The Alzheimer disease center's neuropsychological database initiative

S126

Oral

NASAL AP IMMUNIZATION BURDEN IN PDAPP MICE. Cwthia

A Lemrrr.

Ruth

Mm-i.

Brigham

and

Desai.

Harvard

&iv,

and Women ‘.\ Hmp

Mm-on,

Women’;,

Edward

Hmp

REDUCES

T Spooner,

and

Harvurd

Camhridgr.

MA;

Howard

and Harvard

Med

Sch. Bo.\ton.

AMYLOID-P

Trelawney

Med

J Grenfell,

Sch, Boston.

L Weiner,

Dennis

PROTEIN

MA:

Chica Roanak

J Srlkor,

Brigham

MA

Amyloid accumulatmn and accompanying inflammation play key roles in the pathogen&s of AD. In an effort to reduce the inflammation associated with Apdeposition via mucosal tolerance, we tested the effects of nasal or oral administratton of A@l-40 peptide and a control protein, myelin basic protein (MBP), by treating PDAPP transgenic mice on a weekly basis for 7 mos (ages 5 to 12 mos). Quantitation of Aflimmunoreactivity in brain revealed a substantial (60%) and cignificant (p< I84 0.037) reduction in ADdeposition m mice treated nasally with 25 pg AP/wk as compared with control (untreated and MBP-treated) mice. This reduction was paralleled by a significant decrease in A@42 levels in brain homogenates and was accompanied by decreases in microglial activation and neuritic dystrophy. infiltration of a small number of mononuclear cells immunoreactive for anti-inflammatory cytokines IL-4, IL-IO and TGFP, and a strong humoral antiAPantibody induction in serum. These anti-A@mtibodies: 1.show human AD plaque immunoreactivity and are specific for A@ 2. are of IgGl and IgGZb isotypes; 3. have immunodominant epitopes within the first 15 residues of AP: and 4. have serum concentrations as high as 26 kg/ml as determined by ELISA. Our result? are consistent with those of Schenk et al (Nature, 1999), but use a novel route of A@administration. The data suggest that chronic nasal APimmunization can alter AD neuropathologic processes and could be useful in its prevention and treatment. Currently, we are comparing nasal, IP and a combined APimmunization protocol in two strains of non-tg mice. Preliminary results indicate that in response to APimmuniration, B6D2FI mice produce anti-Apantibodies earlier and in greater quantities than do C57BL6 mice. In addition. combining nasal Apadminiwation wth IP A~injection led to mcreawl antibody production.

EARLY-ONSET AMYLOID DEPOSITION IN TGCRNDB MICE EXPRESSING A MUTANT AMYLOID PRECURSOR PROTEIN TRANSGENE (APP,,,KM670/671NL +V717F)

SEEDING OF P-AMYLOIDOSIS IN PAPP-TRANSGENIC BY THE INTRACEREBRAL INJECTION OF ALZHEIMER EXTRACT lrrry C Wnlkrr. Durhrrm, Koher.

Wiilinm

Roy D Srhwurt:, Loborutlrmy

Pork+Duus

J Llpinski.

Mirhuel

Parke-Davis

Phorm

f~wAl:heirner’s

Phrrnn

Rewxwh

Disrrrse Div.

Am

J Calluhun. Research

Research.

Arbor,

F’eng

Bian,

Div. Ann Arbor,

MICE BRAIN

Rohrrt MI;

Sun City, AZ; Michael

A

Alex E 11 Kane.

MI

A variety of neurodegeneratw dtsorderr are now known to involve the misfolding and abnormal aggregation of specific protein? in the brain. Allhelmer’s disease (AD)

