2. Personalized medicine builds on data
and biomarkers
rker
Prognostic
biomarker
Predictive
biomarker
High disease probability
se High risk / bad
prognosis
Low risk / good
prognosis
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Risk/susceptibility
biomarker
High risk for diseaseLow risk for disease
All patientsAll patients
same treatment
Biomarkers
Traditional medicine
Personalized medicine
3. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Risk/susceptibility markers
4. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Non-invasive
diagnostic marker
5. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Invasive diagnostic marker
6. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Prognostic marker
7. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Predictive marker
Predictive marker
8. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
Predictive marker
Safety markers
Pharmacodynamic markers
Monitoring markers
9. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
10. Risk/susceptibility
biomarker
Risk/susceptibility
biomarker
Non-invasive
diagnostic biomarker
Non-invasive diagnostic
biomarker
Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilityLow disease probability
High risk for diseaseLow risk for disease
No disease confirmation Disease confirmation
High risk / bad
prognosis
Low risk / good
prognosis
Safety biomarker
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Pharmacodynamic /
response biomarker
Monitoring biomarker
- Disease activity
- Pharmacokinetics
(exposure)
All patients
Patients with
confirmed disease
PERSONALIZED
MEDICINE
Risk/susceptibility markers
Non-invasive
diagnostic markers
Invasive
diagnostic markers
Prognostic markers
Predictive markers
Safety markers
Pharmacodynamic markers
Monitoring markers
13. We have several widely used susceptibility/risk biomarkers
in kidney transplantation
• Number of HLA mismatches
• Cross-matches
• Pretransplant PRA%
• Pretransplant DSA
• De novo DSA occurrence
Success story of
HLA genotyping and
antibody profiling
TRANSPLANTATION
MEDICINE
=
FRONTRUNNER IN
PERSONALIZED MEDICINE
14. More personalization in allocation
(AM program) leads to better outcome
Heidt et al confidential
15. More personalization in allocation
(AM program) leads to better outcome
Heidt et al confidential
17. HLA epitope-based organ allocation instead of waiting time
Low resolution
Acceptable MM at the antigen level
High/allelic resolution
Acceptable MM at the epitope level
18. HLA epitope-based organ allocation instead of waiting time
Third-Generation Sequencing (SMRT)
Low resolution
Acceptable MM at the antigen level
High/allelic resolution
Acceptable MM at the epitope level
19. New risk biomarkers in the pipeline
for kidney transplantation
• Epitope mismatch load1
• Genetic assessment for aHUS recurrence
• Urinary or serum suPAR for FSGS recurrence2
• FSGS recurrence panel3
• PLA2R and THSD7A antibodies for recurrence of membranous
glomerulopathy4,5
• Donor-reactive T-cell response6
• …
Risk markers
1Wiebe et al Transplantation 2016; 2Franco Palacios et al Transplantation 2013; 3Delville et al Sci Transl Med 2014;
4Sprangers et al Transplant Rev 2013; 5Tomas et al J Clin Invest 2016; 6Crespo et al Clin Biochem 2016
21. We have several widely used diagnostic biomarkers
in kidney transplantation
Non-invasive:
• Serum creatinine/eGFR
• Proteinuria
• DSAs
• Renal ultrasound exam
Invasive:
• Histology of for-cause (indication) biopsies
• Histology of protocol biopsies
22. Naesens et al. Am J Transplant 2013;13:86–99.
Inflammation + ABMR
Inflammation - ABMR
Normal
Chronic - inflammation
Chronic + inflammation
Transplant glomerulopathy
gs
cv
mm
ah
ct
ci
cg
ti
i
t
ptc
g
v
C4dglom
C4dptc
0 max
Individual lesion score
Inflammation + ABMR
Inflammation - ABMR
Normal
Chronic - inflammation
Chronic + inflammation
Transplant glomerulopathy
gs
cv
mm
ah
ct
ci
cg
ti
i
t
ptc
g
v
C4dglom
C4dptc
0 max
Individual lesion score
23. We are constantly refining the diagnostic Banff classification
1. Racusen LC et al. Kidney Int 1999;55:713–723;
2. Loupy A et al. Am J Transplant 2017;17(1):28–41.
ABMR
2015
TCMR
1997–2015
24. Lesions are non-specific for the underlying etiology:
TCMR and ABMR
Lefaucheur C et al. Lancet 2013;381:313–319.
