The IRE1α/XBP1 pathway sustains cytokine responses of group 3 innate lymphoid cells in inflammatory bowel disease.

Group 3 innate lymphoid cells (ILC3s) are key players in intestinal homeostasis. Endoplasmic reticulum (ER) stress is linked to inflammatory bowel disease (IBD). Herein, we used cell culture, mouse models, and human specimens to examine if ER stress in ILC3s impacts IBD pathophysiology. We show that mouse intestinal ILC3s exhibited a 24h-rhythmic expression pattern of the master ER stress response regulator, IRE1α/XBP1. Proinflammatory cytokine IL-23 selectively stimulated IRE1α/XBP1 in mouse ILC3s through mitochondrial reactive oxygen species (mtROS). IRE1α/XBP1 was activated in ILC3s of mice exposed to experimental colitis and in inflamed human IBD specimens. Mice with Ire1α deletion in ILC3s (Ire1αΔRorc) showed reduced expression of ER stress response and cytokine genes including Il22 in ILC3s and were highly vulnerable to infections and colitis. Administration of IL-22 counteracted their colitis susceptibility. In human ILC3s, IRE1 inhibitors suppressed cytokine production, which was upregulated by an IRE1 activator. Moreover, the frequencies of intestinal XBP1s+ ILC3s in Crohn's disease patients before administration of ustekinumab, an anti-IL-12/IL-23 antibody, positively correlated with response to treatment. We demonstrate that a non-canonical mtROS-IRE1α/XBP1 pathway augments cytokine production by ILC3s and identify XBP1s+ ILC3s as a potential biomarker for predicting response to anti-IL-23 therapies in IBD.

Memory-like differentiation enhances NK cell responses against colorectal cancer.

Metastatic (m) colorectal cancer (CRC) is an incurable disease with a poor prognosis and thus remains an unmet clinical need. Immune checkpoint blockade (ICB)-based immunotherapy is effective for mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) mCRC patients, but it does not benefit the majority of mCRC patients. NK cells are innate lymphoid cells with potent effector responses against a variety of tumor cells but are frequently dysfunctional in cancer patients. Memory-like (ML) NK cells differentiated after IL-12/IL-15/IL-18 activation overcome many challenges to effective NK cell anti-tumor responses, exhibiting enhanced recognition, function, and in vivo persistence. We hypothesized that ML differentiation enhances the NK cell responses to CRC. Compared to conventional (c) NK cells, ML NK cells displayed increased IFN-γ production against both CRC cell lines and primary patient-derived CRC spheroids. ML NK cells also exhibited improved killing of CRC target cells in vitro in short-term and sustained cytotoxicity assays, as well as in vivo in NSG mice. Mechanistically, enhanced ML NK cell responses were dependent on the activating receptor NKG2D as its blockade significantly decreased ML NK cell functions. Compared to cNK cells, ML NK cells exhibited greater antibody-dependent cytotoxicity when targeted against CRC by cetuximab. ML NK cells from healthy donors and mCRC patients exhibited increased anti-CRC responses. Collectively, our findings demonstrate that ML NK cells exhibit enhanced responses against CRC targets, warranting further investigation in clinical trials for mCRC patients, including those who have failed ICB.

SARS-CoV-2 Omicron BA.1 Variant Infection of Human Colon Epithelial Cells.

The Omicron variant of SARS-CoV-2, characterized by multiple subvariants including BA.1, XBB.1.5, EG.5, and JN.1, became the predominant strain in early 2022. Studies indicate that Omicron replicates less efficiently in lung tissue compared to the ancestral strain. However, the infectivity of Omicron in the gastrointestinal tract is not fully defined, despite the fact that 70% of COVID-19 patients experience digestive disease symptoms. Here, using primary human colonoids, we found that, regardless of individual variability, Omicron infects colon cells similarly or less effectively than the ancestral strain or the Delta variant. The variant induced limited type III interferon expression and showed no significant impact on epithelial integrity. Further experiments revealed inefficient cell-to-cell spread and spike protein cleavage in the Omicron spike protein, possibly contributing to its lower infectious particle levels. The findings highlight the variant-specific replication differences in human colonoids, providing insights into the enteric tropism of Omicron and its relevance to long COVID symptoms.

