Belimumab is the only biologic approved for childhood-onset systemic lupus erythematosus (cSLE), yet evidence on the optimal timing of initiation and duration of therapy remains limited. This study aimed to evaluate the impact of belimumab treatment duration and timing of initiation on clinical outcomes in cSLE. This retrospective study included 182 patients with cSLE treated with belimumab at Beijing Children’s Hospital between September 2015 and September 2025. Patients were stratified by timing of initiation (≤ 6 months vs. > 6 months from diagnosis) and treatment duration. Primary outcomes included childhood Lupus Low Disease Activity State (cLLDAS) and childhood Clinical Remission (cCR). In a subgroup of 95 patients with ≥ 2 years of follow-up, outcomes were compared by treatment duration (< 1 year, 1–2 years, ≥ 2 years) and by timing of initiation. Multivariable logistic regression was performed to identify independent predictors. Among 182 patients (81.9

OBJECTIVES:Enthesitis-related arthritis (ERA) is a form of chronic inflammatory arthritis. Even when administered with a combination of non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), and biologics, some patients remain in an active disease state. Antecedent studies have revealed that interleukin-17 (IL-17) plays an important role in the pathogenesis of ERA and have demonstrated the efficacy of IL-17 inhibitors. This real-world, retrospective study aimed to assess the efficacy and safety of secukinumab in patients with ERA. METHODS:This was a retrospective, single-center cohort study of 31 Chinese patients who had been diagnosed with ERA and treated with secukinumab for at least 3 months. The primary outcomes were the proportion of patients achieving JIA ACR 30/50/70/90/100 response criteria and ACR inactive disease, as well as the change in Juvenile Spondyloarthritis Disease Activity (JSpADA) Index from baseline. Secondary outcomes included changes in the number of joints with active arthritis and enthesitis, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Outcomes were assessed every 3 months after secukinumab initiation. The Wilcoxon signed-rank test and paired t-test were used to analyze the data. RESULTS:Male predominance (24/31, 77.4%), late disease onset, HLA-B27 positivity (13/31, 41.9%), and enthesitis (10/31, 32.3%) were the key characteristics of our cohort. The median follow-up duration was 0.9 years (ranging from 0.4 to 2.7 years). At the last follow-up, ACR 30/50/70/90/100 response rates were 87% (27/31), 68% (21/31), 65% (20/31), 32.3% (10/31) and 12.9% (4/31); 25.8% (8/31) of patients achieved ACR inactive disease. JSpADA scores decreased from baseline (median 5.0, IQR: 3.5-5.0) to month 3 (median 3.5, IQR: 2.5-4.0; median difference = 1.25, Z = -4.26, p < 0.001, 95% CI: 0.8 to 2.0), to month 6 to 3.0 (IQR: 2.0-4.0; median difference = 1.5, Z = -3.85, p < 0.001, 95% CI: 1.0 to 2.3), month 9 to 3.0 (IQR: 1.0-3.0; median difference = 2.3, Z = -3.09, p = 0.002, 95% CI: 1.5 to -3.0) and month 12 to 2.5 (IQR: 1.0-3.0; median difference = 2.25, Z = -2.95, p = 0.003, 95% CI: 1.5 to 3.3). The mean active joint count decreased from 9.3 ± 0.7 at baseline to 3.3 ± 0.5 at 12 months. Normalization of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was observed. CONCLUSION:In this retrospective, single-center study, secukinumab appears to be associated with improvement in arthritis and disease activity in Chinese children with ERA. Further studies are needed to investigate the correlation between IL-17 and ERA.

Background and Aims:Liver transplant rejection significantly affects patient prognosis. Myeloid-derived suppressor cells (MDSCs), known for their potent immunoregulatory functions, represent a promising target for managing liver transplant rejection. This study aimed to systematically characterize the diversity of MDSC subsets and their context-dependent functions, particularly within the context of transplant tolerance. Methods:We analyzed clinical and murine liver transplants using single-cell RNA sequencing, bulk RNA sequencing, flow cytometry, multiplex immunohistochemistry, and co-culture assays to phenotype MDSC subsets. Results:Single-cell RNA sequencing analysis of human and murine samples revealed MDSC involvement in transplant rejection. In mice, MDSC scores followed a normal distribution during the first week post-transplant and correlated with clinical flow cytometry data at one month. A distinct LDLR+ monocytic MDSC (M-MDSC) subset was identified and confirmed through spatial mapping by multiplex immunohistochemistry. Flow cytometry demonstrated dynamic changes in LDLR+ M-MDSCs across tissues (liver, spleen, peripheral blood, bone marrow, and lymph nodes), with a peak during acute rejection. Co-culture experiments showed that LDLR-/- M-MDSCs exhibited reduced Arg-1/iNOS expression and an impaired capacity to induce inhibitory receptors (TIGIT, PD1, CTLA-4) or suppress effector molecules (GZMB, IFN-γ, IL-2) in CD8+ T cells. Conclusions:These findings highlight the critical role of MDSCs in liver transplant rejection. LDLR+ M-MDSCs exhibited enhanced immunosuppressive properties, underscoring their potential clinical relevance in mitigating rejection and promoting immune tolerance.