25. Kidney transplant histology is highly problematic
as a diagnostic biomarker
Naesens & Anglicheau – in press.
26. Loupy et al AJT 2017
BANFF 2015 consensus
Invasive diagnostic markers
in the pipeline for kidney transplantation
27. From MMDx website: www.molecular-microscope.com
Invasive diagnostic markers
in the pipeline for kidney transplantation
28. Non-invasive diagnostic markers
in the pipeline for kidney transplantation
• Urinary mRNA
• Urinary miRNA
• Urinary proteins/peptides
• Blood mRNA
• Blood miRNA
• Blood proteins/peptides
• ….
29. 0 25 50 75 100
0
25
50
75
100
Sensitivity for acute rejection (%)
Specifictyforacuterejection(%)
Perforin
Granzyme B
PI-9
CD103
FOXP3
CXCL10
NKG2D
TIM3
Granulysin
Multigene signature
Urinary mRNA
0 25 50 75 100
0
Sensitivity for acute rejection (%)
Multigene signature
Non-invasive urinary mRNA markers
in the pipeline for kidney transplantation lack accuracy
Naesens and Anglicheau, in press
mRNA
30. 0 25 50 75 100
0
25
50
75
100
Sensitivity for acute rejection (%)
Specifictyforacuterejection(%)
Perforin
Granzyme B
PI-9
CD103
FOXP3
CXCL10
NKG2D
TIM3
Granulysin
Multigene signature
Urinary mRNA
0 25 50 75 100
0
Sensitivity for acute rejection (%)
Multigene signature
Non-invasive urinary mRNA markers
in the pipeline for kidney transplantation lack accuracy
mRNA
Naesens and Anglicheau, in press
31. 0 25 50 75 100
0
Sensitivity for acute rejection (%)
Multigene signature
0 25 50 75 100
0
25
50
75
100
Sensitivity for acute rejection (%)
Specifictyforacuterejection(%)
CXCL9
CXCL10
Fractalkine
Urinary proteins
Non-invasive urinary protein markers
in the pipeline for kidney transplantation lack accuracy
Proteins
Naesens and Anglicheau, in press
32. 0 25 50 75 100
0
25
50
75
100
Sensitivity for acute rejection (%)
Specifictyforacuterejection(%)
Blood mRNA
Granzyme B
Perforin
FasL
HLA-DRA
Multigene signature
Non-invasive blood mRNA markers
in the pipeline for kidney transplantation seem promising
Naesens and Anglicheau, in press
mRNA
33. 0 25 50 75 100
0
25
50
75
100
Sensitivity for acute rejection (%)
Specifictyforacuterejection(%)
Blood mRNA
Granzyme B
Perforin
FasL
HLA-DRA
Multigene signature
Non-invasive blood mRNA markers
in the pipeline for kidney transplantation seem promising
Trugraf
kSORT
Naesens and Anglicheau, in press
34. The kSORT assay needs further validation
in cross-sectional cohorts
17 peripheral blood mRNA gene-set
Case-control setting -> PPV?? NPV??
Roedder et al PLOS Med 2014
35. The TruGraf assay needs further validation
200 peripheral blood mRNA geneset
- early-access clinical programs started
- large interventional trials ongoing (like the phase-3 trial with the p53 inhibitor QPI-1002)
- prospective, randomized, multi-center clinical trial ongoing
Kurian et al Am J Transplant 2014
36. AP-HP Paris
CHU Limoges
UZ Leuven
MHH Hannover
Clinical Centers
AP-HP Paris
INSERM Limoges
KU Leuven
Mosaiques Diagnostic GmbH
Analytical Centers (-omics data)
INSERM Toulouse
CEA
CNRS
VITO
Bio-informatics Center
Acureomics
UnivPDes
Inserm-Transfert
Coordination
Cardinal Systems
Urinary + plasma metabolomics
Urinary proteomics
+ peptidomics
Urinary miRNA
Urinary mRNA
Blood + biopsy miRNA
Blood + biopsy mRNA
Biopsy lipidomics, peptidomics, proteomics
Urinary proteomics and peptidomics
Blood + biopsy miRNA
Urinary lipidomics
Urinary proteomics
+ peptidomics
www.biomargin.eu
38. Accuracy of a test determines its clinical value,
not its p-value!
