Schizophrenia (SCZ) shows marked biological heterogeneity, with negative symptoms linked to poor outcomes and hypothesised immune dysregulation. This study examined whether a peripheral cytokine–long non-coding RNA (lncRNA) panel could distinguish patients with SCZ and Brief Negative Symptom Scale (BNSS)-defined subgroups from healthy controls (HC).

Forty-one hospitalised patients with SCZ completed the BNSS and the Positive and Negative Syndrome Scale (PANSS). Twenty HCs, frequency-matched for age and sex, served as comparison samples. Severe negative-symptom subgroups were defined using two BNSS criteria: a broader (SNS1) and a more restrictive (SNS2) threshold. Serum cytokines – interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interleukin-10 (IL-10) – and leukocyte lncRNAs (MALAT1, NEAT1, MEG3) were quantified by enzyme-linked immunosorbent assay and quantitative RT-PCR. Covariate-adjusted logistic and multinomial models (adjusting for age, sex, body mass index, and smoking) assessed discrimination using area under the receiver-operating-characteristic curve (AUC) and interquartile-range odds ratios (OR_IQR).

IL-6 correlated with PANSS Total (ρ = 0.48, p = 0.001) and Negative (ρ = 0.34, p = 0.032) scores and was higher in SCZ than HC (p = 0.033), with further increases in SNS subgroups. NEAT1 was significantly reduced only within BNSS-defined subgroups (p ≤ 0.025). The dual-marker pattern (IL-6 ↑, NEAT1 ↓) showed the strongest discrimination for SNS1 versus HC (AUC = 0.85) and the steepest multinomial contrasts for SNS2 (IL-6 OR_IQR = 4.98; NEAT1 OR_IQR = 0.11).

Elevated IL-6 and decreased NEAT1 define a peripheral signature linked to negative-symptom severity in SCZ and may support biologically informed stratification and longitudinal research.

Longitudinal studies have revealed that raised levels of inflammatory markers and trauma in childhood are associated with psychopathology in adulthood.

To examine whether inflammation in childhood mediates the effects of genetic risk and trauma on psychopathology in early adulthood.

Measures of trauma exposure, inflammation and psychopathology were collected from the Avon Longitudinal Study of Parents and Children. Exposure to trauma was measured from 5 to 11 years of age; C-reactive protein and interleukin-6 levels were measured at 9 years; and depression, anxiety disorders, negative symptoms and psychotic experiences were assessed at 24 years. Polygenic risk scores (PRSs) were created for schizophrenia, depression, anxiety and psychotic experiences. Mediation analyses were conducted using imputed data (N: 7859 to 8700) to investigate whether inflammation mediated the associations of genetic risk and childhood trauma with psychopathology.

Most psychiatric PRSs were associated with multiple psychopathological outcomes in adulthood, with the exception of the PRS for psychotic experiences. Childhood trauma was associated with all psychopathology. However, there was no strong evidence that inflammatory markers in childhood mediated associations among PRSs, trauma and psychopathology. Sensitivity analyses using outcomes from age 18 and PRSs based on single-nucleotide polymorphisms that met more stringent standards of evidence of association gave results consistent with those of our primary analyses.

We found little evidence that interleukin-6 or C-reactive protein mediated the pathway between genetic liability for psychiatric phenotypes or trauma and subsequent psychopathology. Longitudinal investigation of other inflammatory and non-inflammatory pathways is required to identify modifiable targets and inform novel treatment strategies for individuals at genetic or trauma-related risk of psychiatric illness.

Cognitive deficits and immune system dysregulation are core features of psychotic disorders. Among inflammatory markers, interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) have been linked to both psychosis pathophysiology and related cognitive impairments.

We investigated associations among IL-6, TNF-α, and neurocognitive performance in 107 participants: individuals at clinical high risk for psychosis (CHR-P, n = 35), first-episode psychosis (FEP, n = 39), and healthy controls (HC, n = 33). Assessments included memory, processing speed, executive function, and social cognition. Cytokines were measured from fasting serum samples. Analyses included ANOVA, correlations, and multivariate regressions controlling for age, sex, IQ, group, and symptom severity.

TNF-α levels were significantly elevated in FEP compared to CHR-P (p = 0.0251); IL-6 differences were non-significant. FEP showed poorer performance in multiple cognitive domains, especially social cognition. CHR-P individuals exhibited intermediate profiles between FEP and HC in cognition. In adjusted regression models, IL-6 was significantly associated with undermentalization on the MASC task (β = 0.28, p = 0.0337) and showed a trend-level association with slower processing speed (β = 0.98, p = 0.075). TNF-α levels predicted poorer facial emotion recognition (β = −1.37, p = 0.0022). IQ and group were significant covariates in most models.

Our findings suggest that peripheral inflammation, particularly IL-6 and TNF-α, may selectively impact social cognitive functioning in early psychosis. Though modest, these associations highlight potential inflammatory contributions to functional impairment and support further investigation of immunological targets in early intervention.

