A gut bacterial signature in blood and liver tissue characterizes cirrhosis and hepatocellular carcinoma.

BACKGROUND: HCC is the leading cause of cancer in chronic liver disease. A growing body of experimental mouse models supports the notion that gut-resident and liver-resident microbes control hepatic immune responses and, thereby, crucially contribute to liver tumorigenesis. However, a comprehensive characterization of the intestinal microbiome in fueling the transition from chronic liver disease to HCC in humans is currently missing. METHODS: Here, we profiled the fecal, blood, and liver tissue microbiome of patients with HCC by 16S rRNA sequencing and compared profiles to nonmalignant cirrhotic and noncirrhotic NAFLD patients. RESULTS: We report a distinct bacterial profile, defined from 16S rRNA gene sequences, with reduced α-and ß-diversity in the feces of patients with HCC and cirrhosis compared to NAFLD. Patients with HCC and cirrhosis exhibited an increased proportion of fecal bacterial gene signatures in the blood and liver compared to NAFLD. Differential analysis of the relative abundance of bacterial genera identified an increased abundance of Ruminococcaceae and Bacteroidaceae in blood and liver tissue from both HCC and cirrhosis patients compared to NAFLD. Fecal samples from cirrhosis and HCC patients both showed a reduced abundance for several taxa, including short-chain fatty acid-producing genera, such as Blautia and Agathobacter. Using paired 16S rRNA and transcriptome sequencing, we identified a direct association between gut bacterial genus abundance and host transcriptome response within the liver tissue. CONCLUSIONS: Our study indicates perturbations of the intestinal and liver-resident microbiome as a critical determinant of patients with cirrhosis and HCC.

B and T Cell Responses to SARS-CoV-2 Vaccination in Kidney and Liver Transplant Recipients with and without Previous COVID-19.

(1) Background: Vulnerable populations including transplant recipients are jeopardised by COVID-19. Herein, we report on B and T cell responses among liver and kidney organ recipients at our centre. (2) Methods: 23 liver and 45 kidney (14 thereof combined kidney/pancreas) transplanted patients were vaccinated with two doses of BNT162b2 followed by a booster dose of mRNA-1273 in 28 non-responders 4 months thereafter. Anti-SARS-CoV-2-Ig was measured by specific ELISA and virus neutralisation assay; T cell responses were measured by a spike protein-specific IFN-γ release assay. (3) Results: Compared to controls, B and T cell responses were weak in transplant recipients, particularly in those without prior exposure to SARS-CoV-2. Within this group, only 15% after the first and 58.3% after the second vaccination achieved seroconversion. A total of 14 out of 28 vaccination non-responders achieved a seroconversion after a third dose. Vaccination side effects were more frequent in healthy controls. The use of mycophenolate was associated with reduced anti-SARS-CoV-2-Ig production. (4) Conclusions: Our data confirm that vaccination responses are insufficient after standard vaccination in liver and kidney transplant recipients and are affected to a variable degree by specific immunosuppressants, particularly mycophenolate. Monitoring vaccination success and re-vaccinating those who are unresponsive seems prudent to achieve sufficient titres. Overall, prospective large-scale, multinational, multicentre studies or high-quality meta-analyses will be needed to generate personalised vaccination strategies in order to achieve protective immunity in high-risk, hard-to-immunize populations.

Short- and Long-Term Effects of a Prebiotic Intervention with Polyphenols Extracted from European Black Elderberry-Sustained Expansion of Akkermansia spp.

(1) Background: The intestinal microbiome has emerged as a central factor in human physiology and its alteration has been associated with disease. Therefore, great hopes are placed in microbiota-modulating strategies. Among various approaches, prebiotics, substrates with selective metabolization conferring a health benefit to the host, are promising candidates. Herein, we studied the prebiotic properties of a purified extract from European black elderberries, with a high and standardized content of polyphenols and anthocyanins. (2) Methods: The ELDERGUT trial represents a 9-week longitudinal intervention study divided into 3 distinct phases, namely a baseline, an intervention and a washout period, three weeks each. The intervention consisted of capsules containing 300 mg elderberry extract taken twice a day. Patient-reported outcomes and biosamples were collected weekly. Microbiome composition was assessed using 16S amplicon metagenomics. (3) Results: The supplementation was well tolerated. Microbiome trajectories were highly individualized with a profound shift in diversity indices immediately upon initiation and after termination of the compound. This was accompanied by corresponding changes in species abundance over time. Of particular interest, the relative abundance of Akkermansia spp. continued to increase in a subset of participants even beyond the supplementation period. Associations with participant metadata were detected.

