Long-term, low-dose macrolide antibiotic treatment in pediatric chronic airway diseases

Exploring the therapeutic potential of monoclonal antibodies targeting TSLP and IgE in asthma management

BACKGROUND

In recent years, there has been a growing interest in the utilization of biologic therapies for the management of asthma. Both TSLP and IgE are important immune molecules in the development of asthma, and they are involved in the occurrence and regulation of inflammatory response.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to gather information on anti-TSLP antibody and anti-IgE antibody.

RESULTS

This investigation elucidates the distinct mechanistic roles of Thymic Stromal Lymphopoietin (TSLP) and Immunoglobulin E (IgE) in the pathogenesis of asthma, with a particular emphasis on delineating the therapeutic mechanisms and pharmacological properties of monoclonal antibodies targeting IgE and TSLP. Through a meticulous examination of clinical trials involving paradigmatic agents such as omalizumab and tezepelumab, we offer valuable insights into the potential treatment modalities for diseases with shared immunopathogenic pathways involving IgE and TSLP.

CONCLUSION

The overarching objective of this comprehensive study is to delve into the latest advancements in asthma therapeutics and to provide guidance for future investigations in this domain.

A study on viruses and bacteria with particular interest on Mycoplasma pneumoniae in children with exacerbation of asthma from a tertiary care hospital in Sri Lanka

Asthma is a significant public health concern, particularly in children with severe symptoms. Exacerbation of asthma (EOA) is life-threatening, and respiratory infections (RIs) play a crucial role. Though viruses play a significant role in EOA, patients are empirically treated with antibiotics, contributing to antibiotic resistance development. Although there are widely reported associations of EOA with viral or Mycoplasma pneumoniae infections, there are no published data for Sri Lanka. The present study aimed to identify the association of common respiratory viruses, typical respiratory bacterial pathogens and M. pneumoniae in children with EOA and relate them with the compatibility of antimicrobial use. A case-control study was conducted in the paediatric unit of North Colombo Teaching Hospital, Sri Lanka, involving two groups of children between 5 and 15 years of age. Group 1 is children with EOA and Group 2 is children with stable asthma (SA). Each group consisted of 100 children. Sputum/throat swabs were tested for common respiratory viruses using virus-specific fluorescein isothiocyanate-labelled monoclonal antibodies (MAbs), bacteria by routine culture, and M. pneumoniae by real-time polymerase chain reaction. Macrolide resistance in M. pneumoniae was detected using conventional PCR and sequencing specific genetic mutations in the 23S rRNA gene. M. pneumoniae was genotyped using nested multilocus sequence typing, which targeted eight housekeeping genes (ppa, pgm, gyrB, gmk, glyA, atpA, arcC and adk). There was no significant difference in age, gender, demographic or geographical location between the two groups. In children with EOA, antibiotics were used in 66 % (66/100) and macrolides in 42 % (42/100). Samples comprised 78 % (78/100) sputum and 22 % (22/100) throat swabs. Adenovirus was the most common virus identified, and it was significantly higher in children with EOA compared to those with SA. Still, the two groups had no significant difference in typical bacteria findings. M. pneumoniae was detected in one patient with EOA, but none was detected in the SA group. The M. pneumoniae was macrolide-sensitive and ST14 by multilocus sequence typing. This study showed that the empiric use of antibiotics in children with asthma might be better targeted with prior pathogen screening to inform appropriate treatment to minimize antibiotic resistance.

Long-term, Low-Dose Oral Azithromycin Treatment for Chronic Severe Bilateral Blepharokeratoconjunctivitis in Pediatric Patients

PURPOSE

To evaluate the efficacy and safety of oral azithromycin treatment combined with topical antibiotic and anti-inflammatory agents in pediatric patients with chronic severe bilateral blepharokeratoconjunctivitis.