Calpain-2 mediates SARS-CoV-2 entry via regulating ACE2 levels.

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, much effort has been dedicated to identifying effective antivirals against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A number of calpain inhibitors show excellent antiviral activities against SARS-CoV-2 by targeting the viral main protease (Mpro), which plays an essential role in processing viral polyproteins. In this study, we found that calpain inhibitors potently inhibited the infection of a chimeric vesicular stomatitis virus (VSV) encoding the SARS-CoV-2 spike protein but not Mpro. In contrast, calpain inhibitors did not exhibit antiviral activities toward the wild-type VSV with its native glycoprotein. Genetic knockout of calpain-2 by CRISPR/Cas9 conferred resistance of the host cells to the chimeric VSV-SARS-CoV-2 virus and a clinical isolate of wild-type SARS-CoV-2. Mechanistically, calpain-2 facilitates SARS-CoV-2 spike protein-mediated cell attachment by positively regulating the cell surface levels of ACE2. These results highlight an Mpro-independent pathway targeted by calpain inhibitors for efficient viral inhibition. We also identify calpain-2 as a novel host factor and a potential therapeutic target responsible for SARS-CoV-2 infection at the entry step. IMPORTANCE: Many efforts in small-molecule screens have been made to counter SARS-CoV-2 infection by targeting the viral main protease, the major element that processes viral proteins after translation. Here, we discovered that calpain inhibitors further block SARS-CoV-2 infection in a main protease-independent manner. We identified the host cysteine protease calpain-2 as an important positive regulator of the cell surface levels of SARS-CoV-2 cellular receptor ACE2 and, thus, a facilitator of viral infection. By either pharmacological inhibition or genetic knockout of calpain-2, the SARS-CoV-2 binding to host cells is blocked and viral infection is decreased. Our findings highlight a novel mechanism of ACE2 regulation, which presents a potential new therapeutic target. Since calpain inhibitors also potently interfere with the viral main protease, our data also provide a mechanistic understanding of the potential use of calpain inhibitors as dual inhibitors (entry and replication) in the clinical setting of COVID-19 diseases. Our findings bring mechanistic insights into the cellular process of SARS-CoV-2 entry and offer a novel explanation to the mechanism of activities of calpain inhibitors.

Risk of Major Adverse Cardiovascular Events in Immune-Mediated Inflammatory Disorders on Biologics and Small Molecules: Network Meta-Analysis.

BACKGROUND AND AIMS: Recent studies raise concern for increased risk of major adverse cardiovascular events (MACE) with Janus kinase (JAK) inhibitors used to treat immune-mediated inflammatory disorders (IMIDs). We aimed to examine MACE risk with licensed biologics and small molecules used commonly between IMIDs: inflammatory bowel disease, rheumatoid arthritis, psoriasis/psoriatic arthritis, and ankylosing spondylitis. METHODS: Data were obtained from systematic searches (from inception to May 31, 2022) in PubMed, Embase, Ovid Medline, Scopus, Cochrane Central, and ClinicalTrials.gov. Studies that assessed a predefined MACE (myocardial infarction, cerebrovascular accident, unstable angina, cardiovascular death, or heart failure) risk in those ≥18 years of age with IMIDs treated with anti-interleukin (IL)-23 antibodies, anti-IL-12/23, anti-tumor necrosis factor α antibodies (anti-TNF-α), or JAK inhibitors were included in a network meta-analysis using a random-effects model with pooled odds ratios (ORs) reported with 95% credible intervals (CrIs) by drug class and disease state. RESULTS: Among 3528 studies identified, 40 (36 randomized controlled trials and 4 cohort studies) were included in the systematic review, comprising 126,961 patients with IMIDs. Based on network meta-analysis of randomized controlled trials, regardless of disease state, anti-TNF-α (OR, 2.49; 95% CrI, 1.14-5.62), JAK inhibitors (OR, 2.64; 95% CrI, 1.26-5.99), and anti-IL-12/23 (OR, 3.15; 95% CrI, 1.01-13.35) were associated with increased MACE risk compared with placebo. There was no significant difference in the magnitude of the MACE risk between classes or based on IMID type. CONCLUSIONS: Anti-IL-12/23, JAK inhibitors, and anti-TNF-α were associated with higher risk of MACE compared with placebo. The magnitude of the increased MACE risk was not different by IMID type. These results require confirmation in larger prospective studies.