Uterine microbiota plasticity during the menstrual cycle: Differences between healthy controls and patients with recurrent miscarriage or implantation failure.

In contrast to the former notion of a sterile womb, sequencing techniques have proven a bacterial colonization of the uterus. However, timing of microbiota analysis regarding possible intra-cycle variations as well as specific alterations in patients with recurrent miscarriage (RM) or recurrent implantation failure (RIF) remain unknown. In total, n = 20 RM-, n = 20 RIF-patients and n = 10 healthy controls were included in this prospective study. In every subject, uterine flushing was performed during follicular, ovulatory and luteal phase. Bacterial DNA was isolated and 16S amplicon sequencing analysis of the V3-V4 region was carried out. Diversity measures were compared between samples from the disease groups and the control group separately for each timepoint of the menstrual cycle and over time. In the control group a significant decrease of species richness and evenness was shown around ovulation which remained at this lower level during the luteal phase (Shannon index), indicating a more uniform distribution of microbiota (p < 0.05). This loss of diversity during the menstrual cycle was not apparent in RIF and RM patients. A higher similarity was seen in taxonomic distribution between RM and RIF patients compared to the control group. Longitudinal dynamics included increases in Firmicutes (controls and RM only) and a concomitant loss of Proteobacteria in controls that was not present in RIF and RM. We demonstrate longitudinal intra-cycle-dependent changes in the endometrial microbiota of healthy controls. An increased diversity in both patient groups could be the cause or consequence of a micro-environment that is more prone to pregnancy failures.

The Underestimated and Overlooked Burden of Diarrhea and Constipation in Cancer Patients.

PURPOSE OF REVIEW: This review aims to summarize and discuss the diverse causes of two major gastrointestinal dysfunction symptoms, diarrhea and constipation, in cancer patients. We also discuss short- and long-term clinical, economic, and humanistic consequences, including the impact on cancer treatment regimens and patient quality of life, highlighting the limitations of the literature. RECENT FINDINGS: Diarrhea and constipation as a result of cancer and its treatment can risk the success of anti-cancer therapies by requiring treatment delay or withdrawal, and imposes a substantial humanistic burden in patients with cancer. Despite its importance and frequency, gastrointestinal side effects may be overlooked due to the focus on cancer treatment, and the impact on patients may be underestimated. Additionally, the burden reported may not fully reflect current cancer management, particularly the true impact of economic consequences. A full understanding of the burden of diarrhea and constipation in patients with cancer is required, including broad evaluation of clinical considerations, the patient experience, and an updated assessment of economic burden. This would improve caregivers' appreciation of the impact of gastrointestinal dysfunction and aid the prioritization of future research efforts.

Calibrated comparison of SARS-CoV-2 neutralizing antibody levels in response to protein-, mRNA-, and vector-based COVID-19 vaccines.

SARS-CoV-2 neutralizing antibodies have been suggested to reflect the efficacy of COVID-19 vaccines. This study reports the direct comparison of the SARS-CoV-2 neutralizing antibody response elicited by a protein- (NVX-CoV2373), an mRNA- (Comirnaty), and a vector-based (Vaxzevria) COVID-19 vaccine, calibrated against the WHO international SARS-CoV-2 antibody standard, and further supports the use of neutralizing antibody levels as a correlate of protection.

Modelling the benefits of an optimised treatment strategy for 5-ASA in mild-to-moderate ulcerative colitis.