Double-negative T cells (DNTs) are significantly elevated in autoimmune diseases and are thought to play an important role in inflammation. The purpose of this study was to explore their role in childhood-onset systemic lupus erythematosus (cSLE). DNTs, as well as T and B cell subsets in peripheral blood, were detected by flow cytometry in 78 patients, including 34 cSLE. Clinical and laboratory data of cSLE patients were collected to analyze the correlation between DNTs and these indices, including demographics: proportion of female patients and mean age (± SD); Organ involvement: presence of lupus nephritis, neuropsychiatric manifestations, and pulmonary involvement; Hematologic parameters: leukopenia, anemia, and thrombocytopenia (WBC, Hb, and PLT counts); Autoantibody profiles: ANA, anti-dsDNA, and anti-Sm antibodies. The changes in DNT levels after glucocorticoid treatment were observed, and the effects of different doses of glucocorticoids on DNTs were analyzed. DNT levels were significantly increased in the peripheral blood of cSLE patients. DNTs were correlated with SLE disease activity, organ involvement, the production of autoantibodies, naive B cells, and plasmablasts. DNT levels increased after low-dose glucocorticoid treatment (9.12 ± 1.43 vs 14.24 ± 1.36, p < 0.01) but gradually decreased with increasing glucocorticoid doses (14.24 ± 1.36 vs 13.45 ± 1.51 vs 7.45 ± 1.01 vs 4.72 ± 1.20, p < 0.05). DNT levels significantly decreased from the fourth day of glucocorticoid pulse therapy. DNT levels were positively correlated with disease activity in cSLE patients, and the effect of glucocorticoid dose on DNT levels varied.

Mucosal-associated invariant T (MAIT) cells, representing one of the most abundant subsets of unconventional T cells, have been shown to play a significant role in regulating immune responses. However, their immunoregulatory roles in the context of liver transplantation (LT) immunity remain largely undefined. To address this, we conducted single-cell RNA/TCR sequencing, flow cytometry, and multiplex immunohistochemical (mIHC) assays to identify the proportion and characteristics of CD8+ MAIT cells in humans and mice following liver transplantation. We found that CD8+ MAIT cells were prominently represented in the single-cell CD8 profiles of human transplanted livers, demonstrating strong signalling associations with macrophages, whilst the fractional populations of MAIT1 and MAIT17 were distinctly clustered. In parallel, the proportion of CD8+ MAIT cells was significantly elevated in mouse LT models, revealing a dynamic trend where percentages increased at 1 and 2 weeks post-transplant, peaking at 3 weeks. Furthermore, using established MR1 knockout (MR1KO) LT mice, we observed that mice lacking MAIT cells exhibited milder rejection responses, indicating that MR1 mediates rejection by influencing the remodelling of the TCR repertoire after transplantation. Collectively, our study reveals that MAIT cells play a critical role in LT rejection, as MR1KO alleviated inflammatory responses and mitigated rejection via TCR repertoire remodelling. By mapping the dynamic changes of MAIT cells throughout the rejection process, these findings lay the groundwork for further investigations into the role of these cells in transplant immunity.

