Search Results (845)

Sepsis is a complex and life-threatening syndrome arising from a dysregulated immune response to infection that can lead to severe organ dysfunction and increased mortality. This multifactorial condition is marked by intricate interactions between immune, inflammatory, and coagulation pathways, which together contribute to systemic effects and multiorgan damage. The aberrant immune activation seen in sepsis includes profound leukocyte activation, endothelial dysfunction, imbalanced coagulation leading to disseminated intravascular coagulation (DIC), and the production of both pro-inflammatory and anti-inflammatory mediators. These events culminate in pathological alterations that extend beyond the initial site of infection, adversely impacting distant tissues and organs. Early recognition and timely intervention are crucial to mitigate the progression of sepsis and its associated complications. This review aims to explore the underlying biological mechanisms, including host–pathogen interactions, immune dysregulation, and the cascade of systemic and organ-specific effects that define sepsis. By delving into the pathophysiological processes, we intend to provide insights into the determinants of multiorgan failure and inform strategies for therapeutic intervention. Understanding these mechanisms is pivotal for advancing clinical outcomes and reducing mortality rates associated with this critical condition. Full article

Background and Clinical Significance: Hemophagocytic lymphohistiocytosis (HLH) and autoimmune hemolytic anemia (AIHA) are both life-threatening hematologic syndromes that rarely present together outside of malignancy. Advanced acquired immunodeficiency syndrome (AIDS) creates a milieu of profound immune dysregulation and hyperinflammation, predisposing patients to atypical overlaps of these disorders. Case Presentation: A 30-year-old woman with poorly controlled AIDS presented with three weeks of jaundice, fever, and fatigue. Initial labs revealed pancytopenia, hyperbilirubinemia, and elevated ferritin level. Direct anti-globulin testing confirmed warm AIHA (IgG⁺/C3d⁺) with transient cold agglutinins. Despite intravenous immunoglobulin (IVIG), rituximab, and transfusions, she developed hepatosplenomegaly, extreme hyperferritinemia, and sIL-2R > 10,000 pg/mL, meeting HLH-2004 criteria. Bone marrow biopsy excluded malignancy; further work-up revealed Epstein–Barr virus (EBV) viremia and cytomegalovirus (CMV) reactivation. Dexamethasone plus reduced-dose etoposide transiently reduced soluble interleukin-2 receptor (sIL-2R) but precipitated profound pancytopenia, Acute respiratory distress syndrome (ARDS) from CMV/parainfluenza pneumonia, bilateral deep vein thrombosis (DVT), and an ST-elevation myocardial infarction (STEMI). She ultimately died of hemorrhagic shock after anticoagulation despite maximal supportive measures. Conclusions: This case underscores the diagnostic challenges of HLH-AIHA overlap in AIDS, where cytopenias and hyperferritinemia mask the underlying cytokine storm. Pathogenesis likely involved IL-6/IFN-γ overproduction, impaired cytotoxic T-cell function, and molecular mimicry. While etoposide remains a cornerstone of HLH therapy, its myelotoxicity proved catastrophic in this immunocompromised host, highlighting the urgent need for cytokine-targeted agents to mitigate treatment-related mortality. Full article

Sepsis is a life-threatening condition caused by a dysregulated immune response to infection, characterized by an initial hyperinflammatory phase frequently followed by compensatory immunosuppression (CARS). Regulatory T cells (Tregs) play a critical, biphasic role: inadequate suppression during early hyperinflammation fails to control cytokine storms, while excessive/persistent activity in late-phase immunosuppression drives immune paralysis and secondary infection susceptibility. This review explores advances in targeting Treg immunoregulation across bacterial, viral, and fungal sepsis, where pathogenic type critically influenced the types of immunoresponses, shaping Treg heterogeneity in terms of phenotype, survival, and function. Understanding this multifaceted Treg biology offers novel therapeutic avenues, highlighting the need to decipher functional heterogeneity and develop precisely timed, pathogen-tailored immunomodulation to safely harness beneficial Treg roles while mitigating detrimental immunosuppression. Full article

