STAT activation in regulatory CD4+ T cells of patients with primary sclerosing cholangitis.

INTRODUCTION: Regulatory CD4+ T cells (Tregs) are pivotal for inhibition of autoimmunity. Primary sclerosing cholangitis (PSC) is an autoimmune cholestatic liver disease of unknown etiology where contribution of Tregs is still unclear. Activation of the JAK-STAT pathway critically modifies functions of Tregs. In PSC, we studied activation of STAT proteins and Treg functions in response to cytokines. METHODS: In 51 patients with PSC, 10 disease controls (chronic replicative hepatitis C), and 36 healthy controls we analyzed frequencies of Foxp3+CD25+CD127lowCD4+ Tregs, their expression of ectonucleotidase CD39, and cytokine-induced phosphorylation of STAT1, 3, 5, and 6 using phospho-flow cytometry. In parallel, we measured cytokines IFN-gamma, interleukin (IL)-6, IL-2, and IL-4 in serum via bead-based immunoassays. RESULTS: In patients with PSC, ex vivo frequencies of peripheral Tregs and their expression of CD39 were significantly reduced (p < .05 each). Furthermore, serum levels of IFN-gamma, IL-6, IL-2, and IL-4 were markedly higher in PSC (p < .05 each). Unlike activation of STAT1, STAT5, and STAT6, IL-6 induced increased phosphorylation of STAT3 in Tregs of PSC-patients (p = .0434). Finally, STAT3 activation in Tregs correlated with leukocyte counts. CONCLUSIONS: In PSC, we observed enhanced STAT3 responsiveness of CD4+ Tregs together with reduced CD39 expression probably reflecting inflammatory activity of the disease.

[Liver transplantation in viral and autoimmune liver diseases]. / Lebertransplantation bei viralen und autoimmunen Lebererkrankungen.

BACKGROUND: Despite substantial progress in the management of viral and autoimmune liver diseases, these entities remain relevant indications for liver transplantation. AIMS: To provide an overview of the current knowledge regarding the management of viral and autoimmune liver diseases before and after liver transplantation. MATERIALS AND METHODS: Selective literature search, including current guidelines and abstracts of key scientific meetings. RESULTS AND DISCUSSION: Viral and autoimmune liver disease can be effectively treated in most cases, which has resulted in an overall decline in liver transplantations for this indication group. However, hepatitis D infection and primary sclerosing cholangitis remain difficult-to-treat liver diseases in some patients and may progress to end-stage liver disease despite best possible management. Viral or autoimmune hepatitis can lead to fulminant liver failure requiring emergency liver transplantation. In patients who are transplanted due to viral or autoimmune liver disease, specific measures to prevent recurrence of these diseases after transplantation are mandatory. In view of effective treatment modalities for chronic hepatitis B and C, even liver grafts from donors infected with these viruses can be considered for liver transplantation under certain circumstances.

Role of PAR1 -506 deletion/insertion polymorphism in primary sclerosing cholangitis.

AIM: Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease characterized by inflammation of the intra- and extrahepatic bile ducts. Pathogenesis of PSC is still enigmatic but is likely to be multifactorial. Recently, we identified an interleukin-6 (IL-6)-dependent signal transducer and activator of transcription 3 (STAT3) activation in CD4+ TH1 and TH17 cells in PSC. The IL-6/STAT3 pathway was shown to be regulated by protease-activated receptor 1 (PAR1) contributing to inflammation. The role of the PAR1 -506 deletion/insertion (Del/Ins) polymorphism in PSC has not yet been investigated. METHODS: Two hundred eighty four PSC patients (200 patients with inflammatory bowel diseases [IBD] and 84 without IBD) and 309 healthy controls were genotyped for PAR1 rs11267092 (-506 Del/Ins -13 bp). Results were correlated with clinical characteristics and transplant-free survival. RESULTS: The frequency of PAR1 -506 Ins allele carriers (Del/Ins and Ins/Ins) was significantly higher in PSC patients (57.0%) compared to healthy controls (39.8%). Furthermore, carriers of PAR1 -506 Ins allele were more likely to have PSC than noncarriers (odds ratio 2.01; 95% confidence interval, 1.45-2.79). Patients with PSC carrying the PAR1 -506 Ins allele showed significantly higher alanine aminotransferase serum levels (p = 0.0357) and a trend toward shorter transplant-free survival time compared to noncarriers (8.9 ± 6.6 years vs. 10.5 ± 7.1 years; p = 0.076). CONCLUSIONS: Our study shows that PAR1 -506 Ins is significantly more frequent in people with PSC. As PAR1 -506 Ins allele carriers tended to have a shorter transplant-free survival, PAR1 might play a role in the development and course of PSC.

