Upload
vandang
View
215
Download
0
Embed Size (px)
Citation preview
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
1The screen versions of these slides have full details of copyright and acknowledgements
1
Biomarkers for Alzheimer’s Disease
Henrik Zetterberg, MD, PhDProfessor of Neurochemistry
The Sahlgrenska Academy, University of Gothenburg
2
Alzheimer’s disease
3
Neurofibrillary tangles
Neuropathological criteriafor Alzheimer’s disease
Senile plaques
General neuronal loss
Modified from: Blennow et al., Lancet 2006
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
2The screen versions of these slides have full details of copyright and acknowledgements
4
Distribution of brain changesin Alzheimer’s disease
Mild cognitive impairment
Mild dementia Moderate dementia
Severe dementia
5
Molecular pathology
• Senile plaques are composed of a 42 amino acid long aggregation-prone protein called amyloid b 42 (Ab42)
• Neurofibrillary tangles are composed of hyperphosphorylated isoforms of the intraaxonal protein tau (P-tau)
• Neuroaxonal degeneration is reflected by release of intraaxonal tau proteins (all isoforms, total-tau; T-tau)into the brain interstitial fluid that communicates freely with CSF
6
Brain
Proximity to disease
Accessibility
Concentration of analyte
Proteolytic degradation
BloodCSF
Choosing the sample for biomarker analysis
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
3The screen versions of these slides have full details of copyright and acknowledgements
7
Cerebrospinal fluid
Total volume 150 mL, production rate 20 mL per hourStandard volume of sampling, 10-12 mL
Epidural vein
ChoroidPlexus
Choroid Plexus
Choroid Plexus
Circulation of CSF CSF in gray,
Venous blood in orange
8
Is lumbar puncture dangerous?
No. of cases: 395Post LP headache: 2.1 %Meningitis / hematoma: 0
No. of cases: 241Post LP headache: 4.1%Meningitis / hematoma: 0
Andreasen et al., 2001
No. of cases: 342 (428 LP)Post LP headache: 0.9 %Meningitis / hematoma: 0
Peskind et al., 2005
Consecutive studies on complications after LP
No. of cases: 1089Post LP headache: 2.6 %Meningitis / hematoma: 0Zetterberg et al., Eur Neurol, 2010
Blennow et al., 1993
9
Core CSF biomarkersfor Alzheimer’s pathology
Senile plaquesAb42
Neurofibrillary tanglesP-tau
Axonal injuryT-tau
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
4The screen versions of these slides have full details of copyright and acknowledgements
10
CSF biomarkersfor Alzheimer’s pathology - candidates
InflammationCell count
IgG/IgM productiona1-ACT, MCP-1, TNF-a, TGF-b
Oxidative stressF2-isoprostanes
Blood-brain barrier damageCSF/serum albumin ratio
Amyloid pathologyAb42 / Ab40
b-sAPP / a-sAPPBACE1 activity
Neurofibrillary tanglesP-tau
Axonal injuryT-tau
11
Different uses of biomarkers in the evaluation of patients with memory problems
1. To diagnose neuroinflammatory and neuroinfectious conditions CSF cell count
Albumin ratio
Intrathecal IgG and IgM production
Specific inflammatory markers
2. Specific markers of AD neuropathology
T-tau, P-tau and Ab42 as supporting diagnostic markers in the clinic
T-tau, P-tau and Ab42 as additional inclusion criteria in studies of anti-AD drugs
3. Specific markers for drug effect monitoring Reduced levels of T-tau after treatment indicate less intense axonal degeneration
12
CSF biomarkers for AD: Ab1-42
a-secretase Plasmamembrane
g-secretase
b-secretase BACE1
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
5The screen versions of these slides have full details of copyright and acknowledgements
13
Study design: • Consecutive AD cases from a community-based sample• AD (n=53), healthy controls (n=21)
CSF biomarkers for AD: Ab42
Andreasen et al., Arch Neurol 56: 673, 1999
AD Controls
CS
F-Ab
42
0
500
1000
1500
2000
2500 Sensitivity 92%Specificity 95%
14
Data adjusted for:• Age at death
• Education
• Dementia severity
• ApoE4
• Time from diagnosis until death
• PM interval
• Time until Ab42 analysis
• CAA severity
Plaque count
CSF
-Ab42
(pg/
mL)
0 5 10 15 200
20
40
60
80
Non-dementedDemented
Strozyk et al. Neurology 60: 652-656, 2003
Study design:• 155 autopsy cases• Plaque counts - Bielschowsky stain of neocortex and hippocampus• Post-mortem CSF samples