OBJECTIVES: 5-aminosalicylate (mesalazine; 5-ASA) is an established first-line treatment for mild-to-moderate ulcerative colitis (UC). This study aimed to model the benefits of optimising 5-ASA therapy. METHODS: A decision tree model followed 10 000 newly diagnosed patients with mild-to-moderately active UC through induction and 1 year of maintenance treatment. Optimised treatment (maximising dose of 5-ASA and use of combined oral and rectal therapy before treatment escalation) was compared with standard treatment (standard doses of 5-ASA without optimisation). Modelled data were derived from published meta-analyses. The primary outcomes were patient numbers achieving and maintaining remission, with an analysis of treatment costs for each strategy conducted as a secondary outcome (using UK reference costs). RESULTS: During induction, there was a 39% increase in patients achieving remission through the optimised pathway without requiring systemic steroids and/or biologics (6565 vs 4725 for standard). Potential steroidal/biological adverse events avoided included: seven venous thromboembolisms and eight serious infections. Out of the 6565 patients entering maintenance following successful induction on 5-ASA, there was a 21% reduction in relapses when optimised (1830 vs 2311 for standard). This translated into 297 patients avoiding further systemic steroids and 214 biologics. Optimisation led to an average net saving of £272 per patient entering the model for the induction and maintenance of remission over 1 year. CONCLUSION: Modelling suggests that optimising 5-ASA therapy (both the inclusion of rectal 5-ASA into a combined oral and rectal regimen and maximisation of 5-ASA dose) has clinical and cost benefits that supports wider adoption in clinical practice.

Lactobacillus reuteri-an old acquaintance takes on a new task in colorectal tumor surveillance.

In this issue of Cancer Cell, Bell et al. identify the commensal bacterium Lactobacillus reuteri and its major metabolite reuterin as an important gatekeeper and promising target in colorectal cancerogenesis. They decipher a metabolic interplay in which L. reuteri is suppressed by metabolites from dysplastic intestinal epithelial cells which in turn are highly sensitive to the oxidative effects of the electrophile reuterin.

Tofacitinib-Induced Modulation of Intestinal Adaptive and Innate Immunity and Factors Driving Cellular and Systemic Pharmacokinetics.

OBJECTIVE: By interfering with multiple cytokines, human Janus kinase inhibitors (JAKis) are of growing importance in the treatment of malignant and inflammatory conditions. Although tofacitinib has demonstrated efficacy as the first-in-class JAKi in ulcerative colitis many aspects concerning its mode of action and pharmacokinetics remain unresolved. DESIGN: We studied tofacitinib's impact on various primary human innate and adaptive immune cells. In-depth in vivo studies were performed in dextran sodium sulfate-induced colitis in mice. Immune populations were characterized by flow cytometry and critical transcription factors and effector cytokines were analyzed. Pharmacokinetics of tofacitinib was studied by liquid chromatography-tandem mass spectrometry. RESULTS: Tofacitinib inhibited proliferation in CD4+ and CD8+ T cells along with Th1 and Th17 differentiation, while Th2 and regulatory T cell lineages were largely unaffected. Monocytes and macrophages were directed toward an anti-inflammatory phenotype and cytokine production was suppressed in intestinal epithelial cells. These findings were largely reproducible in murine cells of the inflamed mucosa in dextran sulfate sodium colitis. Short-term treatment with tofacitinib had little impact on the mouse microbiota. Strikingly, the degree of inflammation and circulating tofacitinib levels showed a strong positive correlation. Finally, we identified inflammation-induced equilibrative nucleoside transporters as regulators of tofacitinib uptake into leukocytes. CONCLUSIONS: We provide a detailed analysis of the cell-specific immune-suppressive effects of the JAKis tofacitinib on innate and adaptive immunity and reveal that intestinal inflammation critically impacts tofacitinib's pharmacokinetics in mice. Furthermore, we describe an unappreciated mechanism-namely induction of equilibrative nucleoside transporters-enhancing baseline cellular uptake that can be inhibited pharmaceutically.

Multinational evaluation of clinical decision-making in the treatment and management of mild-to-moderate ulcerative colitis.

OBJECTIVES: To understand current thinking and clinical decision-making in the treatment and management of patients with mild-to-moderate ulcerative colitis (UC). METHODS: This multinational, survey-based study was conducted in 2021. Two meetings were held, involving 11 IBD specialists, that used a series of questions and discussion to identify all factors possibly related to the management of UC. The importance of identified factors was assessed using an online questionnaire covering three scenarios - active disease, remission and patient empowerment. Each factor was scored on a scale of 0 (very-unimportant) to 100 (very-important) within each scenario, by a separate group of healthcare professionals working in IBD. RESULTS: A total of 157 individual factors were identified by the 11 IBD specialists and scored in the three scenarios by 56 respondents (52; 93% specialist gastroenterologists) from Europe and North America (25; 45%), South America (19; 34%) and the Middle East, Asia and Australia (12; 21%). For all scenarios, factors related to educating patients regarding UC and its treatment and understanding of patient goals ranked highest, ahead of clinical considerations regarding disease activity and treatment history. Setting realistic short-term treatment targets was a key consideration. 5-ASA optimisation and use of faecal calprotectin monitoring were core strategies across the three scenarios tested. Support for patients during longer-term management of their disease, starting from initial flare, was an important recurring theme. CONCLUSION: The current management approach for mild-to-moderate UC was found to be guided primarily by the patient's perspectives and goals, alongside assessment of their medical and disease history.