OBJECTIVE:To investigate clinicopathological correlations, treatment responses, and predictors of outcomes in childhood lupus nephritis (cLN). METHODS:Retrospective cohort study of 71 biopsy-proven cLN patients at Beijing Children's Hospital (2005-2024). Renal biopsies were classified per 2018 ISN/RPS criteria with activity index (AI) and chronicity index (CI) assessment. RESULTS:Over a median 40-month follow-up, 69.1% were female (mean onset age 10.0 ± 2.3 years). Proliferative LN (Class III/IV ± V) accounted for 76.0%. AI correlated with acute injury markers (creatinine, BUN, proteinuria); CI showed stronger associations with chronic tubular biomarkers but not eGFR. Complete renal remission (CRR) was achieved in 92.8% (mean 13.4 months); 26.6% experienced relapse. Failure to achieve CRR was associated with higher AI (OR = 1.738, p = 0.045), elevated SLEDAI-2K (OR = 1.339, p = 0.023), and lower C3 (OR = 0.002, p = 0.035). Higher CI predicted lower likelihood of achieving LLDAS (OR = 1.425, p = 0.042). Belimumab reduced relapse risk (OR = 0.220, p = 0.043), decreased glucocorticoid doses (8.42 vs. 16.54 mg/day, p = 0.034), and improved LLDAS (68.4% vs. 30.0%, p = 0.006) and clinical remission rates (52.6% vs. 20.0%, p = 0.016). CKD developed in 4.3%; mortality was 1.4%. CONCLUSION:Modern treatment yields favorable outcomes for cLN. Baseline disease activity, hypocomplementemia, and histological AI predict treatment response. AI and CI demonstrate distinct associations with acute and chronic injury. Belimumab offers significant advantages in relapse prevention and glucocorticoid reduction.

Background: Kupffer cells (KCs) are pivotal orchestrators of immune homeostasis following liver transplantation (LT). However, the specific KC subpopulations driving tolerance and their underlying mechanisms remain elusive. Methods: We mapped the post-transplant immune landscape by integrating single-cell RNA sequencing (scRNA-seq) of human and murine grafts with flow cytometry, multiplex immunohistochemistry (mIHC), and in vitro co-culture assays. Furthermore, a murine orthotopic LT model was employed to delineate the longitudinal dynamics of KC subsets during the transition from allograft rejection to tolerance. Results: scRNA-seq identified a unique Apolipoprotein E+ (APOE+) KCs subset serving as a central communication hub, exhibiting robust crosstalk with CD8+Tissue-resident memory T (TRM) cells via the CXCL16-CXCR6 axis. In murine models, while the total KC population fluctuated, the APOE+KC subpopulation was specifically enriched in stable, tolerant grafts. Mechanistically, APOE-Overexpressing KCs significantly suppressed CD8+ TRM proliferation and drove them toward a PD-1+/TIGIT+ exhausted phenotype, thereby dampening alloreactivity. Clinically, we identified a significant inverse correlation between donor serum APOE levels and recipient MELD scores as well as liver injury markers, establishing APOE as a predictive biomarker. Conclusion: We demonstrate that APOE+KC promotes transplant tolerance by inducing CD8+TRM depletion. In addition, donor serum APOE can serve as a potential prognostic biomarker, providing a dual therapeutic target and diagnostic tool for optimizing graft survival.

OBJECTIVE:Establishing a predictive model using clinical indicators for the early identification of JIA-U. METHOD:A cross-sectional study was conducted with 255 patients admitted at Beijing Children's Hospital between 2018 and 2023. The model was fitted using stepwise logistic regression as well as least absolute shrinkage and selection operator (LASSO) regression. Calibration and decision curve analysis were used for validation. RESULTS:The final predictive model included four clinical variables (patient's gender, age at onset, arthritis subtype, and ANA status). A nomogram for risk prediction was developed, which demonstrated good discrimination in both the training cohort (AUC = 0.8417; 95% CI = 0.775-0.9085) and the testing cohort (AUC = 0.782; 95% CI = 0.6752-0.8884). Calibration curves showed that, through bootstrap resampling, the nomogram performed well in predicting the occurrence of uveitis in JIA. CONCLUSION:This study established a predictive model using routine clinical indicators to assess the risk of uveitis in JIA patients.