METHODS

Patients younger than 14 years with chronic and severe bilateral blepharokeratoconjunctivitis were reviewed retrospectively. Consecutive patients receiving oral azithromycin treatment were included. All patients received oral azithromycin (5 mg/kg/single dose daily) for at least 4 weeks combined with topical antibiotic and anti-inflammatory agents. Before and after the treatment, clinical symptoms were noted, and corneal and conjunctival fluorescein staining and corneal neovascularization were graded. Meibomian gland secretion and meibomian gland plugging were also assessed. All patients completed at least 3 months of follow-up after completion of the oral azithromycin treatment. Patients' clinical data at the time of diagnosis and last follow-up visit were statistically compared.

RESULTS

Twenty-nine children (58 eyes, mean age of 6.51 years) were included. The mean time of oral azithromycin use was 5.87 weeks (range: 4 to 10 weeks). Clinical symptoms and signs and visual acuity were significantly improved after treatment. The mean fluorescein staining and corneal neovascularization grades and meibomian gland secretion and meibomian gland plugging scores also improved after treatment (P < .001). Eyelid distortion or fornix shortening was not observed. At the last follow-up visit, all patients were stable with treatment only with daily eyelid hygiene, topical cyclosporine, and artificial tears.

CONCLUSIONS

Long-term, low-dose oral azithromycin combined with topical antibiotic and anti-inflammatory agents is an effective treatment option for pediatric patients with chronic severe bilateral blepharokeratoconjunctivitis. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].

Use of antimicrobials in pediatric wards of five Brazilian hospitals

The use of antimicrobials (AMs) in pediatric infections is common practice and use may be inappropriate leading to antimicrobial resistance. Off-label AM use is also common in this group and can result in drug-related problems. There is lack of DUR data in Brazil and in Latin America, specially for AM pediatric use. The aim of this study was to describe the utilization of AMs in hospitalized children in five hospitals in Brazil. We conducted an observational study of the utilization of AMs in pediatric wards in hospitals in the states of Ceará (CE), Sergipe (SE), Rio de Janeiro (RJ), Rio Grande do Sul (RS) and the Federal District (DF). Data derived from patient medical records and prescriptions were collected over a six-month period in each hospital. The number of AMs used by each patient was recorded, and AM use was assessed using Days of therapy (DOT) and Length of therapy (LOT) per 1000 patient days according to different patient characteristics. Off-label (OL) use was described according to age. The study analyzed data from 1020 patients. The sex and age distributions were similar across the five hospitals. However, differences were found for comorbidities, history of ICU admission and length of hospital stay. The most common diseases were respiratory tract infections. There were wide variations in DOT/1000PD (278-517) and LOT/1000PD (265-390). AM utilization was highest in the hospital in SE. The consumption of second-generation penicillins and cephalosporins was high. The prevalence of OL use of AMs was higher for patients in the RJ hospital, in infants, in patients who underwent prolonged hospital stays, and in patients who used multiple AMs. The AM that showed the highest prevalence of OL use was azithromycin, in both oral and parenteral formulations. Overall AM use was high and showed differences in each setting, possibly influenced by local characteristics and by prescribing standards adopted by pediatricians.

Systematic Review and Meta-analysis: Macrolide in the Treatment of Chronic Rhinosinusitis After Endoscopic Sinus Surgery

OBJECTIVES

To evaluate the efficacy and safety of macrolide antibiotics therapy in patients with chronic rhinosinusitis (CRS) receiving endoscopic sinus surgery.

DATA SOURCES

PubMed, Web of Science, Embase, and Cochrane Library.

REVIEW METHODS

The electronic databases were comprehensively searched on June 2, 2022, for randomized controlled trials on macrolide antibiotics in the treatment of patients undergoing CRS endoscopic surgery. The primary outcome measures were the sinonasal outcome test (SNOT) score and the visual analog scale (VAS) score. The secondary outcome measures were the nasal endoscopy score (NES), the sinus computed tomography score, and adverse events.

RESULTS

A total of 8 studies were included, involving 606 patients who used macrolide for a long time. Meta-analysis showed that no significant difference was observed in SNOT (standardized mean difference [SMD] = -0.13; 95% confidence interval [CI]: -0.38 to 0.13, I2  = 0%) and VAS (SMD = -0.10; 95% CI, -0.88 to 0.68, I2  = 81%) between the macrolide and placebo groups. However, macrolide outperformed the placebo in improving NES (SMD = -0.32; 95% CI, -0.62 to -0.03, I2  = 21%). The use of macrolide did not increase the incidence of adverse events.

