Sigrun Hope

Similar immune profile in bipolar disorder and schizophrenia: selective increase in soluble tumor necrosis factor receptor I and von Willebrand factor

BACKGROUND Alterations in the inflammatory system have been associated with schizophrenia and major depression, while bipolar disorder has been less studied. Most previous studies examined small samples, and the literature is inconsistent with regard to specific underlying immune mechanisms. In the present study, we examined markers representing different inflammatory pathways, and the aim was to investigate whether the levels of inflammatory parameters in a representative sample of bipolar disorder and schizophrenia are elevated compared to healthy controls, and to investigate whether the inflammatory profile is different between the groups. METHODS Plasma levels of soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), high-sensitivity CRP (hs-CRP), soluble CD40L ligand (sCD40L), and von Willebrand factor (vWf) were measured with ELISA techniques in a catchment area based sample of consecutively referred patients with severe mental disorders [N = 311, comprising bipolar disorder (n = 125) and schizophrenia (n = 186)] and in healthy volunteers (n = 244). RESULTS Plasma levels of sTNF-R1 and vWf were statistically significantly increased in both bipolar disorder and schizophrenia compared to controls (p < 0.00001), and were also increased in unmedicated patients, but there were no major differences between the two diagnostic groups. Controlling for age, gender, ethnicity, cardiovascular disorders, kidney and liver function, and other confounders did not affect the results. There were no differences in other inflammation factors between the groups. CONCLUSION The present results indicate specific alterations of endothelium-related inflammation processes in both bipolar disorder and schizophrenia.

Interleukin 1 receptor antagonist and soluble tumor necrosis factor receptor 1 are associated with general severity and psychotic symptoms in schizophrenia and bipolar disorder

BACKGROUND Previous studies suggest elevated inflammation in schizophrenia and bipolar disorder, with increased activity of the Interleukin 1 (IL-1), interleukin 6 (IL-6), tumor necrosis factor (TNF)-alpha, von Willebrand factor (vWf) and osteoprotegerin (OPG). It is unclear how immune activation is involved in the psychopathology. We investigated if elevated inflammation was associated with disease severity (trait) or current symptom level (state), comparing psychotic with general characteristics. METHODS Plasma levels of sTNF receptor 1 (sTNF-R1), IL-1 receptor antagonist (IL-1Ra), IL-6, vWf and OPG were measured with ELISA techniques in 322 patients with schizophrenia spectrum and bipolar disorder. Current symptom level (state) was measured with Global Assessment of Functioning (GAF) and Positive and Negative Syndrome Scale (PANSS). Disease severity (trait) was measured with premorbid adjustment scale (PAS), age at onset, number of psychotic episodes and number and length of hospitalizations. RESULTS After controlling for confounders, IL-1Ra and TNF-R1 were independently associated with GAF, and significantly correlated with PANSS negative and positive, respectively. In addition, Il-1Ra was associated with PAS, and sTNF-R1 with number of hospitalizations and psychotic episodes. VWf was significantly correlated with psychotic episodes, OPG with hospitalizations and IL-6 with history of psychosis. Linear regression analysis showed that GAF remained associated with sTNF-R1 and IL-1Ra with PANSS, after controlling for the other clinical measures. CONCLUSIONS This supports that inflammatory markers, particularly IL-1Ra and sTNF-R1 are associated with both general disease severity and psychotic features. This supports a role of immune activation in the core pathological mechanisms of severe mental disorders.

Increased Systemic Cortisol Metabolism in Patients With Schizophrenia and Bipolar Disorder: A Mechanism for Increased Stress Vulnerability?