Mycoplasma bovis is an important pathogen that is associated with respiratory diseases, mastitis, and arthritis in cattle, leading to significant economic losses in the global cattle industry. Most notably in this study, we pioneer the discovery that its secreted effector ENO1 (α-enolase) directly targets host cytoskeletal proteins for metabolic–immune regulation. Using an innovative GST pull-down/mass spectrometry approach, we made the seminal discovery of β-actin (ACTB) as the primary host target of ENO1—the first reported bacterial effector–cytoskeleton interaction mediating metabolic reprogramming. ENO1–ACTB binding depends on a hydrogen bond network involving ACTB’s 117Glu and 372Arg residues. This interaction triggers (1) glycolytic activation via Glut1 upregulation, establishing Warburg effect characteristics (lactic acid accumulation/ATP inhibition), and (2) ROS-mediated activation of dual inflammatory axes (HIF-1α/IL-1β and IL-6/TNF-α). This work establishes three groundbreaking concepts: (1) the first evidence of a pathogen effector hijacking host ACTB for metabolic manipulation, (2) a novel ‘glycolysis–ACTB–ROS-inflammation’ axis, and (3) the first demonstration of bacterial proteins coordinating a Warburg effect with cytokine storms. These findings provide new targets for anti-infection therapies against Mycoplasma bovis. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing lung disease characterized by chronic inflammation, vascular remodeling, and immune dysregulation. COVID-19, caused by SARS-CoV-2, shares several systemic immunohematologic disturbances with IPF, including cytokine storms, endothelial injury, and prothrombotic states. Unlike general comparisons of viral infections and chronic lung disease, this review offers a focused analysis of the shared hematologic and immunologic mechanisms between COVID-19 and IPF. Our aim is to better understand how SARS-CoV-2 infection may worsen disease progression in IPF and identify converging pathophysiological pathways that may inform clinical management. We conducted a narrative synthesis of the peer-reviewed literature from PubMed, Scopus, and Web of Science, focusing on clinical, experimental, and pathological studies addressing immune and coagulation abnormalities in both COVID-19 and IPF. Both diseases exhibit significant overlap in inflammatory and fibrotic signaling, particularly via the TGF-β, IL-6, and TNF-α pathways. COVID-19 amplifies coagulation disturbances and endothelial dysfunction already present in IPF, promoting microvascular thrombosis and acute exacerbations. Myeloid cell overactivation, impaired lymphocyte responses, and fibroblast proliferation are central to this shared pathophysiology. These synergistic mechanisms may accelerate fibrosis and increase mortality risk in IPF patients infected with SARS-CoV-2. This review proposes an integrative framework for understanding the hematologic and immunologic convergence of COVID-19 and IPF. Such insights are essential for refining therapeutic targets, improving prognostic stratification, and guiding early interventions in this high-risk population. Full article

Background. The STING protein is activated by the second messenger cGAMP to promote the innate immune response against infections. Beyond this role, a chronically overactive STING signaling has been described in several disorders. Patients with severe COVID-19 exhibit a hyper-inflammatory response (the cytokine storm) that is in part mediated by the cGAS-STING pathway. Several STING inhibitors may protect from severe COVID-19 by down-regulating several inflammatory cytokines. This pathway has been implicated in the establishment of an optimal antiviral vaccine response. STING agonists as adjuvants improved the IgG titers against the SARS-CoV-2 Spike protein vaccines. Methods. We investigated the association between two common functional STING1/TMEM173 polymorphisms (rs78233829 C>G/p.Gly230Ala and rs1131769C>T/p.His232Arg) and severe COVID-19 requiring hospitalization. A total of 801 non-vaccinated and 105 fully vaccinated (mRNA vaccine) patients, as well as 300 population controls, were genotyped. Frequencies between the groups were statistically compared. Results. There were no differences for the STING1 variant frequencies between non-vaccinated patients and controls. Vaccinated patients showed a significantly higher frequency of rs78233829 C (230Gly) compared to non-vaccinated patients (CC vs. CG + GG; p = 0.003; OR = 2.13; 1.29–3.50). The two STING1 variants were in strong linkage disequilibrium, with the rs78233829 C haplotypes being significantly more common in the vaccinated (p = 0.02; OR = 1.66; 95%CI = 1.01–2.55). We also studied the LTZFL1 rs67959919 G/A polymorphism that was significantly associated with severe COVID-19 (p < 0.001; OR = 1.83; 95%CI = 1.28–2.63). However, there were no differences between the non-vaccinated and vaccinated patients for this polymorphism. Conclusions. We report a significant association between common functional STING1 polymorphisms and the risk of developing severe COVID-19 among fully vaccinated patients. Full article

