Long-term Macrolide Treatment Research Articles

Long-term macrolide treatment for non-cystic fibrosis bronchiectasis in children: a meta-analysis

Recurrent bacterial infection causes frequent bronchiectasis (BE) exacerbations. The effectiveness and safety of long-term administration of macrolides in BE remain controversial, especially in children who require minimal treatment to prevent exacerbation. We conducted this meta-analysis to determine the usefulness of long-term macrolide use in pediatric BE. We searched PubMed, Cochrane Library databases, Embase, KoreaMed, Igaku Chuo Zasshi, and Chinese National Knowledge Infrastructure databases. We identified randomized controlled trials (RCTs) which elucidated long-term macrolide treatment (≥ 4 weeks) in non-cystic fibrosis BE in children aged < 18 years. The primary outcome was frequency of acute exacerbation; secondary outcomes included changes in pulmonary function, sputum scores, and adverse events including bacterial resistance. We included four RCTs. Long-term macrolide treatment showed a significant decrease in the frequency of exacerbation (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.10–0.87), mean number of exacerbations per patient (mean difference, − 1.40; 95% CI, − 2.26 to − 0.54), and sputum purulence score (mean difference, − 0.78; 95% CI, − 1.32 to − 0.24). However, long-term macrolide treatment was accompanied by an increased carriage of azithromycin-resistant bacteria (OR, 7.13). Long-term macrolide administration prevents exacerbation of BE in children; however, there are risks of increasing antibiotic resistance. Benefits and risks should be weighed and determined on a patient-by-patient basis.

Favorable Response to Long-Term Azithromycin Therapy in Bronchiectasis Patients with Chronic Airflow Obstruction Compared to Chronic Obstructive Pulmonary Disease Patients without Bronchiectasis.

PurposeLong-term macrolide treatment is recommended for patients with chronic obstructive pulmonary disease (COPD) with frequent exacerbations. Bronchiectasis is a common comorbid condition in patients with COPD, for which long-term azithromycin is effective in preventing exacerbation. This study aimed to compare the effect of long-term azithromycin between bronchiectasis patients with chronic airflow obstruction (CAO) and COPD patients without bronchiectasis.Patients and MethodsPatients with CAO who received azithromycin for more than 12 weeks were retrospectively identified at a single referral hospital. CAO was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7, and bronchiectasis was determined using computed tomography. The development of exacerbation and symptom improvement were compared between bronchiectasis patients with CAO and COPD patients without bronchiectasis.ResultsA total of 59 patients (43 in bronchiectasis with CAO group vs 16 in COPD without bronchiectasis group) were included in this study. Compared to COPD patients without bronchiectasis, those in bronchiectasis with CAO group were younger, more likely to be female, and never smokers. There was no difference in the previous exacerbation history or FEV1 between the two groups. The median duration of azithromycin treatment was 15 months (interquartile range, 8–25 months). At the 12-month follow-up, the development of ≥2 moderate or ≥1 severe exacerbations was significantly lower in bronchiectasis with CAO group than in COPD without bronchiectasis group (46.5% vs 87.5%, P = 0.005). The proportion of patients with symptom improvement determined by the COPD assessment test score was also significantly higher in bronchiectasis with CAO group than COPD without bronchiectasis group at the 12-month follow-up (68.2% vs 16.7%, P = 0.004).ConclusionBronchiectasis patients with CAO could benefit more from long-term azithromycin treatment than COPD patients without bronchiectasis.

Neutrophil extracellular traps, disease severity, and antibiotic response in bronchiectasis: an international, observational, multicohort study