The importance of recognizing different kinds of autism spectrum presentations among adults, including subthreshold forms and the broad autism phenotype (BAP), has been increasingly highlighted in recent studies. Meanwhile, the possible involvement of immune system deregulation and altered methylation/trans-sulfuration processes in autism spectrum disorder (ASD) is gaining growing attention, but studies in this field are mainly focused on children. In this framework, the aim of this study was to compare plasmatic concentrations of IL-6 and homocysteine (HCY) among adults with ASD, their first-degree relatives, and healthy controls (CTLs), investigating also possible correlations with specific autism symptoms.

Plasma concentrations of IL-6 and HCY were measured in a group of adult subjects with ASD, their first-degree relatives (BAP group), and healthy controls (CTL). All participants were also evaluated with psychometric instruments.

IL-6 and HCY concentrations were significantly higher in the ASD group than in CTLs, while BAP subjects reported intermediate results. Significant correlations were reported between biochemical parameters and psychometric scales, particularly for the dimension of ruminative thinking.

These findings support the hypothesis of a key involvement of HCY-related metabolism and immune system alteration in autism spectrum pathophysiology. HCY and IL-6 seem to show different associations with specific autism dimensions.

Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers.

We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603).

Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): −0·79, 95 % CI: −1·15, −0·42, I2 = 96 %] and TNF-α levels following soy protein supplementation (MD: −0·16, 95 % CI: −0·26, −0·05, I2 = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: −0·20, 95 % CI: −0·31, −0·08, I2 = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: −0·98, 95 % CI: −1·56, −0·39, I2 = 0 %). These findings may be dependent on participant characteristics and treatment duration.

These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.

Tetralogy of Fallot is a common CHD. Studies have shown a close link between heart failure and myocardial fibrosis. Interleukin-6 has been suggested to be a post-independent factor of heart failure. This study aimed to explore the relationship between IL-6 and myocardial fibrosis during cardiopulmonary bypass.

We downloaded the expression profile dataset GSE132176 from Gene Expression Omnibus. After normalising the raw data, Gene Set Enrichment Analysis and differential gene expression analysis were performed using R. Further, a weighted gene correlation network analysis and a protein–protein interaction network analysis were used to identify HUB genes. Finally, we downloaded single-cell expression data for HUB genes using PanglaoDB.

There were 119 differentially expressed genes in right atrium tissues comparing the post-CPB group with the pre-CPB group. IL-6 was found to be significantly up-regulated in the post-CPB group. Six genes (JUN, FOS, ATF3, EGR1, IL-6, and PTGS2) were identified as HUB genes by a weighted gene correlation network analysis and a protein–protein interaction network analysis. Gene Set Enrichment Analysis showed that IL-6 affects the myocardium during CPB mainly through the JAK/STAT signalling pathway. Finally, we used PanglaoDB data to analyse the single-cell expression of the HUB genes.

Our findings suggest that high expression of IL-6 and the activation of the JAK/STAT signalling pathway during CPB maybe the potential mechanism of myocardial fibrosis. We speculate that the high expression of IL-6 might be an important factor leading to heart failure after ToF surgery. We expect that these findings will provide a basis for the development of targeted drugs.

Preclinical and human studies suggest an association between chronic inflammation and the development of depressive behaviors. This is proposed to occur through downstream effects of inflammatory cytokines on neuroplasticity, neurogenesis and neurotransmitter function, although the neural correlates remain poorly understood in humans.

In Study 1, structural magnetic resonance imaging and serum inflammatory cytokine data were analyzed from 53 psychiatrically healthy female participants. Correlational analyses were conducted between interleukin-6 (IL-6) and volume in a priori regions implicated in the pathophysiology of major depressive disorder (MDD). In Study 2, medical data [including serum inflammatory acute phase reactants (C-reactive protein)] were analyzed for 12 589 participants. Participants were classified as having (n = 2541) v. not having (n = 10 048) probable lifetime MDD using phenotypes derived using machine-learning approaches. Non-parametric analyses compared inflammation between groups, whereas regression analyses probed whether inflammation predicted probable MDD classification while accounting for other variables.

In Study 1, significant negative correlations emerged between IL-6 and hippocampal, caudate, putamen and amygdalar volume. In Study 2, the MDD group showed a higher probability of elevated inflammation than the non-MDD group. Moreover, elevated inflammation was a significant predictor of probable MDD classification.

Findings indicate that inflammation is cross-sectionally related to reduced volume in brain regions implicated in MDD phenotypes among a sample of psychiatrically healthy women, and is associated with the presence of probable MDD in a large clinical dataset. Future investigations may identify specific inflammatory markers predicting first MDD onset.

Activation of the immune-inflammatory response system (IRS) and the compensatory immune-regulatory system (CIRS) and aberrations in endogenous opioids play a role in the pathophysiology of major depressive disorder (MDD). There are no studies which examined the associations between both systems in MDD. The aim of the present study was to examine the relation between β-Endorphin (β-EP), Endomorphin-2, and their mu-opioid receptor (MOR) as well as interleukin (IL)-6 and IL-10, an anti-inflammatory cytokine, in MDD patients.