NAFLD Is Associated With Quiescent Rather Than Active Crohn's Disease.

BACKGROUND AND AIMS: Crohn's disease (CD) confers an increased risk of nonalcoholic fatty liver disease (NAFLD), but the pathogenesis remains poorly understood. We determined if active intestinal inflammation increases the risk of NAFLD in patients with CD. METHODS: Two cohorts (2017/2018 and 2020) with CD and no known liver disease were enrolled consecutively during staging magnetic resonance enterography. We quantified proton density fat fraction, MaRIA (Magnetic Resonance Index of Activity), and visceral adipose tissue. NAFLD was diagnosed when proton density fat fraction ≥5.5%. Synchronous endoscopy was graded by the Simple Endoscopic Score for CD and Rutgeerts score, while clinical activity was graded by the Harvey-Bradshaw index. Cytokine profiling was performed for the 2020 cohort. Transient elastography and liver biopsy were requested by standard of care. RESULTS: NAFLD was diagnosed in 40% (n = 144 of 363), with higher prevalence during radiographically quiescent disease (odds ratio, 1.7; P = .01), independent of body mass index/visceral adipose tissue (adjusted odds ratio, 7.8; P = .03). These findings were corroborated by endoscopic disease activity, but not by aggregate clinical symptoms. Circulating interleukin-8 was independent of body mass index to predict NAFLD, but traditional proinflammatory cytokines were not. NAFLD subjects had similar liver stiffness estimates regardless of CD activity. Definitive or borderline steatohepatitis was present in most patients that underwent liver biopsy. CONCLUSIONS: Quiescent CD is associated with risk of NAFLD. These findings suggest potentially distinct pathogenic mechanisms of NAFLD in patients with CD compared with the prevailing leaky gut hypothesis proposed for individuals without inflammatory bowel disease. Future validation and mechanistic studies are needed to dissect these distinct disease modifying factors.

Crohn's disease patients had an independently increased risk for nonalcoholic fatty liver disease when the disease was quiescent, measured by magnetic resonance/endoscopy, and was unrelated to symptom severity. Nonalcoholic fatty liver disease was associated with the pleiotropic cytokine interleukin (IL)-8/CXCL8 but not with traditional proinflammatory cytokines (eg, tumor necrosis factor α, IL-1, IL-6).

Clostridium difficile in inflammatory bowel disease.

PURPOSE OF REVIEW: The chronic inflammatory bowel diseases (IBD), Crohn's disease, and ulcerative colitis, are associated with an increased risk of symptomatic Clostridium difficile infection (CDI). CDI may also masquerade as an IBD flare and complicate IBD management. This review provides a comprehensive overview of the epidemiology, diagnosis, and treatment of CDI in IBD patients. RECENT FINDINGS: CDI remains common in IBD with complications including flares in disease activity, recurrent CDI episodes, and prolonged hospital stays. Newer IBD therapeutics including vedolizumab, ustekinumab, and tofacitinib are less likely to cause severe CDI. A high index of suspicion, rapid testing via a two-step method, and prompt treatment with vancomycin or fidaxomicin are paramount to managing CDI in IBD patients. Strategies to prevent recurrent CDI (rCDI) include the monoclonal antibody bezlotoxumab as well as fecal microbiota transplantation (FMT). FMT has a robust profile of safety and effectiveness in preventing rCDI in adults and children. SUMMARY: Clinicians must remain vigilant in the prompt diagnosis and treatment of CDI in IBD patients. Corticosteroids, unnecessary antibiotics, and ongoing colonic inflammatory disease are modifiable risk factors. Improved infection control measures, newer IBD medications, and using effective CDI treatments will facilitate a reduced burden of severe CDI and complications for IBD patients.

