Baker's yeast beta glucan supplementation was associated with an improved innate immune mRNA expression response after exercise.

Beta glucans are found in many natural sources, however, only Baker's Yeast Beta Glucan (BYBG) has been well documented to have structure-function effects that are associated with improved innate immune response to stressors (e.g., exercise, infection, etc.). The purpose was to identify a BYBG-associated mRNA expression pattern following exercise. Participants gave IRB-approved consent and were randomized to BYBG (Wellmune®; N=9) or Placebo (maltodextrin; N=10) for 6-weeks prior to performing 90 min of whole-body exercise. Paxgene blood samples were collected prior to exercise (PRE), after exercise (POST), two hours after exercise (2H), and four hours after exercise (4H). Total RNA was isolated and analyzed for the expression of 770 innate immune response mRNA (730 mRNA targets; 40 housekeepers/controls; Nanostring nCounter). The raw data were normalized against housekeeping controls and expressed as Log2 fold change from PRE for a given condition. Significance was set at p < 0.05 with adjustments for multiple comparisons and false discovery rate. We identified 47 mRNA whose expression was changed after exercise with BYBG and classified them to four functional pathways: 1) Immune Cell Maturation (8 mRNA), 2) Immune Response and Function (5 mRNA), 3) Pattern Recognition Receptors and DAMP or PAMP Detection (25 mRNA), and 4) Detection and Resolution of Tissue Damage (9 mRNA). The identified mRNA whose expression was altered after exercise with BYBG may represent an innate immune response pattern and supports previous conclusions that BYBG improves immune response to a future sterile inflammation or infection.

Advances and ongoing challenges in eosinophilic gastrointestinal disorders presented at the CEGIR/TIGERs Symposium at the 2024 American Academy of Allergy, Asthma & Immunology meeting.

The Consortium of Eosinophilic Gastrointestinal disease Researchers (CEGIR) and The International Gastrointestinal Eosinophil Researchers (TIGERs) organized a daylong symposium at the 2024 annual meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured new discoveries in basic and translational research as well as debates on the mechanisms and management of eosinophilic gastrointestinal diseases. Updates on recent clinical trials and consensus guidelines were also presented. We summarize the updates on eosinophilic gastrointestinal diseases presented at the symposium.

Myeloid-derived miR-6236 potentiates adipocyte insulin signaling and prevents hyperglycemia during obesity.

Adipose tissue macrophages (ATMs) influence obesity-associated metabolic dysfunction, but the mechanisms by which they do so are not well understood. We show that miR-6236 is a bona fide miRNA that is secreted by ATMs during obesity. Global or myeloid cell-specific deletion of miR-6236 aggravates obesity-associated adipose tissue insulin resistance, hyperglycemia, hyperinsulinemia, and hyperlipidemia. miR-6236 augments adipocyte insulin sensitivity by inhibiting translation of negative regulators of insulin signaling, including PTEN. The human genome harbors a miR-6236 homolog that is highly expressed in the serum and adipose tissue of obese people. hsa-MIR-6236 expression negatively correlates with hyperglycemia and glucose intolerance, and positively correlates with insulin sensitivity. Together, our findings establish miR-6236 as an ATM-secreted miRNA that potentiates adipocyte insulin signaling and protects against metabolic dysfunction during obesity.

Clostridioides difficile-mucus interactions encompass shifts in gene expression, metabolism, and biofilm formation.