B and T cell response to SARS-CoV-2 vaccination in health care professionals with and without previous COVID-19.

BACKGROUND: In recent months numerous health care professional acquired COVID-19 at the workplace resulting in significant shortages in medical and nursing staff. We investigated how prior COVID-19 affects SARS-CoV-2 vaccination and how such knowledge could facilitate frugal vaccination strategies. METHODS: In a cohort of 41 healthcare professionals with (n=14) and without (n=27) previous SARS-CoV-2 infection, we assessed the immune status before, during and after vaccination with BNT162b2. The humoral immune response was assessed by receptor binding domain ELISA and different SARS-CoV-2 neutralisation assays using wildtype and pseudo-typed viruses. T cell immunity against SARS-CoV-2 surface and nucleocapsid peptides were studied using interferon-γ release assays and intracellular flow cytometry. Vaccine-related side effects were captured. FINDINGS: Prior COVID-19 resulted in improved vaccine responses both in the B and T cell compartment. In vaccine recipients with prior COVID-19, the first vaccine dose induced high antibody concentrations comparable to seronegative vaccine recipients after two injections. This translated into more efficient neutralisation of virus particles, even more pronounced than expected from the RBD ELISA results. Furthermore, T cell responses were stronger in convalescents and particularly strong against the SARS-CoV-2 nucleocapsid protein. INTERPRETATION: Herein, we corroborate recent findings suggesting that in convalescents a single vaccine dose is sufficient to boost adequate in vitro neutralisation of SARS-CoV-2 and therefore may be sufficient to induce adequate protection against severe COVID-19. New spike mutated virus variants render the highly conserved nucleocapsid protein - eliciting strong SARS-CoV-2 specific T cell immunity - an interesting additional vaccine target. FUNDING: Christian Doppler Research Association, Johannes Kepler University Linz.

Immunologically relevant aspects of the new COVID-19 vaccines-an ÖGAI (Austrian Society for Allergology and Immunology) and AeDA (German Society for Applied Allergology) position paper.

BACKGROUND: The vaccines against the coronavirus disease 2019 (COVID-19) approved in the European Union represent a decisive step in the fight against the pandemic. The application of these available vaccines to patients with pre-existing immunological conditions leads to a multitude of questions regarding efficacy, side effects and the necessary patient information. RESULTS: This review article provides insight into mechanisms of action of the currently available severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and summarises the current state of science as well as expert recommendations regarding tolerability of the vaccines. In addition, the potential to develop protective immune responses is determined. A special focus is given on patients under immunosuppression or in treatment with immunomodulatory drugs. Special groups of the population such as children, pregnant women and the elderly are also considered. CONCLUSION: Despite the need for a patient-specific risk-benefit assessment, the consensus among experts is that patients with immunological diseases in particular benefit from the induced immune protection after COVID-19 vaccination and do not have an increased risk of side effects.

When the genome bluffs: a tandem duplication event during generation of a novel Agmo knockout mouse model fools routine genotyping.

BACKGROUND: Genome editing in mice using either classical approaches like homologous recombination or CRISPR/Cas9 has been reported to harbor off target effects (insertion/deletion, frame shifts or gene segment duplications) that lead to mutations not only in close proximity to the target site but also outside. Only the genomes of few engineered mouse strains have been sequenced. Since the role of the ether-lipid cleaving enzyme alkylglycerol monooxygenase (AGMO) in physiology and pathophysiology remains enigmatic, we created a knockout mouse model for AGMO using EUCOMM stem cells but unforeseen genotyping issues that did not agree with Mendelian distribution and enzyme activity data prompted an in-depth genomic validation of the mouse model. RESULTS: We report a gene segment tandem duplication event that occurred during the generation of an Agmo knockout-first allele by homologous recombination. Only low homology was seen between the breakpoints. While a single copy of the recombinant 18 kb cassette was integrated correctly around exon 2 of the Agmo gene, whole genome nanopore sequencing revealed a 94 kb duplication in the Agmo locus that contains Agmo wild-type exons 1-3. The duplication fooled genotyping by routine PCR, but could be resolved using qPCR-based genotyping, targeted locus amplification sequencing and nanopore sequencing. Despite this event, this Agmo knockout mouse model lacks AGMO enzyme activity and can therefore be used to study its physiological role. CONCLUSIONS: A duplication event occurred at the exact locus of the homologous recombination and was not detected by conventional quality control filters such as FISH or long-range PCR over the recombination sites. Nanopore sequencing provides a cost convenient method to detect such underrated off-target effects, suggesting its use for additional quality assessment of gene editing in mice and also other model organisms.