Increased type-I interferon level is associated with liver damage and fibrosis in primary sclerosing cholangitis.

BACKGROUND: The level of type-I interferons (IFNs) in primary sclerosing cholangitis (PSC) was investigated to evaluate its association with disease activity and progression. METHODS: Bioactive type-I IFNs were evaluated in a murine model of PSC and human patients' sera using a cell-based reporter assay and ELISA techniques. In total, 57 healthy participants, 71 PSC, and 38 patients with primary biliary cholangitis were enrolled in this study. RESULTS: Bioactive type-I IFNs were elevated in the liver and serum of multidrug resistance protein 2-deficient animals and showed a correlation with the presence of CD45+ immune cells and serum alanine transaminase levels. Concordantly, bioactive type-I IFNs were elevated in the sera of patients with PSC as compared to healthy controls (sensitivity of 84.51%, specificity of 63.16%, and AUROC value of 0.8267). Bioactive IFNs highly correlated with alkaline phosphatase (r=0.4179, p<0.001), alanine transaminase (r=0.4704, p<0.0001), and gamma-glutamyl transpeptidase activities (r=0.6629, p<0.0001) but not with serum bilirubin. In addition, patients with PSC with advanced fibrosis demonstrated significantly higher type-I IFN values. Among the type-I IFN subtypes IFNα, ß and IFNω could be detected in patients with PSC with IFNω showing the highest concentration among the subtypes and being the most abundant among patients with PSC. CONCLUSIONS: The selectively elevated bioactive type-I IFNs specifically the dominating IFNω could suggest a novel inflammatory pathway that might also have a hitherto unrecognized role in the pathomechanism of PSC.

First-Line Treatment for Advanced Hepatocellular Carcinoma: A Three-Armed Real-World Comparison.

Background and Aim: There are several existing systemic 1st- line therapies for advanced hepatocellular carcinoma (HCC), including atezolizumab/bevacizumab (Atez/Bev), sorafenib and lenvatinib. This study aims to compare the effectiveness of these three 1st-line systemic treatments in a real-world setting for HCC, focusing on specific patient subgroups analysis. Methods: A total of 177 patients with advanced HCC treated with Atez/Bev (n = 38), lenvatinib (n = 21) or sorafenib (n = 118) as 1st line systemic therapy were retrospectively analyzed and compared. Primary endpoints included objective response rate (ORR), progression-free survival (PFS) and 15-month overall survival (15-mo OS). Subgroups regarding liver function, etiology, previous therapy and toxicity were analyzed. Results: Atez/Bev demonstrated significantly longer median 15-month OS with 15.03 months compared to sorafenib with 9.43 months (p = 0.04) and lenvatinib with 8.93 months (p = 0.05). Similarly, it had highest ORR of 31.6% and longest median PFS with 7.97 months, independent of etiology. However, significantly superiority was observed only compared to sorafenib (ORR: 4.2% (p < 0.001); PFS: 4.57 months (p = 0.03)), but not comparing to lenvatinib (ORR: 28.6% (p = 0.87); PFS: 3.77 months (p = 0.10)). Atez/Bev also resulted in the longest PFS in patients with Child-Pugh A and ALBI 1 score and interestingly in those previously treated with SIRT. Contrary, sorafenib was non inferior in patients with impaired liver function. Conclusion: Atez/Bev achieved longest median PFS and 15-mo OS independent of etiology and particularly in patients with stable liver function or prior SIRT treatment. Regarding therapy response lenvatinib was non-inferior to Atez/Bev. Finally, sorafenib seemed to perform best for patients with deteriorated liver function.

[Results of Endoscopic Screening and Therapy of the Duodenum in MUTYH-associated Polyposis]. / Ergebnisse der endoskopischen Vorsorge und Therapie des Duodenums bei MUTYH-assoziierter Polyposis.

