Single-cell analysis of human nasal mucosal IgE antibody secreting cells reveals a newly minted phenotype

Immunoglobulin (Ig) E is central to the pathogenesis of allergic conditions, including allergic fungal rhinosinusitis. However, little is known about IgE antibody secreting cells (ASCs). We performed single-cell RNA sequencing from cluster of differentiation (CD)19+ and CD19- ASCs of nasal polyps from patients with allergic fungal rhinosinusitis (n = 3). Nasal polyps were highly enriched in CD19+ ASCs. Class-switched IgG and IgA ASCs were dominant (95.8%), whereas IgE ASCs were rare (2%) and found only in the CD19+ compartment. Through Ig gene repertoire analysis, IgE ASCs shared clones with IgD-CD27- "double-negative" B cells, IgD+CD27+ unswitched memory B cells, and IgD-CD27+ switched memory B cells, suggesting ontogeny from both IgD+ and memory B cells. Transcriptionally, mucosal IgE ASCs upregulate pathways related to antigen presentation, chemotaxis, B cell receptor stimulation, and survival compared with non-IgE ASCs. Additionally, IgE ASCs have a higher expression of genes encoding lysosomal-associated protein transmembrane 5 (LAPTM5) and CD23, as well as upregulation of CD74 (receptor for macrophage inhibitory factor), store-operated Calcium entry-associated regulatory factor (SARAF), and B cell activating factor receptor (BAFFR), which resemble an early minted ASC phenotype. Overall, these findings reinforce the paradigm that human ex vivo mucosal IgE ASCs have a more immature plasma cell phenotype than other class-switched mucosal ASCs and suggest unique functional roles for mucosal IgE ASCs in concert with Ig secretion.

Extrafollicular IgD+ B cells generate IgE antibody secreting cells in the nasal mucosa

Increased IgE is a typical feature of allergic rhinitis. Local class-switch recombination has been intimated but B cell precursors and mechanisms remain elusive. Here we describe the dynamics underlying the generation of IgE-antibody secreting cells (ASC) in human nasal polyps (NP), mucosal tissues rich in ASC without germinal centers (GC). Using VH next generation sequencing, we identified an extrafollicular (EF) mucosal IgD+ naïve-like intermediate B cell population with high connectivity to the mucosal IgE ASC. Mucosal IgD+ B cells, express germline epsilon transcripts and predominantly co-express IgM. However, a small but significant fraction co-express IgG or IgA instead which also show connectivity to ASC IgE. Phenotypically, NP IgD+ B cells display an activated profile and molecular evidence of BCR engagement. Transcriptionally, mucosal IgD+ B cells reveal an intermediate profile between naïve B cells and ASC. Single cell IgE ASC analysis demonstrates lower mutational frequencies relative to IgG, IgA, and IgD ASC consistent with IgE ASC derivation from mucosal IgD+ B cell with low mutational load. In conclusion, we describe a novel mechanism of GC-independent, extrafollicular IgE ASC formation at the nasal mucosa whereby activated IgD+ naïve B cells locally undergo direct and indirect (through IgG and IgA), IgE class switch.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Practice Patterns in Office-Based Rhinology: Survey of the American Rhinologic Society

BACKGROUND

Recent years have witnessed significant expansion in office-based rhinology. This study assesses practice patterns of the American Rhinologic Society (ARS) membership regarding office-based rhinologic procedures.

METHODS

A 24-item survey was disseminated to the ARS membership from March 15 to May 31, 2016.

RESULTS

A total of 157 physicians (11.9%) completed the survey. Office-based rhinologic procedures were performed by 99% of respondents, with sinonasal debridements (99%), polypectomy (77%), and balloon sinus ostial dilation (56%) being the most common. During a typical month, the number of sinonasal debridements was 0-10 in 23%, 11-20 in 34%, 21-30 in 26%, and >30 in 18%. For polypectomy, 57% of the respondents utilized a microdebrider (reusable electric-24%, disposable vacuum-powered-21%, and both-12%), 36% endoscopic forceps, and 7% a combination of both. With respect to balloon ostial dilation, the frontal sinuses were the most frequently addressed (53%) followed by the maxillary (46%) and sphenoid (39%) sinuses. In-office ethmoidectomies, antrostomies, sphenoidotomies, and frontal sinusotomies without the use of the balloon were performed by 35%, 31%, 24%, and 21% of the respondents, respectively. Thirty percent of respondents used steroid-eluting sinus implants and 10% used computer-assisted surgical navigation in the office setting. Overall, 63% of respondents reported that the number of office-based rhinologic procedures they performed had increased over the last 5 years.

CONCLUSIONS

The present study illustrates the integration of office procedures into rhinologic clinical practice among ARS survey respondents. With ongoing technologic innovations, the scope of office-based rhinology will likely continue to expand in the years to come.

Airway reflux

An ever-increasing number of adult and pediatric disorders have been shown to be influenced or caused by airway reflux. This has become a controversial and complicated aspect of medicine that requires a multidisciplinary approach. Evidence indicates that it is not only the acidic components of gastric refluxate that injure extraesophageal tissues but also the nonacidic components, such as pepsin and bile. There is a realization that proton pump inhibitors will not be effective when nonacidic components of refluxate are causing the problem. New in vitro and in vivo models for the study of airway reflux and new therapeutic and surgical approaches are discussed in this review article.

Laryngopharyngeal Reflux (LPR)

Program Description: Objective: Develop a working algorithm that effectively eliminates dangerous conditions while efficiently provides reasonable alternatives to address LPR symptoms. Methods: use an audience response system in combination with a structured set of questions directed to the audience. End result: a real world proposed treatment algorithm. White paper. Possible basis for outcomes assessment study. The overall goal of this session is to define current practice trends on the management of laryngopharyngeal reflux (LPR) based on actual audience participation/input, and the consideration of appropriate management for a typical patient. Using an interactive panel format, the moderator will prompt panelists to present a quick review of epidemiology, symptomatology, and co-morbid conditions impacting laryngopharyngeal reflux (LPR); diagnosis/differential diagnosis; current evidence on diagnostic and therapeutic management; and future research and management implications. After laying out background, the moderator/panel will consider real world patient management algorithms.

Educational Objectives: 1) Who is the typical patient presenting with laryngopharyngeal reflux (LPR) in an otolaryngology practice? 2) What diagnostic testing options are or should be employed? What are the common treatment pathways? 3) What differential data should be considered? What health care costs impact diagnosis/treatment? When is referral recommended?