OBJECTIVE The hypothalamic-pituitary-adrenal (HPA) axis seems dysregulated and part of the pathophysiology in bipolar disorder and schizophrenia, but the underlying mechanisms are unknown. Recent evidence indicates that systemic cortisol metabolism influences blood cortisol levels and HPA axis functioning. Our objective was to estimate systemic cortisol metabolism by means of the activity of 5α-reductase, 5β-reductase, and 11β-hydroxysteroid dehydrogenase (11β-HSD) in patients with bipolar disorder and schizophrenia spectrum disorders compared to healthy controls. METHOD Inpatients and outpatients aged 18 to 65 years with DSM-IV bipolar disorder (n = 69) or schizophrenia (n = 87) were consecutively recruited to the catchment area-based Thematically Organized Psychosis Research (TOP) study. Healthy controls (n = 169) were randomly selected from statistical records from the same catchment area and were contacted by letter inviting them to participate. Spot urine samples were collected in a cross-sectional manner from November 2006 to November 2008. Urinary free cortisol and cortisone and their metabolites were analyzed with liquid chromatography tandem mass spectrometry and used as indicators of 5α-reductase, 5β-reductase, and 11β-HSD activity. RESULTS The combined patient group had increased activity of 5α-reductase, 5β-reductase, and 11β-HSD2 (all P < .001) compared to controls. Elevated systemic cortisol metabolism was present in both schizophrenia (5α-reductase, 5β-reductase, and 11β-HSD2; all P < .001) and bipolar disorder (5α-reductase [P = .016], 5β-reductase [P = .001], and 11β-HSD2 [P = .007]). CONCLUSIONS The results indicate increased activity of cortisol metabolism in patients with bipolar disorder and schizophrenia compared to healthy controls and suggest that increased systemic cortisol metabolism is involved in the pathophysiology and stress vulnerability in these severe mental disorders. The findings should be explored further in terms of potential new drug targets, and they add to the physiologic rationale for stress coping strategies in these patient groups.

Cardiovascular risk factors during second generation antipsychotic treatment are associated with increased C-reactive protein

OBJECTIVE Severe mental disorder and cardiovascular disease (CVD) are often associated, and inflammation is implicated in both disorders. We investigated whether there is a relationship between CVD risk factors and inflammation in schizophrenia or bipolar disorder, and if second generation antipsychotics (SGA) interact. METHODS We included 361 patients in a naturalistic cross-sectional study, 235 subjects on current SGA treatment and 126 subjects not treated with SGA as controls. Cardiovascular parameters were measured and current medication recorded. Fasting plasma levels of the following cytokines were measured: high sensitivity CRP (hsCRP), soluble tumor necrosis factor receptor 1 (sTNF-R1), osteoprotegerin (OPG), soluble CD40 ligand (sCD40L), interleukin-1 receptor antagonist (IL-1Ra), von Willebrand factor (vWf) and interleukin-6 (IL-6). RESULTS In this relatively young sample of patients with a mean age of 33.3years, the following CVD risk factors were associated with elevated inflammation markers after adjusting for confounders: BMI, triglycerides and glucose with hsCRP (p=0.041-0.001), HDL-cholesterol and triglycerides with sTNF-R1 (p=0.009-0.001) and triglycerides with vWf (p=0.004). In patients treated with SGA, elevated hsCRP was significantly associated with high BMI (p=0.012), and with high glucose levels (p=0.003). CONCLUSION Several CVD risk factors are associated with elevated levels of inflammation markers in young patients with severe mental illness. The interaction between SGA and CVD risk factors on hsCRP levels might indicate a specific inflammatory activation related to SGA induced overweight and hyperglycemia. This suggests that hsCRP could be a valuable marker for future cardiovascular events, particularly in patients treated with SGA.

Inflammatory markers are associated with general cognitive abilities in schizophrenia and bipolar disorder patients and healthy controls

