Progress and Achievements

PUBLISHABLE SUMMARY

The current diagnosis of psychiatric disorders such as schizophrenia (SZ) and mood disorders, is highly subjective, due to the lack of empirical markers or objective tests specific for these diseases. PSYCH-AID searches to fill the gap through the in-parallel study of schizophrenia and mood disorder patients combining, validating and registering sets of biomarker tests already in advanced stages of development via two previous other EU-FP7 projects of partners (MOODINFLAME and SchizDX).

Biomarkers of PSYCH-AID are based on an altered immune response system in conjunction with an abnormal neuro-endocrine set point. The “macrophage-T cell theory of depression and schizophrenia” postulates an aberrant immune state of monocytes/macrophages and T cells in mood disorder and SZ patients and considers this aberrant state of the cells as a driving force contributing to the illnesses, since aberrant levels of inflammatory monocyte/macrophage and T cell cytokines destabilize brain function and the neuro-endocrine system and make the brain and the neuro-endocrine system vulnerable to stress and unknown endogenous factors, thereby leading to psychiatric derailments. To detect these abnormal states, studies have focused mainly on determinations of single molecules in the serum of psychiatric patients. Using this approach outcomes have been inconsistent and not precise and robust enough to consistently detect the abnormal immune-neuro-endocrine state in major disorders and SZ. Apparently further identification of new immune-neuro-endocrine factors (biomarkers) and their combination and integration are required to reach reliable test systems to understand the pathogenesis of psychiatric diseases, to biologically diagnose psychiatric diseases and to identify patients and individuals responsive to existing and novel treatments targeting the abnormal immune-neuro-endocrine system.

PSYCH-AID aimed at the development of clinically applicable blood assays identifying patients/individuals with such altered dynamic immune profiles by combining the efforts of academia and industry in an understanding of the pathogenesis of the major psychiatric diseases, such as major depressive disorder, bipolar disorder and schizophrenia. PSYCH-AID united nine European partners excelling in this field: five academia and five industrial partners.

The strategic objective of PSYCH-AID was to build up a long-lasting, large inter-sectoral, integrative academia-industry consortium in Europe (and the world) for developing empirical immune-neuro-endocrine markers and objective diagnostic and prognostic blood tests for psychiatric disorders through exchanges of researchers.

Indeed an inter-sectoral, integrative academia-industry consortium as well as various interactive activities, i.e. 5 consortium meetings, one large symposium, on a weekly basis work group meetings, numerous telephone and internet meetings and a website (http://www.psychaid.eu/

) have been developed as planned. Also existing interactions in previous EU funded consortia (MOODINFLAME and SchizDX) have been continued and deepened to reach the scientific object. With regard to the exchanges, 24 have been carried out, 3 recruitments have been realized and individual training plans constructed. A drawback, inducing delays, has been the bankruptcy of one of our initial partners (CRL, responsible for the patient database), but counteractive measures have immediately been taken by replacing CRL by RMS. RMS safeguarded the databases and helped in the final integration of the data. This change in partners has in the end not affected reaching the scientific and business objectives. Also one of our partners (EDI) has changed its business strategy half-way the project. Since we had realized the exchanges with this partner in the first

half of the project and since the business objective has been taken over by another partner (APD), this change in strategy of EDI has not affected the overall outcome of the project.

PSYCH-AID’s scientific objective was to identify, mutually correlate and validate sets of empirical immune-neuro-endocrine marker profiles for the diagnosis and prognosis of various mood disorders, such as patients with Major Depressive Disorder (MDD), Bipolar Disorder (BD), Postpartum Psychosis (PP) and Schizophrenia (SZ). This has largely been realized and has also led to a model for the pathogenesis of these disorders, leading to a comprehensive usage of these new diagnostic and prognostic procedures. For this purpose

We have collected sufficient patients and controls and their material to carry out the planned analyses (WP4).
Large numbers of patients and their controls have been collected (see Table) and large numbers of assays have been carried out on large panels of serum, plasma and collected immune cells. We have reached the number of patients envisaged at the start of the project and fully reached the objective of this sub-aim.