MUTYH-associated polyposis (MAP) is a very rare autosomal recessive polyposis syndrome. It is caused by a homozygous or compound heterozygous germline mutation in the MUTYH gene. MAP is characterised by numerous colorectal adenomas; furthermore there is an increased risk for colorectal cancer (CRC). However, the phenotype can be highly variable; for example, affected individuals also have an increased risk of polyps of the upper gastrointestinal tract and development of duodenal carcinomas.This study included 15 patients with evidence of a pathogenic MUTYH variant, who were screened at the National Center for Hereditary Tumor Syndromes. Oesophagogastroduodenoscopy (EGD) results were prospectively recorded in a database from 2012 to 2023.At least one EGD (median 4, range 1-15) was performed in 15 patients, seven of whom carried a homozygous and 8 a compound heterozygous pathogenic MUTYH variant. The median surveillance period was 115 months (range, 3-215 months). The median age at baseline was 44 (range 17-65) years. A total of 72 EGDs were performed (median 4; range 1-15). Five patients had duodenal adenomas; histology showed tubular adenomas with low grade intraepithelial dysplasia (LGIEN) in all of these cases. The total number of duodenal adenomas detected was 48, and the median number was 3 (range, 1-37). Neither high grade intraepithelial neoplasia (HGIEN) nor duodenal cancer was detected during the surveillance period.Patients with MUTYH-associated polyposis should be managed in a multidisciplinary centre for hereditary tumour disease. Our cohort showed more patients with duodenal adenomas than in previously published data. However, no progression to HGIEN or duodenal carcinomas was observed as a result of the endoscopic therapy performed.

Liquid Biopsy in Organ Damage: small extracellular vesicle chip-based assessment of polytrauma.

Background: Despite major advances in medicine, blood-borne biomarkers are urgently needed to support decision-making, including polytrauma. Here, we assessed serum-derived extracellular vesicles (EVs) as potential markers of decision-making in polytrauma. Objective: Our Liquid Biopsy in Organ Damage (LiBOD) study aimed to differentiate polytrauma with organ injury from polytrauma without organ injury. We analysed of blood-borne small EVs at the individual level using a combination of immunocapture and high-resolution imaging. Methods: To this end, we isolated, purified, and characterized small EVs according to the latest Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines from human blood collected within 24 h post-trauma and validated our results using a porcine polytrauma model. Results: We found that small EVs derived from monocytes CD14+ and CD14+CD61+ were significantly elevated in polytrauma with organ damage. To be precise, our findings revealed that CD9+CD14+ and CD14+CD61+ small EVs exhibited superior performance compared to CD9+CD61+ small EVs in accurately indicating polytrauma with organ damage, reaching a sensitivity and a specificity of 0.81% and 0.97%, respectively. The results in humans were confirmed in an independent porcine model of polytrauma. Conclusion: These findings suggest that these specific types of small EVs may serve as valuable, non-invasive, and objective biomarkers for assessing and monitoring the severity of polytrauma and associated organ damage.

Early combination therapy of COVID-19 in high-risk patients.

PURPOSE: Prolonged shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been observed in immunocompromised hosts. Early monotherapy with direct-acting antivirals or monoclonal antibodies, as recommended by the international guidelines, does not prevent this with certainty. Dual therapies may therefore have a synergistic effect. METHODS: This retrospective, multicentre study compared treatment strategies for corona virus disease-19 (COVID-19) with combinations of nirmatrelvir/ritonavir, remdesivir, molnupiravir, and/ or mABs during the Omicron surge. Co-primary endpoints were prolonged viral shedding (≥ 106 copies/ml at day 21 after treatment initiation) and days with SARS-CoV-2 viral load ≥ 106 copies/ml. Therapeutic strategies and risk groups were compared using odds ratios and Fisher's tests or Kaplan-Meier analysis and long-rank tests. Multivariable regression analysis was performed. RESULTS: 144 patients were included with a median duration of SARS-CoV-2 viral load ≥ 106 copies/ml of 8.0 days (IQR 6.0-15.3). Underlying haematological malignancies (HM) (p = 0.03) and treatment initiation later than five days after diagnosis (p < 0.01) were significantly associated with longer viral shedding. Prolonged viral shedding was observed in 14.6% (n = 21/144), particularly in patients with underlying HM (OR 3.5; 95% CI 1.2-9.9; p = 0.02). Clinical courses of COVID-19 were mild to moderate with only few adverse effects potentially related to combination treatment. CONCLUSION: Early combination treatment of COVID-19 effectively prevented prolonged viral shedding in 85.6% of cases. Considering the rapid viral clearance rates and low toxicity, individualized dual therapy approaches may be beneficial in high-risk patients.