RBM47 regulates intestinal injury and tumorigenesis by modifying proliferation, oxidative response, and inflammatory pathways.

RNA-binding protein 47 (RBM47) is required for embryonic endoderm development, but a role in adult intestine is unknown. We studied intestine-specific Rbm47-knockout mice (Rbm47-IKO) following intestinal injury and made crosses into ApcMin/+ mice to examine alterations in intestinal proliferation, response to injury, and tumorigenesis. We also interrogated human colorectal polyps and colon carcinoma tissue. Rbm47-IKO mice exhibited increased proliferation and abnormal villus morphology and cellularity, with corresponding changes in Rbm47-IKO organoids. Rbm47-IKO mice adapted to radiation injury and were protected against chemical-induced colitis, with Rbm47-IKO intestine showing upregulation of antioxidant and Wnt signaling pathways as well as stem cell and developmental genes. Furthermore, Rbm47-IKO mice were protected against colitis-associated cancer. By contrast, aged Rbm47-IKO mice developed spontaneous polyposis, and Rbm47-IKO ApcMin/+ mice manifested an increased intestinal polyp burden. RBM47 mRNA was decreased in human colorectal cancer versus paired normal tissue, along with alternative splicing of tight junction protein 1 mRNA. Public databases revealed stage-specific reduction in RBM47 expression in colorectal cancer associated independently with decreased overall survival. These findings implicate RBM47 as a cell-intrinsic modifier of intestinal growth, inflammatory, and tumorigenic pathways.

Corticosteroids Increase the Risk of Invasive Fungal Infections More Than Tumor Necrosis Factor-Alpha Inhibitors in Patients With Inflammatory Bowel Disease.

Background: Invasive fungal infections are a devastating complication of inflammatory bowel disease (IBD) treatment. We aimed to determine the incidence of fungal infections in IBD patients and examine the risk with tumor necrosis factor-alpha inhibitors (anti-TNF) compared with corticosteroids. Methods: In a retrospective cohort study using the IBM MarketScan Commercial Database we identified US patients with IBD and at least 6 months enrollment from 2006 to 2018. The primary outcome was a composite of invasive fungal infections, identified by ICD-9/10-CM codes plus antifungal treatment. Tuberculosis (TB) infections were a secondary outcome, with infections presented as cases/100 000 person-years (PY). A proportional hazards model was used to determine the association of IBD medications (as time-dependent variables) and invasive fungal infections, controlling for comorbidities and IBD severity. Results: Among 652 920 patients with IBD, the rate of invasive fungal infections was 47.9 cases per 100 000 PY (95% CI 44.7-51.4), which was more than double the TB rate (22 cases [CI 20-24], per 100 000 PY). Histoplasmosis was the most common invasive fungal infection (12.0 cases [CI 10.4-13.8] per 100 000 PY). After controlling for comorbidities and IBD severity, corticosteroids (hazard ratio [HR] 5.4; CI 4.6-6.2) and anti-TNFs (HR 1.6; CI 1.3-2.1) were associated with invasive fungal infections. Conclusions: Invasive fungal infections are more common than TB in patients with IBD. The risk of invasive fungal infections with corticosteroids is more than double that of anti-TNFs. Minimizing corticosteroid use in IBD patients may decrease the risk of fungal infections.

