived from mutations in PSEN1 and PSEN2; all of these except tau were elevated in individuals with prodromal dementia, while none except Abeta were elevated in aged APPswe mice. These results are consistent with the amyloid hypothesis of AD and extend it to include widespread protein insolubility, not exclusively Abeta insolubility, early in AD pathogenesis even before the onset of clinical dementia.

Zhang J, Goodlett DR, Quinn JF, Peskind E, Kaye JA, Zhou Y, Pan C, Yi E, Eng J, Wang Q, Aebersold RH, Montine TJ. · Department of Pathology, University of Washington School of Medicine, Seattle, WA 98104, USA. · J Alzheimers Dis. · Pubmed #15851850 No free full text.

Abstract: Biomarkers to assist in the diagnosis and medical management of Alzheimer disease (AD) are a pressing need. We have employed a proteomic approach, microcapillary liquid chromatography mass spectrometry of proteins labeled with isotope-coded affinity tags (ICAT), to quantify relative changes in the proteome of human cerebrospinal fluid (CSF) obtained from the lumbar cistern. Using CSF from well-characterized AD patients and age-matched controls at 2 different institutions, we quantified protein concentration ratios of 42% of the 390 CSF proteins that we have identified and found differences > or = 20% in over half of them. We confirmed our findings by western blot and validated this approach by quantifying relative levels of amyloid precursor protein and cathepsin B in 17 AD patients and 16 control individuals. Quantitative proteomics of CSF from AD patients compared to age-matched controls, as well as from other neurodegenerative diseases, will allow us to generate a roster of proteins that may serve as specific biomarker panels for AD and other geriatric dementias.