Depression and suicidality: A link to premature T helper cell aging and increased Th17 cells.

BACKGROUND: Previous research has demonstrated a strong link between immune system abnormalities and Major Depressive Disorder (MDD). High suicide risk is a major complication of MDD and has recently been linked to strong (neuro-)immune alterations, but little is known on the link between circulating immune cell composition and suicidal risk status. METHODS: Here, we assessed percentages of circulating peripheral blood mononuclear cells with focus on T helper cell subsets (memory T helper cells, Th1, Th2, Th17 and T regulatory cells) in a large and well-matched cohort of 153 patients diagnosed with MDD and 153 age and sex matched controls. We explored the association of these cell populations with suicide risk while accounting for age, sex, BMI, depression severity and childhood trauma. RESULTS: Patients with MDD had reduced percentages of NK cells, and higher percentages of B and T cells in line with current literature. Further exploration of T-cells revealed a robustly elevated number of memory T helper cells, regardless of age group. Patients at high risk for suicide had the highest memory T helper cells and additionally showed a robust increase of Th17 cells compared to other suicide risk groups. CONCLUSIONS: The higher abundance of memory T helper cells points towards premature aging of the immune system in MDD patients, even during young adulthood. Patients at high risk for suicide show the clearest immune abnormalities and may represent a clinically relevant subtype of depression.

Development of an Enzyme-Linked Immune Sorbent Assay to Measure Nivolumab and Pembrolizumab Serum Concentrations.

BACKGROUND: Treatment with monoclonal antibodies (mAbs) against programmed cell death protein 1 receptor is subject to high variation in treatment outcome among cancer patients. For these agents, no exposure-response (ER) relationships have been investigated in routine health care settings. However, ER relationships have been identified for several other mAbs used in oncology. Methods to conveniently measure serum concentrations of anti-programmed cell death protein 1 mAbs in routine health care may clarify possible ER relationships. Therefore, the authors aimed to develop an enzyme-linked immune sorbent assay (ELISA) for the measurement of both nivolumab and pembrolizumab serum concentrations of treated cancer patients. METHODS: Optimal capture antigen and detection antibody concentrations were selected based on titrations. Nivolumab calibration standards ranging from 0.2 to 300 ng/mL were tested in duplicate. Accuracy was assessed in 2 recovery experiments. Intra- and interassay variations were assessed on 3 different days by 2 independent technicians. The developed ELISA was also set up for pembrolizumab calibration curves. Cross-reactivity of nivolumab measurements with ipilimumab was assessed. Of one nivolumab treated patient, serum concentrations in follow up samples were measured and presented. RESULTS: Nivolumab calibration standards of 0.20-25 ng/mL were used. Nivolumab trough concentrations after 1 cycle in 8 patients ranged from 17.3 to 31.1 mcg/mL. The range of accuracy was 84%-105%, whereas intra- and interassay variations showed a coefficient of variation of 5.5% and 10.1%, respectively. No cross-reactivity with ipilimumab was detected. Pembrolizumab trough concentrations (n = 8) ranged from 9.1 to 19.7 mcg/mL after 1 infusion. CONCLUSIONS: The in-house-developed ELISA provides the opportunity to measure both nivolumab and pembrolizumab serum concentrations. This may help identify possible ER relationships in treated cancer patients and may potentially lead to dose adjustments in the future.

Th17 cells correlate positively to the structural and functional integrity of the brain in bipolar depression and healthy controls.

Abnormalities of T cell-mediated immune activation, in the absence of active somatic immune diseases, have consistently been reported in mood disorders. Apart from being important players in the regulation of cells of the immune system, T cells are essential for normal brain development. We here report studies on the relationship between circulating levels of T helper cells and structural and functional brain imaging in depressed bipolar patients. Since the CCL20-CCR6 axis is an important entry to the brain we differentiated the various T helper cell subpopulations on the basis of their chemokine receptor expression. METHODS: FACS staining was performed for Th1, Th2, Th17, Th22 and T regulatory cells on frozen leukocytes of 25 consecutively admitted inpatients affected by a major depressive episode, without psychotic features, in the course of Bipolar Disorder I and 21 healthy controls. The frequency of the T helper populations was associated with DTI and fMRI data acquired on a Philips 3.0 Tesla scanner. Tract based spatial statistic was used to obtain measures of white matter integrity (fractional anisotropy, axial, radial and mean diffusivity) from a standard DTI sequence with 35 directions. Patients were also studied for fMRI through a moral valence decision task were subjects had to decide whether morally tuned stimuli were positive or negative. RESULTS: The percentage of circulating Th17 (CCR6+CXCR3negCCR4+CCR10neg) cells correlated positively with higher fractional anisotropy in fiber tracts contributing to the functional integrity of the brain both in patients and healthy controls, while the frequency of circulating T regulatory (CD4+CD25+FOXP3+) cells correlated positively with higher radial and mean diffusivity in patients. The frequency of circulating T regulatory cells also correlated to lower neuronal responses to negative versus positive morally tuned stimuli in the right dorsolateral prefrontal cortex of patients. Th1 cells correlated negatively with white matter integrity in several tracts (healthy controls), while the cells showed a positive correlation to the levels of pro-inflammatory cytokines (patients). CONCLUSION: This study shows a new putative role for Th17 cells. Th17 cells are not only playing a role in inducing autoimmunity and auto-inflammation, but might also play a counter intuitive anabolic role in the maintenance of the functional and structural integrity of the brain.