The therapeutic target of COVID-19 is focused on controlling inflammation and preventing fibrosis. Collagen–polyvinylpyrrolidone (collagen-PVP) and pirfenidone both have the ability to control the cytokine storm observed in rheumatic and fibrotic disorders. In this work, our aim was to understand the benefits of treatment with each of these drugs in patients with severe COVID-19. In total, 36 patients were treated with dexamethasone and enoxaparin, but 26 were allocated collagen-PVP or pirfenidone (n = 15 and 11, respectively); the clinical and metabolic effects were compared among them. Since pirfenidone works via transcriptional mechanisms, we performed a human genome microarray assay using RNA isolated from fibroblast and monocyte cultures treated with the biodrug, with the aim of hypothesising a possible mechanism of action for collagen-PVP. Our results showed that hospital stay duration, quick COVID-19 severity index (qCSI), and admission to the intensive care unit were statistically significantly lower (p < 0.02) in patients treated with collagen-PVP or pirfenidone when compared with the control group, and that only collagen-PVP normalised serum glucose at discharge. Ingenuity Pathway Analysis showed that the cell cycle, inflammation, and cell surface–extracellular matrix interactions could be regulated with collagen-PVP via the downmodulation of proinflammatory cytokines, while Th2 anti-inflammatory response signalling could be upregulated. Furthermore, the downregulation of some of the genes involved in nitric oxide production showed a possible control for JAK in the IFN-γ pathway, allowing for the possibility of controlling inflammation through the JAK/STAT pathway, as has been observed for pirfenidone and other immunomodulators, such as ruxolitinib. Full article

This review summarizes the available evidence on hyaluronic acid’s (HA’s) role in immune response. HA is one of many components in the extracellular matrix that transmits signals from the extracellular microenvironment to cellular effector systems in immune cells. The final effect of these interactions depends on the type of cells and receptors used and the size of HA particles. HA’s activation of intracellular signaling pathways leads to an immune response involving the release of pro- or anti-inflammatory cytokines and chemokines. These play a crucial role in defense mechanisms, such as protecting against pathogens and tissue healing after injuries. HA, as a signaling particle, is also involved in the intensification of the cytokine storm during COVID-19. Multifold increases in HA content in the lungs and the strength of its impact on the immune system define an “HA storm”. The molecular mechanisms involved in inflammation and initiation, including the promotion of cancer, also begin in the microenvironment, and hyaluronic acid is a key element. In this paper, we focus on intra- and intercellular signaling pathways using HA participation rather than injection preparation based on HA use for esthetic treatment. Full article

Background: Sepsis and septic shock are major contributors to global morbidity and mortality. The “cytokine storm,” a hyper-inflammatory response, plays a central role in sepsis pathophysiology, leading to multi-organ failure. Extracorporeal cytokine adsorption therapies, such as CytoSorb, Toraymyxin, Oxiris, HA330/380, and Seraph 100 Microbind, aim to mitigate the inflammatory response by removing circulating cytokines and other mediators. Methods: A comprehensive search of Scopus and PubMed was conducted for studies published from January 2020 to May 2025. The search terms included “sepsis,” “septic shock,” and “extracorporeal cytokine adsorption.” Relevant studies, including clinical trials and meta-analyses, were included to assess the efficacy and safety of these therapies. Results: Extracorporeal cytokine adsorption has shown promising results in reducing cytokine levels, improving organ function, and decreasing vasopressor requirements. However, evidence regarding mortality reduction remains inconsistent. Studies have demonstrated benefits in sepsis, ARDS, and cardiogenic shock, improving organ recovery and inflammatory markers. Conclusions: Extracorporeal cytokine adsorption is a potential adjunctive therapy in sepsis management, offering improvements in organ function and inflammatory control. While the mortality benefit remains uncertain, ongoing research and large-scale clinical trials are essential to define its clinical role and optimize its application. Full article