The study included 60 depressed drug-free male patients and 30 matched controls. Serum β-EP, Endomorphin-2, MOR, IL-6 and IL-10 levels were measured using ELISA techniques.

The results revealed a significant increase in serum β-EP, MOR, IL-6 and IL-10 in MDD patients versus healthy controls. MOR levels were strongly associated with IL-10 levels. There were no significant correlations between endogenous opioids and IL-6 and IL-10.

The results show that MOR levels may function as a possible component of the CIRS whilst there is no evidence that β-EP and EM-2 may modify the IRS. The significant correlation between MOR levels and IL-10 may be explained through central activation of the HPA-axis and increased B-cell numbers expressing MOR as a response to cytokine over-secretion in MDD.

To identify developmental sub-groups of depressive symptoms during the second decade of life, a critical period of brain development, using data from a prospective birth cohort. To test whether childhood intelligence and inflammatory markers are associated with subsequent persistent depressive symptoms.

IQ, a proxy for neurodevelopment, was measured at age 8 years. Interleukin 6 (IL-6) and C-reactive protein, typical inflammatory markers, were measured at age 9 years. Depressive symptoms were measured six times between 10 and 19 years using the short mood and feelings questionnaire (SMFQ), which were coded as binary variable and then used in latent class analysis to identify developmental sub-groups of depressive symptoms.

Longitudinal SMFQ data from 9156 participants yielded three distinct population sub-groups of depressive symptoms: no symptoms (81.2%); adolescent-onset symptoms (13.2%); persistent symptoms (5.6%). Lower IQ and higher IL-6 levels in childhood were independently associated with subsequent persistent depressive symptoms in a linear, dose–response fashion, but not with adolescent-onset symptoms. Compared with the group with no symptoms the adjusted odds ratio for persistent depressive symptoms per s.d. increase in IQ was 0.80 (95% CI, 0.68–0.95); that for IL-6 was 1.20 (95% CI, 1.03–1.39). Evidence for an association with IL-6 remained after controlling for initial severity of depressive symptoms at 10 years. There was no evidence that IL-6 moderated or mediated the IQ-persistent depressive symptom relationship.

The results indicate potentially important roles for two distinct biological processes, neurodevelopment and inflammation, in the aetiology of persistent depressive symptoms in young people.

Vegetarian diets contain various anti-inflammatory components. We aimed to investigate the effects of vegetarianism on inflammatory biomarkers when compared with omnivores.

Systematic review and meta-analysis.

Literature search was conducted in Science Direct, Proquest, MEDLINE and Google Scholar up to June 2016. Summary estimates and corresponding 95 % CI were derived via the DerSimonian and Laird method using random effects, subgroup analyses were run to find the source of heterogeneity and a fixed-effect model examined between-subgroup heterogeneity.

Studies were included if they evaluated effects of any type of vegetarianism compared with omnivores on circulating levels of inflammatory biomarkers. No restriction was made in terms of language or the date of study publications.

Eighteen articles were included. Pooled effect size showed no difference in high-sensitivity C-reactive protein (hs-CRP) levels in vegetarians v. omnivores (Hedges’ g=−0·15; 95 % CI −0·35, 0·05), with high heterogeneity (I2=75·6 %, P<0·01). A subgroup analysis by minimum duration of vegetarianism showed that a minimum duration of 2 years vegetarianism was associated with lower hs-CRP levels v. omnivores (Hedges’ g=−0·29; 95 % CI −0·59, 0·01), with moderate heterogeneity (I2=68·9 %, P<0·01). No significant effect was found in studies using a minimum duration of 6 months of vegetarianism, with low heterogeneity. Vegetarianism was associated with increased IL-6 concentrations (0·21 pg/ml; 95 % CI 0·18, 0·25), with no heterogeneity (I2=0·0 %, P=0·60).

The meta-analysis provides evidence that vegetarianism is associated with lower serum concentrations of hs-CRP when individuals follow a vegetarian diet for at least 2 years. Further research is necessary to draw appropriate conclusions regarding potential associations between vegetarianism and IL-6 levels. A vegetarian diet might be a useful approach to manage inflammaging in the long term.

IL-6 plays the role as a physiological neuromodulator involved in dopaminergic, serotonergic and other neurotransmissions. The aim of the present association study was to examine the effect of the G/C -174 polymorphism of the IL-6 gene on disposition to alcoholism.

We investigated the relationship between the G/C -174 polymorphism of the IL-6 gene and alcohol dependence in 281 alcoholics and 242 control subjects.

The significant difference in G allele frequency between alcoholic group (0.52) and control group (0.59) was found (P < 0.03).

To our knowledge, this is the first finding providing evidence for an association between alcoholism and the polymorphism of the IL-6 gene. The background of the relationship between the IL-6 gene and alcoholism is discussed.