Deficiencies of the T and natural killer cell system in major depressive disorder: T regulatory cell defects are associated with inflammatory monocyte activation.

BACKGROUND: In a previous study, we found an up-regulated inflammatory monocyte gene expression profile in major depressive disorder (MDD) patients aged ⩾ 28 years and a down-regulated inflammatory gene expression profile in MDD patients aged<28 years. In the same sample of patients, we aimed to investigate immune dysregulation in the lymphocyte arm of the immune system, particularly in the context of the described monocyte (de-)activation states. METHODS: From deep frozen leukocytes, circulating percentages of monocytes, lymphocytes, B, T, and natural killer (NK) cells, and various functional subsets of T and T helper (Th) cells (Th1, Th2, Th17, and natural T regulatory cells) were measured in N=50 MDD patients and N=58 age- and gender-matched healthy controls (HC). In addition, serum levels of interleukin (IL)-6, sCD25, IL-7, IL-3, SCF, IGF-BP2, and EGF were evaluated. RESULTS: MDD patients were in general characterized by an impaired maturation of Th2 cells, Th17 cells, and NK cells and by decreased serum levels of IL-7 and sCD25. MDD patients aged ⩾ 28 years additionally exhibited decreased percentages of CD4(+)CD25(high)FoxP3(+) T regulatory cells, next to signs of the above described partial T cell defects. Natural T regulatory cells were inversely associated with the pro-inflammatory state of the monocytes (r=-.311; p=.034) that characterized this patient subgroup. CONCLUSIONS: Deficiencies of the NK and T (regulatory) cell system and inflammatory monocyte immune activation co-occur as partly interrelated phenomena within the same MDD patients.

Clinical characteristics of inflammation-associated depression: Monocyte gene expression is age-related in major depressive disorder.

Increased inflammatory activation might only be present in a subgroup of depressed individuals in which immune processes are especially relevant to disease development. We aimed to analyze demographic, depression, and trauma characteristics of major depressive disorder (MDD) patients with regard to inflammatory monocyte gene expression. Fifty-six naturalistically treated MDD patients (32 ± 12 years) and 57 healthy controls (HC; 31 ± 11 years) were analyzed by the Inventory of Depressive Symptomatology (IDS) and by the Childhood Trauma Questionnaire (CTQ). We determined the expression of 38 inflammatory and immune activation genes including the glucocorticoid receptor (GR)α and GRß genes in purified CD14(+) monocytes using quantitative-polymerase chain reaction (RT-qPCR). Monocyte gene expression was age-dependent, particularly in MDD patients. Increased monocyte gene expression and decreased GRα/ß ratio were only present in MDD patients aged ⩾ 28 years. Post hoc analyses of monocyte immune activation in patients <28 years showed two subgroups: a subgroup with a severe course of depression (recurrent type, onset <15 years) - additionally characterized by panic/arousal symptoms and childhood trauma - that had a monocyte gene expression similar to HC, and a second subgroup with a milder course of the disorder (73% first episode depression, onset ⩾15 years) - additionally characterized by the absence of panic symptoms - that exhibited a strongly reduced inflammatory monocyte activation compared to HC. In conclusion, monocyte immune activation was not uniformly raised in MDD patients but was increased only in patients of 28 years and older.

Higher T central and lower effector memory cells in bipolar disorder: A differentiation abnormality?