Nonalcoholic Fatty Liver Disease Is a Risk Factor for Thiopurine Hepatotoxicity in Crohn's Disease.

Background: Patients with Crohn's disease (CD) are predisposed to nonalcoholic fatty liver disease (NAFLD). CD management often includes thiopurines which can promote hepatotoxicity. We aimed to identify the role of NAFLD on the risk of developing liver injury from thiopurines in CD. Methods: In this prospective cohort analysis, CD patients at a single center were recruited 6/2017-5/2018. Patients with alternative liver diseases were excluded. The primary outcome was time to elevation of liver enzymes. Patients underwent MRI with assessment of proton density fat fraction (PDFF) on enrollment, where NAFLD was defined as PDFF >5.5%. Statistical analysis was performed using a Cox-proportional hazards model. Results: Of the 311 CD patients studied, 116 (37%) were treated with thiopurines, 54 (47%) of which were found to have NAFLD. At follow-up, there were 44 total cases of elevated liver enzymes in those treated with thiopurines. Multivariable analysis demonstrated that NAFLD was a predictor of elevated liver enzymes in patients with CD treated with thiopurines (HR 3.0, 95% CI 1.2-7.3, P = .018) independent of age, body mass index, hypertension, and type 2 diabetes. Steatosis severity by PDFF positively correlated with peak alanine aminotransferase (ALT) at follow-up. Kaplan-Meier analysis demonstrated poorer complication-free survival (log-rank 13.1, P < .001). Conclusions: NAFLD at baseline is a risk factor for thiopurine-induced hepatotoxicity in patients with CD. The degree of liver fat positively correlated with the degree of ALT elevation. These data suggest that evaluation for hepatic steatosis be considered in patients with liver enzyme elevations with thiopurine therapy.

Sleep Disturbance and SARS-CoV-2 Vaccinations in Patients With Chronic Inflammatory Disease.

OBJECTIVE: Immunocompromised patients with chronic inflammatory disease (CID) may have experienced additional psychosocial burden during the COVID-19 pandemic due to their immunocompromised status. This study was undertaken to determine if vaccination would result in improved patient-reported outcomes longitudinally among individuals with CID undergoing SARS-CoV-2 vaccination regardless of baseline anxiety. METHODS: Data are from a cohort of individuals with CID from 2 sites who underwent SARS-CoV-2 vaccination. Participants completed 3 study visits before and after 2 messenger RNA vaccine doses in the initial vaccination series when clinical data were collected. Patient-reported outcomes were measured using the Patient-Reported Outcomes Measurement Information System 29-item Health Profile and expressed as T scores, with 2 groups stratified by high and low baseline anxiety. Mixed-effects models were used to examine longitudinal changes, adjusting for age, sex, and study site. RESULTS: A total of 72% of the cohort was female with a mean ± SD age of 48.1 ± 15.5 years. Overall, sleep disturbance improved following both doses of SARS-CoV-2 vaccinations, and anxiety decreased after the second dose. Physical function scores worsened but did not meet the minimally important difference threshold. When stratifying by baseline anxiety, improvement in anxiety, fatigue, and social participation were greater in the high anxiety group. Physical function worsened slightly in both groups, and sleep disturbance improved significantly in the high anxiety group. CONCLUSION: Sleep disturbance decreased in a significant and meaningful way in patients with CID upon vaccination. In patients with higher baseline anxiety, social participation increased, and anxiety, fatigue, and sleep disturbance decreased. Overall, results suggest that SARS-CoV-2 vaccination may improve mental health and well-being, particularly among those with greater anxiety.

Inflammatory Bowel Disease Is Associated With an Increased Risk of Incident Acute Arterial Events: Analysis of the United Kingdom Biobank.