Severe COVID-19 disproportionately impacts patients with comorbidities such as type 1 diabetes (T1D), type 2 diabetes (T2D), obesity (OBCD), cardiovascular disease (CVD), hypertension (HTN), and cerebrovascular disease (CeVD), affecting 10–30% of cases. This study elucidates shared molecular mechanisms by identifying common hub genes and genetic variants across these conditions using an integrative bioinformatics approach. We curated 5463 COVID-19-related genes from DisGeNET, GeneCards, T-HOD, and other databases, comparing them with gene sets for T1D (324 genes), T2D (497), OBCD (835), CVD (1756), HTN (837), and CeVD (1421). Functional similarity analysis via ToppGene, hub gene prediction with cytoHubba, and Cytoscape-based protein–protein interaction networks identified four hub genes—CCL2, IL6, IL10, and TLR4—consistently shared across all conditions (p < 1.0 × 10⁻⁵). Enrichr-based gene ontology and KEGG analyses revealed cytokine signaling and inflammation as key drivers of COVID-19 cytokine storms. Polymorphisms like IL6 rs1800795 and TLR4 rs4986790 contribute to immune dysregulation, consistent with previous genomic studies. These genes suggest therapeutic targets, such as tocilizumab for IL6-driven inflammation. While computational, requiring biochemical validation, this study illuminates shared pathways, advancing prospects for precision medicine and multi-omics research in high-risk COVID-19 populations. Full article

Background: Coronavirus disease 2019 (COVID-19) involves a complex interplay of dysregulated immune responses, a pro-inflammatory cytokine storm, endothelial injury, and thrombotic complications. This study aimed to evaluate the impact of kidney function on clinical, laboratory, and outcome parameters in patients hospitalized with COVID-19. Methods: We conducted a retrospective analysis of 359 patients admitted during the first wave of COVID-19, stratified by estimated glomerular filtration rate (eGFR < 60 vs. ≥60 mL/min/1.73 m²). Data on demographics, vital signs, laboratory values, and clinical outcomes—including mortality, hemodialysis requirement, intensive care unit (ICU) admission, and mechanical ventilation (MV)—were collected. Univariate and multivariate linear regression, as well as area under the receiver operating characteristic curve (AUC-ROC) analyses, were performed. A p-value < 0.05 was considered statistically significant. Results: Patients with an eGFR < 60 were older and more likely to have systemic hypertension, chronic kidney disease, a history of solid organ transplantation, and immunosuppressive therapy. This group showed higher rates of mortality (41.6% vs. 19.2%), hemodialysis requirement (32.3% vs. 9.6%), ICU admission (50.9% vs. 37.9%), and MV (39.8% vs. 21.2%). Laboratory results revealed acidosis, anemia, lymphopenia, elevated inflammatory markers, and hyperkalemia. Conclusions: An admission eGFR < 60 mL/min/1.73 m² is associated with worse clinical outcomes in COVID-19 and may serve as a simple, early marker for risk stratification. Full article

Elderly individuals infected with SARS-CoV-2 are at higher risk of developing cytokine storms and severe outcomes, yet specific biomarkers remain unclear. In this study, we investigated the alteration of primary bile acid metabolism in elderly patients with severe COVID-19 using untargeted metabolomics (n = 31), followed by targeted metabolomics to compare patients with disease progression (n = 16) to those without (n = 48). Significant reductions in chenodeoxycholic acid (CDCA) and glycochenodeoxycholic acid (GCDCA) levels were identified in severe cases, with GCDCA levels at admission correlating strongly with peak inflammatory markers. In vitro, CDCA, GCDCA, and their receptors, Farnesoid X Receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5), effectively inhibited the inflammatory response induced by SARS-CoV-2. NOD-like receptor pathway, activated by SARS-CoV-2, may modulate inflammatory cytokines under the treatment of CDCA, GCDCA, and TGR5. CDCA and GCDCA levels at admission predicted disease progression, suggesting their potential as biomarkers for severe COVID-19 in the elderly and highlighting their regulatory role in inflammation, pointing to new therapeutic avenues. Full article

Background/Objectives: Inflammatory bowel disease (IBD) is a chronic inflammatory condition encompassing ulcerative colitis (UC) and Crohn’s disease (CD). The role of environmental factors in the pathogenesis of IBD remains elusive. Nevertheless, evidence suggests a pivotal role of viruses, specifically Epstein–Barr virus (EBV), in the progression of IBD through mechanisms such as molecular mimicry and bystander activation. Our previous findings demonstrate EBV DNA’s significant role in exacerbating colitis symptoms and elevating the levels of the pro-autoimmune cytokine interleukin-17A (IL-17A) in an IBD mouse model via toll-like receptor 9 (TLR9). Therefore, we aimed to examine the role of EBV particles in the pathogenesis of IBD, and the potential role of TLR9 inhibition in ameliorating disease outcomes. Methods: Three days post colitis induction, EBV particles were intra-rectally injected into female C57BL/6J mice, followed by the intra-peritoneal administration of TLR9 inhibitor. Thereupon, mice were monitored daily and the disease activity index (DAI), colon lengths, and damage scores, as well as the number of cells, double-positive for IL-17A+ and IFN-γ+, and triple-positive for IL-17A+, IFN-γ+, and FOXP3+, were evaluated. Results: Our findings revealed a significant role of TLR9 inhibition in mitigating colitis features in an EBV-injected IBD mouse model compared to the control group. Conclusions: These results indicate an essential role of TLR9 in initiating immune responses against recurrent EBV reactivation events, which ultimately contributes to inflammation aggravation in IBD patients. Consequently, TLR9 could serve as a potential therapeutic target to alleviate the severe symptoms of IBD in EBV-infected individuals. Full article

