Poster Presentations: P1P226

P1-201 COMPOUNDS IN EXHALED AIR FOR THE

DETECTION OFALZHEIMER’S DISEASE

Jan-Philipp Bach1, Maike Gold2, Akira Hattesohl2, Dirk L€ubbe3,

David Mengel2, Severin Schmid2, Bj€orn Tackenberg2, J€urgen Rieke2,

Sasidhar Madulla4, J€org Ingo Baumbach4, Joan Michelis5, Judith Alferink6,

Wolfgang Oertel2, Frank Jessen7, Claus Vogelmeier2, Richard Dodel2,

Rembert Koczulla2, 1Philipps University of Marburg, Marburg, Germany;2Philipps-University of Marburg, Marburg, Germany; 3University of

Giessen, Giessen, Germany; 4B&S Analytik, Dortmund, Germany;5University of Bonn, Bonn, Germany; 6University of M€unster, M€unster,

Germany; 7University of Bonn, Department of Psychiatry, Bonn, Germany.

Contact e-mail: goldm@staff.uni-marburg.de

Background:Alzheimer’s disease (AD) is a chronic neurodegenerative dis-

order that mainly affects elderly people. Diagnosing AD on clinical grounds

is difficult; as a result, surrogate markers have been extensively investigated.

The measurement of amyloid-beta (Ab), tau-protein and phosphorylated

tau-protein in cerebrospinal fluid has become an established biomarker in

fluids for the diagnosis of AD; however, a classification function is required,

and the specificity is rather low. Novel pulmonary diagnostic tools have been

applied to identify patients with lung cancer and asthma, including an elec-

tronic nose device (eNose) and ion-mobility spectrometry (IMS). In this

study, we introduce these techniques to the field of Alzheimer’s disease.

Methods: We used two non-invasive methods to discriminate betweenAD

patients and healthy controls -an eNose and IMS using exhaled breath or ex-

haled breath condensate. Exhaled breath condensate was also analyzed for

different Ab species as well as tau-protein and phosphorylated tau-protein

were analyzed using ELISA. Furthermore we analyzed human lung tissue

for Ab species applyingMSD-ELISA andWestern-Blot.Results:By apply-

ing IMS we identified several substances that enable the differentiation be-

tween healthy control and AD patients with both a high sensitivity and

specificity (81 % and 95 %, respectively). Furthermore, we identified Ab

species in the lung tissue of healthy controls and within the exhaled breath

condensate in both groups; however, no significant differences within the

groups were detected. Conclusions: These data may open a new field in

the early diagnosis of AD. In addition, the technique might be suitable for

clinical studies. Further research is required to evaluate the significance of

these pulmonary findings in relation to the pathophysiology of AD.

P1-202 DYNAMIC OPTICAL IMAGING OFA CLEAVABLE

CPP-BOUND DUAL NIR FLUORESCENT/MRI

PROBE TARGETING CATHEPSIN D

Table 1

Demographics

All M+

(n¼19)

PSEN1

(n¼6)

APPswe

(n¼9)

APParc

(n¼4)

All M-

(n¼17)

Age (SD) 46,7 (11,9) 33,7(7,0) 51,2 (12,1) 50 (6,6) 47,8 (10,2)

Years to

onset (SD)

-7,7 (12,3) -21,3 (7,0) -1,8 (12,1) -7 (6,6) -6,9

ApoEε4

carrier

9/19 3/6 5/9 1/4 7/17

Normal

cognition

13/19 5/6 4/9 4/4 17/17

MCI 3 1 2 - -

AD 3 - 3 - -

Jonatan Snir1, Mojmir Suchy1, Alex X. Li2, Keith St. Lawrence3,

Robert H. E. Hudson4, Stephen Pasternak5, Robert Bartha1, 1Robarts

Research Institute (UWO), London, Ontario, Canada; 2Robarts Research

Institute (UWO), London, Ontario, Canada; 3Lawson Health Research

Institute, London, Ontario, Canada; 4Western University (UWO) Chemistry

Department, London, Ontario, Canada; 5Western University (UWO),

London, Ontario, Canada. Contact e-mail: jsnir@robarts.ca

Background:Cathepsin D (CatD) is a lysosomal protease found in elevated

levels in Alzheimer’s disease (AD) and is a potential biological marker. We

have developed a contrast agent to detect CatD, consisting of an MRI/fluo-

rescent moiety linked to a cell penetrating peptide (CPP) bymeans of a CatD

cleavage site. In fixed time-point experiments, this agent is preferentially

taken up in transgenic AD animals compared to controls. The purpose of

this pilot study is to characterize the in vivo performance of a Near Infra-

Red (NIR) labelled version of this CA in live animals. Methods: Six adult

C57Bl/6 wild-type (WT) mice and six adult 5XFAD transgenic mice (AD)