Objective:To characterize the clinical features, risk factors, and outcomes of juvenile idiopathic arthritis-associated uveitis (JIA-U), aiming to improve early detection and management strategies. Methods:This study conducted a retrospective cohort analysis of JIA patients diagnosed and treated at the Department of Rheumatology at Beijing Children's Hospital (2016-2023), with subgroup evaluation of JIA-U cases. Results:Among 1494 JIA patients, 72 (4.82%) developed uveitis. The oligoarticular subtype (OJIA, 47.2%) and enthesitis-related arthritis (ERA, 27.8%) predominated. Uveitis onset occurred at a median of 10 months post-arthritis diagnosis (range: 0-86 months), with 93% manifesting within 4 years. Chronic anterior uveitis was the most frequent phenotype. ANA positivity and HLA-B27 were significantly associated uveitis. First-line acute management involved topical corticosteroids, with methotrexate escalation for severe cases and TNF-α inhibitors (adalimumab preferred) for refractory disease. Ocular complications arose in 25.9% during follow-up. Conclusion:Uveitis, often bilateral and insidious, is a common extra-articular manifestation of JIA. Absent arthritis signs may delay diagnosis, highlighting the need for regular screening and close rheumatology-ophthalmology collaboration to optimize outcomes.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that causes immune system overactivity and organ damage. Among T-cell subsets involved in SLE, CD4 and CD8 double-negative αβT (DNT) cells have attracted attention in recent years, although their role in SLE remains poorly understood. Examining the minute intricacies, particularly signaling pathway modifications is crucial, as it may unveil potential therapeutic targets and lead to the development of more effective treatments. Our study found increased DNT cells in pediatric SLE patients, with elevated IL-10 signaling. These IL-10-producing DNT cells were positively related to disease activity defined by SLE Disease Activity Index (SLEDAI), and were further elevated in patients with lupus nephritis. Additionally, our results indicated that IL-10-producing DNT cells correlated positively with anti-Sm autoantibodies. Collectively, our study revealed that modulation of IL-10 production within DNT-cell subset could affect both immune regulation and autoantibody production, contributing to the immunological dysregulation in SLE.

ObjectivesThis study aims to investigate CD4+ central memory T cells (CD4+ TCM) levels in childhood-onset systemic lupus erythematosus (cSLE) and their association with disease activity, clinical features, and treatment responses.MethodsA total of 202 children with newly diagnosed, untreated rheumatic diseases were recruited, comprising 64 cases of cSLE, 71 cases of juvenile idiopathic arthritis, 31 cases of juvenile dermatomyositis, 36 cases of autoinflammatory diseases, and 22 healthy controls. Lymphocyte subsets were analyzed using multi-color flow cytometry, and clinical data and laboratory test results were collected. The correlation between CD4+ TCM levels and SLEDAI scores, clinical manifestations, autoantibodies, and kidney injury markers was examined. Subsequently, 21 cSLE patients underwent follow-up assessments and retesting post-treatment.ResultsThe proportion of CD4+ TCM (44.3 ± 11.5%) in cSLE was significantly higher compared to those with other pediatric rheumatic diseases (p < .05). A negative correlation was observed between the level of CD4+ TCM and the SLEDAI-2000 score (r = -0.255, p = .021), indicating that higher disease activity was associated with lower CD4+ TCM levels. Furthermore, CD4+ TCM levels were negatively correlated with oral ulcers (r = -0.285, p = .011) and positively correlated with leukopenia (r = 0.302, p = .008). In terms of laboratory indicators, CD4+ TCM showed negative correlations with anti-dsDNA antibodies (r = -0.294, p = .009) and anti-histone antibodies (r = -0.232, p = .033), while exhibiting a positive correlation with anti-Sm antibodies (r = 0.245, p = .025). Additionally, CD4+ TCM demonstrated significant negative correlations with early renal injury markers, urinary transferrin (r = -0.315, p = .008), and urinary microalbumin (r = -0.284, p = .015). CD4+ TCM was strongly negatively correlated with CD4+ Naive cells (r = -0.831, p < .001), positively correlated with other memory cell subsets, and negatively correlated with IFN-α levels (r = -0.364, p = .031). Longitudinal analysis revealed a time-dependent biphasic pattern in CD4+ TCM levels. Cyclophosphamide-treated patients showed significantly increased CD4+ TCM levels compared to non-cyclophosphamide groups (p = .034).ConclusionsCD4+ TCM likely plays a central immune regulatory role in cSLE, with its levels closely associated with disease activity, specific autoantibody production, and early organ damage. Post-treatment changes in CD4+ TCM levels may indicate therapeutic efficacy and suggest their potential as biomarkers, offering a fresh perspective on immune memory regulation in cSLE and exploring novel treatment approaches.

