Dose-Intensified Infliximab Rescue Therapy for Severe Ulcerative Colitis Does Not Reduce Short-term Colectomy Rates or Increase Postoperative Complications.

BACKGROUND: Dose-intensified rescue therapy with infliximab for hospitalized patients with ulcerative colitis has become increasingly popular in recent years. However, there is ongoing debate about both the efficacy of these regimens to reduce the rate of colectomy and the associated risks of increased infliximab exposure. OBJECTIVE: The purpose of this study was to compare the colectomy and postoperative complication rates in hospitalized patients with severe ulcerative colitis receiving standard infliximab induction therapy (3 doses of 5 mg/kg at weeks 0, 2, and 6) and dose-intensified regimens including a higher weight-based dosing or more rapid interval. DESIGN: This was a retrospective cohort study. SETTINGS: This study was conducted at an academic tertiary care hospital. PATIENTS: A total of 145 adult patients received inpatient rescue infliximab therapy for the treatment of ulcerative colitis between 2008 and 2020. MAIN OUTCOME MEASURES: The primary outcome was colectomy rate within 3 months of rescue therapy. Secondary outcomes include mid-term colectomy rates, as well as perioperative complications in patients receiving colectomy within 3 months of rescue infliximab initiation. RESULTS: The proportion of dose-intensified regimens increased over time. Unadjusted 3-month colectomy rates were 14% in patients who received standard rescue infliximab dosing, 16% in patients given a single dose-escalated dose, and 24% in patients given multiple inpatient dose-escalated doses. These rates were not statistically significantly different. Of the patients requiring colectomy within 3 months of infliximab rescue, those who received multiple inpatient doses of dose-escalated therapy had a higher percentage of colectomy during the initial hospitalization but a lower rate of perioperative complications. LIMITATIONS: This study was limited by the use of retrospective data and the limited power to account for the heterogeneity of disease. CONCLUSIONS: No significant difference was found in colectomy rates between patients receiving standard or dose-intensified regimens. However, dose-intensified regimens, including multiple inpatient doses given to patients with more severe disease, were not associated with a greater risk of perioperative complications. See Video Abstract at http://links.lww.com/DCR/B864 . LA TERAPIA DE RESCATE CON DOSIS INTENSIFICADA DE INFLIXIMAB EN COLITIS ULCEROSA GRAVE NO REDUCE LAS TASAS DE COLECTOMA A CORTO PLAZO NI AUMENTA LAS COMPLICACIONES POSOPERATORIAS: ANTECEDENTES:La terapia de rescate de dosis intensificada con infliximab para pacientes hospitalizados con colitis ulcerosa se ha vuelto cada vez más popular en los últimos años. Sin embargo, existe un debate en curso sobre la eficacia de estos regímenes para reducir la tasa de colectomía y los riesgos asociados a una mayor exposición al infliximab.OBJETIVO:El propósito de este estudio fue comparar las tasas de colectomía y complicaciones posoperatorias en pacientes hospitalizados con colitis ulcerosa grave que recibieron terapia estándar de inducción de infliximab (3 dosis de 5 mg/kg en las semanas 0, 2, 6) y regímenes de dosis intensificada que incluyen una dosificación más alta basada en el peso o intervalo más rápido.DISEÑO:Fue un estudio de cohorte retrospectivo.ENTORNO CLÍNICO:Este estudio se realizó en un hospital académico de tercer nivel.PACIENTES:Un total de 145 pacientes adultos que recibieron terapia de rescate con infliximab para el tratamiento de la colitis ulcerosa entre 2008 y 2020.PRINCIPALES MEDIDAS DE VALORACIÓN:El resultado principal fue la tasa de colectomía dentro de los 3 meses posteriores a la terapia de rescate. Los resultados secundarios incluyen tasas de colectomía a mediano plazo, así como las complicaciones perioperatorias en pacientes que reciben colectomía dentro de los 3 meses posteriores al inicio de infliximab de rescate.RESULTADOS:La proporción de regímenes de dosis intensificada aumentó con el tiempo. Las tasas de colectomía de 3 meses no ajustadas fueron del 14% en los pacientes que recibieron dosis estándar de infliximab de rescate, del 16% en los pacientes que recibieron una dosis única escalonada y del 24% en los pacientes que recibieron múltiples dosis hospitalarias escalonadas. Estas tasas no fueron estadísticamente significativas. De los pacientes que requirieron colectomía dentro de los 3 meses posteriores al rescate de infliximab, aquellos que recibieron terapia de múltiples dosis hospitalarias escalonadas tuvieron un mayor porcentaje de colectomía durante la hospitalización inicial pero una menor tasa de complicaciones perioperatorias.LIMITACIONES:Datos retrospectivos y poder limitado para explicar la heterogeneidad de la enfermedad.CONCLUSIONES:No se encontraron diferencias significativas en las tasas de colectomía entre los pacientes que recibieron regímenes estándar o de dosis intensificada. Sin embargo, los regímenes de dosis intensificadas, incluidas múltiples dosis hospitalarias administradas a pacientes con enfermedad más grave, no se asociaron con un mayor riesgo de complicaciones perioperatorias. Consulte Video Resumen en http://links.lww.com/DCR/B864 . (Traducción-Dr. Ingrid Melo ).

Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function.

Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-ß1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing.

A case study of recurrent myocardial infarction secondary to socioeconomic challenges and nonadherence: Pre-discharge screening.

Medication nonadherence following myocardial infarction (MI) is prevalent and increases the risk of recurrent cardiovascular events. Socioeconomic factors including medication cost, financial insecurity, and poor health literacy are associated with nonadherence. We present a patient with a history of recurrent MI who was nonadherent due to socioeconomic challenges. Our patient subsequently developed ST-elevation MI secondary to in-stent thrombosis. This case illustrates the importance of pre-discharge screening for barriers to adherence.

Higher-risk SIPAT score predicts increased risk of long-term mortality in orthotopic heart transplant recipients.

BACKGROUND: Orthotopic heart transplantation (OHT) improves survival in eligible patients. Organ scarcity necessitates extensive clinical and psychosocial evaluations before listing. The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) predicts risk for poor psychosocial outcomes and morbidity in the first year post-transplant, yet it is unknown whether it predicts long-term outcomes. METHODS: Blinded examiners obtained data from a retrospective cohort of 51 OHT recipients from a high-volume center. Patients with "Excellent" or "Good" SIPAT score indicating low psychosocial risk for transplant (E/G) were compared with those who met "Minimum Acceptable Criteria" or were "High Risk" (MAC/HR). Associations were examined between SIPAT group and outcomes. RESULTS: MAC/HR versus E/G recipients had significantly reduced survival in the 10 years post-OHT (mean 6.7 vs 8.8 years, p = 0.027; 55% vs 82% survival proportions, p = 0.037). MAC/HR patients were more likely to live in a county with greater income inequality (p = 0.025) and have psychiatric history pre-OHT (p = 0.046). Both groups had otherwise similar demographics and medical history. A lower proportion of MAC/HR patients adhered to medications post-OHT and a greater proportion had psychiatric illness, though differences were not significant. CONCLUSIONS: Higher-risk SIPAT scores predict reduced long-term survival post-OHT. Further efforts are crucial to improve outcomes in higher-risk patients.

Geographic Variation in the Quality of Heart Failure Care Among U.S. Veterans.