The aim of this study was to elucidate the nature of T cell abnormalities in bipolar disorder (BD). With the use of multicolor flow cytometry, we first quantified the composition of the different memory and pro-inflammatory immune subpopulations in samples of 58 patients with BD and compared them to 113 healthy controls. Second, to assess if cytomegalovirus infection was related to the resulted immune subpopulation compositions in the two groups, we measured cytomegalovirus-specific antibodies in serum. Thirdly, we assessed differences between the two groups in the serum levels of the immune cell differentiation factor interleukin-7. Compared to healthy controls, patients showed significantly higher T helper-17, T regulatory and T central memory cells (CD4+ and CD8+). Besides, patients showed significantly lower CD4+ T effector memory and CD4+ T effector memory re-expressing RA cells. Cytomegalovirus infection was not related to the observed abnormalities, with the exception of T helper-17 cells. This immune subpopulation was significantly higher only in patients seropositive to cytomegalovirus infection. Finally, interleukin-7 levels were significantly lower in BD compared to healthy controls. In conclusion, the aberrant levels of T memory cell populations in BD may suggest a T cell differentiation abnormality. The role of interleukin-7 in this putative abnormality should be further investigated.

Down-regulation of inflammation-protective microRNAs 146a and 212 in monocytes of patients with postpartum psychosis.

BACKGROUND: Postpartum psychosis (PP) is thought to belong to the bipolar spectrum. Recently we described an immune activation signature in monocytes of patients with PP using gene expression profiling. Immune activation genes are regulated by microRNAs (miRNAs). We therefore profiled miRNA expression in monocytes of PP patients to identify differentially expressed miRNAs between PP and the healthy state. METHODS: In a profiling study we carried out miRNA profiling using TaqMan array human microRNA A cards v2.0 and monocytes of 8 PP patients. Data were analyzed against monocytes of healthy postpartum women (CP). Nine miRNAs were selected and tested using individual Q-PCR in a larger validation study on monocytes of 20 PP patients, 20 CP and 20 healthy non-postpartum women (HC). RESULTS: In the validation study miR-146a expression was significantly down-regulated in the monocytes of first onset PP patients as compared to CP and HC; miR-212 expression was significantly down-regulated in PP patients with prior bipolar disorder. In silico miR-146a targeted 4 genes of the previously described monocyte activation signature in bipolar disorder; miR-212 targeted 2 of such genes. In a correlation study decreased expression of miR-146a in monocytes was related to decreased natural T regulator cells in PP patients; decreased miR-212 was correlated to increased Adrenomedulin and decreased IL-6 expression in monocytes and to higher Th2 cell levels. CONCLUSIONS: This study identified changes in miR-146a and -212 expression in PP. Since these miRNAs are linked to inflammation, the study strengthens the view that PP is an inflammation-like condition.

Premature T cell aging in major depression: A double hit by the state of disease and cytomegalovirus infection.

Introduction: Previous research indicates that premature T cell senescence is a characteristic of major depressive disorder (MDD). However, known senescence inducing factors like cytomegalovirus (CMV) infection or, probably, childhood adversity (CA) have not been taken into consideration so far. Objective: Differentiation and senescent characteristics of T cells of MDD patients were investigated in relation to healthy controls (HC), taking the CMV seropositivity and CA into account. Methods: 127 MDD and 113 HC of the EU-MOODSTRATIFICATION cohort were analyzed. Fluorescence activated cell sorting (FACS) analysis was performed to determine B, NK, and T cell frequencies. In a second FACS analysis, naïve, effector memory (Tem), central memory (Tcm), effector memory cells re-expressing RA (TEMRA), as well as CD28+ and CD27+ memory populations, were determined of the CD4+ and CD8+ T cell populations in a subsample (N = 35 MDD and N = 36 HC). CMV-antibody state was measured by IgG ELISA and CA by the Childhood Trauma Questionnaire. Results: We detected a CMV-antibody positivity in 40% of MDD patients (35% HC, n. s.) with seropositive MDD cases showing a higher total childhood trauma score. Second, a higher inflation of memory CD4+ T helper cells in CMV seronegative patients as compared to seronegative HC and reduced numbers of naïve CD4+ T helper cells in CMV seropositive patients (not in CMV seropositive HC) were found. Third, a higher inflation of memory CD8+ T cytotoxic cells in CMV seropositive cases as compared to CMV seropositive HC, particularly of the TEMRA cells, became apparent. Higher percentages of CD4+ TEMRA and late stage CD27-CD28- TEMRA cells were similar in both HC and MDD with CMV seropositivity. Overall, apportioning of T cell subpopulations did not differ between CA positive vs negative cases. Conclusions: MDD patients show several signs of a CMV independent "MDD specific" premature T cell aging, such as a CMV independent increase in CD4+ T memory cells and a latent naïve CD4 T-cell reduction and a latent CD8+ T-cell increase. However, these two latent T cell senescence abnormalities only become evident with CMV infection (double hit).