BACKGROUND The mechanisms underlying cognitive impairment in schizophrenia and bipolar disorders are largely unknown. Immune abnormalities have been found in both disorders, and inflammatory mediators may play roles in cognitive function. We investigated if inflammatory markers are associated with general cognitive abilities. METHODS Participants with schizophrenia spectrum (N=121) and bipolar spectrum (N=111) disorders and healthy controls (N=241) were included. General intellectual abilities were assessed using the Wechsler Abbreviated Scale of Intelligence (WASI). Serum concentrations of the following immune markers were measured: Soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin 1 receptor antagonist (IL-1Ra), osteoprotegerin, von Willebrand factor, C-reactive protein, interleukin-6 and CD40 ligand. RESULTS After adjusting for age, sex and diagnostic group, significant negative associations with general cognitive function were found for sTNF-R1 (p=2×10(-5)), IL-1Ra (p=0.002) and sCD40 ligand (p=0.003). Among patients, the associations remained significant (p=0.006, p=0.005 and p=0.02) after adjusting for possible confounders including education, smoking, psychotic and affective symptoms, body mass index, cortisol, medication and time of blood sampling. Subgroup analysis, showed that general cognitive abilities were significantly associated with IL-1Ra and sTNF-R1 in schizophrenia patients, with sCD40L and IL-1Ra in bipolar disorder patients and with sTNF-R1 in healthy controls. CONCLUSION The study shows significant negative associations between inflammatory markers and general cognitive abilities after adjusting for possible confounders. The findings strongly support a role for inflammation in the neurophysiology of cognitive impairment.

Sex-specific cortisol levels in bipolar disorder and schizophrenia during mental challenge--relationship to clinical characteristics and medication.

OBJECTIVE Our objective was to examine the cortisol release during a mental challenge in severe mental disorders versus healthy controls (HC), analyzing effects of sex, clinical characteristics and medication, and comparing Bipolar Disorder (BD) to Schizophrenia (SCZ). METHODS Patients with BD and SCZ (n=151) were recruited from a catchment area. HC (n=98) were randomly selected from the same area. Salivary samples were collected before and after a mental challenge and cortisol levels determined. RESULTS During the challenge there was an interaction between group and sex (P = 0.015) with male patients having a blunted cortisol release compared to male HC (P = 0.037). Cortisol change did not differ significantly between BD and SCZ. In all patients, the cortisol change correlated with number of psychotic episodes (r = -0.23, P = 0.025), and in females patients, with number of depressive episodes (r = -0.33, P = 0.015). Patients using antidepressants had a greater cortisol release during challenge than those not using antidepressants (P = 0.043). CONCLUSIONS Male patients with severe mental disorders seem to have a uniform abnormal cortisol release during mental challenges which associates with clinical course, and with beneficial effects of antidepressants.

Osteoprotegerin levels in patients with severe mental disorders

BACKGROUND Severe mental disorders are associated with elevated levels of inflammatory markers. In the present study, we investigated whether osteoprotegerin (OPG), a member of the tumour necrosis factor receptor family involved in calcification and inflammation, is elevated in patients with severe mental disorders. METHODS We measured the plasma levels of OPG in patients with severe mental disorders (n = 312; 125 with bipolar disorder and 187 with schizophrenia) and healthy volunteers (n = 239). RESULTS The mean plasma levels of OPG were significantly higher in patients than in controls (t531 = 2.6, p = 0.01), with the same pattern in bipolar disorder and schizophrenia. The increase was significant after adjustment for possible confounding variables, including age, sex, ethnic background, alcohol consumption, liver and kidney function, diabetes, cardiovascular disease, autoimmune diseases and levels of cholesterol, glucose and C-reactive protein. LIMITATIONS Owing to the cross-sectional design, it is difficult to determine causality. CONCLUSION Our results indicate that elevated OPG levels are associated with severe mental disorders and suggest that mechanisms related to calcification and inflammation may play a role in disease development.

Up-regulation of NOTCH4 gene expression in bipolar disorder.