PURPOSE:Post-transplant immune rejection affects graft function. Interaction between neutrophil extracellular traps (NETs) with specific immune cells and the specific mechanism in liver transplantation were still unclear. METHOD:Clinical patients RNA-Seq results were used for GSEA and KEGG analysis. C57BL/6 and C3H mouse models and clinical samples were use to describe the disease phenotype characteristics through multiple immunofluorescence, flow cytometry and etc. Cell co-culture experiments were performed to clarify the mechanism pathway process. RESULTS:RNA-Seq results analysis indicated that the NETs formation pathway was upregulated. Animal models confirmed that in liver transplant immune rejection status the formation of NETs in situ and peripheral cells increased and the level of cell-free DNA (cf-DNA) in peripheral cells increased. Reactive oxygen species (ROS) as a predisposing factor for NETs accumulated more in immune rejection status and NETs are rich in mitochondrial DNA (mtDNA). NETs promote dendritic cell maturation through STING-related pathways. NETs formation increases in patients with liver transplant immune rejection and is positively correlated with disease severity. CONCLUSION:We found that NETs can regulate dendritic cell maturation through STING-related pathways after liver transplantation, which may ultimately promote the occurrence of liver transplant rejection, providing a new perspective for clinical diagnosis, treatment and prevention of liver transplant rejection.

Immune rejection poses a major challenge in organ transplantation, with tissue-resident memory T (TRM) cells playing a critical role in graft rejection. This study investigated the impact of CCR8 on TRM cells using single-cell RNA sequencing (scRNA-seq), flow cytometry, and immunohistochemistry. The results show that CCR8 expression was upregulated on CD8⁺ TRM cells after transplantation, peaking on day 7. Blocking or knocking out CCR8, as well as neutralizing CCL1 and CCL8, significantly reduced CD8⁺ TRM cell accumulation in the graft and their cytokine production. These treatments prolonged graft survival, alleviated rejection severity, and impaired the ability of CD8⁺ TRM cells to produce GZMB, IFN-γ, and IL-2. Single-cell analysis of skin transplantation revealed that loss of CCR8 disrupted macrophage-T cell interactions, particularly CD8⁺ TRM-macrophage crosstalk, while enhancing CD40, PD-L1, and NRG signaling. These findings suggest that targeting CCR8 to limit the accumulation and function of CD8⁺ TRM cells may be an effective strategy to alleviate transplant rejection.

IntroductionUnderstanding CD8+ tissue-resident memory T cells (TRM) spatial characteristics in hepatocellular carcinoma (HCC) is challenging, and clarifying the spatial feature changes following immunotherapy represents an urgent research gap.MethodsThis study employs a multi-omics approach to analyze the spatial distribution and intercellular interactions of TRM cells in HCC tissues using radiomics, single-cell sequencing, and multiplex immunofluorescence histochemistry (m-IHC).ResultsOur results show that the number of CD8+ TRM cells in HCC increases following immunotherapy. Furthermore, after dividing tumor tissues into the tumor core (TC), invasion margin (IM), and normal tissue (N), a increase in CD8+ TRM cells from the IM to the TC can be observed. Consistent with the results of single-cell sequencing analysis, this change in spatial characteristics may be associated with the interactions between CD8+ TRM cells and CD68+ cells.DiscussionImmunotherapy can modify the spatial characteristics of CD8+ TRM cells via regulating their crosstalk with other immune cells, and the spatial distribution of CD8+ TRM cells in the HCC tumor microenvironment (TME) correlates with immune checkpoint blockade (ICB) therapeutic efficacy. Clarifying the mechanisms of action of immunotherapeutic drugs and developing a non-invasive radiomics model to predict CD8⁺ TRM cell dynamics will facilitate the clinical management of HCC.

Abstract Background Circular RNA (circRNA) plays an important role in the pathogenesis of many diseases and can be used as a biomarker for diagnosis or disease monitoring. However, reports on circRNA in childhood‐onset systemic lupus erythematosus (cSLE) are limited. Therefore, this study aimed to investigate circEPSTI1 expression in cSLE and evaluate its potential as a biomarker for diagnosing cSLE. Methods This study included 70 children diagnosed with cSLE, 20 diagnosed with juvenile idiopathic arthritis (JIA), 20 diagnosed with juvenile dermatomyositis (JDM), and 50 healthy children at the Rheumatology Department of Beijing Children's Hospital from January 2019 to December 2019. Quantitative polymerase chain reaction was used to determine circEPSTI1 expression in the children. Correlations between circEPSTI1 and clinical features were assessed using Spearman's correlation test. Additionally, we calculated the receiver operating characteristic curve to assess the diagnostic efficacy. Results We found that circEPSTI1 expression was higher in children with cSLE (4.62 ± 3.55) than that in healthy children (1.00 ± 0.45), those with JDM (1.06 ± 0.76), and those with JIA (0.96 ± 0.48). The area of the curve of circEPSTI1 was 0.892 (95% confidence interval [CI]: 0.832–0.952, p < 0.001) to discriminate children with SLE from healthy children, with a specificity of 0.814 and a sensitivity of 0.922. Children with lupus nephritis showed a higher circEPSTI1 expression than healthy children, those with JDM, and those with JIA. In addition, circEPSTI1 expression in children with SLE showed significant correlations with the SLE Disease Activity Index (p < 0.0001) and C3 concentrations (p = 0.001). Conclusion Our study suggests that circEPSTI1 is a promising biomarker for the diagnosis and monitoring of cSLE.