CSF Ab42 reflects plaque pathology
15
CSF Ab42 reflects plaque pathology (2)
General idea verified in PIB-PET studies:• Negative correlation between CSF-Ab1-42 and PIB retention in the brain
Fagan AM et al., Ann Neurol 2006Forsberg A et al., Neurobiol Aging 2008
Posterior cingulum
PIB
(RO
I/ref
)
Ab1-42
MCI non-converters MCI converters
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
6The screen versions of these slides have full details of copyright and acknowledgements
16
Diagnostic value
>100 papers
High total-tau and phospho-tau and low Ab1-42 in CSF =
85-95% sensitive and specific for AD in AD-control and longitudinal MCI studies
17
Comb. of Ab42/P-tau and T-tau:
• Sens. for MCI-AD 95%
• Spec. against other MCI 87%
Prediction of incipient ADin MCI cases using CSF biomarkers
Hansson et al., Lancet Neurol 2006
Study design: • Follow-up study on MCI (>4 years)• Lumbar puncture and analysis of Aβ42 and variants of tau in CSF• MCI n=134 57 MCI → AD
56 MCI → MCI21 MCI → other dementias
Months
18 Buchhave et al., Arch Gen Psychiat 2012
Combination of Ab42/P-tau and T-tau:• T-tau > 350 pg/mL• Ab42 / P-tau ratio < 6.5
• Sens. for MCI-AD - 88%• Spec. non MCI-AD - 94%
• PPV - 94%• NPV - 89%
Prediction of AD within 10 yearsin patients with MCI
Cum
sur
viva
l
Time under risk for AD (months)
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
7The screen versions of these slides have full details of copyright and acknowledgements
19
CSF biomarkers for Alzheimer’s disease –diagnostic performance in a homogeneous
mono-center population, 2010
• AD patients: n=32
• Stable MCI: n=13
• Other dementias: n=15
• Controls: n=20
Johansson P et al., Journal of Alzheimer's Disease 24(3): 537-546, 2011
Sens
itivi
ty%
100% - Specificity%
20Sensitivity 83% Specificity 88%
Ab42
/P-ta
u 181
ratio
MCI-AD vs. controls MCI-AD vs. stable MCI + MCI-other
CSF T-tau (ng/L)
Sensitivity 83% Specificity 72%
Mattsson et al., JAMA 2009
Prediction of incipient AD in MCI cases using CSF biomarkers in a multi-center study
Ab42
/P-ta
u 181
ratio
CSF T-tau (ng/L)
21
The Alzheimer’s Association QC programfor CSF biomarkers
• Goal 1 - Establish a standardized protocol for lumbar puncture and CSF processing
• Goal 2 - Monitor analytical variability
• Goal 3 - Establish a detailed protocol for laboratory proceduresfor AD CSF biomarkers
• Goal 4 - Improved quality and stability of assays
Please sign up if you perform Alzheimer biomarker analyses: [email protected]
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
8The screen versions of these slides have full details of copyright and acknowledgements
22
Can CSF markers predict development of ADin pre-symptomatic individuals?
Study design:• Population-based study, 55 healthy individuals
• LP at baseline, mean age 72
• Follow-up 8 years later: 45 remained normal, 10 AD with dementia or drop in MMSE > -5
Gustafson et al., JNNP 2007
Normal →Dementia/
MMSE drop
0
200
400
600
800
1000
1200
p = 0.006 r = 0.40 p< 0.05
Change in MMSE
Bas
elin
e C
SF
Ab42
-12 -9 -6 -3 0 3
1400
1200
1000
800
600
400
Normal →Normal
Bas
elin
e C
SF
Ab42
23
Can CSF markers predict development of ADin pre-symptomatic individuals? (2)
Study design:• Clinical study on 57 healthy elderly individuals
• LP at baseline
• Follow-up during 3 years
Stomrud et al., Dement Geriatr Cogn Disord 2007; 24: 118-124
CSF Ab42 is lower in healthy elderly who will develop cognitive disurbances
Subjective memory impairment affecting quality of life (memQoL) at follow-up
No YesNo YesNo Yes
24
Can we measure Ab oligomers in CSF?
Xia W et al., Arch Neurol. 2009 Feb; 66(2): 190-9Fukumoto H et al., FASEB J. 2010 Aug; 24(8): 2716-26
Y
Y
Abet
a
Y
YAb
eta
Abeta
Epitopeblocked
= 82E1, N-terminus-specific MAbY= biotin= avidin-HRP = chemiluminescent substrate
Abeta = b-Amyloid
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
9The screen versions of these slides have full details of copyright and acknowledgements
25 Hölttä et al., in preparation
Can we measure Ab oligomers in CSF? (2)
Controls AD
Con
c pg
/mL
Oligomer in-house assay
P<0.0001
26
Are CSF biomarkers dynamic?