Faecal Biomarkers in Inflammatory Bowel Diseases: Calprotectin Versus Lipocalin-2-a Comparative Study.

BACKGROUND AND AIMS: Faecal biomarkers, particularly calprotectin [FCAL], have become important diagnostic and monitoring tools in inflammatory bowel diseases [IBD]. As FCAL is mainly produced by neutrophils, we hypothesised that faecal lipocalin-2 [FLCN2], also expressed by intestinal epithelial cells [IEC], could be beneficial in specific clinical situations. METHODS: We compared clinical and endoscopic activity-related correlations between FCAL and FLCN2, assayed from the same sample, in a cohort of 132 patients (72 Crohn's disease [CD]) and 40 controls. A detailed analysis of cellular origins was done by confocal microscopy and flow cytometry. To evaluate the potential to detect low-grade inflammation, we studied faecal and tissue concentrations in a cohort with clinical, endoscopic, and histological remission. RESULTS: There was an excellent correlation between FCAL and FLCN2 [rS = 0.87, p <0.001] and comparable sensitivity and specificity to predict clinical and endoscopic disease activity, with optimal thresholds for endoscopic activity of 73.4 and 1.98 µg/g in ulcerative colitis [UC] and 78.4 and 0.56 µg/g in Crohn's disease for FCAL and FLCN2, respectively. Strong co-expression of both proteins was observed in granulocytes and macrophages. IECs expressed LCN2 but not CAL. In our IBD cohort in deep remission neither FCAL nor FLCN2 was different from controls; yet mucosal LCN2 but not CAL expressions remained elevated in the rectum of UC and the ileum of CD patients. CONCLUSIONS: This study corroborates the diagnostic equivalence of FLCN2 and FCAL in IBD. In remission, persistent mucosal overexpression renders LCN2 an attractive candidate for molecular inflammation warranting further investigation.

Alpha-1 antitrypsin governs alcohol-related liver disease in mice and humans.

OBJECTIVE: Alcohol-related liver disease (ALD) is a global healthcare problem with limited treatment options. Alpha-1 antitrypsin (AAT, encoded by SERPINA1) shows potent anti-inflammatory activities in many preclinical and clinical trials. In our study, we aimed to explore the role of AAT in ALD. DESIGN: An unselected cohort of 512 patients with cirrhosis was clinically characterised. Survival, clinical and biochemical parameters including AAT serum concentration were compared between patients with ALD and other aetiologies of liver disease. The role of AAT was evaluated in experimental ALD models. RESULTS: Cirrhotic ALD patients with AAT serum concentrations less than 120 mg/dL had a significantly higher risk for death/liver transplantation as compared with patients with AAT serum concentrations higher than 120 mg/dL. Multivariate Cox regression analysis showed that low AAT serum concentration was a NaMELD-independent predictor of survival/transplantation. Ethanol-fed wild-type (wt) mice displayed a significant decline in hepatic AAT compared with pair-fed mice. Therefore, hAAT-Tg mice were ethanol-fed, and these mice displayed protection from liver injury associated with decreased steatosis, hepatic neutrophil infiltration and abated expression of proinflammatory cytokines. To test the therapeutic capability of AAT, ethanol-fed wt mice were treated with human AAT. Administration of AAT ameliorated hepatic injury, neutrophil infiltration and steatosis. CONCLUSION: Cirrhotic ALD patients with AAT concentrations less than 120 mg/dL displayed an increased risk for death/liver transplantation. Both hAAT-Tg mice and AAT-treated wt animals showed protection from ethanol-induced liver injury. AAT could reflect a treatment option for human ALD, especially for alcoholic hepatitis.