Reduced numbers of naïve CD4 + T cells and an altered CD4/CD8 balance in depressed common variable immune deficiency (CVID) patients. Is thymosin-α1 a possible treatment?

In the 1990's the macrophage-T-cell-theory of depression was posed stating that low grade inflammation and an abnormal T cell system destabilize the development and function of the emotional brain in such a way, that individuals become ultrasensitive to stress. Recently we gathered evidence that indeed higher frequencies of CD4+ memory T cells, lower frequencies of naive CD4 + T cells, higher frequencies of CD8 + T cells (the latter two in part elicited by Cytomegalovirus, CMV, infection) are a characteristic of Major Depressive Disorder (MDD). In MDD patients with a history of childhood trauma and severe depression monocytes are inflammatory activated. Low grade inflammation and T cell system defects have also been reported in patients with Common Variable Immune Deficiency (CVID) (next to antibody production defects). CVID patients show a higher prevalence of mild depression. The aim of this study was to determine T cell frequencies and monocyte inflammatory activation in CVID patients with and without depression. This study confirms that CVID patients have CMV independent decreases in the frequency of naïve CD4 + T cells and it de novo shows a CMV dependent increase in the expression of inflammatory genes in monocytes. CVID patients with depression are additionally characterized by a CMV independent increase in the frequency of naïve CD8 + T cells, while lacking monocyte inflammatory activation. In conclusion, depressed CVID patients have T cell abnormalities comparable to that of patients with regular MDD. These abnormalities are presently targeted by thymosin α1 in an open-label proof of concept trial.

Immunological profiling in long COVID: overall low grade inflammation and T-lymphocyte senescence and increased monocyte activation correlating with increasing fatigue severity.

Background: Many patients with SARS-CoV-2 infection develop long COVID with fatigue as one of the most disabling symptoms. We performed clinical and immune profiling of fatigued and non-fatigued long COVID patients and age- and sex-matched healthy controls (HCs). Methods: Long COVID symptoms were assessed using patient-reported outcome measures, including the fatigue assessment scale (FAS, scores ≥22 denote fatigue), and followed up to one year after hospital discharge. We assessed inflammation-related genes in circulating monocytes, serum levels of inflammation-regulating cytokines, and leukocyte and lymphocyte subsets, including major monocyte subsets and senescent T-lymphocytes, at 3-6 months post-discharge. Results: We included 37 fatigued and 36 non-fatigued long COVID patients and 42 HCs. Fatigued long COVID patients represented a more severe clinical profile than non-fatigued patients, with many concurrent symptoms (median 9 [IQR 5.0-10.0] vs 3 [1.0-5.0] symptoms, p<0.001), and signs of cognitive failure (41%) and depression (>24%). Immune abnormalities that were found in the entire group of long COVID patients were low grade inflammation (increased inflammatory gene expression in monocytes, increased serum pro-inflammatory cytokines) and signs of T-lymphocyte senescence (increased exhausted CD8+ TEMRA-lymphocytes). Immune profiles did not significantly differ between fatigued and non-fatigued long COVID groups. However, the severity of fatigue (total FAS score) significantly correlated with increases of intermediate and non-classical monocytes, upregulated gene levels of CCL2, CCL7, and SERPINB2 in monocytes, increases in serum Galectin-9, and higher CD8+ T-lymphocyte counts. Conclusion: Long COVID with fatigue is associated with many concurrent and persistent symptoms lasting up to one year after hospitalization. Increased fatigue severity associated with stronger signs of monocyte activation in long COVID patients and potentially point in the direction of monocyte-endothelial interaction. These abnormalities were present against a background of immune abnormalities common to the entire group of long COVID patients.

TREM-1 and DAP12 expression in monocytes of patients with severe psychiatric disorders. EGR3, ATF3 and PU.1 as important transcription factors.