In a healthy colon, the stratified mucus layer serves as a crucial innate immune barrier to protect the epithelium from microbes. Mucins are complex glycoproteins that serve as a nutrient source for resident microflora and can be exploited by pathogens. We aimed to understand how the intestinal pathogen, Clostridioides difficile, independently uses or manipulates mucus to its benefit, without contributions from members of the microbiota. Using a 2-D primary human intestinal epithelial cell model to generate physiologic mucus, we assessed C. difficile-mucus interactions through growth assays, RNA-Seq, biophysical characterization of mucus, and contextualized metabolic modeling. We found that host-derived mucus promotes C. difficile growth both in vitro and in an infection model. RNA-Seq revealed significant upregulation of genes related to central metabolism in response to mucus, including genes involved in sugar uptake, the Wood-Ljungdahl pathway, and the glycine cleavage system. In addition, we identified differential expression of genes related to sensing and transcriptional control. Analysis of mutants with deletions in highly upregulated genes reflected the complexity of C. difficile-mucus interactions, with potential interplay between sensing and growth. Mucus also stimulated biofilm formation in vitro, which may in turn alter the viscoelastic properties of mucus. Context-specific metabolic modeling confirmed differential metabolism and the predicted importance of enzymes related to serine and glycine catabolism with mucus. Subsequent growth experiments supported these findings, indicating mucus is an important source of serine. Our results better define responses of C. difficile to human gastrointestinal mucus and highlight flexibility in metabolism that may influence pathogenesis. IMPORTANCE: Clostridioides difficile results in upward of 250,000 infections and 12,000 deaths annually in the United States. Community-acquired infections continue to rise, and recurrent disease is common, emphasizing a vital need to understand C. difficile pathogenesis. C. difficile undoubtedly interacts with colonic mucus, but the extent to which the pathogen can independently respond to and take advantage of this niche has not been explored extensively. Moreover, the metabolic complexity of C. difficile remains poorly understood but likely impacts its capacity to grow and persist in the host. Here, we demonstrate that C. difficile uses native colonic mucus for growth, indicating C. difficile possesses mechanisms to exploit the mucosal niche. Furthermore, mucus induces metabolic shifts and biofilm formation in C. difficile, which has potential ramifications for intestinal colonization. Overall, our work is crucial to better understand the dynamics of C. difficile-mucus interactions in the context of the human gut.

A Multicenter, Retrospective Outcome Analysis of Vancomycin Area Under the Curve versus Trough-Based Dosing Strategies in Patients with Burn OR Inhalational Injuries (MONITOR).

Vancomycin is a glycopeptide antibiotic that requires close therapeutic monitoring. Prolonged exposure to elevated concentrations increases risk for serious adverse effects such as nephrotoxicity. However, sub-therapeutic concentrations may lead to bacterial resistance and clinical failure or death. The most recent Infectious Diseases Society of America (IDSA) publication regarding therapeutic monitoring of vancomycin recommends utilizing area under the curve (AUC)-based monitoring to maximize clinical success. Despite the guideline recommendation for AUC-guided dosing, many institutions still use trough-only monitoring in their practices, including those caring for patients with acute burn injuries. Following burn injury, patients are at a higher risk for infections, multi-organ failure, and pharmacokinetic alterations. The primary objective of this multi-center retrospective study is to determine optimal therapeutic monitoring of vancomycin by comparing clinical success between AUC vs. trough-based monitoring in burn patients. MONITOR was a multicenter, retrospective study of patients with thermal or inhalation injury admitted to one of 13 burn centers from 1/1/17 to 8/31/22 who received vancomycin. Demographic and clinical course data, including acute kidney injury (AKI) incidence and clinical success were obtained. Patients were evaluated for clinical success and grouped according to method of monitoring and adjusting doses: AUC vs. trough-based monitoring. Clinical success was a composite definition and lack of meeting any 1 of 5 criteria: 1) persistent infection, 2) relapse, 3) antibiotic failure (clinical worsening), 4) AKI, 5) death. Five-hundred seventeen vancomycin courses were assessed from 485 patients. There was no difference in the rate of clinical success between AUC monitored and the trough-only monitored groups. Incidence of AKI was higher in the trough-only group; however, was not statistically significant after controlling for renal function on admission, past medical history of chronic kidney disease (CKD), and concomitant nephrotoxins.

Systematic review and meta-analysis of Biodegradable Temporizing Matrix application for complex wound reconstruction.

Biodegradable Temporizing Matrix (BTM) is a synthetic dermal template recently developed to reconstruct complex wounds. Current literature describes BTM outcomes in the presence of infection and other comorbidities but are limited by small sample sizes. The purpose of this systemic review and meta-analysis was to determine current breadth and success of BTM use for complex wound closure. Databases were searched to identify previously published studies describing BTM use in human wounds. Studies were excluded if conducted in vitro, using non-human animals, or for procedures irrelevant to wound care. Twenty-four studies met inclusion criteria, representing 202 patients. The most common injury treated with BTM was burns (68 cases, 33.7%) followed by acute surgical wounds (59 cases, 29.2%). The large majority of patients did not experience any post-operative infections (76.6%). Infected wounds were associated with a 7.5-day delay from BTM to grafting. Univariate regression analyses showed a negative association between time to BTM implantation and age, exposed muscle, and exposed tendon (p < 0.001). Ninety-two percent of patients received BTM implantation less than 2 weeks from admission. Eighty-four percent of patients had a greater than 95% BTM take. The median time to STSG was 34 days, and 92% of patients experienced a greater than 95% STSG survival. To our knowledge, this is the first reported systemic review on the application of BTM for wound reconstruction. According to the published data, BTM is versatile dermal template for complex wounds coverage with low risk of infection, high template take rate, and excellent autograft survival.

