Depressive-like phenotype evoked by lifelong nutritional omega-3 deficiency in female rats: Crosstalk among kynurenine, Toll-like receptors and amyloid beta oligomers.

Depression is one of the most common psychiatric diseases and the prevalence of depressive symptoms in women is almost twice compared to men, although the reasons of this gender difference are not fully understood yet. Recently, soluble amyloid beta (Aß)1-42 peptide has been receiving great importance in the development of depression, also considering that depression is highly comorbid with Alzheimer's disease and other neurodegenerative illnesses. The central role played by Aß in the development of depressive-like symptoms in rodents has been evidenced in environmental rodent model of depression. Indeed, we have previously found that lifelong exposure to n-3 polyunsaturated fatty acids (PUFA) deficient diet in female rats at 8 weeks of life leads to depressive like- symptoms and higher susceptibility to stress associated with increased Aß levels. In order to understand if such effects were maintained over time, rats were exposed to the same diet regimen until 6 or 21 weeks of life. We found that both timepoints of exposure to n-3 PUFA deficient diet lead to depressive-like phenotype. Furthermore, a significant alteration in brain neurochemistry was retrieved. In particular, in hippocampal area a significant reduction in serotonin (5-HT) and noradrenaline (NA) content was evidenced. Considering the prominent role of NA in counterbalancing neuroinflammatory state, we quantified in the same brain area kynurenine levels, a metabolite of tryptophan implicated in inflammatory state and brought to the fore for its implication in depression. Interestingly, kynurenine levels were significantly increased in hippocampus (HIPP) of female rats exposed to such diet. In addition, lifelong deficiency in n-3 PUFA dietary intake led to systemic increase of corticosterone, hence hypothalamic pituitary adrenal (HPA) axis hyperactivation, and higher proinflammatory cytokine production. Increased production of kynurenine, along with HPA axis hyperactivation, have been associated with immune system modulation, particularly through Toll-like receptor type 2 (TLR2) and Toll-like receptor type 4 (TLR4) involvement. In addition, it has been shown that soluble forms of Aß1-42 can induced depressive like-phenotype in consequence to a crosstalk between TLR4 and 5-HTergic system. Thus, considering that in this model we have previously reported increased plasma Aß1-42 level, we quantified TRL2 and 4 expression in HIPP of treated rats. We found that chronic exposure to a diet characterized by very low n-3 PUFA content led to higher expression of TLR2 and TLR4 in HIPP of female treated rats, indicating an activation of the immune system and was accompanied by increased expression of oligomeric Aß. Taken together, our data indicate that the pro-depressive effects induced by a diet poor in n-3 PUFA can be attributable to a shift of hippocampal tryptophan metabolism toward inflammatory metabolite ultimately corresponding to altered immune response and increased Aß oligomerization.

Lack of Difference in Tocilizumab Efficacy in the Treatment of Severe COVID-19 Caused by Different SARS-CoV-2 Variants.

Tocilizumab (TOC) is presumed to be an effective and safe treatment for severe COVID-19, but its usefulness has not been yet investigated for different SARS-CoV-2 variants. This study aimed to evaluate the influence of TOC on mortality in patients with severe COVID-19 caused by Delta and non-Delta SARS-CoV-2 variants. In a retrospective analysis, we compared the medical records of 78 and 224 patients with severe COVID-19 due to Delta and non-Delta variants, respectively. A total of 30 patients with Delta and 84 with non-Delta variants were treated with TOC in addition to standard therapy. There were no statistically significant differences in mortality rate when comparing Delta vs. non-Delta patients nor when comparing those treated with TOC vs. not treated with TOC in both variants. Using a logistic regression model, in the examined population as a whole, we found an increased (p < 0.05) risk of death as leukocyte and erythrocyte counts decreased and as procalcitonin increased. Increased procalcitonin was significant for mortality in the Delta group, while decreased IL-6, leukocytes, and platelets and increased fibrinogen and procalcitonin were significant in the non-Delta group. Tocilizumab efficacy in severe COVID-19 does not differ between Delta or non-Delta virus variants. The Delta variant of SARS-CoV-2 does not increase mortality when compared to other virus strains.