Regulatory T Cell Inhibition by P60 Combined with Adenoviral AFP Transduced Dendritic Cells for Immunotherapy of Hepatocellular Carcinoma.

BACKGROUND & AIMS: Vaccination with tumor-associated antigen-pulsed dendritic cells leads to specific T-cell response against hepatocellular carcinoma. However, clinical response has been shown to be limited. High regulatory T-cell count is associated with poor prognosis and seems to mediate immune tolerance in hepatocellular carcinoma. Forkhead box P3-peptide inhibitor P60 has been shown to specifically inhibit regulatory T-cell function in murine models. Aim of this study was to investigate whether P60 can improve the immune response induced by vaccination with adenovirus-transduced dendritic cells expressing alpha-fetoprotein in subcutaneous and orthotopic murine models for hepatocellular carcinoma. METHODS: Mice developing subcutaneous or orthotopic HCC received daily treatment with P60 starting at different tumor stages. Additionally, mice were vaccinated twice with dendritic cells expressing alpha-fetoprotein. RESULTS: In a preventive setting prior to tumor engraftment, vaccination with alpha-fetoprotein-expressing dendritic cells significantly decreased tumor growth in a subcutaneous model (p = .0256), but no further effects were achieved by addition of P60. However, P60 enhanced the antitumoral effect of a vaccination with alpha-fetoprotein-expressing dendritic cells in established subcutaneous and orthotopic hepatocellular carcinoma characterized by high Treg levels (p = .011). CONCLUSION: In this study, we showed that vaccination with alpha-fetoprotein-expressing dendritic cells in combination with a specific inhibition of regulatory T-cells by using P60 leads to synergistic tumor inhibition and prolonged survival. This emphasizes the importance of regulatory T-cells inhibition for obtaining an effective antitumoral immune response in hepatocellular carcinoma.

Deficient Immune Response following SARS-CoV-2 Vaccination in Patients with Hepatobiliary Carcinoma: A Forgotten, Vulnerable Group of Patients.

Introduction: Data on immune response rates following vaccination for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in patients with hepatobiliary carcinoma (HBC) are rare. However, impaired immunogenicity must be expected due to the combination of chronic liver diseases (CLDs) with malignancy and anticancer treatment. Methods: In this prospective, longitudinal study, 101 patients were included, of whom 59 were patients with HBC under anticancer treatment. A cohort of patients with a past medical history of gastrointestinal cancer, of whom 28.6% had HBC without detectable active tumor disease having been off therapy for at least 12 months, served as control. Levels of SARS-CoV-2 anti-spike IgG, surrogate neutralization antibodies (sNABs), and cellular immune responses were compared. In uni- and multivariable subgroup analyses, risk factors for impaired immunogenicity were regarded. Data on rates and clinical courses of SARS-CoV-2 infections were documented. Results: In patients with HBC under active treatment, levels of SARS-CoV-2 anti-spike IgG were significantly lower (2.55 log10 BAU/mL; 95% CI: 2.33-2.76; p < 0.01) than in patients in follow-up care (3.02 log10 BAU/mL; 95% CI: 2.80-3.25) 4 weeks after two vaccinations. Antibody levels decreased over time, and differences between the groups diminished. However, titers of SARS-CoV-2 sNAB were for a longer time significantly lower in patients with HBC under treatment (64.19%; 95% CI: 55.90-72.48; p < 0.01) than in patients in follow-up care (84.13%; 95% CI: 76.95-91.31). Underlying CLD and/or liver cirrhosis Child-Pugh A or B (less than 8 points) did not seem to further impair immunogenicity. Conversely, chemotherapy and additional immunosuppression were found to significantly reduce antibody levels. After a third booster vaccination for SARS-CoV-2, levels of total and neutralization antibodies were equalized between the groups. Moreover, cellular response rates were balanced. Clinically, infection rates with SARS-CoV-2 were low, and no severe courses were observed. Conclusion: Patients with active HBC showed significantly impaired immune response rates to basic vaccinations for SARS-CoV-2, especially under chemotherapy, independent of underlying cirrhotic or non-cirrhotic CLD. Although booster vaccinations balanced differences, waning immunity was observed over time and should be monitored for further recommendations. Our data help clinicians decide on individual additional booster vaccinations and/or passive immunization or antiviral treatment in patients with HBC getting infected with SARS-CoV-2.