Clinic&

Research

II

and cerebral P-amyloid angiopathy are marked by the copious deposition of APin the parenchyma and vasculature of the brain, but the events that initiate e-amyloidosis in vivoremain unknown. Because amyloid polymenzation tends not to occur below a critical concentration of the amyloidogenic protein, we reasoned that mxe overexpressing the human pAPP gene would be an advantageous model for testing the hypothesis that cerebral P-amyloidosis can be accelerated by the intrxerebral injection of AD-brain extract. Dilute (1%) extracts of autopsy-derived neocortical samples from four cases of AD, one age-matched control with mild P-amyloidosis, and one young control were injected unilaterally into the hippocampus and neocortex of 3-month-old Tg2576 (Hsiao) PAPP-transgenic mice and into age-matched, wild-type littermate controls. Five months later, the brains were analyzed immunohistochemically for Apdeposition. At this age (8 months), which precedes the normal appearance of ADdeposits in Tg 2576 mice. diffwe and compact parenchymal and vascular deposits of APwere found in the AD-tissue-injected hippocampuq and neocortex of Tg2576 mice. Mice analyzed at 5 days, 2 weeks and 4 weeks post-infusion had no Abdeposita, suggesting a lag-phase. Injection of age-matched control brain extract induced only very limited Apdeposition in Tg2576 mice. There was no APimmunoreactivity in uninjected, saline-injected, or young control extractinjected Tg2576 mice, nor m any wild-type mu. The results show that senile plaque\ and cerebral amyloid angiopathy can be seeded in viva by a single injection of dilute AD brain extract, demonstrating a key pathogenic commonality between ADamyloidosis and other neurodegenerative diseases involving abnormal protein polymerization. This experimental paradigm can be employed to clarify the conditions that initiate amyloidogenesis in viva, and may also yield animal model, that more faithfully replicate the pathology of Alzheimer’s disease and other cerebral proteopathies.

p&J

WITHDRAWN

Oral Presentation:

piJ Michuel

We have created a novel line of transgemc (Tg) mice with very early-onset Alzheimer Disease (AD) related pathology. A wan&gene was constructed by inserting an APP695 cDNA encoding a compound mutant form of thi\ protein (KM670N/67lNL + V7 l7F) into the cos.Tet prion promoter expression vector. Microinjectlons were carried out in two genetic background\, C57BLh/C3H and FVB/N x 129s~. which are believed to protect agaimt the toxic effects of APP overexpression. Though we have yet to isolate high copy-number tramgenes from the FVB/N x 129S.v background, the TgCRNDX line expressing high levels of APP was established in a hybrid C57BL6/ C3H background. Abis readily detectable in the brains of TgCRND8 mice by conventional western blotting, from 120 days onwards. Amyloid plaques can be detected in the cortex and hippocampus by immunohistochemistry from 60 days, with tlorid deposits prewnt at thic timepoint when the APP transgene is co-expressed with familial Alzheimer Disease mutant alleles of either PSl or PS2. Abplaques in young mice are of the immature type. Congophilic and birefringent Abdeposits been in older animals, although neurofibrillary tangles have yet to be detected. Plaque deposition is attenuated by repeated immunization with Abl-42 peptide. though significant depostts rtill remain in animal\ treated on a monthly basin for 4-6 months. TgCRNDX mice exhibit postnatal lethality, such that - 40% of mice die by pwtnatal day LOO. Lastly, TgCRND8 mice display cognitive deficit!, in the water-maze paradigm, a\ dexribed elsewhere. TgCRNDX mice may comprise a useful platform to decipher the impact of amylold deposition and amyloid~directed therapeutics on neuronal and cognitive function.

Presentation:

Clinical

Research

THE ALZHEIMER DISEASE CENTERS’ CAL DATABASE INITIATIVE Gvundmun.

Univ

of CA, La Jolla,

II

NEUROI’SYCHOLOGI-

CA

Prevention of Alzheimer’s dtsease (AD) is necessary if we are to forestall the huge economic and societal burden that is predicted to occur due to AD over the next 50 years. Randomized. double-blind, placebo-controlled trials to prevent AD in normal elderly individuals are likely to prowde the beat evidence that a putative agent is effective. A problem with current prevention studies is the expense associated with the large number of subjects and the long trial duration that is required. This occurs because of the relatively low conversion rate to AD in the normal elderly population over the time course of a clinical trial. Since MCI (Mild Cognitive Impairment) is known to be a significant risk factor for the development of AD, other trial design\ that might be useful are MCI prevention trials or trials utilizing cognitive decline as the primary endpoint. To plan such trials, the Neuropsychological Database Initiative was funded by the Natmnal Institute on Aging to enable sixteen Alrheimer Disease Centers to pool neuropsychological and diagnostic data collected from approximately 4000 normal elderly individuals into a common database. At baseline, the cohort had a mean age of 72.7 (62% women), a mean education of 15.0 years, a mean MMSE score of 2X.5 and a mean delayed paragraph recall score (Logical Memory II from the WMS-RI of 18.X (approximately the 75th percentile for normals in this age group). After 4 years of follow-up only 2% developed a diagnosis of AD whereas 10% developed MCI. These findings suggest that a diagnosi\ of MCI would he a more