CONCLUSION

Long-term use of macrolide after CRS surgery may not significantly improve the quality of life and disease severity of the patients but may play a role in improving postoperative NES in patients with CRS. There is still no sufficient evidence to determine whether the disease phenotype of CRS or the patient's race will affect the efficacy of long-term use of macrolide after CRS.

[Recent research on the relationship between pulmonary microbiome and asthma endotypes in children]

Bronchial asthma is not considered a singular disease, but rather a collection of syndromes with multiple phenotypes and mechanisms that involve various signaling pathways. It typically emerges during the preschool years, and its etiology is intricate and diverse. In recent years, the advancement of high-throughput sequencing technology has revealed that early alterations in lung microbiota may be associated with asthma incidence and progression. Moreover, significant variations in lung microbiota have been observed among different airway inflammation profiles, known as asthma endotypes. Hence, a comprehensive understanding of the characteristics of lung microbiota in children with asthma can aid in managing disease progression and improving long-term prognosis. Additionally, such insights may spark novel approaches to diagnosing and treating childhood asthma.

Surveillance of Antimicrobial Prescriptions in Community Pharmacies Located in Tokyo, Japan

An antimicrobial resistance (AMR) Action Plan was launched in 2016 to prevent the spread of antimicrobial-resistant bacteria in Japan. Additional support for the appropriate use of pediatric antimicrobial agents was initiated in 2018 to promote the appropriate use of antimicrobial agents in the community. To evaluate the effectiveness of the AMR Action Plan in the community, we investigated antimicrobial prescriptions in community pharmacies. Data on prescriptions for antimicrobial agents dispensed in 42 community pharmacies located in the Tama district, Tokyo, Japan, were collected between April 2013 and December 2019. In this study, we employed the DPY, which was calculated as defined daily doses (DDDs)/1000 prescriptions/year. The DPY is the number of antimicrobial agents used (potency) per 1000 antimicrobial prescriptions dispensed in pharmacies per year. The number of prescriptions for third-generation cephalosporins, fluoroquinolones, and macrolides decreased after the initiation of the AMR Action Plan; the DPYs of these antimicrobial agents decreased significantly by 31.4%, increased by 15.8%, and decreased by 23.6%, respectively (p < 0.05). The number of antimicrobial prescriptions for pediatric patients has been decreasing since 2018. Declines in the DPYs of third-generation cephalosporins, fluoroquinolones, and macrolides were higher in pediatric pharmacies than in other pharmacies. Our data suggest that the AMR Action Plan and additional support for the appropriate use of antimicrobial agents in children influenced the number of antimicrobial prescriptions in community pharmacies in Japan.

The Impact of Long-Term Macrolide Exposure on the Gut Microbiome and Its Implications for Metabolic Control

Long-term low-dose macrolide therapy is now widely used in the treatment of chronic respiratory diseases for its immune-modulating effects, although the antimicrobial properties of macrolides can also have collateral impacts on the gut microbiome. We investigated whether such treatment altered intestinal commensal microbiology and whether any such changes affected systemic immune and metabolic regulation. In healthy adults exposed to 4 weeks of low-dose erythromycin or azithromycin, as used clinically, we observed consistent shifts in gut microbiome composition, with a reduction in microbial capacity related to carbohydrate metabolism and short-chain fatty acid biosynthesis. These changes were accompanied by alterations in systemic biomarkers relating to immune (interleukin 5 [IL-5], IL-10, monocyte chemoattractant protein 1 [MCP-1]) and metabolic (serotonin [5-HT], C-peptide) homeostasis. Transplantation of erythromycin-exposed murine microbiota into germ-free mice demonstrated that changes in metabolic homeostasis and gastrointestinal motility, but not systemic immune regulation, resulted from changes in intestinal microbiology caused by macrolide treatment. Our findings highlight the potential for long-term low-dose macrolide therapy to influence host physiology via alteration of the gut microbiome. IMPORTANCE Long-term macrolide therapy is widely used in chronic respiratory diseases although its antibacterial activity can also affect the gut microbiota, a key regulator of host physiology. Macrolide-associated studies on the gut microbiota have been limited to short antibiotic courses and have not examined its consequences for host immune and metabolic regulation. This study revealed that long-term macrolides depleted keystone bacteria and impacted host regulation, mediated directly by macrolide activity or indirectly by alterations to the gut microbiota. Understanding these macrolide-associated mechanisms will contribute to identifying the risk of long-term exposure and highlights the importance of targeted therapy for maintenance of the gut microbiota.