INTRODUCTION: Immune activation is a characteristic of schizophrenia (SCZ), bipolar disorder (BD) and unipolar major depressive disorder (MDD). The triggering receptor expressed on myeloid cells 1 (TREM-1), its' adaptor molecule DAP12 and their transcription factor (TF) PU.1 are important key genes in inflammation and expressed in activated monocytes and microglia. AIM: To test: (1) if the expressions of TREM-1, DAP12 and PU.1 are increased in monocytes of patients with severe psychiatric disorders and (2) if PU.1 and the TFs ATF3 and EGR3 (which have been found as prominent increased monocyte genes in previous studies) are involved in the regulation of TREM-1 and DAP12 expression. METHODS: Using Q-PCR, we studied the gene expression of TREM-1, DAP12, PU.1, ATF3 and EGR3 in the monocytes of 73 patients with severe psychiatric disorders (27 recent onset SCZ patients, 22 BD patients and 24 MDD patients) and of 79 healthy controls (HC). Using in silico TF binding site prediction and in vivo chromatin immunoprecipitation (ChIP), we studied the actual binding of EGR3, ATF3 and PU.1 to the promoter regions of TREM-1 and DAP12. RESULTS: 1. TREM-1 gene expression was increased in the monocytes of SCZ and BD patients and tended to be increased in the monocytes of MDD patients. 2. DAP12 gene levels were neither increased in the monocytes of SCZ, BD, nor MDD patients. 3. PU.1 expression levels were increased in the monocytes of MDD patients, but not in those of SCZ and BD patients. 4. TREM-1 expression levels correlated in particular to ATF3 and EGR3 expression levels, DAP12 expression levels correlated in particular to PU.1 expression levels. 5. We found using binding site prediction and ChIP assays that the TFs EGR3 and ATF3 indeed bound to the TREM-1 promoter, PU.1 bound to both the TREM-1 and DAP12 promoter. CONCLUSION: In this study, we provide evidence that TREM-1 gene expression is significantly increased in monocytes of SCZ and BD patients and that the TREM-1 gene is a target gene of the TFs ATF3 and EGR3. In MDD patients, PU.1 gene expression was increased with a tendency for TREM-1 gene over expression. Our observations support the concept that monocytes are in a pro-inflammatory state in severe psychiatric conditions and suggest differences in monocyte inflammatory set points between SCZ, BD and MDD.

Activation and deactivation steps in the tryptophan breakdown pathway in major depressive disorder: A link to the monocyte inflammatory state of patients.

It is unclear how the tryptophan (TRP) breakdown pathway relates to the activated inflammatory state of patients with major depressive disorder (MDD). We determined in two different cohorts of patients with MDD (n = 281) and healthy controls (HCs) (n = 206) collected for the EU-MOODINFLAME project: We then correlated outcomes to each other, and to the clinical characteristics of patients. Both cohorts of patients differed clinically; patients of the Munich cohort (n = 50) were less overweight, less medicated, were less in the current episode and showed a higher HAM-D 17 score as compared with patients of the Muenster cohort (n = 231). An increased expression of ICCGs was found in the circulating monocytes of patients of both cohorts; this was in particular evident in the Munich cohort. In contrast, ISGs monocyte expression levels tended to be reduced (both cohorts). TRP serum levels were linked to the pro-inflammatory (ICCGs) monocyte state of patients; a decrease in TRP serum levels was found in the Munich cohort; TRP levels correlated negatively to patient's HAM-D 17 score. Contrary to what expected, KYN serum levels were not increased in patients (both cohorts); and an increased KYN/TRP ratio was only found in the Munich patients (who showed the lowest TRP serum levels). IDO-1 monocyte expression levels were decreased in patients (both cohorts) and negatively associated to their pro-inflammatory (ICCGs) monocyte state. Thus, a depletion of TRP via an ICCGs-inflammatory IDO activation is not likely in MDD. Downstream from KYN, and regarding compounds influencing glutamate receptors (GR), reduced serum levels of KYNA (NMDA-R antagonist), 3-HK (NMDA-R agonist), and XA (mGlu2/3 agonist) were found in patients of both cohorts; PIC serum levels (NMDA-R antagonist) were increased in patients of both cohorts. Reduced QUIN serum levels (NMDA-R agonist) were found in patients of the Muenster cohort,only. 3-HK levels correlated to the monocyte inflammatory ICCG state of patients. The ultimate effect on brain glutamate receptor triggering of this altered equilibrium between peripheral agonists and antagonists remains to be elucidated.

Monocyte mitochondrial dysfunction, inflammaging, and inflammatory pyroptosis in major depression.