Bronchiectasis is predominantly a neutrophilic inflammatory disease. There are no established therapies that directly target neutrophilic inflammation because little is understood of the underlying mechanisms leading to severe disease. Neutrophil extracellular trap (NET) formation is a method of host defence that has been implicated in multiple inflammatory diseases. We aimed to investigate the role of NETs in disease severity and treatment response in bronchiectasis. In this observational study, we did a series of UK and international studies to investigate the role of NETs in disease severity and treatment response in bronchiectasis. First, we used liquid chromatography-tandem mass spectrometry to identify proteomic biomarkers associated with disease severity, defined using the bronchiectasis severity index, in patients with bronchiectasis (n=40) in Dundee, UK. Second, we validated these biomarkers in two cohorts of patients with bronchiectasis, the first comprising 175 patients from the TAYBRIDGE study in the UK and the second comprising 275 patients from the BRIDGE cohort study from centres in Italy, Spain, and UK, using an immunoassay to measure NETs. Third, we investigated whether pathogenic bacteria had a role in NET concentrations in patients with severe bronchiectasis. In a separate study, we enrolled patients with acute exacerbations of bronchiectasis (n=20) in Dundee, treated with intravenous antibiotics for 14 days and proteomics were used to identify proteins associated with treatment response. Findings from this cohort were validated in an independent cohort of patients who were admitted to the same hospital (n=20). Fourth, to assess the potential use of macrolides to reduce NETs in patients with bronchiectasis, we examined two studies of long-term macrolide treatment, one in patients with bronchiectasis (n=52 from the UK) in which patients were given 250 mg of azithromycin three times a week for a year, and a post-hoc analysis of the Australian AMAZES trial in patients with asthma (n=47) who were given 500 mg of azithromycin 3 times per week for a year. Sputum proteomics identified that NET-associated proteins were the most abundant and were the proteins most strongly associated with disease severity. This finding was validated in two observational cohorts, in which sputum NETs were associated with bronchiectasis severity index, quality of life, future risk of hospital admission, and mortality. In a subgroup of 20 patients with acute exacerbations, clinical response to intravenous antibiotic treatment was associated with successfully reducing NETs in sputum. Patients with Pseudomonas aeruginosa infection had a lessened proteomic and clinical response to intravenous antibiotic treatment compared with those without Pseudomonas infections, but responded to macrolide therapy. Treatment with low dose azithromycin was associated with a significant reduction in NETs in sputum over 12 months in both bronchiectasis and asthma. We identified NETs as a key marker of disease severity and treatment response in bronchiectasis. These data support the concept of targeting neutrophilic inflammation with existing and novel therapies. Scottish Government, British Lung Foundation, and European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC).

Impact of Bronchiectasis on Incident Nontuberculous Mycobacterial Pulmonary Disease: A 10-Year National Cohort Study

Impact of Bronchiectasis on Incident Nontuberculous Mycobacterial Pulmonary Disease: A 10-Year National Cohort Study

Neutrophil Extracellular Traps are Increased in Severe Bronchiectasis and Reduced by Long-Term Azithromycin Treatment

Background: Bronchiectasis is predominantly a neutrophilic inflammatory disease. There are no established therapies that directly target neutrophilic inflammation because of a lack of understanding of the underlying mechanisms leading to severe disease. Neutrophil extracellular trap (NET) formation is a mode of host defence that has been implicated in multiple inflammatory diseases. Methods: We conducted a series of UK and international studies to investigate the role of NETs in disease severity and treatment response in bronchiectasis. Nano LC/MS-MS was used to identify proteomic markers associated with disease severity, defined using the bronchiectasis severity index (BSI) (n=40). These were validated in two cohorts (n=175 and n=275) using a validated immunoassay to measure NETs. 20 patients with acute exacerbations of bronchiectasis were treated with intravenous antibiotics for 14 days and proteomics used to identify proteins associated with treatment response. Two studies of long-term macrolide treatment, one in bronchiectasis and a post-hoc analysis of the AMAZES trial in asthma, investigated the effect of macrolide treatment on NETs. Findings: 96 proteins were differentially expressed in sputum between severe and mild bronchiectasis. The most abundant and most discriminating were proteins known to be NET proteins. This was validated in two observational cohorts where sputum NETs were associated with BSI, quality of life, lung function, future risk of hospital admissions and mortality. Antibiotic treatment in 20 patients was associated with 23 significantly down-regulated and 16 up-regulated proteins, with the “neutrophil degranulation” pathway being most strongly implicated in response. Patients with Pseudomonas aeruginosa infection had a blunted proteomic and clinical response to treatment. Treatment with low dose azithromycin was associated with a significant reduction in NETs in sputum over 12 months in both bronchiectasis and asthma. Interpretation: NETs are identified as a key marker of disease severity and treatment response in bronchiectasis. Funding: Supported by the Scottish Government Chief Scientist Office (Senior Clinical Fellowship to JDC) and British Lung Foundation through the BLF Chair of Respiratory Research. Supported by the European Bronchiectasis Network (EMBARC), a European Respiratory Society Clinical Research Collaboration. Declaration of Interests: None to declare Ethics Approval Statement: The studies were approved by local research ethics committees and patients provided informed consent.