Severe pediatric asthma endotypes: current limits and future perspectives

INTRODUCTION

Although rare, pediatric severe therapy-resistant asthma (STRA) is a highly heterogeneous, resource-demanding disease that differs significantly from severe adult asthma and whose pathogenesis is still poorly understood.

AREAS COVERED

This review summarizes the latest 10 years of English-written studies defining pediatric STRA endotypes using lung-specific techniques such as bronchoalveolar lavage and endobronchial biopsy. Results of the studies and limits on the field are discussed, together with some future perspectives.

EXPERT OPINION

Over the years, it has become increasingly clear that 'one size does not fit all" in asthma. However, "Does an extremely tailored size fit more than one?'. Only using multicentric, longitudinal pediatric studies, will we be able to answer. Three issues could be particularly critical for future research. First, to provide, if existing, a distinction between prepuberal STRA and puberal STRA endotypes to understand the transition from pediatric to adult STRA and to design effective, tailored therapies in adolescents, usually suffering from poorer asthma control. Second, design early treatments for pediatric airway remodeling to preserve lifelong good lung function. Finally, to better characterize inflammation before and during biological therapies, to provide clues on whether to stop or change treatments.

The Mechanism of Action and Clinical Efficacy of Low-Dose Long-Term Macrolide Therapy in Chronic Rhinosinusitis

Various chronic inflammatory airway diseases can be treated with low-dose, long-term (LDLT) macrolide therapy. LDLT macrolides can be one of the therapeutic options for chronic rhinosinusitis (CRS) due to their immunomodulatory and anti-inflammatory actions. Currently, various immunomodulatory mechanisms of the LDLT macrolide treatment have been reported, as well as their antimicrobial properties. Several mechanisms have already been identified in CRS, including reduced cytokines such as interleukin (IL)-8, IL-6, IL-1β, tumor necrosis factor-α, transforming growth factor-β, inhibition of neutrophil recruitment, decreased mucus secretion, and increased mucociliary transport. Although some evidence of effectiveness for CRS has been published, the efficacy of this therapy has been inconsistent across clinical studies. LDLT macrolides are generally believed to act on the non-type 2 inflammatory endotype of CRS. However, the effectiveness of LDLT macrolide treatment in CRS is still controversial. Here, we reviewed the immunological mechanisms related to CRS in LDLT macrolide therapy and the treatment effects according to the clinical situation of CRS.

Bacterial resistance to antibacterial agents: Mechanisms, control strategies, and implications for global health

The spread of bacterial drug resistance has posed a severe threat to public health globally. Here, we cover bacterial resistance to current antibacterial drugs, including traditional herbal medicines, conventional antibiotics, and antimicrobial peptides. We summarize the influence of bacterial drug resistance on global health and its economic burden while highlighting the resistance mechanisms developed by bacteria. Based on the One Health concept, we propose 4A strategies to combat bacterial resistance, including prudent Application of antibacterial agents, Administration, Assays, and Alternatives to antibiotics. Finally, we identify several opportunities and unsolved questions warranting future exploration for combating bacterial resistance, such as predicting genetic bacterial resistance through the use of more effective techniques, surveying both genetic determinants of bacterial resistance and the transmission dynamics of antibiotic resistance genes (ARGs).

Prescribed daily-dose-based metrics of oral antibiotic use for hospitalized children in Japan

OBJECTIVE

Defined daily-dose (DDD)-based metrics are frequently used to measure antibiotic consumption. However, they are unsuitable for the pediatric population because they are defined using the maintenance dose for 70-kg adults. Moreover, children have large body weight variations. We assessed the prescribed daily dose (PDD) and PDD-based metrics of oral antibiotics for children to develop an alternative to DDD-based metrics in Japan.