OBJECTIVE Immunopathogenic mechanisms have been implicated in schizophrenia and bipolar disorder, and genome-wide association studies (GWAS) point to the major histocompatibility complex, a region that contains many immune-related genes. One of the strongest candidate risk genes for schizophrenia and bipolar disorder is the NOTCH4 gene within the major histocompatibility complex. The authors investigated the NOTCH4 gene expression in individuals with bipolar disorder and schizophrenia relative to healthy comparison subjects and identified putative expression quantitative trait loci in and around the NOTCH4 gene. METHOD The authors measured and compared NOTCH4 mRNA in whole blood in 690 individuals (479 patients and 211 healthy comparison subjects) and adjusted for a range of confounders. The authors also genotyped 20 single-nucleotide polymorphisms (SNPs) and investigated possible associations between expression quantitative trait loci and NOTCH4 expression. RESULTS The authors found a strong association between NOTCH4 expression and bipolar disorder after adjusting for a range of confounders and multiple testing. In addition, seven SNPs within the NOTCH4 gene region were associated with enhanced NOTCH4 mRNA levels. Three of these expression quantitative trait loci were independent (not in linkage disequilibrium). CONCLUSIONS The results indicate that the association between NOTCH4 DNA markers and bipolar disorder is related to altered function at the mRNA level, supporting the notion that NOTCH4 pathways are involved in the pathophysiology of bipolar disorder.

Inflammatory evidence for the psychosis continuum model

BACKGROUND Inflammation and immune activation have been implicated in the pathophysiology of severe mental disorders. Previous studies of inflammatory markers, however, have been limited with somewhat inconsistent results. AIMS We aimed to determine the effect sizes of inflammatory marker alterations across diagnostic groups of the psychosis continuum and investigate association to antipsychotic medications. METHODS Plasma levels of soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin 1 receptor antagonist (IL-1Ra), osteoprotegerin (OPG), and von Willebrand factor (vWf) were measured in patients (n=992) with schizophrenia spectrum (SCZ, n=584), schizoaffective disorder (SA, n=93), affective spectrum disorders (AFF, n=315), and healthy controls (HC, n=638). RESULTS Levels of sTNF-R1 (p=1.8×10(-8), d=0.23) and IL-1Ra (p=0.002, d=0.16) were increased in patients compared to HC. The SCZ group had higher levels of sTNF-R1 (p=8.5×10(-8), d=0.27) and IL-1Ra (p=5.9×10(-5), d=0.25) compared to HC, and for sTNF-R1 this was also seen in the SA group (p=0.01, d=0.3) and in the AFF group (p=0.002, d=0.12). Further, IL-1Ra (p=0.004, d=0.25) and vWf (p=0.02, d=0.21) were increased in the SCZ compared to the AFF group. There was no significant association between inflammatory markers and use of antipsychotic medication. CONCLUSION We demonstrate a small increase in sTNF-R1 and IL-1Ra in patients with severe mental disorders supporting a role of inflammatory mechanisms in disease pathophysiology. The increase was more pronounced in SCZ compared to AFF supporting a continuum psychosis model related to immune factors.

Dose-dependent social-cognitive effects of intranasal oxytocin delivered with novel Breath Powered device in adults with autism spectrum disorder: a randomized placebo-controlled double-blind crossover trial

The neuropeptide oxytocin has shown promise as a treatment for symptoms of autism spectrum disorders (ASD). However, clinical research progress has been hampered by a poor understanding of oxytocin’s dose–response and sub-optimal intranasal delivery methods. We examined two doses of oxytocin delivered using a novel Breath Powered intranasal delivery device designed to improve direct nose-to-brain activity in a double-blind, crossover, randomized, placebo-controlled trial. In a randomized sequence of single-dose sessions, 17 male adults with ASD received 8 international units (IU) oxytocin, 24IU oxytocin or placebo followed by four social-cognitive tasks. We observed an omnibus main effect of treatment on the primary outcome measure of overt emotion salience as measured by emotional ratings of faces (η2=0.18). Compared to placebo, 8IU treatment increased overt emotion salience (P=0.02, d=0.63). There was no statistically significant increase after 24IU treatment (P=0.12, d=0.4). The effects after 8IU oxytocin were observed despite no significant increase in peripheral blood plasma oxytocin concentrations. We found no significant effects for reading the mind in the eyes task performance or secondary outcome social-cognitive tasks (emotional dot probe and face-morphing). To our knowledge, this is the first trial to assess the dose-dependent effects of a single oxytocin administration in autism, with results indicating that a low dose of oxytocin can significantly modulate overt emotion salience despite minimal systemic exposure.