were studied using a GE eXplore Optix pre-clinical whole animal imager

(excitation/collection at 780/845 nm) prior to and following CA administra-

tion (5 nmol). To examine the CPP contribution to signal, a version of the

CA lacking the CPP and CatD targeting site was also studied in adult WT

mice (N¼6). The optical signal decay rates (attenuation coefficient l 1hr)

of the washout curve for the first hour after peak enhancement was deter-

mined by linear regression (R 2 �0.9). A student’s t-test was used to com-

pare groups (p<0.05 considered significant). Results: In WT mice, the

washout of the CA that included a CPP domain was much slower (l 1hr

¼ -0.516 0.13 sec -1) than the washout of the CAwithout the CPP domain

(l 1hr¼ -1.056 0.35 sec -1 , p<0.05). The washout of the CA that included

a CPP domain was even slower in the ADmice (l 1hr¼ -0.336 0.13 sec -1)

compared to the WT mice (p¼0.05). The data suggest that evaluation of the

CA enhancement withinw1 hour post maximum fluorescence signal could

allow differentiation between the AD andWTmouse models.Conclusions:

This pilot study demonstrates prolonged retention of a contrast agent target-

ing CatD conjugated to a CPP within brain tissue leading to a slower wash-

out. Furthermore, a differential washout of this CatD agent was observed

between AD and WT mice up to one hour after the maximum uptake.

P1-203 THE EFFECTS OF GENE MUTATIONS ON THE

CEREBROSPINAL FLUID LEVELS OF SOLUBLE

AMYLOID PRECURSOR PROTEINS IN FAMILIAL

ALZHEIMER’S DISEASE

Steinunn Thordardottir1, Anne Kinhult-St�ahlbom1, Ove Almkvist1,

Maria Eriksdotter Jonhagen2, Henrik Zetterberg3, Kaj Blennow3,

Caroline Graff4, 1Karolinska Institute, Huddinge, Sweden; 2Karolinska

Institute, Division of Clinical Geriatrics, Stockholm, Sweden; 3Sahlgrenska

Academy, University of Gothenburg, M€olndal, Sweden; 4Karolinska

Institute, Huddinge, Sweden. Contact e-mail: steinunn.thordardottir@

karolinska.se

Background: The amyloid precursor protein (APP) is processed either by

a -secretase in a nonamyloidogenic pathway, generating sAPP a, or in an

amyloidogenic pathway where BACE1 cleaves APP releasing sAPPb. Stud-

ies have shown that sAPP a and sAPPb are unaltered or mildly elevated in

MCI and sporadic AD. We compared the levels of sAPP a and sAPPb be-

tween carriers of mutations leading to familial Alzheimer disease

(PSEN1, APPswe and APParc) and non-carriers from the same families.

Methods:Cerebrospinal fluid samples were collected from a total of 36 sub-

jects, 6 PSEN1 mutation carriers, 9 APPswe carriers, 4 APParc carriers and

17 non-carriers (table 1). Concentrations of sAPP a and sAPPb were deter-

mined using the MSD sAPP a/sAPP bMultiplex assay (Meso Scale Discov-

ery, Gaithersburg, Maryland, USA). The levels of sAPP a and sAPPb in

mutation carriers (M+) and non-carriers (M-) were compared using the

Mann-Whitney U-test. Results: When comparing all mutation carriers

with non-carriers, or PSEN1 carriers with non-carriers, there was no signif-

icant difference in the levels of sAPP a or sAPPb. The carriers of the

APPswe mutation however had significantly lower levels of both sAPP

a and sAPPb compared to the non-carriers and the APParc carriers had sig-

nificantly higher levels of sAPP b than the non-carriers. There was no cor-

relation between sAPP a or sAPPb levels and years to expected disease

onset in any of the groups. Conclusions: Autosomal dominant mutations

leading to familial Alzheimer disease can be associated with high or low

levels of sAPP a and sAPP b, depending on the specific mutation. The lower

sAPPb levels in APPswe mutation carriers are expected as the mutation de-

stroys the neo-epitope recognized by the capturing antibody in the sAPP