Comparison between regular additional endobiliary radiofrequency ablation and photodynamic therapy in patients with advanced extrahepatic cholangiocarcinoma under systemic chemotherapy.

Background and aims: Extrahepatic cholangiocarcinoma (eCCA) remains a malignancy with a dismal prognosis. The first-line standard of care includes systemic chemotherapy (SC) and biliary drainage through stenting. Endobiliary ablative techniques, such as photodynamic therapy (ePDT) and radio-frequency ablation (eRFA), have demonstrated feasibility and favorable survival data. This study aimed to compare the oncologic outcome in patients treated with SC and concomitant eRFA or ePDT. Method: All patients with eCCA were evaluated for study inclusion. Sixty-three patients receiving a combination of SC and at least one endobiliary treatment were retrospectively compared. Results: Patients were stratified into three groups: SC + ePDT (n = 22), SC + eRFA (n = 28), and SC + ePDT + eRFA (n = 13). The median overall survival (OS) of the whole cohort was 14.2 months with no statistically significant difference between the three therapy groups but a trend to better survival for the group receiving ePDT as well as eRFA, during SC (ePDT + SC, 12.7 months; eRFA + SC, 13.8 months; ePDT + eRFA + SC, 20.2 months; p = 0.112). The multivariate Cox regression and subgroup analysis highlighted the beneficial effect of eRFA on OS. Overall, combined therapy was well tolerated. Only cholangitis occurred more often in the SC + eRFA group. Conclusion: Additional endobiliary ablative therapies in combination with SC were feasible. Both modalities, eRFA and ePDT, showed a similar benefit in terms of survival. Interestingly, patients receiving both regimes showed the best OS indicating a possible synergism between both ablative therapeutic techniques.

No evidence for neuronal damage or astrocytic activation in cerebrospinal fluid of Neuro-COVID-19 patients with long-term persistent headache.

Headache is one of the most common neurological manifestations of COVID-19, but it is unclear whether chronic headache as a symptom of Post-COVID-19 is associated with ongoing CNS damage. We compared cerebrospinal fluid (CSF) levels of markers of CNS damage and inflammation in Post-COVID-19 patients with persistent headache to hospitalized acute COVID-19 patients with neurological symptoms and to non-COVID-19 disease-controls. CSF levels of neurofilament light chain, Ubiquitin carboxyl-terminal hydrolase L1 and Tau were similar in patients with persistent headache in post-COVID-19 compared to acute COVID-19 patients and all control groups. Levels of glial fibrillary astrocytic protein were lower in patients with persistent headache in post-COVID-19 compared to some control groups of patients with neurological disease. Therefore, our pilot study of CSF markers indicates that persistent post-COVID-19 headache is not a sign of underlying neuronal damage or glial activation.

Long-Term Clinical Outcome of Abdomino-Thoracic Lymphatic Interventions of Traumatic and Non-Traumatic Lymphatic Leakage in Adults.

The aim of this study was to retrospectively evaluate the long-term results of lymphatic interventions in adults with abdomino-thoracic lymphatic pathologies. Management of abdomino-thoracic chylous effusions in adults undergoing X-ray-lymphangiography with or without lymph-vessel embolization (LVE) from 2010-2018 was reviewed. Patients underwent lymphangiography alone when imaging showed normal findings or lymphatic obstruction without leakage or reflux; otherwise, LVE was performed (leakage, reflux, obstruction with leakage or reflux, lymphatic masses). Technical and clinical success, complications, and long-term outcomes were assessed. 78 patients (47 male, median age 56.3 years) were treated for chylous effusions (60.3% traumatic, 39.7% non-traumatic). Lymphangiography showed leakage (48.7%), reflux (14.1%), obstruction (28.2%), lymphatic masses (5.1%), and normal findings (3.8%). Embolization was performed in 49/78 (62.8%) cases. Overall, treatment was clinically successful in 74.4% (mean follow-up of 28 months), with significant differences between LVE and lymphangiography (91.8% vs. 44.8%; p < 0.001), traumatic and non-traumatic etiologies (89.4% vs. 51.6%; p < 0.001), and leakage locations (p = 0.003). The clinical success of LVE did not differ between leakage etiologies or locations. Complications occurred in 5 patients (2/5 needed treatment). Patients survived significantly longer after successful treatment (2679 vs. 927 days; p = 0.044) and without malignancy (3214 vs. 1550 days; p = 0.043). Lymphatic interventions are safe and effective. LVE should be attempted whenever feasible, as success is high (>90%). Successful intervention has a positive effect on patient survival.