BACKGROUND & AIMS: Population-based studies have suggested an increased risk of acute arterial events (AAEs) in patients with inflammatory bowel disease (IBD). We aimed to assess the risk of incident AAEs and premature AAEs, adjusted for diet, physical activity, and inflammation biomarkers, in participants with IBD in the UK Biobank (UKB) METHODS: UKB participants with IBD and without prevalent AAEs at enrollment were matched to random non-IBD controls. A Cox regression model, adjusting for baseline cardiovascular and IBD risk factors, diet, physical activity, and high-sensitivity C-reactive protein, estimated adjusted hazard ratios (aHRs) for association between IBD and AAEs or premature AAEs (age, <55 years for men and <65 years for women). Predictors of AAEs within the IBD cohort were identified in a Cox model adjusting for disease severity (IBD-related hospitalizations or surgeries). RESULTS: Among 455,950 UKB participants, 5094 with IBD were matched to 20,376 non-IBD controls. After a median follow-up period of 12.4 years, participants with IBD had a higher incident rate of AAE (924.1 vs 730.9 per 100,000 person years; P < .001), risk of all AAEs (aHR, 1.19; 95% CI, 1.08-1.31; P < .001), and premature AAEs (aHR, 1.38; 95% CI, 1.11-1.72; P = .001). High-sensitivity C-reactive protein levels (highest quartile: aHR, 1.53; 95% CI, 1.15-2.03) and disease severity (aHR, 5.40; 95% CI, 4.03-7.22) were independent predictors of AAE in IBD. CONCLUSIONS: In a prospective cohort, there was an increased risk of incident AAEs and premature AAEs in IBD participants. Beyond traditional AAE risk factors, quantifiable indices of IBD disease activity and severity were independent predictors of AAEs.

TBX21 Methylation as a Potential Regulator of Immune Suppression in CMS1 Subtype Colorectal Cancer.

Cytotoxic T lymphocyte (CTL) infiltration is associated with survival, recurrence, and therapeutic response in colorectal cancer (CRC). Immune checkpoint inhibitor (ICI) therapy, which requires CTLs for response, does not work for most CRC patients. Therefore, it is critical to improve our understanding of immune resistance in this disease. We utilized 2391 CRC patients and 7 omics datasets, integrating clinical and genomic data to determine how DNA methylation may impact survival and CTL function in CRC. Using comprehensive molecular subtype (CMS) 1 patients as reference, we found TBX21 to be the only gene with altered expression and methylation that was associated with CTL infiltration. We found that CMS1 patients with high TBX21 expression and low methylation had a significant survival advantage. To confirm the role of Tbx21 in CTL function, we utilized scRNAseq data, demonstrating the association of TBX21 with markers of enhanced CTL function. Further analysis using pathway enrichment found that the genes TBX21, MX1, and SP140 had altered expression and methylation, suggesting that the TP53/P53 pathway may modify TBX21 methylation to upregulate TBX21 expression. Together, this suggests that targeting epigenetic modification more specifically for therapy and patient stratification may provide improved outcomes in CRC.

Gastrointestinal Manifestations of Coronavirus Disease 2019 Across the United States: A Multicenter Cohort Study.

Background and Aims: Gastrointestinal (GI) symptoms occur among patients diagnosed with coronavirus disease 2019 (COVID-19), and there is clear evidence that SARS-CoV-2, the causative pathogen, infects the GI tract. In this large, multicenter cohort study, we evaluated variations in gastrointestinal and hepatic manifestations of COVID-19 throughout the United States (US). Methods: Patients hospitalized with a positive COVID-19 test prior to October 2020 were identified at 7 US academic centers. Demographics, presenting symptoms, laboratory data, and hospitalization outcomes were abstracted. Descriptive and regression analyses were used to evaluate GI manifestations and their potential predictors. Results: Among 2031 hospitalized patients with COVID-19, GI symptoms were present in 18.9%; diarrhea was the most common (15.2%), followed by nausea and/or vomiting (12.6%) and abdominal pain (6.0%). GI symptoms were less common in the Western cohort (16.0%) than the Northeastern (25.6%) and Midwestern (26.7%) cohorts. Compared to nonintensive care unit (ICU) patients, ICU patients had a higher prevalence of abnormal aspartate aminotransferase (58.1% vs 37.3%; P < .01), alanine aminotransferase (37.5% vs 29.3%; P = .01), and total bilirubin (12.7% vs 9.0%; P < .01). ICU patients also had a higher mortality rate (22.7% vs 4.7%; P < .01). Chronic liver disease was associated with the development of GI symptoms. Abnormal aspartate aminotransferase or alanine aminotransferase was associated with an increased risk of ICU admission. Conclusion: We present the largest multicenter cohort of patients with COVID-19 across the United States. GI manifestations were common among patients hospitalized with COVID-19, although there was significant variability in prevalence and predictors across the United States.