Area under a
ROC curve
Interpretation
0.90 – 1.00 Excellent
0.80 – 0.90 Good
0.70 – 0.80 Fair
0.60 – 0.70 Poor
0.50 – 0.60 Fail
False positive rate (1 – Specificity)
Truepositiverate(Sensitivity)
Perfect test
AUC=1.00
Good test
AUC=0.85
Failed test
AUC=0.50
Positive predictive value (PPV) and negative predictive
value (NPV) take disease prevalence into account
39. eGFR at 1 year is associated with graft outcome,
and is a fair prognostic marker
ROC for graft failure
5 year after biopsy
according to 1 year MDRD eGFR
0 20 40 60 80 100
0
20
40
60
80
100
100% - Specificity%
Sensitivity%
AUC=0.77
p<0.0001
MRDR eGFR at 1 year
and graft failure
1 5 10 15
0
20
40
60
80
100
Time after biopsy (years)
Graftsurvival(%)
>70 mL/min
60-70 mL/min
50-60 mL/min
log-rank
P<0.0001
40-50 mL/min
30-40 mL/min
20-30 mL/min
<20 mL/min
Speaker’s own unpublished data
40. Proteinuria is a risk factor for graft failure
but a poor prognostic marker
Naesens M et al J Am Soc Nephrol 20153 months 1 year 2 yearsD
Time after transplantation (years)
572
119
40
430
68
16
163
23
7
532
102
33
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
>1.0 g/24h
Time after transplantation (yea
495
104
38
416
70
13
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
>1.0 g/24h
Biopsy time points
(N=1335)
1 5 10
0
20
40
60
80
100
Time after biopsy (years)
Percentsurvival
>3.0 g/24h
< 0.3 g/24h
0.3-1.0 g/24h
1.0-3.0 g/24h
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
1.0-3.0 g/24h
>3.0 g/24h
548
319
150
30
449
237
94
18
297
156
53
11
646
390
208
51
log-rank
P <0.0001
Proteinuria
B C
0 20 40 60 80 100
0
20
40
60
80
100
False Positive Fraction (%)
TruePositiveFraction(%)
AUC=0.66
(95% CI 0.63-0.69)
P <0.0001
Biopsy time points
(N=1335)
3 months
(N=914)
100
)
1 year
(N=778)
100
)
2 years
(N=731)
100
)
)
D
572
119
40
430
68
16
163
23
7
532
102
33
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
>1.0 g/24h
495
104
38
160
28
7
416
70
13
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
>1.0 g/24h
Biopsy time points
(N=1335)
1 5 10
0
20
40
60
80
100
Time after biopsy (years)
Percentsurvival
>3.0 g/24h
< 0.3 g/24h
0.3-1.0 g/24h
1.0-3.0 g/24h
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
1.0-3.0 g/24h
>3.0 g/24h
548
319
150
30
449
237
94
18
297
156
53
11
646
390
208
51
log-rank
P <0.0001
Proteinuria
B C
0 20 40 60 80 100
0
20
40
60
80
100
False Positive Fraction (%)
TruePositiveFraction(%)
AUC=0.66
(95% CI 0.63-0.69)
P <0.0001
Biopsy time points
(N=1335)
5 10 152
0
20
40
60
80
Time after transplantation (years)
0.3-1.0 g/24h
> 1.0 g/24h
572
119
40
430
68
16
163
23
7
532
102
33
log-rank
P <0.0001
at risk
g/24h
g/24h
g/24h
5 10
0
20
40
60
80
Time after transplantation (y
Percentsurviv
495
104
38
416
70
13
log-rank
P <0.0001
No. at risk
<0.3 g/24h
0.3-1.0 g/24h
>1.0 g/24h
Biopsy time points
(N=1335)
60
80
100
>3.0 g/24h
< 0.3 g/24h
0.3-1.0 g/24h
1.0-3.0 g/24h
Proteinuria
C
60
80
100
Fraction(%)
Biopsy time points
(N=1335)
41. Starzl TE et al Ann Surg 1974;180(4):606–614
ct ci ah cvi
64 cases transplanted between 1962–1964
in Colorado and Denver
42. The CADI score is an imperfect prognostic marker,
despite the significant association with graft failure
CADI score
in indication biopsy
1 5 10 15
0
20
40
60
80
100
Time after biopsy (years)