Efficacy and safety of pentosan polysulfate sodium in people with symptomatic knee osteoarthritis and dyslipidaemia: protocol of the MaRVeL trial.

INTRODUCTION: Knee osteoarthritis (OA) is the most prevalent arthritis type and a leading cause of chronic mobility disability. While pain medications provide only symptomatic pain relief; growing evidence suggests pentosan polysulfate sodium (PPS) is chondroprotective and could have anti-inflammatory effects in knee OA. This study aims to explore the efficacy and safety of oral PPS in symptomatic knee OA with dyslipidaemia. METHODS AND ANALYSIS: MaRVeL is a phase II, single-centre, parallel, superiority trial which will be conducted at Royal North Shore Hospital, Sydney, Australia. 92 participants (46 per arm) aged 40 and over with painful knee OA and mild to moderate structural change on X-ray (Kellgren and Lawrence grade 2 or 3) will be recruited from the community and randomly allocated to receive two cycles of either oral PPS or placebo for 5 weeks starting at baseline and week 11. Primary outcome will be the 16-week change in overall average knee pain severity measured using an 11-point Numeric Rating Scale. Main secondary outcomes include change in knee pain, patient global assessment, physical function, quality of life and other structural changes. A biostatistician blinded to allocation groups will perform the statistical analysis according to the intention-to-treat principle. ETHICS AND DISSEMINATION: The protocol has been approved by the NSLHD Human Research Ethics Committee (HREC) (2021/ETH00315). All participants will provide written informed consent online. Study results will be disseminated through conferences, social media and academic publications. TRIAL REGISTRATION NUMBERS: Australian New Zealand Clinical Trial Registry (ACTRN12621000654853); U1111-1265-3750.

IL-27 maintains cytotoxic Ly6C+ γδ T cells that arise from immature precursors.

In mice, γδ-T lymphocytes that express the co-stimulatory molecule, CD27, are committed to the IFNγ-producing lineage during thymic development. In the periphery, these cells play a critical role in host defense and anti-tumor immunity. Unlike αß-T cells that rely on MHC-presented peptides to drive their terminal differentiation, it is unclear whether MHC-unrestricted γδ-T cells undergo further functional maturation after exiting the thymus. Here, we provide evidence of phenotypic and functional diversity within peripheral IFNγ-producing γδ T cells. We found that CD27+ Ly6C- cells convert into CD27+Ly6C+ cells, and these CD27+Ly6C+ cells control cancer progression in mice, while the CD27+Ly6C- cells cannot. The gene signatures of these two subsets were highly analogous to human immature and mature γδ-T cells, indicative of conservation across species. We show that IL-27 supports the cytotoxic phenotype and function of mouse CD27+Ly6C+ cells and human Vδ2+ cells, while IL-27 is dispensable for mouse CD27+Ly6C- cell and human Vδ1+ cell functions. These data reveal increased complexity within IFNγ-producing γδ-T cells, comprising immature and terminally differentiated subsets, that offer new insights into unconventional T-cell biology.

Finite element analysis of patient-specific additive-manufactured implants.