Reactogenicity of the Messenger RNA SARS-CoV-2 Vaccines Associated With Immunogenicity in Patients With Autoimmune and Inflammatory Disease.

OBJECTIVE: Little is known regarding the reactogenicity and related SARS-CoV-2 vaccine response in patients with chronic inflammatory disease (CID). Our objective was to characterize the adverse event profile of CID patients following SARS-CoV-2 vaccination and understand the relationship between reactogenicity and immunogenicity of SARS-CoV-2 vaccines. METHODS: CID patients and healthy controls eligible to receive messenger RNA (mRNA) SARS-CoV-2 vaccines participated in 3 study visits (pre-vaccine, after dose 1, and after dose 2) in which blood and clinical data were collected. Assessment of adverse events were solicited within 7 days of receiving each dose. Serum anti-SARS-CoV-2 spike IgG ± antibody titers were quantified following vaccination. Statistical analysis was performed utilizing mixed models and tobit regressions, with adjustment for covariates. RESULTS: The present study included 441 participants (322 CID patients and 119 control subjects). Compared to controls, CID patients reported greater symptom severity after dose 1 (P = 0.0001), including more myalgia and fatigue (P < 0.05). For immunogenicity, a higher symptom severity after dose 1 and a higher number of symptoms after dose 2 was associated with higher antibody titers (P ≤ 0.05). Each increase of 1 symptom was associated with a 15.1% increase in antibody titer. Symptom association was strongest with site pain after dose 1 (105%; P = 0.03) and fatigue after dose 2 (113%; P = 0.004). CONCLUSION: Patients with CID have a distinct reactogenicity profile following SARS-CoV-2 vaccination compared to controls. Furthermore, there is an association between increased reactogenicity and increased vaccine response. This finding may speak to the more variable immunogenicity in CID patients and may be an important indicator of vaccine response to the novel SARS-CoV-2 vaccines.

Systematic Review With Meta-analysis: Safety and Effectiveness of Combining Biologics and Small Molecules in Inflammatory Bowel Disease.

Background: Combining biologics and small molecules could potentially overcome the plateau of drug efficacy in inflammatory bowel disease (IBD). We conducted a systematic review and meta-analysis to assess the safety and effectiveness of dual biologic therapy (DBT), or small molecule combined with a biologic therapy (SBT) in IBD patients. Methods: We searched MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, and Clinical trials.gov until November 3, 2020, including studies with 2 or more IBD patients on DBT or SBT. Main outcome was safety assessed as pooled rates of adverse events (AEs) and serious AEs (SAEs) for each combination. Effectiveness was reported as pooled rates of clinical, endoscopic, and/or radiographic response and remission. The certainty of evidence was rated according to the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework. Results: Of the 3688 publications identified, 13 studies (1 clinical trial, 12 observational studies) involving 266 patients on 7 different combinations were included. Median number of prior biologics ranged from 0 to 4, and median duration of follow-up was 16-68 weeks. Most common DBT and SBT were vedolizumab (VDZ) with anti-tumor necrosis factor (aTNF, n = 56) or tofacitinib (Tofa, n = 57), respectively. Pooled rates of SAE for these were 9.6% (95% confidence interval [CI], 1.5-21.4) for VDZ-aTNF and 1.0% (95% CI, 0.0-7.6) for Tofa-VDZ. The overall certainty of evidence was very low due to the observational nature of the studies, and very serious imprecision and inconsistency. Conclusions: DBT or SBT appears to be generally safe and may be effective in IBD patients, but the evidence is very uncertain.

