The upper respiratory tract is compromised in the early period of COVID-19, but SARS-CoV-2 tropism at the cellular level is not fully defined. Unlike recent single-cell RNA-Seq analyses indicating uniformly low mRNA expression of SARS-CoV-2 entry–related host molecules in all nasal epithelial cells, we show that the protein levels are relatively high and that their localizations are restricted to the apical side of multiciliated epithelial cells. In addition, we provide evidence in patients with COVID-19 that SARS-CoV-2 is massively detected and replicated within the multiciliated cells. We observed these findings during the early stage of COVID-19, when infected ciliated cells were rapidly replaced by differentiating precursor cells. Moreover, our analyses revealed that SARS-CoV-2 cellular tropism was restricted to the nasal ciliated versus oral squamous epithelium. These results imply that targeting ciliated cells of the nasal epithelium during the early stage of COVID-19 could be an ideal strategy to prevent SARS-CoV-2 propagation.

Despite medical and surgical treatments, some cases of nasal polyps (NP) exhibit recidivism. However, the endotype of refractory chronic rhinosinusitis with NP (CRSwNP) remains unclear. Therefore, the objective of this study was to characterize the immunological profile of refractory CRSwNP. The control (n =23), primary NP group (pNP, n =70) and refractory NP group (rNP, n =86) were enrolled in this study. Patients who underwent revision surgeries due to failed maximal medical treatment after primary surgery were defined as the rNP group. A total of 18 inflammatory markers were investigated in nasal tissues using multiplex cytokine assay or enzyme-linked immunosorbent assay. The clinical characteristics of rNP included more extensive disease and worse clinical course after surgery. Additionally, rNP subjects showed higher infection rate (mucopurulence and culture-positive rate), more frequent use of antibiotics and suffered from symptomatic bacterial infection, increased asthma morbidity compared to pNP. Cytokine profile analysis showed that levels of Th17-associated mediators (myeloperoxidase, interleukin (IL)-8, IL-17A and IL-23), B-cell activating factor (BAFF) and Th1 cytokine (interferon-γ) were up-regulated in rNP compared to controls and pNP. Human neutrophil elastase-positive cells were also enhanced in rNP compared with pNP. Upregulation of Th17/Th1mediators and BAFF were observed in rNP, regardless of tissue eosinophilia or asthmatic comorbidity. Interestingly, eosinophilic markers, such as eosinophil cationic protein and C-C motif chemokine ligand 24, were up-regulated in asthmatic rNP compared to pNP and controls. Levels of anti-dsDNA immunoglobulin (Ig) G and IgA were up-regulated in rNP and highest in asthmatic eosinophilic rNP among subtypes of rNP. Our results suggest that Th17/Th1-associated mediators and BAFF may play a role and be a potential therapeutic target in refractory CRSwNP. Additionally, eosinophilic markers and autoantibodies may contribute to refractoriness in asthmatic rNP.

Endoscopic prelacrimal medial maxillectomy (EPMM) was previously reported to treat maxillary inverted papilloma. This study aimed to compare prelacrimal recess approach with the conventional Caldwell-Luc approach (CLA) to remove benign maxillary sinus tumors and to evaluate the usefulness of this approach based on our experience. Ten patients who underwent EPMM at our hospital from January 2013 to December 2017 were reviewed. We also reviewed 30 patients who underwent benign maxillary sinus tumor resection via CLA during the same period. From medical records, postoperative pathological results complications due to surgery, and recurrence rate were evaluated. There were eight inverted papilloma, one ameloblastoma, and one ossifying fibroma in the EPMM group. In the CLA group, all 30 cases were inverted papilloma. There were no cases of failure at gross total removal during surgery, and no recurrences were observed during follow-up in either groups. Mean follow-up period was 13.0 months in CLA group and 10.8 months in EPMM group. Regarding postoperative complications, 11 patients of the CLA group (37%) and three patients of the EPMM group (30%) had numbness around the cheek and upper lip area after surgery (P=0.715). In the CLA group, there were eight patients who had numbness lasting more than 3 months after surgery, and two patients had numbness for more than 1 year. However, facial numbness disappeared within 3 months in all patients in the EPMM group, in which epiphora was not observed. EPMM is the effective surgical approach for resecting benign maxillary sinus tumor compared with CLA. Although facial numbness was reported in EPMM, the duration of numbness was shorter than CLA.

Background: Cerebrospinal fluid (CSF) leakage is a complication that any surgeon working in the field of skull base surgery does not wish to encounter. The surgical approach to the skull base often varies, and the various sizes and locations of skull base lesions make it difficult to determine the cause of CSF leakage. However, it is useful to investigate which factors contribute to postoperative CSF leakage. Methods: Related studies were identified by searching the following databases: PubMed/Medline, Embase, and Web of Sciences through December 2019. Random-effects models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The Newcastle-Ottawa scale was used to evaluate the quality of observational studies. Results: Our search yielded 56 retrospective cohort studies involving a total of 11,826 skull base surgical procedures. The overall rate of postoperative CSF leakage was 7.2%. The effect of obesity on postoperative CSF leakage had an OR of 1.88, and the effect of perioperative radiotherapy on postoperative CSF leakage yielded an OR of 1.87. High intraoperative CSF flow rate also had a significant OR of 2.98. On the other hand, a pedicled vascularized flap efficiently reduced the risk of postoperative CSF leakage. Defect size and the presence or absence of a lumbar drain had no effect on postoperative CSF leakage. Conclusions: This comprehensive quantitative assessment of postoperative CSF leakage showed that obesity, perioperative radiotherapy, and high intraoperative CSF flow rate raised the risk of CSF leakage; however, a pedicled vascularized flap can effectively reduce the risk of postoperative CSF leakage.

Min JY, et al. Allergy Asthma Immunol Res. 2023 Jul;15(4):437-450. https://doi.org/10.4168/aair.2023.15.4.437