Introduction: Bone tumors, characterized by diverse locations and shapes, often necessitate surgical excision followed by custom implant placement to facilitate targeted bone reconstruction. Leveraging additive manufacturing, patient-specific implants can be precisely tailored with complex geometries and desired stiffness, enhancing their suitability for bone ingrowth. Methods: In this work, a finite element model is employed to assess patient-specific lattice implants in femur bones. Our model is validated using experimental data obtained from an animal study (n = 9). Results: The results demonstrate the accuracy of the proposed finite element model in predicting the implant mechanical behavior. The model was used to investigate the influence of reducing the elastic modulus of a solid Ti6Al4V implant by tenfold, revealing that such a reduction had no significant impact on bone behavior under maximum compression and torsion loading. This finding suggests a potential avenue for reducing the endoprosthesis modulus without compromising bone integrity. Discussion: Our research suggests that employing fully lattice implants not only facilitates bone ingrowth but also has the potential to reduce overall implant stiffness. This reduction is crucial in preventing significant bone remodeling associated with stress shielding, a challenge often associated with the high stiffness of fully solid implants. The study highlights the mechanical benefits of utilizing lattice structures in implant design for enhanced patient outcomes.

In situ pulmonary mucus hydration assay using rotational and translational diffusion of gold nanorods with polarization-sensitive optical coherence tomography.

Significance: Assessing the nanostructure of polymer solutions and biofluids is broadly useful for understanding drug delivery and disease progression and for monitoring therapy. Aim: Our objective is to quantify bronchial mucus solids concentration (wt. %) during hypertonic saline (HTS) treatment in vitro via nanostructurally constrained diffusion of gold nanorods (GNRs) monitored by polarization-sensitive optical coherence tomography (PS-OCT). Approach: Using PS-OCT, we quantified GNR translational (DT) and rotational (DR) diffusion coefficients within polyethylene oxide solutions (0 to 3 wt. %) and human bronchial epithelial cell (hBEC) mucus (0 to 6.4 wt. %). Interpolation of DT and DR data is used to develop an assay to quantify mucus concentration. The assay is demonstrated on the mucus layer of an air-liquid interface hBEC culture during HTS treatment. Results: In polymer solutions and mucus, DT and DR monotonically decrease with increasing concentration. DR is more sensitive than DT to changes above 1.5 wt. % of mucus and exhibits less intrasample variability. Mucus on HTS-treated hBEC cultures exhibits dynamic mixing from cilia. A region of hard-packed mucus is revealed by DR measurements. Conclusions: The extended dynamic range afforded by simultaneous measurement of DT and DR of GNRs using PS-OCT enables resolving concentration of the bronchial mucus layer over a range from healthy to disease in depth and time during HTS treatment in vitro.

Recessively Inherited Deficiency of Secreted WFDC2 (HE4) Causes Nasal Polyposis and Bronchiectasis.

Rationale: Bronchiectasis is a pathological dilatation of the bronchi in the respiratory airways associated with environmental or genetic causes (e.g., cystic fibrosis, primary ciliary dyskinesia, and primary immunodeficiency disorders), but most cases remain idiopathic. Objectives: To identify novel genetic defects in unsolved cases of bronchiectasis presenting with severe rhinosinusitis, nasal polyposis, and pulmonary Pseudomonas aeruginosa infection. Methods: DNA was analyzed by next-generation or targeted Sanger sequencing. RNA was analyzed by quantitative PCR and single-cell RNA sequencing. Patient-derived cells, cell cultures, and secretions (mucus, saliva, seminal fluid) were analyzed by Western blotting and immunofluorescence microscopy, and mucociliary activity was measured. Blood serum was analyzed by electrochemiluminescence immunoassay. Protein structure and proteomic analyses were used to assess the impact of a disease-causing founder variant. Measurements and Main Results: We identified biallelic pathogenic variants in WAP four-disulfide core domain 2 (WFDC2) in 11 individuals from 10 unrelated families originating from the United States, Europe, Asia, and Africa. Expression of WFDC2 was detected predominantly in secretory cells of control airway epithelium and also in submucosal glands. We demonstrate that WFDC2 is below the limit of detection in blood serum and hardly detectable in samples of saliva, seminal fluid, and airway surface liquid from WFDC2-deficient individuals. Computer simulations and deglycosylation assays indicate that the disease-causing founder variant p.Cys49Arg structurally hampers glycosylation and, thus, secretion of mature WFDC2. Conclusions: WFDC2 dysfunction defines a novel molecular etiology of bronchiectasis characterized by the deficiency of a secreted component of the airways. A commercially available blood test combined with genetic testing allows its diagnosis.

Widespread variation in molecular interactions and regulatory properties among transcription factor isoforms.