Graftsurvival(%)
CADI 0
CADI 1
CADI 2-3
log-rank
P<0.0001
CADI 4-5
CADI 6-7
CADI 8-9
CADI >9
ROC for graft failure
5 year after biopsy
according to CADI score
0 20 40 60 80 100
0
20
40
60
80
100
100% - Specificity%
Sensitivity%
AUC=0.65
p<0.0001
CADI score
in indication biopsy
1 5 10 15
0
20
40
60
80
100
Time after biopsy (years)
Graftsurvival(%)
CADI 0
CADI 1
CADI 2-3
log-rank
P<0.0001
CADI 4-5
CADI 6-7
CADI 8-9
CADI >9
ROC for graft failure
5 year after biopsy
according to CADI score
0 20 40 60 80 100
0
20
40
60
80
100
100% - Specificity%
Sensitivity%
AUC=0.65
p<0.0001
ROC for 5 year graft loss
N=1335 indication biopsies
Speaker’s own unpublished data
43. Prognostic models within a disease phenotype show
which patients need treatment
Loupy A et al. J Am Soc Nephrol 2015;26(7):1721–1731.
44. Prognostic models within a disease phenotype show
which patients need treatment
50%
Loupy A et al. J Am Soc Nephrol 2015;26(7):1721–1731.
45. We lack good prognostic biomarkers in
kidney transplantation
• eGFR
• Proteinuria
• Histology
have on itself insufficient prognostic capacity
In addition, and even more importantly, these markers reflect primarily
past injury, and not future/ongoing injury
We do not identify those the patients that need treatment
46. Adapted from Naesens et al.
J Am Soc Nephrol 2016;27(1):281–292.
0.3-1.0 vs. <0.3 g/24h
1.0-3.0 vs. <0.3 g/24h
>3.0 vs. <0.3 g/24h
30-45 vs. >45 mL/min/m2
15-30 vs. >45 mL/min/m2
<15 vs. >45 mL/min/m2
g+ptc ≥2 vs. <2
Banff grade 1 vs. 0
Banff grade 2-3 vs. 0
Banff grade 1 vs. 0
Banff grade 2-3 vs. 0
Present vs. absent
Present vs. absent
0.1 1 10 100
Proteinuria
eGFR
IFTA
Transplant
glomerulopathy
GNF
PVAN
microcirc. inflammation
Hazard ratio (95% CI)
for kidney graft loss
Prognostic model?
Several prognostic markers are independent risk factors
for graft failure
Decide who to treat
Surrogate endpoint
47. iBox provides a prognostic nomogram,
but is not (yet) disease-specific
Loupy, Aubert, Orandi, Naesens et al submitted
48. iBox provides a prognostic nomogram,
but is not (yet) disease-specific
ROC-AUC = 0.81-0.84
Loupy, Aubert, Orandi, Naesens et al submitted
49. Prognostic markers
in the pipeline for kidney transplantation
• Edmonton classifier for graft loss1
• Edmonton “ABMR molecular score”2
• GOCAR 13-geneset3
1Einecke et al J Clin Invest 2010; 2Loupy et al JASN 2013; 3O’Connell Lancet 2016
50. Molecular “Risk score” predicts graft outcome
better than histology or proteinuria
Low risk score
High risk score
Time after biopsy
Survivalprobability
Einecke et al J Clin Invest 2010
AUC=0.83
Risk score for graft loss:
Early biopsies:
Sensitivity = 100%
Specificity = 41%
PPV = 5%
NPV = 100%
Late biopsies:
Sensitivity = 83%
Specificity = 63%
PPV = 47%
NPV = 90%
51. INTERCOM STUDY
(multicenter)
ABMR Score -
Histology -
ABMR Score -
Histology +
ABMR Score +
Histology +
ABMR Score +
Histology -
Halloran et al Am J Transplant 2013
ABMR score for graft loss:
Sensitivity = 75%
Specificity = 81%
PPV = 48%
NPV = 93%
ROC AUC=0.81
Molecular “ABMR score” predicts graft outcome
better than histology of ABMR
52. “GoCAR 13-gene score” predicts CADI
better than clinical and pathological parameters
O’Connell, Zhang et al Lancet 2016
53. GoCAR score for graft loss:
PPV = ???