Oral Presentation:

Clinical

Reseurch II

S127

frequent endpoint than AD in prevention trials lasting several years and that MCI prevention trials could be performed with fewer participants than those utilizing AD as the primary endpoint. The Neuropsychological Database Initiative is further investtgating the utility of early cognitive decline on specific neuropsychological measures to determine which, If any, might also be useful surrogate endpoints for AD prevention trials.

THE

LONGITUDINAL

MENT

BASIS

OF

MILD

COGNITIVE

IMPAIR-

(MCI)

A cohort of 88 patients dlagno\ed with MCI wab retested using the same neuropsychological tat battery one-year after previous testing. Working on the hypothesir that MCI (as defined m the European Consensus Guidelines) is on a continuum with Alzheimer’s Disease) AD, the results showed a 32% conversion to a diagnosis of possible/probable AD, and a worsening as measured by the battery in a further 40% of cases. Of those that remained stable, the history in some suggested possible vascular aetIology and in others was not suggestive of AD, m terms of fulfilling the newer guidelines. The results lend support to the assumption that MCI is, in fact. pre-Abheimer’s Disease. As the prevalence of MCI iE estimated at 18.35% (Callaham, 199.5) of over 65 s, this is an important area to target. Memory Clinics in particular, need to focus on these groups as well informed patients and carers may expect a better prognosis and exposure to treatment modalities.

HETEROGENEITY WITH Nmla

MILD

IN CEREBRAL

COGNITIVE

T Lautenschlager,

Alexrznder

Grrmuny;

Satoshi Minoshima,

Alcrartdrr

F Kurt,

Univ

METABOLISM

IMPAIRMENT: Drzrzp.

of Michigan.

Tech Univ Muenchrn,

Tech

Univ

Ann Arbor,

Mum&n

IN PATIENTS

A PET STUDY. Muenchen.

Murnchen

MI; Markus Schwaigw,

Germun~

Objectives: To investigate cerebral metabolism using functional brain imaging in patients with a clinical diagnosis of mild cognitive impairment (MCI) and its relation to the outcome at one-year follow-up. Methods: Patients were recruited at a university outpatient research center. MCI was diagnosed according to the criteria suggested by Petersen et al. At baseline they underwent dedicated lXF FDG PET. PET data were analyred using a brain mapping technique (3D-SSP, NEUROSTAT) that performs pixelwiw comparison to stereotactically normalized individual PET image sets to o normal database. Metabolic activity maps and Z-score maps, depicting area\ of hypometabohsm. were evaluated visually and quantitatively (with 22 predefined ROI’S). Patients were clinically reevaluated one year later. Results: 36 patients (21 m&5. I5 female\) entered the study. The mean age at examination was 68.97 (47-X4 years). 19% chowed a metabolic pattern consirtent with early AD, 17% revealed isolated hut significant metabolic abnormalities such a~ hypometaholism of posterior cingulate region, 17% showed hypometaholic change\ in AD-typical regions but Z-scores were not stgnificant. 2 patient? had multi-focal discrete abnormalities, 3 subjects showed frontal-dominant metabolic reductions and 33% had no definite metabolic abnormalities. Follow-up data are available on I7 patients, IO of whom converted to dementia. 6 out of 10 c~n~etters showed AD-typical hypometabolism at baseline. Of the remaining 4 converte~b 3 had abnormalities in the posterior cingulate region and one had no definite metabolic abnormality. Among the 7 patients who did not convert 2 had no metabolic abnormality, 3 showed non-significant metabolic changes in AD-typical regions, and 2 showed a dominant metabolic reduction in the frontal lobe. Conclusions: Patients with clinically diagnosed MCI show heterogeneous cerebral metabolic findings. One third have AD-typlcal patterns. Out of IO patients who converted to dementia to date 90% show AD-typical patterns. ‘The number of patients is still very small to this ongoing study, but the measurement of cerebral mrtahoh\m may have predictive value in patients with MCI.