BACKGROUND: The burden of heart failure is growing. Guideline-directed medical therapies (GDMT) reduce adverse outcomes in heart failure with reduced ejection fraction (HFrEF). Whether there is geographic variation in HFrEF quality of care is not well described. OBJECTIVES: This study evaluated variation nationally for prescription of GDMT within the Veterans Health Administration. METHODS: A cohort of Veterans with HFrEF had their address linked to hospital referral regions (HRRs). GDMT prescription was defined using pharmacy data between July 1, 2020, and July 1, 2021. Within HRRs, we calculated the percentage of Veterans prescribed GDMT and a composite GDMT z-score. National choropleth maps were created to evaluate prescription variation. Associations between GDMT performance and demographic characteristics were evaluated using linear regression. RESULTS: Maps demonstrated significant variation in the HRR composite score and GDMT prescriptions. Within HRRs, the prescription of beta-blockers to Veterans was highest with a median of 80% (IQR: 77.3%-82.2%) followed by angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitors (69.3%; IQR: 66.4%-72.1%), sodium-glucose cotransporter-2 inhibitors (10.3%; IQR: 7.7%-12.8%), mineralocorticoid receptor antagonists (29.2%; IQR: 25.8%-33.9%), and angiotensin receptor-neprilysin inhibitors (12.2%; IQR: 8.6%-15.3%). HRR composite GDMT z-scores were inversely associated with the HRR median Gini coefficient (R = -0.13; P = 0.0218) and the percentage of low-income residents (R = -0.117; P = 0.0413). CONCLUSIONS: Wide geographic differences exist for HFrEF care. Targeted strategies may be required to increase GDMT prescription for Veterans in lower-performing regions, including those affected by income inequality and poverty.

Resident and elicited murine macrophages differ in expression of their glycomes and glycan-binding proteins.

The pleiotropic functions of macrophages in immune defense, tissue repair, and maintenance of tissue homeostasis are supported by the heterogeneity in macrophage sub-populations that differ both in ontogeny and polarization. Although glycans and glycan-binding proteins (GBPs) are integral to macrophage function and may contribute to macrophage diversity, little is known about the factors governing their expression. Here, we provide a resource for characterizing the N-/O-glycomes of various murine peritoneal macrophage sub-populations, demonstrating that glycosylation primarily reflects developmental origin and, to a lesser degree, cellular polarization. Furthermore, comparative analysis of GBP-coding genes in resident and elicited macrophages indicated that GBP expression is consistent with specialized macrophage functions and correlates with specific types of displayed glycans. An integrated, semi-quantitative approach was used to confirm distinct expression patterns of glycans and their binding proteins across different macrophages. The data suggest that regulation of glycan-protein complexes may be central to macrophage residence and recruitment.

Continuous Formation of Ultrathin, Strong Collagen Sheets with Tunable Anisotropy and Compaction.

The multiscale organization of protein-based fibrillar materials is a hallmark of many organs, but the recapitulation of hierarchal structures down to fibrillar scales, which is a requirement for withstanding physiological loading forces, has been challenging. We present a microfluidic strategy for the continuous, large-scale formation of strong, handleable, free-standing, multicentimeter-wide collagen sheets of unprecedented thinness through the application of hydrodynamic focusing with the simultaneous imposition of strain. Sheets as thin as 1.9 µm displayed tensile strengths of 0.5-2.7 MPa, Young's moduli of 3-36 MPa, and modulated the diffusion of molecules as a function of collagen nanoscale structure. Smooth muscle cells cultured on engineered sheets oriented in the direction of aligned collagen fibrils and generated coordinated vasomotor responses. The described biofabrication approach enables rapid formation of ultrathin collagen sheets that withstand physiologically relevant loads for applications in tissue engineering and regenerative medicine, as well as in organ-on-chip and biohybrid devices.

Modulation of lymphocyte-mediated tissue repair by rational design of heterocyclic aryl hydrocarbon receptor agonists.

Aryl hydrocarbon receptor (AHR) is an essential regulator of gut immunity and a promising therapeutic target for inflammatory bowel disease (IBD). Current AHR agonists are inadequate for clinical translation due to low activity, inadequate pharmacokinetics, or toxicity. We synthesized a structurally diverse library and used integrated computational and experimental studies to discover mechanisms governing ligand-receptor interaction and to design potent drug leads PY109 and PY108, which display physiochemical drug-likeness properties, desirable pharmacokinetic profiles, and low toxicity. In a murine model of dextran sulfate sodium-induced colitis, orally administered compounds increase interleukin-22 (IL-22) production and accelerate mucosal healing by modulating mucosal adaptive and innate lymphoid cells. AHR and IL-22 pathway induction was confirmed using RNA sequencing and characterization of the lymphocyte protein-protein interaction network. Significant induction of IL-22 was also observed using human T cells from patients with IBD. Our findings support rationally designed AHR agonists for IBD therapy.