Interleukin-6 inhibitors reduce mortality in coronavirus disease-2019: An individual patient data meta-analysis from randomized controlled trials.

OBJECTIVE: To assess the efficacy of IL-6 inhibitors compared to standard of care (SOC) in COVID-19 patients. DATA SOURCES: A systematic review of the MEDLINE and Scopus databases (last search: October 8th, 2021) was performed according to the PRISMA statement. STUDY SELECTION: Randomized control trials (RCTs) comparing IL-6 inhibitors to SOC in hospitalized COVID-19 patients were deemed eligible. DATA EXTRACTION AND SYNTHESIS: Individual patient data were extracted from the Kaplan-Meier curves or were obtained from authors of included studies. Additionally, the reviewers independently abstracted data and assessed study quality of each eligible report. RESULTS: Eleven studies were identified, incorporating 7467 patients (IL-6 inhibitors: 4103, SOC: 3364). IL-6 inhibitors were associated with decreased risk for death compared to SOC at the one-stage meta-analysis (Hazard Ratio [HR]: 0.75, 95% Confidence interval [CI]: 0.69-0.82, p<0.0001) and the two-stage meta-analysis (HR: 0.85, 95%CI: 0.77-0.93, p<0.001, I2 = 0.0%). Meta-regression analysis revealed that the difference in OS between the two groups was not influenced by the mean age of patients. At secondary meta-analyses, IL-6 inhibitors were associated with decreased odds for intubation OR:0.74, 95%CI:0.65-0.85, p<0.001, I2=0.0%). IL-6 inhibitors were associated with increased odds for discharge compared to SOC (OR:1.28, 95% CI:1.15-1.42, p<0.001, I2=0.0%). CONCLUSIONS AND RELEVANCE: This meta-analysis of individual patient data from randomized trials shows that IL-6 inhibitors significantly reduce the risk of death compared to SOC. IL-6 inhibitors are also associated with better outcomes in terms of intubation and discharge rates compared to SOC.

Incomplete ART adherence is associated with higher inflammation in individuals who achieved virologic suppression in the START study.

INTRODUCTION: Suboptimal ART adherence, despite HIV viral suppression, has been associated with chronic residual inflammation. Whether this association extends to individuals who initiate ART during early HIV infection remains unknown, which was the objective of this study. METHODS: Plasma levels of interleukin-6 (IL-6), high-sensitivity C-reactive protein, serum amyloid A protein (SAA), IL-27, soluble intercellular adhesion molecule-1, soluble vascular adhesion molecule-1, D-dimer and the CD4+/CD8+ T-cell ratio, were analysed at baseline and eight months after ART initiation in treatment-naïve participants with HIV and CD4+ T-cells >500 cells/mm3 enrolled in the immediate arm of START. Adherence was assessed by seven-day self-report. Multivariable linear regression was utilized to analyse the association between ART adherence and each biomarker at the eight-month visit in participants who achieved virologic suppression (<50 copies/mL). RESULTS: We evaluated 1627 participants (422 female) who achieved virologic suppression at the eight-month visit in the period between 2009 and 2013. Median (IQR) CD4+ T-cell count before ART was 651 (585, 769) cells/mm3 . Incomplete adherence was reported in 109 (7%) participants at the eight month visit. After adjusting for covariates, plasma IL-6 was 1.12 (95% CI, 1.00 to 1.26; p = 0.047) fold higher in participants reporting incomplete versus 100% adherence. A similar association for SAA was observed in an exploratory analysis (1.29 (95% CI 1.04 to 1.60); p = 0.02). No significant differences in other biomarkers were observed. CONCLUSIONS: Incomplete ART adherence was associated with higher IL-6 levels in individuals who achieved virologic suppression early after ART initiation in START. A potential similar association for SAA requires confirmation. These findings suggest a role for identifying strategies to maximize ART adherence even during virologic suppression. ClinicalTrials.gov number: NCT00867048.