BACKGROUND: The macrophage theory of depression states that macrophages play an important role in Major Depressive Disorder (MDD). METHODS: MDD patients (N = 140) and healthy controls (N = 120) participated in a cross-sectional study investigating the expression of apoptosis/growth and lipid/cholesterol pathway genes (BAX, BCL10, EGR1, EGR2, HB-EGF, NR1H3, ABCA1, ABCG1, MVK, CD163, HMOX1) in monocytes (macrophage/microglia precursors). Gene expressions were correlated to a set of previously determined and reported inflammation-regulating genes and analyzed with respect to various clinical parameters. RESULTS: MDD monocytes showed an overexpression of the apoptosis/growth/cholesterol and the TNF genes forming an inter-correlating gene cluster (cluster 3) separate from the previously described inflammation-related gene clusters (containing IL1 and IL6). While upregulation of monocyte gene cluster 3 was a hallmark of monocytes of all MDD patients, upregulation of the inflammation-related clusters was confirmed to be found only in the monocytes of patients with childhood adversity. The latter group also showed a downregulation of the cholesterol metabolism gene MVK, which is known to play an important role in trained immunity and proneness to inflammation. CONCLUSIONS: The upregulation of cluster 3 genes in monocytes of all MDD patients suggests a premature aging of the cells, i.e. mitochondrial apoptotic dysfunction and TNF "inflammaging", as a general feature of MDD. The overexpression of the IL-1/IL-6 containing inflammation clusters and the downregulation of MVK in monocytes of patients with childhood adversity indicates a shift in this condition to a more severe inflammation form (pyroptosis) of the cells, additional to the signs of premature aging and inflammaging.

Prospective real-world study on the pharmacokinetics of pembrolizumab in patients with solid tumors.

BACKGROUND: Dosing schemes of pembrolizumab (anti-programmed cell death protein 1 monoclonal antibody) are solely based on pharmacokinetic (PK) modelling derived from phase I-III trials. The current study aimed to determine factors affecting PK and its relationship with clinical outcome in the real-world setting. METHODS: Advanced-stage cancer patients, who were treated with pembrolizumab monotherapy (2 mg/kg Q3W or 200 mg flat Q3W), were prospectively included for serial sampling to obtain trough concentrations. A PK model was generated, covariate effects assessed and internally validated by a bootstrap procedure. PK parameters were related to overall survival (OS) and the occurrence of immune-related adverse events (irAEs). RESULTS: 588 serum samples derived from 122 patients with (non-)small-cell lung cancer ([N]SCLC), malignant pleural mesothelioma (MPM), melanoma and urothelial cell cancer (UCC) were analyzed. Median follow-up was 2.2 years. A one-compartment PK model was generated: body surface area (BSA) and serum albumin had a significant effect on drug clearance (CL; covariate estimate 1.46 and -1.43, respectively), and serum lactate dehydrogenase (LDH) on the distribution volume(Vd; 0.34). A significant inverse CL-OS relationship was determined for NSCLC (HR:1.69; 95%CI1.07-2.68; p=0.024) and MPM (HR: 3.29; 95% CI 1.08 to 10.09; p=0.037), after correction for prognostic factors, which could not confirmed for melanoma (p=0.22) or UCC (p=0.34). No relationship could be determined between CL and grade >3 irAEs (p=0.70). CONCLUSIONS: High interpatient variability of pembrolizumab PK is determined by BSA and serum albumin (on CL) and LDH (on Vd). A strong inverse CL-OS relationship was demonstrated for NSCLC and MPM, which could not be observed for melanoma and UCC. The findings suggest that personalized dosing should be prospectively explored.

Childhood trauma, suicide risk and inflammatory phenotypes of depression: insights from monocyte gene expression.

Circulating monocytes contribute to inflammatory processes. We here validate abnormal expression of inflammation-related genes in monocytes of a large and well-characterised group of MDD patients, and relate the outcomes to pertinent clinical characteristics. Thirty-two genes of a previously established inflammation-related gene signature were assessed in 197 patients with MDD, and 151 controls collected during the EU-MOODINFLAME project. Monocyte gene- expression data were related to age, sex, BMI, depression severity, childhood adversity (CA) and suicide risk (SR). Three distinct gene profiles were identified within the MDD group (downregulated, mixed upregulated and strongly upregulated genes). Patients in the merged upregulated groups had a significantly higher prevalence of CA and high SR. Using hierarchical clustering of the genes, we found a cluster of mainly cytokine (production)-related genes; patients with SR had a significantly higher expression of this cluster than patients without SR (particularly for IL-6, IL1A and IL1B). Such difference did not emerge for patients with and without CA. A downregulated gene profile was found for patients not exposed to CA and without SR (particularly for glucocorticoid-signalling genes NR3C1a and HSPA1/B). No inflammatory changes were observed for healthy controls exposed to CA. Our data show that inflammatory activation in MDD is not uniform, and that immunologically discernible phenotypes of depression can be linked to CA and high SR. The absence of monocyte inflammatory activation in healthy controls exposed to CA suggests an inflammatory involvement in MDD-prone individuals exposed to early stressors, but not healthy controls.