Myosteatosis independently predicts transplant-free survival in patients with primary sclerosing cholangitis.

BACKGROUND: Primary Sclerosing Cholangitis (PSC) is a progressive cholestatic liver disease with liver transplantation (LT) as the only curative therapy. Some regions use body-weight-loss as standard-exception criteria for organ allocation but data on the impact of body composition on survival of patients with PSC is scarce. METHODS: Abdominal MRI of PSC patients were quantitatively analyzed for intramuscular fat fraction (IMFF) as surrogate of myosteatosis. Clinical and laboratory data were retrieved from patient records. Primary outcome was transplant-free survival (TFS). RESULTS: 116 PSC patients were included. Median age was 38 (18-71) years with 74 (64%) male patients. 15 (13%) patients had significant weigh loss. IMFF was significantly associated with survival. Multivariate regression analysis showed IMFF ≥ 15% as independent predictor for TFS (p = 0.032, HR 3.215 CI 1.104-9.366), but not significant weight loss (p = 0.618). CONCLUSION: IMFF is independently associated with TFS in patients with PSC and may identify patients with more urgent need for LT. NCT03584204.

Impaired immunogenicity after vaccination for SARS-CoV-2 in patients with gastrointestinal cancer: does tumor entity matter?

Background: SARS-CoV-2 immunogenicity in patients with gastrointestinal cancer (GI cancer) following second and third vaccination was analyzed. Methods: A total of 125 patients under active anticancer therapy or in follow-up care were included in this prospective study. Seroprevalence of SARS-CoV-2 anti-spike and surrogate neutralization antibodies (NABs) was measured. Results: Four weeks after second vaccination, adequate titers of SARS-CoV-2 anti-spike immunoglobulin G (IgG) [≥282.0 binding antibody units (BAU)/mL] were found in 62.2% of patients under treatment versus 96.3% of patients in follow-up care (P<0.01). Sufficient titers of SARS-CoV-2 surrogate NAB (≥85.0%) were found in 32.7% of patients under treatment versus 70.6% in follow-up care (P<0.01). Titers of SARS-CoV-2 anti-spike IgG were especially low in patients with colorectal cancer (CRC). For SARS-CoV-2 surrogate NAB, patients with hepatocellular carcinoma (HCC) and with pancreaticobiliary cancer showed the lowest titers (P<0.01). SARS-CoV-2 anti-spike IgG and SARS-CoV-2 surrogate NAB were associated with a correlation coefficient of 0.93. Reaching a titer of SARS-CoV-2 anti-spike IgG ≥482.0 BAU/mL, protective levels of SARS-CoV-2 surrogate NAB (≥85.0%) could be assumed. Following booster vaccination, all patients reached effective antibody titers. Conclusions: Patients with active GI cancer showed impaired immunogenicity after second SARS-CoV-2 vaccination which was overcome by booster vaccination. Our findings were tumor-related and pronounced in patients with CRC and HCC. Waning immunity over time and antibody escape phenomena by variant of concern Omicron must be considered in these especially vulnerable patients.

IL-6-Dependent STAT3 Activation and Induction of Proinflammatory Cytokines in Primary Sclerosing Cholangitis.