Psychaid table

We have refined the monocyte expression fingerprints (transcriptomics) (WP5),
We have established the key genes for a test system to determine the inflammatory state of the monocytes in psychiatric disease and have defined a mRNA expression fingerprint as well as a miRNA expression fingerprint with around 10 key components. A principle component analysis showed the following genes to predict most of the inflammatory signatures as found in the three most important inflammatory profiles: IL1B, IL6, CCL20, CXCL2 and IL1A (for cluster 1); NAB2, STX1A, PTPN7 (for signature 2) and MXA (for the IFN cluster 3). In microRNA studies MiR-146a and MiR-155 were found to be a key microRNAs controlling the inflammatory state of circulating monocytes and the organism as a whole. Apart from these three sets of inflammatory and motility/adhesion genes, new sets of genes have been evaluated to be part of the biomarker gene signatures specific for sub-groups of patients with different diagnoses and prognoses. These new sets of genes include the glucocorticoid receptor genes and the KAT/KMO enzymes, playing a role in the trypcat metabolism (see WP7).
We have identified a number of proteomic biomarker profiles (proteomics) (WP6),

All planed proteomic tests have been performed and of all studies databases of statistically significant proteomic changes observed in the serum of MDD, BD and SZ individuals compared to controls have been created.

  1. a)  A selected list of approximately 50 candidate immuno-neuro-endocrine biomarkers has been validated for schizophrenia.
  2. b)  We have selected a panel of 8 immune and neurotrophic growth and differentiation factors (S100B, BDNF, IGF-BP2, EGF, PDGF-BB, SCF, IL-7, sCD25) for the characterization of growth and differentiation problems in the myeloid, lymphoid and neuronal lineage in psychiatric patients.
  3. c)  We have selected a panel of 10 inflammatory factors ( IL-1β, IL-1Ra, IL-6, TNFα, IL-10, IL-15, CCL2, PTX3, s-ICAM and hsCRP) to characterize the inflammatory state of psychiatric patients.
  4. d)  A FACS protocol was validated for the determination of the frequency of lymphocytes, monocytes,NK cells, B cells, CD3+ T cells, CD8+ cytotoxic T cells, CD4+ T helper naïve and memory cells, and Th1, Th2, Th17 and natural T regulatory cells to characterize the PBMC population of psychiatric patients.

We have identified further biochemical biomarker profiles, in particular tryptophan catabolite profiles (trypcats) (WP7),
Assays have been standardized via an EQUAS system and a panel of various trypcats have been tested in the large majority of mood disorder patients

  1. a)  Key abnormal trypcat pathways appeared to be the Tryptophan/Kynurenin pathway, the KynureninA/Kynurenin pathway, the 3HK/Kynurenin pathway and the 5-HIAA pathway.
  2. b)  Antibodies have been developed against QUIN and KynA, but appeared not sufficient for ELISA usage. They can and have been used for immuno-histochemistry studies.

We have validated these differential marker profiles for disease specificity (WP8)
We have validated monocyte gene expression, monocyte and lymphocyte subsets, various growth factors and various inflammatory compounds and trypcats for specific immune dysregulation patterns coupled to major depression, bipolar disorder and schizophrenia and to outcomes to SSRI/SNRI, COX-2 inhibitor therapy in mood disorder patients and to outcomes of anti-psychotic therapy in schizophrenia patients. Using the above described marker profiles we can
a) Distinguish a depressive episode in the course of MDD from one in the course of BD (which is relevant for therapy, i.e. lithium or not) using serum levels of SCF and BDNF and the circulating frequencies of TH17, Th2 and natural T regulatory cells,
B) Distinguish schizophrenia from major mood disorders using the expression of signature 2 genes in monocytes
C) Predict responsiveness to SSRI/SNRIs using the monocyte gene expression, CD8 and NK frequencies D) Predict responsiveness to COX-2 therapy in addition to an SSRI using the monocyte/lymphocyte ratio and the naïve/memory T cell ratio
D) Predict responsiveness to anti-psychotics in schizophrenia using the H-FABP/CD36 axis and IL-10.

PSYCH-AID’s business objective was the commercialisation the various test systems (WP9). As consortium we were the first to develop a marketable test system to aid in the diagnosis of schizophrenia (via Myriad) (see WP9). We have now developed a number of validated diagnostic and prognostic reagents and procedures, particularly in the above described fields of the distinction between a depression in the course of BD or MDD (relevant for therapy), the outcome of SSRI/SNRI treatment and the outcome of anti- psychotics in schizophrenia. The assay systems to perform the relevant assays for these purposes are commercially available, but often expensive. Less expensive smaller platforms for key inflammatory and growth factors are under development by APD.

We have also developed an user-friendly app to file the outcomes of psychiatric scoring lists.