Most human Transcription factors (TFs) genes encode multiple protein isoforms differing in DNA binding domains, effector domains, or other protein regions. The global extent to which this results in functional differences between isoforms remains unknown. Here, we systematically compared 693 isoforms of 246 TF genes, assessing DNA binding, protein binding, transcriptional activation, subcellular localization, and condensate formation. Relative to reference isoforms, two-thirds of alternative TF isoforms exhibit differences in one or more molecular activities, which often could not be predicted from sequence. We observed two primary categories of alternative TF isoforms: "rewirers" and "negative regulators", both of which were associated with differentiation and cancer. Our results support a model wherein the relative expression levels of, and interactions involving, TF isoforms add an understudied layer of complexity to gene regulatory networks, demonstrating the importance of isoform-aware characterization of TF functions and providing a rich resource for further studies.

Mucus polymer concentration and in vivo adaptation converge to define the antibiotic response of Pseudomonas aeruginosa during chronic lung infection.

The airway milieu of individuals with muco-obstructive airway diseases (MADs) is defined by the accumulation of dehydrated mucus due to hyperabsorption of airway surface liquid and defective mucociliary clearance. Pathological mucus becomes progressively more viscous with age and disease severity due to the concentration and overproduction of mucin and accumulation of host-derived extracellular DNA (eDNA). Respiratory mucus of MADs provides a niche for recurrent and persistent colonization by respiratory pathogens, including Pseudomonas aeruginosa, which is responsible for the majority of morbidity and mortality in MADs. Despite high concentration inhaled antibiotic therapies and the absence of antibiotic resistance, antipseudomonal treatment failure in MADs remains a significant clinical challenge. Understanding the drivers of antibiotic tolerance is essential for developing more effective treatments that eradicate persistent infections. The complex and dynamic environment of diseased airways makes it difficult to model antibiotic efficacy in vitro. We aimed to understand how mucin and eDNA concentrations, the two dominant polymers in respiratory mucus, alter the antibiotic tolerance of P. aeruginosa. Our results demonstrate that polymer concentration and molecular weight affect P. aeruginosa survival post antibiotic challenge. Polymer-driven antibiotic tolerance was not explicitly associated with reduced antibiotic diffusion. Lastly, we established a robust and standardized in vitro model for recapitulating the ex vivo antibiotic tolerance of P. aeruginosa observed in expectorated sputum across age, underlying MAD etiology, and disease severity, which revealed the inherent variability in intrinsic antibiotic tolerance of host-evolved P. aeruginosa populations. IMPORTANCE: Antibiotic treatment failure in Pseudomonas aeruginosa chronic lung infections is associated with increased morbidity and mortality, illustrating the clinical challenge of bacterial infection control. Understanding the underlying infection environment, as well as the host and bacterial factors driving antibiotic tolerance and the ability to accurately recapitulate these factors in vitro, is crucial for improving antibiotic treatment outcomes. Here, we demonstrate that increasing concentration and molecular weight of mucin and host eDNA drive increased antibiotic tolerance to tobramycin. Through systematic testing and modeling, we identified a biologically relevant in vitro condition that recapitulates antibiotic tolerance observed in ex vivo treated sputum. Ultimately, this study revealed a dominant effect of in vivo evolved bacterial populations in defining inter-subject ex vivo antibiotic tolerance and establishes a robust and translatable in vitro model for therapeutic development.

Effect of glycemic variability on infectious outcomes in critically Ill burn patients.