27 Zetterberg et al., Arch Neurol 2006
Are CSF biomarkers dynamic? (2)
After a Bout (7-10 d)
After Rest (3 mo)
After a Bout (7-10 d)
After Rest (3 mo)
After a Bout (7-10 d)
After Rest (3 mo)
Glia
l Fib
rilla
ry A
cidi
c P
rote
in, n
g/L
Tota
l Tau
, ng/
L
Neu
rofil
amen
t Lig
ht P
rote
in, n
g/L
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
10The screen versions of these slides have full details of copyright and acknowledgements
28
AD drug development
29
If you are interested in details of this, please read:
Zetterberg, H. et al., (2010) Alzheimers Res Ther 2(6): 32
30
Biomarkers in studies of inhibitionof Ab aggregation
Change from Baselineat Week 12
CS
F A
b 42(p
g/m
L)C
SF
Ab 4
0(p
g/m
L)
Trial design:• Randomized, double-blind,• placebo-controlled, parallel study• 12 weeks oral treatment
with 0 mg (placebo), 50mg and 250mg of PBT-2
CS
F A
b 40(p
g/m
L)C
SF
Ab 4
2(p
g/m
L)
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
11The screen versions of these slides have full details of copyright and acknowledgements
31
CSF biomarkers in active Ab immunotherapy trials
Gilman S, et al. Arch Neurol 2005
• Reduction with treatment (in antibody reponders) on the downstream biomarker T-tau
• No clear effect on b-amyloid (Ab42)
Placebo Placebo Antibody responders
Antibody responders
CSF Ab42 CSF T-tau
Cha
nge f
rom
bas
elin
e (pg
/mL)
Cha
nge f
rom
bas
elin
e (pg
/mL)
CSF substudy in the AN1792 trial (active β-amyloid immunization)• Paired CSF samples (baseline and 1 year) from AD cases:
antibody responders n=11, placebo n=10
32
CSF biomarkers in passive Abimmunotherapy trials
Blennow, Zetterberg et al. Arch Neurol 2012
Phase II bapineuzumab trials:• CSF samples from 27 bapineuzumab and 19 placebo cases
• CSF samples taken at baseline and 1 year
p=0.0013
CSF T-Tau
Cha
nge
at W
eek
54 (p
g/m
l)
-150
-100
-50
0
50
100
CSF P-Tau
Cha
nge
at W
eek
54 (p
g/m
l)
-15
-10
-5
0
5 p=0.027
p=0.0305
Bapineuzumab Placebo Bapineuzumab Placebo
CSF Ab1-42
Cha
nge
at W
eek
54 (p
g/m
l)
Bapineuzumab Placebo -30
-20
-10
0
10
20
Cha
nge
a t W
eek
54 (p
g/m
l)
0
50
100
150
p=0.0159
Cha
nge
at W
eek
54 (p
g/m
l)
-600
-400
-200
0
200
400
600
Bapineuzumab Placebo Bapineuzumab Placebo
CSF Abx-42 CSF Ab1-40
33
Phase III clinical trails on bapineuzumab
Sperling R, presented at EFNS 2012
Phase III bapineuzumab APOE e4 trial:• Multicenter, randomized, double- blind, placebo-controlled trial
• Mild-moderate AD (MMSE 16-26)
• Bapineuzumab n=658
• Placebo n=432
Main outcome: change in ADAS-Cog over 18 months
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
12The screen versions of these slides have full details of copyright and acknowledgements
34
CSF biomarkers in the Phase III bapineuzumab trial
Sperling R, presented at EFNS 2012
Phase III bapineuzumab APOE e4 trial:• Multicenter, randomized, double- blind, placebo-controlled trial
• Mild-moderate AD (MMSE 16-26)
• Bapineuzumab n=658
• Placebo n=432
Secondary outcome: change in CSF phospho-tau over 18 months
35
The current situation in AD drug development:
• Promising biomarker changes but no clinical benefit
• Too little, too late?
• Studies on preclinical AD needed
• Are we missing something?
36
Summary
• CSF biomarkers can monitor the neuropathology of AD:– T-tau is a marker of cortical axonal degeneration
– P-tau is a marker of neurofibrillary tangle pathology
– Ab1-42 is a marker of plaque pathology
• These markers have high diagnostic accuracy and have been implemented in the recently revised clinical criteria for Alzheimer’s disease (http://www.alz.org/research/diagnostic_criteria/)
• Current research is aiming at establishing biomarkers for microglial activation and synapse loss
Biochemical markers together with neuroimaging and clinical evaluation allow for making a pre-dementia diagnosis of AD and
can be used to detect biochemical treatment effects in clinical trials of anti-AD drug candidates
Biomarkers for Alzheimer’s diseaseProf. Henrik Zetterberg
13The screen versions of these slides have full details of copyright and acknowledgements
37
Clinical Neurochemistry Laboratory
Sahlgrenska University Hospital
Mölndal/Gothenburg, Sweden
Thanks for listening!
Funding: The Swedish Research Council, Swedish Brain Power, JPND and the Alzheimer’s Association
38