CD23+IgG1+ memory B cells are poised to switch to pathogenic IgE production in food allergy.

Food allergy is caused by allergen-specific immunoglobulin E (IgE) antibodies, but little is known about the B cell memory of persistent IgE responses. Here, we describe, in human pediatric peanut allergy, a population of CD23+IgG1+ memory B cells arising in type 2 immune responses that contain high-affinity peanut-specific clones and generate IgE-producing cells upon activation. The frequency of CD23+IgG1+ memory B cells correlated with circulating concentrations of IgE in children with peanut allergy. A corresponding population of "type 2-marked" IgG1+ memory B cells was identified in single-cell RNA sequencing experiments. These cells differentially expressed interleukin-4 (IL-4)- and IL-13-regulated genes, such as FCER2/CD23+, IL4R, and germline IGHE, and carried highly mutated B cell receptors (BCRs). In children with high concentrations of serum peanut-specific IgE, high-affinity B cells that bind the main peanut allergen Ara h 2 mapped to the population of "type 2-marked" IgG1+ memory B cells and included clones with convergent BCRs across different individuals. Our findings indicate that CD23+IgG1+ memory B cells transcribing germline IGHE are a unique memory population containing precursors of high-affinity pathogenic IgE-producing cells that are likely to be involved in the long-term persistence of peanut allergy.

Role of Primary Care in Bridging Gaps in the Health Care System for Vulnerable Children in the United States of America: A Sickle Cell Disease Case Study.

Sickle cell disease (SCD) is a life-threatening condition. Given the nature of the disease and associated complications with high mortality and morbidity rates, it is imperative that patients are diagnosed in early infancy, are established with specialists and general pediatric care immediately, and receive continuity in care. A percentage of patients diagnosed with SCD fall within a vulnerable, at-risk population. This population may face greater social barriers that lead to missed or late diagnosis and therefore delayed management, significantly increasing the risk of morbidity and mortality. Screening tools such as state newborn screens help to identify the diagnosis early. However, patients in vulnerable, at-risk populations who are not established in the health care system may not receive timely communication about their illness and necessary next steps for care. We present a case of a 12-month-old female who is an example of one of the many patients who despite having undergone newborn screening, fell through the cracks due to social barriers including housing instability, food insecurity, and lack of access to transportation. This paper emphasizes the need for and provides a real example of the benefit of access to longitudinal primary care for vulnerable patients. We also demonstrate the role of primary care in clearing the care gaps and coordinating services quickly to ultimately prevent life-threatening complications specifically for children with previously undiagnosed chronic illnesses.

The memory of pathogenic IgE is contained within CD23 + IgG1 + memory B cells poised to switch to IgE in food allergy.

Food allergy is caused by allergen-specific IgE antibodies but little is known about the B cell memory of persistent IgE responses. Here we describe in human pediatric peanut allergy CD23 + IgG1 + memory B cells arising in type 2 responses that contain peanut specific clones and generate IgE cells on activation. These 'type2-marked' IgG1 + memory B cells differentially express IL-4/IL-13 regulated genes FCER2 / CD23, IL4R , and germline IGHE and carry highly mutated B cell receptors (BCRs). Further, high affinity memory B cells specific for the main peanut allergen Ara h 2 mapped to the population of 'type2-marked' IgG1 + memory B cells and included convergent BCRs across different individuals. Our findings indicate that CD23 + IgG1 + memory B cells transcribing germline IGHE are a unique memory population containing precursors of pathogenic IgE. One-Sentence Summary: We describe a unique population of IgG + memory B cells poised to switch to IgE that contains high affinity allergen-specific clones in peanut allergy.

A Virtual Clinical Reasoning Case for Medical Students Using an Ophthalmology Model: A Case of Red Eye.