In Vivo Models for the Study of Fibrosis.

Significance: Fibrosis and scar formation pose a substantial physiological and psychological burden on patients and a significant public health burden on the economy, estimated to be up to $12 billion a year. Fibrosis research is heavily reliant on in vivo models, but variations in animal models and differences between animal and human fibrosis necessitates careful selection of animal models to study fibrosis. There is also an increased need for improved animal models that recapitulate human pathophysiology. Recent Advances: Several murine and porcine models, including xenograft, drug-induced fibrosis, and mechanical load-induced fibrosis, for different types of fibrotic disease have been described in the literature. Recent findings have underscored the importance of mechanical forces in the pathophysiology of scarring. Critical Issues: Differences in skin, properties of subcutaneous tissue, and modes of fibrotic healing in animal models and humans provide challenges toward investigating fibrosis with in vivo models. While porcine models are typically better suited to study cutaneous fibrosis, murine models are preferred because of the ease of handling and availability of transgenic strains. Future Directions: There is a critical need to develop novel murine models that recapitulate the mechanical cues influencing fibrosis in humans, significantly increasing the translational value of fibrosis research. We advocate a translational pipeline that begins in mouse models with modified biomechanical environments for foundational molecular and cellular research before validation in porcine models that closely mimic the human condition.

Adipose-Derived Stem Cell-Seeded Hydrogels Increase Endogenous Progenitor Cell Recruitment and Neovascularization in Wounds.

Adipose-derived mesenchymal stem cells (ASCs) are appealing for cell-based wound therapies because of their accessibility and ease of harvest, but their utility is limited by poor cell survival within the harsh wound microenvironment. In prior work, our laboratory has demonstrated that seeding ASCs within a soft pullulan-collagen hydrogel enhances ASC survival and improves wound healing. To more fully understand the mechanism of this therapy, we examined whether ASC-seeded hydrogels were able to modulate the recruitment and/or functionality of endogenous progenitor cells. Employing a parabiosis model and fluorescence-activated cell sorting analysis, we demonstrate that application of ASC-seeded hydrogels to wounds, when compared with injected ASCs or a noncell control, increased the recruitment of provascular circulating bone marrow-derived mesenchymal progenitor cells (BM-MPCs). BM-MPCs comprised 23.0% of recruited circulating progenitor cells in wounds treated with ASC-seeded hydrogels versus 8.4% and 2.1% in those treated with controls, p < 0.05. Exploring the potential for functional modulation of BM-MPCs, we demonstrate a statistically significant increase in BM-MPC migration, proliferation, and tubulization when exposed to hydrogel-seeded ASC-conditioned medium versus control ASC-conditioned medium (73.8% vs. 51.4% scratch assay closure; 9.1% vs. 1.4% proliferation rate; 10.2 vs. 5.5 tubules/HPF; p < 0.05 for all assays). BM-MPC expression of genes related to cell stemness and angiogenesis was also significantly increased following exposure to hydrogel-seeded ASC-conditioned medium (p < 0.05). These data suggest that ASC-seeded hydrogels improve both progenitor cell recruitment and functionality to effect greater neovascularization.

Microfluidic single-cell transcriptional analysis rationally identifies novel surface marker profiles to enhance cell-based therapies.

Current progenitor cell therapies have only modest efficacy, which has limited their clinical adoption. This may be the result of a cellular heterogeneity that decreases the number of functional progenitors delivered to diseased tissue, and prevents correction of underlying pathologic cell population disruptions. Here, we develop a high-resolution method of identifying phenotypically distinct progenitor cell subpopulations via single-cell transcriptional analysis and advanced bioinformatics. When combined with high-throughput cell surface marker screening, this approach facilitates the rational selection of surface markers for prospective isolation of cell subpopulations with desired transcriptional profiles. We establish the usefulness of this platform in costly and highly morbid diabetic wounds by identifying a subpopulation of progenitor cells that is dysfunctional in the diabetic state, and normalizes diabetic wound healing rates following allogeneic application. We believe this work presents a logical framework for the development of targeted cell therapies that can be customized to any clinical application.