Low-Grade Inflammation as a Predictor of Antidepressant and Anti-Inflammatory Therapy Response in MDD Patients: A Systematic Review of the Literature in Combination With an Analysis of Experimental Data Collected in the EU-MOODINFLAME Consortium.

Low-grade inflammation plays a role not only in the pathogenesis of major depressive disorder (MDD) but probably also in the poor responsiveness to regular antidepressants. There are also indications that anti-inflammatory agents improve the outcomes of antidepressants. Aim: To study whether the presence of low-grade inflammation predicts the outcome of antidepressants, anti-inflammatory agents, or combinations thereof. Methods: We carried out a systematic review of the literature on the prediction capability of the serum levels of inflammatory compounds and/or the inflammatory state of circulating leukocytes for the outcome of antidepressant/anti-inflammatory treatment in MDD. We compared outcomes of the review with original data (collected in two limited trials carried out in the EU project MOODINFLAME) on the prediction capability of the inflammatory state of monocytes (as measured by inflammatory gene expression) for the outcome of venlafaxine, imipramine, or sertraline treatment, the latter with and without celecoxib added. Results: Collectively, the literature and original data showed that: 1) raised serum levels of pro-inflammatory compounds (in particular of CRP/IL-6) characterize an inflammatory form of MDD with poor responsiveness to predominately serotonergic agents, but a better responsiveness to antidepressant regimens with a) (add-on) noradrenergic, dopaminergic, or glutamatergic action or b) (add-on) anti-inflammatory agents such as infliximab, minocycline, or eicosapentaenoic acid, showing-next to anti-inflammatory-dopaminergic or lipid corrective action; 2) these successful anti-inflammatory (add-on) agents, when used in patients with low serum levels of CRP/IL-6, decreased response rates in comparison to placebo. Add-on aspirin, in contrast, improved responsiveness in such "non-inflammatory" patients; 3) patients with increased inflammatory gene expression in circulating leukocytes had a poor responsiveness to serotonergic/noradrenergic agents. Conclusions: The presence of inflammation in patients with MDD heralds a poor outcome of first-line antidepressant therapies. Immediate step-ups to dopaminergic or glutamatergic regimens or to (add-on) anti-inflammatory agents are most likely indicated. However, at present, insufficient data exist to design protocols with reliable inflammation parameter cutoff points to guide such therapies, the more since detrimental outcomes are possible of anti-inflammatory agents in "non-inflamed" patients.

Markers of neuroinflammation influence measures of cortical thickness in bipolar depression.

We tested if peripheral levels of cytokines and chemokines associate to grey matter volumes, cortical thickness and fMRI neural responses to a moral valence decision task in bipolar patients. ICAM1 and CCL4 negatively correlated with cortical thickness in Inferior Temporal Gyrus, and sCD25 in Parahippocampal Gyrus. TNF-α, Interleukine-8, and CCL2 correlated positively with cortical thickness in the Anterior Cingulate Cortex, and with lower BOLD responses to negative stimuli. Markers of immune activation are associated with measures of brain structural and functional integrity in bipolar depression.

Fatigue in Sjögren's Syndrome: A Search for Biomarkers and Treatment Targets.

Background: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease, where patients often suffer from fatigue. Biological pathways underlying fatigue are unknown. In this study aptamer-based SOMAscan technology is used to identify potential biomarkers and treatment targets for fatigue in pSS. Methods: SOMAscan® Assay 1.3k was performed on serum samples of healthy controls (HCs) and pSS patients characterized for interferon upregulation and fatigue. Differentially expressed proteins (DEPs) between pSS patients and HC or fatigued and non-fatigued pSS patients were validated and discriminatory capacity of markers was tested using independent technology. Results: Serum concentrations of over 1,300 proteins were compared between 63 pSS patients and 20 HCs resulting in 58 upregulated and 46 downregulated proteins. Additionally, serum concentrations of 30 interferon positive (IFNpos) and 30 interferon negative (IFNneg) pSS patients were compared resulting in 25 upregulated and 13 downregulated proteins. ELISAs were performed for several DEPs between pSS patients and HCs or IFNpos and IFNneg all showing a good correlation between protein levels measured by ELISA and relative fluorescence units (RFU) measured by the SOMAscan. Comparing 22 fatigued and 23 non-fatigued pSS patients, 16 serum proteins were differentially expressed, of which 14 were upregulated and 2 were downregulated. Top upregulated DEPs included neuroactive synaptosomal-associated protein 25 (SNAP-25), alpha-enolase (ENO1) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1). Furthermore, the proinflammatory mediator IL36a and several complement factors were upregulated in fatigued compared to non-fatigued pSS patients. ROC analysis indicated that DEPs showed good capacity to discriminate fatigued and non-fatigued pSS patients. Conclusion: In this study we validated the use of aptamer-based proteomics and identified a novel set of proteins which were able to distinguish fatigued from non-fatigued pSS patients and identified a so-called "fatigue signature."