Introduction: Triggered by the COVID-19 pandemic, medical education has moved online, tasking medical educators with developing virtual learning experiences. This is particularly challenging for less-represented disciplines, such as ophthalmology. We designed a red eye clinical reasoning case for preclinical medical students, which can be delivered virtually, using video conference software. Methods: We developed a 90-minute red eye/clinical reasoning workshop for which prereading was assigned to students. We then delivered a virtual development session to nonophthalmologist copreceptors and provided a session faculty guide. The entire first-year medical student class (No. = 140) participated in one of four identical workshops, which included virtual small- and large-group discussions. Students completed a knowledge pre- and posttest, and an optional session postsurvey. Results: Knowledge gains from pretest (No. = 94) to posttest (No. = 73) were statistically significant (p < .05), with average scores improving from 57% to 70%. Overall, students were satisfied, rating the following items 4 or 5 out of 5: session (86%, No. = 31), virtual format (83%, No. = 30), and if they recommended future use (69%, No. = 35). Discussion: This novel, virtual clinical reasoning case simulated small- and large-group learning, achieved knowledge gains, and was well received by students. Minor technical challenges were encountered but successfully remedied, without apparent disruption to learning. This virtual medical education model can be used to enhance ophthalmology education in preclinical medical students and can be adapted for virtual design of other curricular content.

Reported Marijuana and Tobacco Smoke Incursions Among Families Living in Multiunit Housing in New York City.

BACKGROUND: While public knowledge on the prevalence and adverse health effects of secondhand tobacco smoke exposure is well established, information on the prevalence of secondhand marijuana smoke (SHMS) exposure is limited. METHODS: A convenience sample of parents of children attending 1 of 4 pediatric practices in the Mount Sinai Health System completed an anonymous questionnaire assessing demographics, housing characteristics, and the child's health status, as well as smoke incursions and household smoking behaviors. RESULTS: About 450 parents completed the survey between 2018 and 2019; those with incomplete data were excluded, and 382 surveys were included in the analysis. Approximately 40% of the children were white; the median age was 15 months (interquartile range: 5-40 months). About 30.9% (n = 118) of participants reported marijuana incursions in their home while with their child, while 33.5% (n = 122) reported tobacco smoke incursions. SHMS exposure differed by race (P = .0043); and by housing types (P < .0001). Participants in New York City Housing Authority (NYCHA) developments were more likely to report smelling SHMS (adjusted odds ratio = 3.45, 95% confidence interval = 1.18, 10.10], P = .02). Those in Section 8 housing were also more likely to report smelling SHMS, but the association was not significant (adjusted odds ratio = 3.29, 95% confidence interval = 0.94, 11.55, P = .06). Approximately two thirds of the participants reported viewing marijuana smoke as being harmful to their child. CONCLUSIONS: About one third of the families enrolled in the study reported smelling SHMS while at home with their child. Reported marijuana smoke exposure was associated with living in NYCHA housing. Policies that limit all smoke in multiunit housing should be supported.

Preseason Pediatrics: an Interactive Preclinical Curriculum Enhances Knowledge and Skills in Medical Students.

INTRODUCTION: Medical students have limited preclinical exposure to pediatrics. We created an optional preclinical curriculum for first-year medical students called "Preseason Pediatrics" (PSP). This 6-month curriculum teaches pediatric-specific knowledge and clinical skills, consisting of monthly resident-led didactic sessions followed by complementary resident-mentored clinical experiences. METHODS: Participants completed a survey before and after completion of PSP. Knowledge was assessed with multiple-choice questions pertaining to each topic covered in PSP and perceived skills, with a 5-point Likert scale ranging from not at all (1) to extremely (5) for skills taught. Skill maintenance was assessed with a newborn objective structured clinical exam (OSCE) 6 months after PSP completion in 2016. Students beginning their pediatric clerkship also completed a survey, comparing students who did and did not complete PSP. RESULTS: From 2014 to 2017, 135 first-year medical students participated. Percent correct scores on pediatric knowledge increased in 4/5 topics covered, and students perceived increases in their pediatric skills in all course domains. 86.8% (n = 92/106) of students reported feeling more prepared for the pediatric clerkship. 94.3% (n = 100/106) would recommend the PSP experience to other students. Third-year students who participated in PSP reported higher comfort with pediatric patients prior to their clerkship. CONCLUSIONS: PSP is a successful novel preclinical program introducing students to pediatrics. We demonstrated that didactics paired with resident-mentored clinical experiences improved pediatric knowledge, clinical-based skills, and perceived clerkship preparedness. Students may academically and professionally benefit from such earlier exposure to pediatrics.