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis and preventing autoimmune diseases. Recent advances in immunometabolism have revealed the pivotal role of mitochondrial dynamics and metabolism in shaping Treg functionality. Tregs depend on oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) to support their suppressive functions and long-term survival. Mitochondrial processes such as fusion and fission significantly influence Treg activity, with mitochondrial fusion enhancing bioenergetic efficiency and reducing reactive oxygen species (ROS) production, thereby promoting Treg stability. In contrast, excessive mitochondrial fission disrupts ATP synthesis and elevates ROS levels, impairing Treg suppressive capacity. Furthermore, mitochondrial ROS act as critical signaling molecules in Treg regulation, where controlled levels stabilize FoxP3 expression, but excessive ROS leads to mitochondrial dysfunction and immune dysregulation. Mitophagy, as part of mitochondrial quality control, also plays an essential role in preserving Treg function. Understanding the intricate interplay between mitochondrial dynamics and Treg metabolism provides valuable insights for developing novel therapeutic strategies to treat autoimmune disorders and enhance immunotherapy in cancer.

Objective: Double-negative T cells (DNTs) were significantly elevated in autoimmune diseases and were thought to play an important role in inflammation. The purpose of this study was to explore its important role in children with systemic lupus erythematosus (cSLE). Methods: The DNTs, T and B cell subsets of peripheral blood were detected by flow cytometry in 78 patients, and clinical and laboratory data of cSLE patients were collected to analyze the correlation between DNTs and the above indexes. The changes of DNTs after glucocorticoids were detected, and the effects of different doses of glucocorticoids on DNTs were analyzed. Results: DNTs was significantly increased in peripheral blood of cSLE patients. DNTs were associated with SLE disease severity and organ involvement, as well as with the production of autoantibodies, Naive B cell and plasmablast cells. The level of DNTs increased after low-dose glucocorticoid treatment, but the proportion of DNTs gradually decreased with the increase of glucocorticoid dose. Conclusion: DNTs was positively correlated with disease severity in cSLE patients, and the effect of glucocorticoid dose on DNTs was different.

BACKGROUNDS:Hepatic ischemia-reperfusion injury (IRI) triggers macrophage activation, which in turn mediates inflammatory responses and affects tissue repair and injury severity. Pentraxin 3 (PTX3) is vital in immune regulation and inflammatory processes. In this study, we aim to investigate the potential role of PTX3 in macrophage-mediated hepatic IRI. METHODS:Gene expression profiles and single-cell data were obtained from the Gene Expression Omnibus (GEO) database. Immunohistochemistry was used to evaluate the expression levels of PTX3, CD68, and CD86 in samples from the human and mouse hepatic IRI models. The effects of PTX3 knockdown or overexpression on macrophage polarization were assessed in Raw264.7. PTX3 knockdown/ overexpression in Raw264.7 and co-culturing with AML12 were performed under conditions of hypoxia-reoxygenation (H/R) to examine pyroptosis and injury in AML12. RESULTS:PTX3 expression was significantly upregulated in both human and mouse hepatic IRI model samples. Bulk and single-cell RNA-seq data analyses revealed that PTX3 is associated with inflammatory response pathways and macrophage activation. Macrophages with high PTX3 expression exhibit M1-like characteristics. Similarly, overexpression of PTX3 promotes M1 polarization of Raw264.7 after H/R, while the knockdown group exhibits reduced M1 polarization. Co-culture results indicated that pyroptosis in AML12 was significantly reduced after H/R in the PTX3 knockdown group, whereas the PTX3 overexpression group exhibited the opposite outcome. CONCLUSION:PTX3 regulates macrophage polarization during hepatic IRI, consequently influencing hepatocellular pyroptosis.