Correlation between nivolumab exposure and treatment outcomes in non-small-cell lung cancer.

INTRODUCTION: Nivolumab treatment is subject to large interpatient variability in both efficacy and toxicity, which may partly be explained by differences in nivolumab exposure. Exposure-response relationships in regular healthcare have not been extensively investigated for nivolumab. Therefore, we aimed to identify possible exposure-response relationships in nivolumab-treated patients with non-small-cell lung cancer (NSCLC). METHODS: Patients with NSCLC who started second-line nivolumab therapy (3 mg/kg Q2W) between May 5th 2016 and August 1st 2017, and from whom serial blood samples, toxicity data and outcome data were prospectively collected, were included. Follow-up was carried out until November 1st 2017. Patients were classified according to the best overall response (BOR) based on the Response Evaluation Criteria in Solid Tumours, v1.1, and toxicities according to the Common Terminology Criteria for Adverse Events. Nivolumab trough concentrations were measured after 2, 4 and 10 weeks of treatment, excluding dose delays, and calculated geometric means were tested versus BOR or toxicity using analysis of variance and an independent samples t-test, respectively. Overall survival (OS) and progression-free survival were compared between high and low trough concentration groups. RESULTS: Seventy-six patients were evaluable for analyses. Responders (n = 15) had higher mean trough concentrations than patients with progression (n = 33): 47% higher after 2 weeks (p = 0.001), 53% higher after 4 weeks (p = 0.008) and 73% higher after 10 weeks (p = 0.002). Higher trough concentrations were associated with longer OS (p = 0.001). CONCLUSIONS: This study shows that patients with NSCLC with a response to nivolumab had a higher nivolumab exposure than patients with progression, indicating a potential exposure-response relationship. Further clinical research should focus on clarifying these exposure-response relationships.

A prospective cohort study on the pharmacokinetics of nivolumab in metastatic non-small cell lung cancer, melanoma, and renal cell cancer patients.

BACKGROUND: Nivolumab is administered in a weight-based or fixed-flat dosing regimen. For patients with non-small cell lung cancer (NSCLC), a potential exposure-response relationship has recently been reported and may argue against the current dosing strategies. The primary objectives were to determine nivolumab pharmacokinetics (PK) and to assess the relationship between drug clearance and clinical outcome in NSCLC, melanoma, and renal cell cancer (RCC). METHODS: In this prospective observational cohort study, individual estimates of nivolumab clearance and the impact of baseline covariates were determined using a population-PK model. Clearance was related to best overall response (RECISTv1.1), and stratified by tumor type. RESULTS: Two-hundred-twenty-one patients with metastatic cancer receiving nivolumab-monotherapy were included of whom 1,715 plasma samples were analyzed. Three baseline parameters had a significant effect on drug clearance and were internally validated in the population-PK model: gender, BSA, and serum albumin. Women had 22% lower clearance compared to men, while the threshold of BSA and albumin that led to > 20% increase of clearance was > 2.2m2 and < 37.5 g/L, respectively. For NSCLC, drug clearance was 42% higher in patients with progressive disease (mean: 0.24; 95% CI: 0.22-0.27 L/day) compared to patients with partial/complete response (mean: 0.17; 95% CI: 0.15-0.19 L/day). A similar trend was observed in RCC, however, no clearance-response relationship was observed in melanoma. CONCLUSIONS: Based on the first real-world population-PK model of nivolumab, covariate analysis revealed a significant effect of gender, BSA, and albumin on nivolumab clearance. A clearance-response relationship was observed in NSCLC, with a non-significant trend in RCC, but not in melanoma. Individual pharmacology of nivolumab in NSCLC appears important and should be prospectively studied.