Update on pharmacotherapy for adult bronchiectasis

Bronchiectasis refers to abnormal dilatation of the bronchi, which leads to the failure of mucus clearance and increased risk of infection. Pharmacotherapy for stable bronchiectasis includes oral or inhaled mucoactive agents, anti-inflammatory therapy, inhaled bronchodilators, long-term antibiotics, and long-term macrolide treatment. Among them, mucoactive agents are the most common adjunctive agents to airway clearance techniques. When patients with impaired lung function suffer from dyspnea, inhaled bronchodilators may be prescribed to relieve the symptom. Long-term macrolide treatment has been proven to prevent exacerbation in patients with frequent bronchiectasis exacerbation. If exacerbation occurs despite the above mentioned treatments, one or two weeks of antibiotics should be prescribed to cover respiratory bacteria that include &lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt;. Because evidence supporting the use of pharmacotherapy for bronchiectasis is weak, further research is warranted.

Long-term macrolide antibiotics for the treatment of bronchiectasis in adults: an individual participant data meta-analysis

Bronchiectasis guidelines recommend long-term macrolide treatment for patients with three or more exacerbations per year without Pseudomonas aeruginosa infection. Randomised controlled trials suggest that long-term macrolide treatment can prevent exacerbations in adult patients with bronchiectasis, but these individual studies have been too small to do meaningful subgroup analyses. We did a systematic review and individual patient data (IPD) meta-analysis to explore macrolide benefit in subpopulations, including those in which macrolide therapy is not currently recommended. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science from Jan 1, 2000, to Sept 30, 2018, to identify double blind, randomised, placebo-controlled trials of macrolide antibiotics in adult patients with bronchiectasis. We applied no language restrictions. Randomised controlled trials were eligible if treatment was defined a priori as long term and had a primary or secondary outcome of bronchiectasis exacerbations. Studies in patients with cystic fibrosis bronchiectasis were excluded. The primary outcome of the meta-analysis was frequency of exacerbations requiring treatment with antibiotics. Secondary endpoints were time to first exacerbation, change in quality of life according to the St George's Respiratory Questionnaire (SGRQ), and change in FEV1. IPD meta-analysis was done using fixed effects models adjusting for age, sex, FEV1, and trial. We did prespecified subgroup analyses for each of the primary and secondary endpoints using one-step meta-analysis only. Subgroups were defined by age, sex, previous exacerbation frequency, smoking status, inhaled corticosteroid use at baseline, body-mass index at baseline, cause, C-reactive protein at baseline, baseline FEV1 percentage of predicted, SGRQ total score, and Pseudomonas aeruginosa in sputum culture at baseline. The meta-analysis is registered with the PROSPERO international register of systematic reviews, number CRD42018102908. Of 234 identified studies, we included three randomised controlled trials, and IPD was obtained for 341 participants. Macrolide antibiotics reduced the frequency of exacerbations (adjusted incidence rate ratio [IRR] 0·49, 95% CI 0·36 to 0·66; p<0·0001). We also found that macrolide treatment improved the time to first exacerbation (adjusted hazard ratio 0·46, 0·34 to 0·61; p<0·0001) and was associated with improved quality of life measured by the SGRQ (mean improvement 2·93 points, 0·03 to 5·83; p=0·048). Macrolides were not associated with a significant improvement in FEV1 (67 mL at 1 year, -22 to 112; p=0·14). Effect estimates in prespecified subgroup analyses revealed a reduced frequency of exacerbations in all prespecified subgroups, including a high level of benefit in patients with P aeruginosa infection (IRR 0·36, 0·18-0·72; p=0·0044) and in patients with one to two exacerbations per year (0·37, 0·16-0·88; p=0·025). Studies were rated as low risk of bias across all domains. Long-term macrolide treatment significantly reduces the frequency of exacerbations in patients with bronchiectasis, with similar benefits observed in all subgroups based on patient characteristics. This finding suggests that macrolides might be considered in patients in whom macrolides are not indicated according to the current guidelines, particularly if alternative approaches to reduce exacerbations have been unsuccessful. However, downsides of long-term macrolide treatment must also be taken into account. European Respiratory Society.

Long-term macrolide treatment for the prevention of acute exacerbations in COPD: a systematic review and meta-analysis.