Multiple lines of evidence suggest that endothelial dysfunction is a key player in the pathogenesis of COVID-19, with cytokine storm as one of the main primary causes. Among the mechanisms underlying endothelial damage, clinical findings identify alterations in arginine metabolism, as patients with severe COVID-19 exhibit lower levels of nitric oxide synthase (eNOS) and upregulated arginase. In this study, we investigated, in human endothelial cells (HUVECs), the effect of conditioned medium from macrophages activated with SARS-CoV-2 Spike protein (CM_S1) on arginine metabolism. The results indicate that CM_S1 causes a marked decrease in eNOS and an increase in arginase, along with a greater intracellular arginine content and the induction of the CAT2 transporter. These effects are ascribable to the inflammatory mediators released by macrophages in CM_S1, mainly TNFα and IL-1β. Since infliximab, an antibody targeting TNFα, and baricitinib, an inhibitor of the JAK/STAT pathway, correct the observed imbalance between eNOS and arginase, our findings suggest the potential efficacy of a combined therapy to counteract endothelial dysfunction in COVID-19. Full article

Background: Influenza B usually causes mild illness in children. Severe and fatal cases can occur when complicated by secondary Staphylococcus aureus (S. aureus) pneumonia, including community-acquired methicillin-resistant Staphylococcus aureus (MRSA). We present a rare, rapidly progressive fatal case in an adolescent with no known medical history to highlight diagnostic and therapeutic pitfalls. Case Presentation: A 16-year-old boy with no known underlying conditions (unvaccinated for influenza) presented critically ill at “Sf. Ioan” Clinical Emergency Pediatric Hospital in Galați after one week of high fever and cough. He was in respiratory failure with septic shock, requiring immediate intubation and vasopressors. Chest X-ray (CXR) showed diffuse bilateral infiltrates (acute respiratory distress syndrome, ARDS). Initial laboratory tests revealed leukopenia, severe thrombocytopenia, disseminated intravascular coagulation (DIC), rhabdomyolysis, and acute kidney injury (AKI). Reverse transcription polymerase chain reaction (RT-PCR) confirmed influenza B, and blood cultures grew MRSA. Despite maximal intensive care, including mechanical ventilation, antibiotics (escalated for MRSA), antiviral therapy, and cytokine hemoadsorption therapy, the patient developed refractory multi-organ failure and died on hospital day 6. Autopsy revealed bilateral necrotizing pneumonia (NP) without radiographic cavitation, underscoring the diagnostic challenge. Discussion: The initial chest radiography showed diffuse bilateral pulmonary infiltrates, predominantly in the lower zones, with an ill-defined, patchy, and confluent appearance. Such appearance, in our case, was more suggestive of rapid progressive NP caused by MRSA rather than the typical pneumococcal one. This is one of the few reported cases of influenza B–MRSA coinfection with fulminant rhabdomyolysis and autopsy-confirmed necrosis. Our fulminant case illustrates the synergistic virulence of influenza and MRSA. Toxin-producing MRSA strains can cause NP and a “cytokine storm,” causing capillary leak, ARDS, shock, and DIC. Once multi-organ failure ensues, the prognosis is grim despite aggressive care. The absence of early radiographic necrosis and delayed anti-MRSA therapy (initiated after culture results) likely contributed to the poor outcome. Conclusions: Influenza B–MRSA co-infection, though rare, demands urgent empiric anti-MRSA therapy in severe influenza cases with leukopenia or shock, even without radiographic necrosis. This fatal outcome underscores the dual imperative of influenza vaccination and early, aggressive dual-pathogen targeting in high-risk presentations. Full article