PSYCHAID has allowed the construction of a new pathogenesis model for major mood disorders and schizophrenia leading to new diagnostics and therapies
Both the data of the schizophrenia (SCZ) patients and the data on the major depressive (MDD) and bipolar (BD) patients collected in the PSYCHAID project allow for the construction of a reliable and further testable new model for the pathogenesis of MDD, BD and SCZ integrating the new data from PSYCHAID with earlier data from MOODINFLAME and from the literature (see figure in the addendum).

This new model has led – as mentioned above – to new diagnostic approaches: The determination of the monocyte gene pattern, of relevant lymphocyte subsets and sets of growth factors and cytokines is important to determine and follow the imbalance in the neuro-immuno-endocrine system potentially leading to these various psychiatric illnesses. We have developed such diagnostic systems, which are commercially available (see WP 9).

This model has also led and will lead to new interventions with immune modulatory therapies, like COX-2 inhibition therapy used in MOODINFLAME and PSYCHAID. The studies in PSYCHAID and MOODINFLAME have shown that COX-2 inhibitor therapy is advantageous in MDD in addition to SSRI’s and can be followed by the above new diagnostics and by T cell determinations by FACS.

Our consortium has been and is one of the leading groups in unravelling the immune-neuro-endocrine underpinnings of psychiatric disease and translating knowledge into clinically applicable approaches and test systems. The European community will benefit from this competitive lead. Since the disorders have a serious impact on the quality of life of the individuals affected, an improved diagnosis and prognosis will substantially contribute to improving the quality of life in Europe and elsewhere. Our data will change psychiatry! Furthermore, PSYCH-AID has given the researchers involved a platform to acquire complementary skills, and has boosted the careers of its fellows and supervisors.

psychaid-model

The model (see figure):
1. Lymphoid and myeloid generation defects are central, due to inborn (MHC dependent) or early postnatal abnormalities (abuse, severe peri-natal infections). This results in inborn low numbers of T cells, poor T helper subpopulation maturation, low numbers of T regulatory cells, low numbers of immunogenic and tolerogenic DC and reduced levels of essential immune/neurogenic growth factors. Episodes of excessive inflammatory responses to danger hits occur on this background.
2. This immune profile sets the stage for liability for infections and for liability for (thyroid) autoimmune reactions due to additional gene (CTLA4; PTPN22) and/or environmental (iodine, microbes) influences.
3. This immune profile also sets the stage for an abnormal development of fronto-limbic brain systems. Both the T cell defects and the (episodic) monocyte activation with high levels of circulating cytokines are capable of eliciting brain developmental abnormalities, i.e. reductions in grey matter in frontal and parietal brain areas and poor connectivity in white matter tracts in the cortico-limbic region. These brain abnormalities in turn will lead to abnormal psychiatric reactions to stressors.
4. In individuals later developing a major depressive disorder (MDD) the immune defects worsen– during aging – leading to more severe defects of the regulator T cell population and a permanently low threshold for monocyte/macrophage inflammatory activation. This in turn leads to episodes of high rises of pro-inflammatory cytokines elicited by the multiple danger hits as indicated (postpartum period, disturbed lipid metabolism, obesity, gut flora, chronic and acute stress, etc.).

5. In individuals who later develop bipolar disorder (BD), the T cell defects are partially restored after adolescence which is reflected in higher levels of hematopoietic growth factors, a normal maturation of the T helper populations and a normal gene expression profile of monocytes. Yet lymphocyte/monocyte ratio’s stay low. In such an imbalanced immune system the various “danger” hits (post-partum period, infections, gut flora) are apparently capable of still inducing excessive rises in the inflammatory monocyte gene expression in a characteristic pattern A of both increases in cluster 1 and 2 genes. There is also a rise in the production of pro-inflammatory cytokines. Such immune activations co-occur with active episodes of the disease.

6. In individuals who later develop schizophrenia (SCZ) the T cell defects are partially restored after adolescence like in bipolar disorder, yet again lymphocyte/monocyte ratio’s stay low. Again in this imbalanced immune system the various “danger” hits (post-partum period, infections, gut flora) are again capable of inducing excessive changes in the inflammatory monocyte gene expression, but now in a characteristic pattern B with as hallmark a decrease in cluster 2 genes and a variable up regulation of cluster 1 genes. The production of cytokines is of mixed type of both pro- and anti-inflammatory cytokines.

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31-05-2016 Publishable Summary
21-07-2014 Publishable Summary