NPV = ???
ROC AUC=0.84
“GoCAR 13-gene score” predicts graft failure
better than clinical and pathological parameters
O’Connell, Zhang et al Lancet 2016
58. y
Non-invasive
diagnostic biomarker
stic Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilitylity
High risk for disease High risk / bad
prognosis
Low risk / good
prognosis
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Patients with
confirmed disease
Prognostic biomarker
Predictive biomarker
59. Prognostic biomarker
Predictive biomarker
y
Non-invasive
diagnostic biomarker
stic Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilitylity
High risk for disease High risk / bad
prognosis
Low risk / good
prognosis
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Patients with
confirmed disease
60. Prognostic biomarker
Predictive biomarker
y
Non-invasive
diagnostic biomarker
stic Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilitylity
High risk for disease High risk / bad
prognosis
Low risk / good
prognosis
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Patients with
confirmed disease
61. Prognostic biomarker
Predictive biomarker
y
Non-invasive
diagnostic biomarker
stic Invasive diagnostic
biomarker
Prognostic
biomarker
Predictive
biomarker
High disease probabilitylity
High risk for disease High risk / bad
prognosis
Low risk / good
prognosis
Predicted benefit from
treatment X, not Y
Predicted benefit from
treatment Y, not X
Start treatment X Start treatment Y
Patients with
confirmed disease
?
62. We urgently need new therapies for the high-risk patients,
through awareness and renewed investment
1 2 3 40 5
0
50
100
Years after transplantation
Survivalprobability(%)
(death-censored)
Transplanted in UZ Leuven
01/01/2011 - 01/09/2016
No HLAAbs (N=508)
Non-DSA HLAAbs (N=110)
DSA (N=58)
Log-rank P = 1.9E-05
1 2 3 40 5
0
50
100
Years after transplantation
Survivalprobability(%)
(overallgraftsurvival)
Transplanted in UZ Leuven
01/01/2011 - 01/09/2016
No HLAAbs (N=508)
Non-DSA HLAAbs (N=110)
DSA (N=58)
Log-rank P = 3.9E-03
Naesens et al - unpublished
Dear colleagues, our profession is changing rapidly. I am a nephrologist, taking care of kidney transplant patients, and together with all of you, I am witnessing one of the major paradigm shift in the history of medicine. While in traditional medicine, we have treated our patients according to what we think is best for the patient population as a whole, we are now moving towards personalized medicine, where we provide specific treatment X to individual patients, and treatment Y to other individuals. This personalized or individualized treatment builds on data, often big data, and biomarkers. This is what this presentation will be about. I will guide you through how I see kidney transplant pathology has a place in this transition of traditional to personalized.
When we discuss biomarkers, we should be very careful. There are many different types of biomarkers, and each of them has a specific place in personalization of medicine.
Why personalized medicine? This buzz-word is used all the time, but clearly illustrates a crucial aspect of medicine, and the changing paradigms in our profession.
In more traditional medicine, think of e.g. transplantation, we treat all the patients the same way, and hope that the treatment will be beneficial for the group of patients.
In personalized medicine, we are trying to pick those patients from the population that benefit from the treatment, and also identify which patients need which treatment to get better outcome.
And for that, we need patient data, often big data, and biomarkers.
When I say biomarkers, it is becoming obvious that there are many different types of biomarkers, and that we need to be clear on these different biomarker types.
It is important to clearly identify the different types of biomarkers, as this is crucial in understanding how we can use the available biomarkers for real clinical benefit.
Risk markers are very important, as they provide us tools to know which patients need extra attention, to be maximally efficient, and not waste time and money to patients who have no risk for disease.