Capillary force seeding of hydrogels for adipose-derived stem cell delivery in wounds.

Effective skin regeneration therapies require a successful interface between progenitor cells and biocompatible delivery systems. We previously demonstrated the efficiency of a biomimetic pullulan-collagen hydrogel scaffold for improving bone marrow-derived mesenchymal stem cell survival within ischemic skin wounds by creating a "stem cell niche" that enhances regenerative cytokine secretion. Adipose-derived mesenchymal stem cells (ASCs) represent an even more appealing source of stem cells because of their abundance and accessibility, and in this study we explored the utility of ASCs for hydrogel-based therapies. To optimize hydrogel cell seeding, a rapid, capillary force-based approach was developed and compared with previously established cell seeding methods. ASC viability and functionality following capillary hydrogel seeding were then analyzed in vitro and in vivo. In these experiments, ASCs were seeded more efficiently by capillary force than by traditional methods and remained viable and functional in this niche for up to 14 days. Additionally, hydrogel seeding of ASCs resulted in the enhanced expression of multiple stemness and angiogenesis-related genes, including Oct4, Vegf, Mcp-1, and Sdf-1. Moving in vivo, hydrogel delivery improved ASC survival, and application of both murine and human ASC-seeded hydrogels to splinted murine wounds resulted in accelerated wound closure and increased vascularity when compared with control wounds treated with unseeded hydrogels. In conclusion, capillary seeding of ASCs within a pullulan-collagen hydrogel bioscaffold provides a convenient and simple way to deliver therapeutic cells to wound environments. Moreover, ASC-seeded constructs display a significant potential to accelerate wound healing that can be easily translated to a clinical setting.

Aging disrupts cell subpopulation dynamics and diminishes the function of mesenchymal stem cells.

Advanced age is associated with an increased risk of vascular morbidity, attributable in part to impairments in new blood vessel formation. Mesenchymal stem cells (MSCs) have previously been shown to play an important role in neovascularization and deficiencies in these cells have been described in aged patients. Here we utilize single cell transcriptional analysis to determine the effect of aging on MSC population dynamics. We identify an age-related depletion of a subpopulation of MSCs characterized by a pro-vascular transcriptional profile. Supporting this finding, we demonstrate that aged MSCs are also significantly compromised in their ability to support vascular network formation in vitro and in vivo. Finally, aged MSCs are unable to rescue age-associated impairments in cutaneous wound healing. Taken together, these data suggest that age-related changes in MSC population dynamics result in impaired therapeutic potential of aged progenitor cells. These findings have critical implications for therapeutic cell source decisions (autologous versus allogeneic) and indicate the necessity of strategies to improve functionality of aged MSCs.

Diabetes impairs the angiogenic potential of adipose-derived stem cells by selectively depleting cellular subpopulations.

INTRODUCTION: Pathophysiologic changes associated with diabetes impair new blood vessel formation and wound healing. Mesenchymal stem cells derived from adipose tissue (ASCs) have been used clinically to promote healing, although it remains unclear whether diabetes impairs their functional and therapeutic capacity. METHODS: In this study, we examined the impact of diabetes on the murine ASC niche as well as on the potential of isolated cells to promote neovascularization in vitro and in vivo. A novel single-cell analytical approach was used to interrogate ASC heterogeneity and subpopulation dynamics in this pathologic setting. RESULTS: Our results demonstrate that diabetes alters the ASC niche in situ and that diabetic ASCs are compromised in their ability to establish a vascular network both in vitro and in vivo. Moreover, these diabetic cells were ineffective in promoting soft tissue neovascularization and wound healing. Single-cell transcriptional analysis identified a subpopulation of cells which was diminished in both type 1 and type 2 models of diabetes. These cells were characterized by the high expression of genes known to be important for new blood vessel growth. CONCLUSIONS: Perturbations in specific cellular subpopulations, visible only on a single-cell level, represent a previously unreported mechanism for the dysfunction of diabetic ASCs. These data suggest that the utility of autologous ASCs for cell-based therapies in patients with diabetes may be limited and that interventions to improve cell function before application are warranted.