DESIGN

We performed observational study using data from the Japanese administrative claims database between April 2018 and March 2019.

METHODS

Of 453,001 patients (aged 1 month-15 years), 564,326 admissions to 1,159 hospitals were included. We showed the median PDD (mg/day and mg/kg/day) and PDD-based metrics for 8 antibiotics for each age category (1 month to <1 year old and 1-6, 7-12, and 13-15 years old). We also assessed the relationship between PDD-based metrics and days of therapy (DOT)-based metrics using a scatter plot and correlation.

RESULTS

In total, 86,389 patients (19.1%) were prescribed oral antibiotics; amoxicillin, macrolides, and third-generation cephalosporins were the most common. The PDD (mg/day) for each antibiotic increased with age to 7-12 years old, when an adult dose was reached. The PDD (mg/kg/day) decreased with age to 13-15 years old, due to increasing body weight. The relationship between PDD per 1,000 patient days and DOT per 1,000 patient days differed depending on the antibiotic.

CONCLUSIONS

PDD-based metrics stratified by age could characterize antibiotic consumption, even with body-weight variations. Therefore, PDD-based metrics, in addition to DOT-based metrics, are helpful benchmarks for antibiotic use in children.

Ocular Rosacea microBiome Study (ORBS)-sub-microbial versus antibiotic dosing of doxycycline versus placebo in treatment of symptomatic ocular rosacea: study protocol for a parallel-arm randomized clinical trial

BACKGROUND

Ocular rosacea is common and is often managed with long-term antibiotic treatment. Doxycycline is the most commonly selected antibiotic for the treatment of rosacea. As there is no established standard of care treatment dose for rosacea, prescribed doses of doxycycline vary widely. The FDA classifies 40 mg daily dose of doxycycline for ocular rosacea as sub-microbial in comparison to an antibiotic dose of 200 mg daily. However, this "sub-microbial" dose has never been evaluated in patients with ocular rosacea, and even the sub-microbial dose has potential to alter systemic mucosa flora. Here, we present a randomized controlled trial using RNA sequencing to fully characterize the impact of sub-microbial antibiotic dosing of doxycycline on antimicrobial resistance and bacterial composition of the ocular and gut flora.

METHODS

In a triple-masked parallel randomized control trial, patients with ocular rosacea will be randomized to three arms: a 40-mg dose of doxycycline, a 200-mg antibiotic dose of doxycycline, or placebo. Collected rectal and lower eyelid samples will be compared for frequency of antimicrobial resistance genetic determinants and microbiome diversity. A subjective ocular surface disease index survey and objective tear breakup time measurement will be determined.

DISCUSSION

These results will enhance our understanding of the overall systemic impact of long-term systemic sub-microbial antibiotic dosing for the treatment of chronic recurrent ocular inflammatory diseases.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.org (NCT05296837) on March 22, 2022.

Pyroptosis and respiratory diseases: A review of current knowledge

Pyroptosis is a relatively newly discovered programmed cell death accompanied by an inflammatory response. In the classical view, pyroptosis is mediated by caspases-1,-4,-5,-11 and executed by GSDMD, however, recently it was demonstrated that caspase-3 and-8 also participate in the process of pyroptosis, by cleaving GSDMD/E and GSDMD respectively. Different from autophagy and apoptosis, many pores are formed on the cell membrane during pyroptosis, which makes the cell membrane lose its integrity, eventually leading to the release of cytokines interleukin(IL)-1β and IL-18. When the body is infected with pathogens or exposed to some stimulations, pyroptosis could play an immune defense role. It is found that pyroptosis exists widely in infectious and inflammatory respiratory diseases such as acute lung injury, bronchial dysplasia, chronic obstructive pulmonary disease, and asthma. Excessive pyroptosis may accompany airway inflammation, tissue injury, and airway damage, and induce an inflammatory reaction, leading to more serious damage and poor prognosis of respiratory diseases. This review summarizes the relationship between pyroptosis and related respiratory diseases.