INTRODUCTION: Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with periductal inflammation and fibrosis. Genetic studies suggest inflammatory cytokines and IL-6-dependent activation of transcription factor STAT3 as pivotal steps in PSC pathogenesis. However, details of inflammatory regulation remain unclear. METHODS: We recruited 50 patients with PSC (36 with inflammatory bowel disease, 14 without inflammatory bowel disease), 12 patients with autoimmune hepatitis, and 36 healthy controls to measure cytokines in the serum, bile, and immune cell supernatant using bead-based immunoassays and flow cytometry and immunohistochemistry to analyze phosphorylation of STATs in immune cells. Finally, we analyzed cytokines and STAT3 phosphorylation of T cells in the presence of JAK1/2 inhibitors. RESULTS: In PSC, IL-6 specifically triggered phosphorylation of STAT3 in CD4 + T cells and lead to enhanced production of interferon (IFN) gamma and interleukin (IL)-17A. Phospho-STAT3-positive CD4 + T cells correlated with systemic inflammation (C-reactive protein serum levels). Combination of immunohistology and flow cytometry indicated that phospho-STAT3-positive cells were enriched in the peribiliary liver stroma and represented CD4 + T cells with prominent production of IFN gamma and IL-17A. JAK1/2 inhibitors blocked STAT3 phosphorylation and production of IFN gamma and IL-6, whereas IL-17A was apparently resistant to this inhibition. DISCUSSION: Our results demonstrate systemic and local activation of the IL-6/STAT3 pathway in PSC. Resistance of IL-17A to STAT3-targeted inhibition points to a more complex immune dysregulation beyond STAT3 activation.

Identification and characterization of a hepatic IL-13-producing ILC3-like population potentially involved in liver fibrosis.

BACKGROUND AND AIMS: Human innate lymphoid cells (ILCs) are critically involved in the modulation of homeostatic and inflammatory processes in various tissues. However, only little is known about the composition of the intrahepatic ILC pool and its potential role in chronic liver disease. Here, we performed a detailed characterization of intrahepatic ILCs in both healthy and fibrotic livers. APPROACH AND RESULTS: A total of 50 livers (nonfibrotic = 22, and fibrotic = 29) were analyzed and compared with colon and tonsil tissue (each N = 14) and peripheral blood (N = 32). Human intrahepatic ILCs were characterized ex vivo and on stimulation using flow cytometry and single-cell RNA sequencing. ILC differentiation and plasticity were analyzed by both bulk and clonal expansion experiments. Finally, the effects of ILC-derived cytokines on primary human HSteCs were studied. Unexpectedly, we found that an "unconventional" ILC3-like cell represented the major IL-13-producing liver ILC subset. IL-13 + ILC3-like cells were specifically enriched in the human liver, and increased frequencies of this cell type were found in fibrotic livers. ILC3-derived IL-13 production induced upregulation of proinflammatory genes in HSteCs, indicating a potential role in the regulation of hepatic fibrogenesis. Finally, we identified KLRG1-expressing ILC precursors as the potential progenitor of hepatic IL-13 + ILC3-like cells. CONCLUSIONS: We identified a formerly undescribed subset of IL-13-producing ILC3-like cells that is enriched in the human liver and may be involved in the modulation of chronic liver disease.

Surgical site infections are independently associated with the development of postoperative acute-on-chronic liver failure in liver cirrhosis.

Acute-on-chronic liver failure (ACLF) is associated with organ failure and high short-term mortality. Bacterial infections and surgery have been reported as major precipitants for ACLF. However, detailed characterization of postoperative infections after elective surgery in patients with liver cirrhosis and their impact on the development of ACLF have not been investigated yet. A total of 235 patients with cirrhosis without ACLF and proven bacterial infections undergoing elective surgery were included. The primary end point was the development of ACLF within 28 days after surgery, and secondary end points were infection development within 28 days and 3-month ACLF-related mortality. Cox regression analysis was used for identification of risk factors associated with ACLF development, infection development, and mortality. A total of 86 patients (37%) developed ACLF within 28 days after surgery. Patients with new postoperative infections had significantly higher rates of associated ACLF episodes within 28 days (51% vs. 24%, p < 0.001) and higher 3-month mortality ( p < 0.05) than patients without postoperative infections. New infections after surgery [HR: 2.43 (1.59-3.71), p < 0.001] and organ/space surgical site infections [HR: 2.46 (1.26-4.80), p = 0.01] in particular were independent risk factors associated with ACLF development 28 days after surgery. Extensive procedures were associated with the development of new postoperative infection episodes within 28 days. Infections treated with initial appropriate empirical antibiotic strategies showed significantly improved survival. This study characterizes and identifies bacterial infections in general and organ/space surgical site infection in particular as precipitating events for the development of ACLF after elective surgery in patients with cirrhosis. Postoperative ACLF combined with infections leads to higher postoperative short-term mortality than each condition separately, especially in extensive procedures. Interdisciplinary care, early identification of postoperative ACLF and infections, and adequate, broad, and early treatment strategies are needed to improve postoperative outcome.