In high-risk patients, you need to know the timing when disease processes start, preferably at the subclinical level. This search for early disease manifestations typically needs repeated assessment, and should thus be done with non-invasive markers,; eg in blood samples, urine samples, ultrasound examinations etc. Invasive markers cannot be repeated too often, because of their invasiveness and thus risk of side effects of the monitoring on itself. Something we of course need to avoid at all times. Non-invasive markers provide you the probability of active or beginning disease.
Very often, the disease is then confirmed and the exact phenotype is often determined based on invasive markers, like biopsies.
Disease confirmation, but also phenotypic classification, diagnostic fine-tuning
Once the disease/diagnosis is confirmed, you cannot yet start treatment. Ideally, first it is necessary to know which patients will cure even without treatment, and which patients have bad prognosis if not treated. We need to know for which patients treatment is necessary, and in which patients treatment and treatment-associated side efffects and costs can be avoided. This is done with prognostic biomarkers.
And it is only the integration of all these different markers that brings us the potential of true personalized medicine.
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Only with this integration of many different types of biomarkers, we can come to true personalized medicine.
Urinary 3-gene mRNA expression signature, and wide range of other suggested molecules 3, 44
Wide range of urinary target proteins like CXCL10 and CXCL9 3
Blood 17 gene mRNA expression “kSORT™” 47
Blood 200-gene mRNA expression (“Trugraf”) 46
Several blood and urine miRNAs 3
Molecular microscope for allograft pathology
The problem is to define how we can use this to improve on the gold standard, which is histology.
Urinary 3-gene mRNA expression signature, and wide range of other suggested molecules 3, 44
Wide range of urinary target proteins like CXCL10 and CXCL9 3
Blood 17 gene mRNA expression “kSORT™” 47
Blood 200-gene mRNA expression (“Trugraf”) 46
Several blood and urine miRNAs 3
Molecular microscope for allograft pathology
Once a diagnosis is made, it is clear that we then need to identify which patients or diseases need treatment, and which not. No all rejections are deleterious for outcome, not all histological changes need treatment.
And this brings us to a crucial issue in biomarker research. IT IS NOT THE P-VALUES THAT COUNT, BUT THE ACCURACY OF THE MARKER.
The fact that histology is an ideal instrument for evaluating kidney allograft prognosis was already evident for Tom Starzl and his team, in the publication they made of the first 64 cases of succesful kidney transplants wordlwide. They performed protocol-specified biopsies at 2 years after transplantation, and discovered that several biopsies had chronic injury, as is illustrated in this slide.
You cannot use on-of phenomena (like ABMR present vs. absent) to calculate a prognostic value.
The accuracy of the diagnosis of ABMR for prediction of survival after 8 years is very low: 50% chance to still have your graft, 50 % chance of graft loss.
This risk score was calculated on only the late biopsies!
NB. The predictive performance was explicitly mentioned in the manuscript
Predictive performance (apart from ROC AUC) was NOT mentioned in the manuscript, but could be deducted
ABMR score for graft loss:
Sensitivity = 24/32 = 75%
Specificity = 33/293 = 81%
PPV = 24/50 = 48%
NPV = 108/116 = 93%
ROC AUC=0.81
This study is on late ABMR, and perhaps not representative of early ABMR? (the prevalence of early ABMR in these low-risk cohorts is less than 2% of biopsies with molecular assessment). In addition, these indications biopsies had lots of chronic injury, concomitant diseases etc.
As in cancer, homogenous and well phenotyped cohorts are needed to ascertain whether the molecularmicroscope strategy could be helpful and add to the conventional assessments.
Interesting : both histology of TCMR and TCMR molecular microscope score were not associated with graft survival.
This risk score was calculated on only the late biopsies!
NB. The predictive performance was explicitly mentioned in the manuscript
This risk score was calculated on only the late biopsies!
NB. The predictive performance was explicitly mentioned in the manuscript
Problem: very few novel drugs developed in transplantatation. Predictive marker development for prediction of novel treatment success therefore severely hampered.
Problem: very few novel drugs developed in transplantatation. Predictive marker development for prediction of novel treatment success therefore severely hampered.