This document presents the results of a study aiming to identify potential noninvasive biomarkers for diagnosing idiopathic portal hypertension (IPH) through metabolomic profiling. The study analyzed plasma samples from 33 IPH patients, 33 cirrhotic patients, and 33 healthy volunteers. Multivariate analysis identified subsets of 28 and 31 metabolites that differentiated IPH patients from cirrhotic patients and healthy volunteers, respectively, with excellent predictive accuracy. While validation in larger studies is still needed, the identified metabolic profiles may provide noninvasive means of diagnosing IPH and gaining insight into its pathogenesis.
7. Idiopathic Portal Hypertension
(Noncirrhotic Portal Fibrosis, Hepatoportal Sclerosis)
Etiology: (unknown)
Recurrent infections
Altered immune response
Genetic predisposition
(HLA-DR3 )
Hypercoagulability
HIV infection
Diagnosis :
based on the presence of unequivocal portal
hypertension and a definite histological exclusion of
cirrhosis and any other specific disorder that is able to
8. Study Aim
The need for a less invasive diagnostic method
Liver biopsy might not be helpful to diagnose IPH
Importance of metabolomics in clinical research..
Aim of the study:
“to discover a noninvasive metabolomic profile in
plasma allowing differentiating IPH from healthy
individuals and from patients with CH”
10. Patients
Diagnosis criteria:
Signs of portal hypertension
Exclusion of cirrhosis
Exclusion of hepatic venous thrombosis
Other exclusions:
Patients with other conditions such as thrombosis,
hepatocellular CA, liver biopsy with <6 complete portal
tracts
HIV patients were only included if IPH diagnosis was
unequivocal
“only patients with unequivocal IPH were included in
the study”
11. Blood samples: were collected in citrate-containing tubes
and centrifuged then stored at -80C
99 samples were collected
Ethical statement: informed consent was given to all
participants
Experimental procedures:
(A global metabolite profiling UPLC-MS methodology)
LC-MS system:
UPLC-(TOF)MS
Source: ESI @150◦C
Column: 1 mm i.d. × 100 mm Acquity 1.7 μm C8 BEH column
(Waters)
M.P: A:0.05%FA B: CAN (0.05%FA) gradient flow
12. Data processing:
LC-MS data processing: Noise reduction identify relevant
peak intensities normalization to other peaks in the sample
inter-assay normalization to reference sample following
linear regression method.
Pairwise univariate data analysis was performed in IPH vs.
CH samples and IPH vs. HVs, to eliminate biomarkers that do
not discriminate between groups
13. Multivariate data analysis:
Missing variables were not considered
t-test P value corrected by multiple comparisons and VIP
score (estimates the importance of each variable in the
projection PLS model) “VIP ≥1”
Results are 202 (IPH-CH) and 57 (IPH-HV) significant
markers (P<0.05)
Markers with higher VIP (2.2/2.1) were selected to build a
PLS-DA model to discriminate IPH from CH and IPH from HV.
Markers selection is based on strong parameters: (1-0.7) of both:
R2 (goodness of fit)
Q2 (goodness of prediction)
14. Model validation was done by:
using training (2/3 of data) and test sets (1/3 of data) to predict class
membership and class discrimination [X100 “random” times]
corresponding random sampling cross-validated AUC measures were
determined for each set as (mean±SD) to check sensitivity and
specificity
Heatmaps were created to represent the selected models
A hierarchical clustering algorithm was performed on both
variables and samples.
20. The PLS-DA models show a clear differentiation of IPH
vs. cirrhotic patients & IPH vs. healthy controls based
on a subset of 28 & 31 metabolites respectively, with an
excellent predictive power (based on R2 and Q2 values)
& AUC.
The cross-validation showed an excellent performance
of both models with a good sensibility, specificity, and
AUC in the training and testing sets.
In this study: sub analysis of the metabolomic profile of
IPH patients was unable to cluster patients into different
IPH groups and the author suggested to study larger
population of patients
Thus this study supports the use of metabolomic
profiling to diagnose the disease rather than identifying
the etiology
• Some of the detected metabolites may reflect some of
the drugs that patients are taking. However, it seems
21. Study limitations
Patient number:
however, as IPH is a rare condition, a sample over 30
patients could be considered adequate
lack of an external validation set:
since this is a pilot study; such external validation
studies will be more appropriate at a later step, when the
specific metabolites included in the models could be
identified with new technologies.
However, the existence of metabolites discriminating
IPH from CH and HV opens the interesting possibility
that the identification of these specific metabolites
may disclose some keys for a better understanding of
the pathogenesis of IPH
22. CONCLUSION
The results from this study disclose a subset of
putative biomarkers of IPH
patients with IPH could be identified based on
their metabolic profile, obviating the need for
invasive investigations and facilitating the correct
diagnosis of this uncommon disease.
Types of portal hypertension: cirrhotic and non-cirrhotic…..
1962Vitamin A toxicity, methotrexate and 6-mercaptopurineHarmanci, O. and Y. Bayraktar (2007). "Clinical characteristics of idiopathic portal hypertension." World J Gastroenterol 13(13): 1906-1911.familial aggregation of IPH and a high frequency of HLA-DR3 have been observed among Indian patientsHLA-DR3 is associated with early-age onset myasthenia gravis, Hashimoto's thyroiditis (along with DR5), primary sclerosing cholangitis,[2] and opportunistic infections in AIDS,[3] but lowered risk for cancers
VIP score, the Variable Importance in the Projection,