Can secondary lymphoid organs exert a favorable effect on the mild course of COVID-19 in children?

Possible role of endoplasmic reticulum stress in the pathogenesis of chronic adenoiditis and adenoid hypertrophy: A prospective, parallel-group study

Background

Adenoid tissue is a first-line host defense secondary lymphoid organ, especially in childhood. The endoplasmic reticulum (ER) is required to maintain balanced cellular activity. With impaired ER functions, protein accumulation occurs, resulting in ER stress, which plays a role in the etiopathogenesis of many diseases.

Objective

We aimed to investigate the relationship between ER stress and adenoid tissue disorders, thereby elucidating the mechanisms of immunity-related diseases.

Methods

Fifty-four pediatric patients (>3 years old) who underwent adenoidectomy for chronic adenoiditis (CA) or adenoid hypertrophy (AH) were enrolled in this prospective, parallel-group clinical study. Adenoids were divided into two groups (CA or AH) based on their size and evaluated for ER stress pathway and apoptosis pathway markers by Real-time PCR and Western blot analysis.

Results

ER stress pathway markers significantly differed between the CA and AH groups. Children with CA had higher ER stress marker levels than the AH group (p < .001 for ATF-4, ATF-6, and GRP78, and p < .05 for EDEM1, CHOP, EIF2AK3, ERNI, and GRP94). Apoptosis pathway marker levels (BAX and BCL-2) were not different between groups.

Conclusions

ER stress contributes to the etiopathogenesis of adenoid tissue diseases and the pathogenesis of adenoid tissue disorders, which are part of the immune response. These results may guide the development of new and alternative treatments for immune system disorders.

Treatment of recurrent acute tonsillitis-a systematic review and clinical practice recommendations

Background

There is an ongoing debate on the indications for tonsil surgery in both children and adults with recurrent acute tonsillitis. The aim is to provide practical recommendations for diagnostics and treatment for recurrent acute tonsillitis including evidence-based decision making for tonsillectomy.

Methods

A systematic literature search in PubMed, Embase, Web of Science, and ScienceDirect from 2014 until April 2023 resulted in 68 articles. These were the basis for the review and a comprehensive series of consensus statements on the most important diagnostics and indications for both non-surgical and surgical therapy. A consensus paper was circulated among the authors and members of the International Head and Neck Scientific Group until a final agreement was reached for all recommendations.

Results

The differentiation between sore throat and tonsillitis patient episodes is mostly not feasible and hence is not relevant for diagnostic decision making. Diagnostics of a tonsillitis/sore throat episode should always include a classification with a scoring system (Centor, McIssac, FeverPAIN score) to estimate the probability of a bacterial tonsillitis, mainly due to group A streptococcus (GAS). In ambiguous cases, a point-of-care test GAS swab test is helpful. Consecutive counting of the tonsillitis/sore throat episodes is important. In addition, a specific quality of life score (Tonsillectomy Outcome Inventory 14 or Tonsil and Adenoid Health Status Instrument) should be used for each episode. Conservative treatment includes a combination of paracetamol and/or non-steroidal anti-inflammatory drugs. In case of high probability of bacterial tonsillitis, and only in such cases, especially in patients at risk, standard antibiotic treatment is initiated directly or by delayed prescription. Tonsillectomy is indicated and is highly effective if the patient has had ≥7 adequately treated episodes in the preceding year, ≥5 such episodes in each of the preceding 2 years, or ≥3 such episodes in each of the preceding 3 years. An essential part of surgery is standardized pain management because severe postoperative pain can be expected in most patients.

Conclusion

It is necessary to follow a stringent treatment algorithm for an optimal and evidence-based treatment for patients with recurrent acute tonsillitis. This will help decrease worldwide treatment variability, antibiotic overuse, and avoid ineffective tonsillectomy.