After acute burn injury, patients experience a hypermetabolic state often complicated by a stress-induced hyperglycemia. Recent research points towards glycemic variability as a contributing factor in adverse outcomes in critically ill patients. In burn patients, greater glycemic variability has been associated with increased rates of mortality and sepsis. However, no studies to date have examined the impact of glycemic variability on rates of infection in this population or determined which measure may be most useful. Infection, and subsequent sepsis, remains the leading contributor to morbidity and mortality after burn injury. The primary objective of this study is to evaluate the relationship between different measures of glycemic variability and infectious complications in burn patients. This retrospective study included patients admitted to a single American Burn Association-verified burn center between January 1, 2020 and December 31, 2020 with burn or inhalation injury. The primary outcome was a composite of autograft loss, mortality, and proven infection. Secondary outcomes included hospital length of stay and a further analysis of the proven infection component of the composite primary outcome. In addition to mean glucose, several different measures of glycemic variability were used for comparison, including standard deviation, coefficient of variation, mean amplitude of glycemic excursions, and J-index. Outcomes were analyzed using multiple logistic regression analysis while controlling for revised Baux score. A quantile analysis was performed to do determine the optimal mean threshold. Three hundred and ninety-two patients were admitted and screened for inclusion during the study period. Most patients were excluded due to a LOS less than 72 h. 112 patients were included in the study. Of the 112 patients, 22.3% experienced an infectious complication (25 patients with 28 complications). Mean glucose (OR 1.024; 95% CI 1.004-1.045) and J-index (OR 1.044; 95% CI 1.003-1.087) were associated with occurrence of infectious complications. Regarding target mean glucose threshold, a daily mean glucose above 150 mg/dL showed the strongest association with infectious complications (OR 3.634; 95% CI 1.008-13.101). Mean glucose, standard of deviation, and J-index were all independently associated with proven infection.

Retrospective Review of Outcomes Related to Early Therapy Intervention Following Application of Cultured Epidermal Autografts in Severely Burned Patients.

Cultured epidermal autografts (CEA) have since become more prevalent in the treatment of burn-injured patients with limited available donor sites for adequate wound closure, resulting in decreased mortality rates and an increased number of these patients requiring burn therapy services to achieve optimal functional outcomes at discharge. However, the use and postoperative management of CEA continue to be controversial due large to the physiological fragility and expense of CEA, leading to variable postoperative treatment practices across burn centers. As such, minimal research is available regarding patient outcomes following CEA application, specifically related to burn therapy intervention. Thus, a retrospective chart review was conducted on a series of 10 patients, 18 years of age or older, admitted to a single, American Burn Association verified burn center, between April 2015 and April 2023, who required CEA and received pre- and postoperative treatment by burn therapists in accordance with center-specific burn rehabilitation guidelines. The resulting patient outcomes, in response to early implementation of therapy interventions post-CEA surgery, demonstrated optimal functional status for patients upon discharge and positive long-term implications.

Self-Sustaining Water Microdroplet Resonators Using 3D-Printed Microfluidics.

Microdroplet resonators provide an excellent tool for optical studies of water, but water microdroplets are difficult to maintain outside a carefully controlled environment. We present a method for maintaining a water microdroplet resonator on a 3D-printed hydrophobic surface in an ambient environment. The droplet is maintained through a passive microfluidic system that supplies water to the droplet through a vertical channel at a rate equivalent to its evaporation. In this manner, we are able to create and passively maintain water microdroplet resonators with quality factors as high as 3×108.

The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes.

Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.

COVID-19 and Asthma Onset in Children.

BACKGROUND AND OBJECTIVES: Respiratory viral infections increase risk of asthma in infants and children. Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus can cause severe lung inflammation and prolonged respiratory symptoms. We sought to determine whether SARS-CoV-2 infection modified pediatric incident asthma risk. METHODS: This retrospective cohort study examined children ages 1 to 16 within the Children's Hospital of Philadelphia Care Network who received polymerase chain reaction (PCR) testing for SARS-CoV-2 between March 1, 2020 and February 28, 2021. Multivariable Cox regression models assessed the hazard ratio of new asthma diagnosis between SARS-CoV-2 PCR positive and SARS-CoV-2 PCR negative groups within an 18-month observation window. Models were adjusted for demographic characteristics, socioeconomic variables, and atopic comorbidities. RESULTS: There were 27 423 subjects included in the study. In adjusted analyses, SARS-CoV-2 PCR positivity had no significant effect on the hazard of new asthma diagnosis (hazard ratio [HR]: 0.96; P = .79). Black race (HR: 1.49; P = .004), food allergies (HR: 1.26; P = .025), and allergic rhinitis (HR: 2.30; P < .001) significantly increased the hazard of new asthma diagnosis. Preterm birth (HR: 1.48; P = .005) and BMI (HR: 1.13; P < .001) significantly increased the hazard of new asthma diagnosis for children <5 years old. CONCLUSIONS: SARS-CoV-2 PCR positivity was not associated with new asthma diagnosis in children within the observation period, although known risk factors for pediatric asthma were confirmed. This study informs the prognosis and care of children with a history of SARS-CoV-2 infection.