CLINICAL 15741DEMENTIA

AND IMAGING IN A MEMORY

CHARACTERISTICS

OF VASCULAR

CLINIC

Background : Vascular dementia (VaD) is a preventable dementia due to various cerebrovascular pathology. Design : From a prospectively constituted standardized database, we studied demographic, clinical, and imaging data in patients with possible or probable VaD first attending the Lille memory clinic between 1992 and 1997. We compared three sets of diagnostic criteria : DSM-IV, NINDS-AIREN, and ICD-IO research critena. Cerebral atrophy. white matter changes, and focal lesions were rated on CT and MRI scans with reference scales. Results : Of 306 patients with clinical diagnosis of VaD, imaging was available in 208. Of these 208 VaD cases. 87% tulfilled the DSM-IV critena. 258 the ICD-IO criteria. and 27% the NINDS-AIREN

criteria; 13% had vascular cognitive impairment not wvere enough to meet DSM-IV criteria of dementia. Menwomen ratio was 0.55. At first visit, mean (standard deviation) age war 72(7.5) years, duration of the disease was 3.7 (3.5) years, and Mini Mental Status examination score was 22 (6). Clinical onset wasprogressive in 62%. acute in 29%, subacute in 9%. Course was progressive in 47%. fluctuating in 22% stable in 16%. stepwise in 12%. and showed improvement in 3%. Previous history of stroke was reported in only 39%. Death occured in 21% of patients during the follow-up period (mean 3 years).White matter changes were ohserved m 94%, and focal lesions in 75%. White matter changes wtthout focal lesions were observed in 25%. Lacunar Infarcts were present in 64%, terrltortal infarcts in 26% and hemorrhages in 3%. Conclusions : Bettercharacterization of patients with VaD attending a memory clinic is desirable for assessing treatment efficacy. Traditional VaD criteria exclude patients with vascular cognitive impaimlent at the beginning. The concept of VaD should be extended to include patients with vascular cognitive impairment wthout dementia.

PLASMA

AND

CEREBROSPINAL

OF HOMOCYSTEINE MER’S

FLUID

ARE INCREASED

CONCENTRATIONS

IN SPORADIC

ALZHEI-

DISEASE.

Homocysteine (HCY) is a sulphurated amino acid that has heen recently recognized as an Independent risk factor for cardiovascular disease and it has been also proposed as a possible risk factor for cerebrovascular disease and Alzheimer Disease (AD). Low dietary intake vitamin 812, B6 or folic acld can cause an increase in HCY concentration in plasma. In order to evaluate the possible role of this amino acid in sporadic AD (SAD) and in familial AD (FAD) we have performed a cawcontrol study on 92 indwiduals: 63 definite AD (55 SAD and 8 FAD) and 28 control subjects (C). All indtviduals were exammed and had a neuropathologic characterization according to the CERAD protocol. HCY concentratxxx were performed by HPLC on plasma samples and on cerebrospinal fluid (CSF). ApoE genotype was evaluated after Hhal digestion of PCR amplified apoE genomic DNA. ApoE carriers had slightly higher lewls of HCY both in plama and in CSF as compared uith apoE carrots. Subjects with more severe forms of SAD had higher plasma levels of HCY. In summary htgher HCY level is not a phenomenon generally associated with AD, but appeara to be associated only with sporadic AD. HCY concentration is mcreaxd both 111plasma and m CSF and the ratio is similar in all the groups of the wdy. In conclusion these results are consl\tent with the hypothesis that HCY can be regarded a a possible environmental risk factor for SAD.

HCY concentrations

Total

FAD SAD C

AD

in plasma

and CSF

Plasma-HCY

CSF-HCY

P/CSF ratio

10.9 k 3.7 8.4 + 1.6 11.5 + 3.9” 9.7 + 2.6

0.11 i- 0.10

125.7 -t 67.0 96.9 i- 38.6 131.3 -t 70.4 119.8 5 47.1

0.08 + 0.04 0.12 -’ 0.1 1

0.09 2 0.05

Mean -C SD. Values are expretsed in FM. * SAD vs. FAD p = 0.01 (Mann Whitney test)