Impact of vitamin D in children with chronic tonsillitis (immunohistochemical study of CD68 polarisation and proinflammatory cytokines estimation)

Inflammatory processes are increasingly attributed to macrophage polarization. Proinflammatory macrophages promote T helper (Th) 1 response, tissue repair, and Th2 responses. Detection of macrophages in tissue sections is facilitated by CD68. Our study is focused on the expression of CD68 and the estimation of proinflammatory cytokines in children's patients with chronic tonsillitis secondary to vitamin D supplementation. This hospital-based Randomized prospective case-control study was conducted on 80 children with chronic tonsillitis associated with vitamin D deficiency where (40 received vitamin D 50,000 IU weekly for 3-6 months and 40 received 5 ml distilled water as placebo). The serum 25-hydroxyvitamin D [25(OH)D] was measured using an Enzyme-linked immunosorbent assay on all included children. Different histological and immunohistochemical studies for the detection of CD68 were done. There was a significantly lower serum level of 25(OH)D in the placebo group versus the vitamin D group (P < 0.001). The levels of pro-inflammatory cytokines, TNFα, and IL-2 significantly increased in the placebo group as compared to the vitamin D group (P < 0.001). The increased level of IL-4 and IL-10 in the placebo group as compared to the vitamin D group was insignificant (P = 0.32, 0.82) respectively. Vitamin D supplementation alleviated the deleterious effect of chronic tonsillitis on the histological structure of the tonsil. Tonsillar tissues of the children in the control and vitamin D groups demonstrated a highly statistically significantly lower number of CD68 immunoexpressing cells compared with those in the placebo group (P < 0.001). Low vitamin D may play a role in chronic tonsillitis. Vitamin D supplementation could help reduce the occurrence of chronic tonsillitis in susceptible children.

CCL20/CCR6 Mediated Macrophage Activation and Polarization Can Promote Adenoid Epithelial Inflammation in Adenoid Hypertrophy

Background

Adenoid hypertrophy (AH) is a chronic or acute obstruction-related ailment of the upper respiratory tract that arises as an inflammatory response to exposure of bacteria, viruses or allergies. Activation and polarization of macrophages are key processes in inflammation-related disorders like AH and CCL20/CCR6 axis is a critical therapeutic target.

Purpose

To determine that CCL20/CCR6 mediated macrophage activation and polarization can promote adenoid epithelial inflammation in AH.

Methods

To support this claim, CCL20 and CCR6 expressions were studied in clinical AH samples. In addition, the expressions of cytokines such as TNF-α, IL-1β, IL-6, IL-17, IL-10 and TGF-β were analysed. In vitro, human adenoid epithelial cells were co-cultured with polarized THP-1 and T lymphocyte H9 cells to study the expressions of several inflammatory markers.

Results

The expressions of M1 macrophage markers CD86 and IL-17 were significantly increased, whereas the expressions of M2 macrophage markers CD206 and FOXP3 were significantly decreased. The THP-1 cells were successfully polarized to M0, M1 and M2 macrophages. The survival of macrophages improved after 24 hr of induction and enhanced TGF-β expression was observed. The expressions of the inflammatory cytokines IL-6, TNF-α, IL-1β and CCL20 increased significantly.

Conclusion

Collectively, these results suggest that the CCL20/CCR6 mediated macrophage activation and polarization into M1-type macrophages can promote adenoid epithelial inflammation in AH. Further studies are warranted to determine the roles of inflammatory markers in the pathophysiology of AH and identifying potential targets.

Impact of tonsillectomy on COVID-19 pandemic: an observational study of the incidence and prognosis

BACKGROUND

Due to many different reasons such as possible coronavirus colonization in tonsillar tissue, decreased enzymatic antiviral activity, decreased cytokine activity from palatine tonsil tissue and reduced humoral and cellular immune response, tonsillectomy may alter the incidence of Covid-19.

AIMS/OBJECTIVES

To reveal the frequency of Covid-19 in patients who underwent tonsillectomy and to analyze the effect of tonsillectomy on the severity of the disease.