The LRRC family of BK channel regulatory subunits: potential roles in health and disease.

Large conductance K+ channels, termed BK channels, regulate a variety of cellular and physiological functions. Although universally activated by changes in voltage or [Ca2+ ]i , the threshold for BK channel activation varies among loci of expression, often arising from cell-specific regulatory subunits including a family of leucine rich repeat-containing (LRRC) γ subunits (LRRC26, LRRC52, LRRC55 and LRRC38). The 'founding' member of this family, LRRC26, was originally identified as a tumour suppressor in various cancers. An LRRC26 knockout (KO) mouse model recently revealed that LRRC26 is also highly expressed in secretory epithelial cells and partners with BK channels in the salivary gland and colonic goblet cells to promote sustained K+ fluxes likely essential for normal secretory function. To accomplish this, LRRC26 negatively shifts the range of BK channel activation such that channels contribute to K+ flux near typical epithelial cell resting conditions. In colon, the absence of LRRC26 increases vulnerability to colitis. LRRC26-containing BK channels are also likely important regulators of epithelial function in other loci, including airways, female reproductive tract and mammary gland. Based on an LRRC52 KO mouse model, LRRC52 regulation of large conductance K+ channels plays a role both in sperm function and in cochlear inner hair cells. Although our understanding of LRRC-containing BK channels remains rudimentary, KO mouse models may help define other organs in which LRRC-containing channels support normal function. A key topic for future work concerns identification of endogenous mechanisms, whether post-translational or via gene regulation, that may impact LRRC-dependent pathologies.

Reg4 Interacts with CD44 to Regulate Proliferation and Stemness of Colorectal and Pancreatic Cancer Cells.

Regenerating Gene 4 (Reg4) is highly upregulated in gastrointestinal (GI) malignancies including colorectal and pancreatic cancers. Numerous studies demonstrated an association between higher Reg4 expression and tumor aggressiveness, intrinsic resistance to apoptotic death, and poor outcomes from GI malignancies. However, the precise receptor and underlying signaling mechanism have remained unknown. Although we previously reported a Reg4-mediated induction of EGFR activity in colorectal cancer cells, a direct interaction between Reg4 and EGFR was not observed. This study is focused on identifying the cell surface binding partner of Reg4 and dissecting its role in colorectal cancer and pancreatic cancer growth and stem cell survival. In vitro models of human colorectal cancer and pancreatic cancer were used to evaluate the results. Results of this study find: (i) Reg4 interacts with CD44, a transmembrane protein expressed by a population of colorectal cancer and pancreatic cancer cells; (ii) Reg4 activates regulated intramembrane proteolysis of CD44 resulting in γ-secretase-mediated cleavage and release of the CD44 intracytoplasmic domain (CD44ICD) that functions as a transcriptional activator of D-type cyclins involved in the regulation of cancer cell proliferation and Klf4 and Sox2 expression involved in regulating pluripotency of cancer stem cells; and (iii) Reg4 significantly increases colorectal cancer and pancreatic cancer cell proliferation and their clonogenic potential in stem cell assays. IMPLICATIONS: These results suggest that pro-proliferative and pro-stemness effects of Reg4 are mediated through γ-secretase-mediated CD44/CD44ICD signaling, hence strategies to disrupt Reg4-CD44-γ-secretase-CD44ICD signaling axis may increase cancer cell susceptibility to chemo- and radiotherapeutics.