MATERIALS AND METHODS

Patients aged between 15 and 65 and had a history of tonsillectomy were compared with control group in terms of incidence and severity of Covid-19 disease.

RESULTS

A 4% Covid rRT-PCR test positivity rate was detected in patients with tonsillectomy whereas; it was 6.8% in the control group with a statistically significant difference. However, in terms of disease severity there was no difference between the two groups.

CONCLUSIONS AND SIGNIFICANCE

It has been proven that tonsillectomy surgery does not pose an additional risk in terms of COVID 19 disease severity. The positive effect of tonsillectomy in terms of disease frequency has been even demonstrated for the first time in the literature.

Relationship of endoplasmic reticulum stress with the etiopathogenesis of chronic tonsillitis and tonsillar hypertrophy in pediatric patients: a prospective, parallel-group study

OBJECTIVES

Tonsil tissue is a very important component of the human immunity system, contributing to the functioning of the cellular and humoral defence system, especially in childhood. The endoplasmic reticulum (ER) is an organelle that has a very important function in the balanced functioning of cells, in which the accumulation of a cellular protein called ER stress occurs in case of dysfunction. ER stress influences the pathogenesis of many diseases and immune system functions. We aimed to investigate the relation between the diseases of tonsil tissue and ER stress response to elucidate the mechanisms of diseases related with the immune system.

METHODS

A prospective study was conducted in 46 children aged between 2 and 16 years who underwent tonsillectomy for chronic tonsillitis or tonsillar hypertrophy. Tonsil tissue was separated into two groups according to their size and evaluated in terms of ER stress markers and apoptosis markers by Real-time PCR and Western blot analysis.

RESULTS

The ΔCT levels of ER stress markers (ATF4, ATF6, CHOP, GRP78, EIF2AK3, ERN1, GRP94) were greater in children with chronic tonsillitis (p < 0.005). In contrast, the tonsillar hypertrophy group had greater ΔCT levels of apoptosis markers (BAX, BCL-2) according to the Real-time PCR method (p < 0.005). According to the Western blot analysis, the normalized levels of ATF4, ATF6, CHOP, GRP78, and ERN1 genes were found greater in the chronic tonsillitis group than the tonsillar hypertrophy group. There was no difference between the two groups in terms of normalized BCL-2 and BAX levels by Western blot analysis.

CONCLUSION

This is the first study in the literature investigating the effect of the ER stress pathway on the etiopathogenesis of tonsil diseases. It was concluded that the ER stress pathway plays a role in the etiopathogenesis of chronic tonsillitis. Investigating the relationship between ER stress and structures such as the tonsil tissue that make up the immune system can help create new treatment strategies.

CLINICAL TRIAL REGISTRATION

Trial Registration ClinicalTrials.gov Identifier: NCT04653376.

Complexity of immune responses in COVID-19

The global COVID-19 pandemic has caused substantial morbidity and mortality to humanity. Remarkable progress has been made in understanding both the innate and adaptive mechanisms involved in the host response to the causative SARS-CoV-2 virus, but much remains to be discovered. Robust upper airway defenses are critical in restricting SARS-CoV-2 replication and propagation. Further, the nasal abundance of viral uptake receptor, ACE2, and the host epithelial transcriptional landscape, are associated with differential disease outcomes across different patient cohorts. The adaptive host response to systemic COVID-19 is heterogeneous and complex. Blunted responses to interferon and robust cytokine generation are hallmarks of the disease, particularly at the advanced stages. Excessive immune cell influx into tissues can lead to substantial collateral damage to the host akin to sepsis. This review offers a contemporary summary of these mechanisms of disease and highlights potential avenues for diagnostic and therapeutic development. These include improved disease stratification, targeting effectors of immune-mediated tissue damage, and blunting of immune cell-mediated tissue damage.