BackgroundAcute exacerbation of COPD (AECOPD) is associated with an increased hospitalization and mortality. Azithromycin and erythromycin are the recommended drugs to reduce the risk of exacerbations. However, the most suitable duration of therapy and drug-related adverse events are still a matter of debate. The aim of this meta-analysis was to assess the current evidence regarding the efficacy and safety of long-term macrolide treatment for COPD.Materials and methodsWe comprehensively searched PubMed, Embase, the Cochrane Library, and the Web of Science and performed a systematic review and cumulative meta-analysis of all randomized controlled trials (RCTs) and retrospective studies.ResultsEleven RCTs and one retrospective study including a total of 2,151 cases were carried out. Long-term macrolide treatment significantly reduced the total number of cases with one or more exacerbations (OR=0.40; 95% CI=0.24–0.65; P<0.01) and the rate of exacerbations per patient per year (risk ratio [RR]=0.60; 95% CI=0.45–0.78; P<0.01). Subgroup analyses showed that the minimum duration for drug efficacy for both azithromycin and erythromycin therapy was 6 months. In addition, macrolide therapy could improve the St George Respiratory Questionnaire (SGRQ) total score (P<0.01) but did not achieve the level of clinical significance. The frequency of hospitalizations was not significantly different between the treatment and control groups (P=0.50). Moreover, chronic azithromycin treatment was more likely to increase adverse events (P<0.01).ConclusionProphylactic azithromycin or erythromycin treatment has a significant effect in reducing the frequency of AECOPD in a time-dependent manner. However, long-term macrolide treatment could increase the occurrence of adverse events and macrolide resistance. Future large-scale, well-designed RCTs with extensive follow-up are required to identify patients in whom the benefits outweigh risks.

The effect of long-term macrolide treatment on respiratory microbiota composition in non-cystic fibrosis bronchiectasis: an analysis from the randomised, double-blind, placebo-controlled BLESS trial

Long-term macrolide treatment has proven benefit in inflammatory airways diseases, but whether it leads to changes in the composition of respiratory microbiota is unknown. We aimed to assess whether long-term, low-dose erythromycin treatment changes the composition of respiratory microbiota in people with non-cystic fibrosis bronchiectasis. Microbiota composition was determined by 16S rRNA gene sequencing of sputum samples from participants in the BLESS trial, a 12-month, double-blind, placebo-controlled trial of twice-daily erythromycin ethylsuccinate (400 mg) in adult patients with non-cystic fibrosis bronchiectasis and at least two infective exacerbations in the preceding year. The primary outcome was within-patient change in respiratory microbiota composition (assessed by Bray-Curtis index) between baseline and week 48, comparing erythromycin with placebo. The BLESS trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12608000460303. The BLESS trial took place between Oct 15, 2008, and Dec 14, 2011. Paired sputum samples were available from 86 randomly assigned patients, 42 in the placebo group and 44 in the erythromycin group. The change in microbiota composition between baseline and week 48 was significantly greater with erythromycin than with placebo (median Bray-Curtis score 0·52 [IQR 0·14-0·78] vs 0·68 [0·46-0·93]; median difference 0·16, 95% CI 0·01-0·33; p=0·03). In patients with baseline airway infection dominated by Pseudomonas aeruginosa, erythromycin did not change microbiota composition significantly. In those with infection dominated by organisms other than P. aeruginosa, erythromycin caused a significant change in microbiota composition (p=0·03 [by analysis of similarity]), representing a reduced relative abundance of Haemophilus influenzae (35·3% [5·5-91·6] vs 6·7% [0·8-74·8]; median difference 12·6%, 95% CI 0·4-28·3; p=0·04; interaction p=0·02) and an increased relative abundance of P aeruginosa (0·02% [0·00-0·33] vs 0·13% [0·01-39·58]; median difference 6·6%, 95% CI 0·1-37·1; p=0·002; interaction p=0·45). Compared with placebo, erythromycin reduced the rate of pulmonary exacerbations over the 48 weeks of the study in patients with P. aeruginosa-dominated infection (median 1 [IQR 0-3] vs 3 [2-5]; median difference -2, 95% CI -4 to -1; p=0·01), but not in those without P. aeruginosa-dominated infection (1 [0-2] vs 1 [0-3]; median difference 0, -1 to 0; p=0·41; interaction p=0·04). Long-term erythromycin treatment changes the composition of respiratory microbiota in patients with bronchiectasis. In patients without P. aeruginosa airway infection, erythromycin did not significantly reduce exacerbations and promoted displacement of H. influenzae by more macrolide-tolerant pathogens including P. aeruginosa. These findings argue for a cautious approach to chronic macrolide use in patients without P. aeruginosa airway infection. Mater Adult Respiratory Research Trust Fund.

Long-term macrolide treatment for chronic respiratory disease

Long-term macrolide treatment was first shown to alter the natural history of diffuse panbronchiolitis (DPB) in the late 1980s. Since then, macrolides have been demonstrated to exert anti-inflammatory and immunomodulatory activity in addition to being antimicrobial. Indeed, their spectrum of action extends to the regulation of leukocyte function and production of inflammatory mediators, control of mucus hypersecretion, resolution of inflammation and modulation of host defence mechanisms. As such, the potential benefit of macrolide antibiotics has been evaluated in a variety of chronic respiratory diseases. The best studied condition is cystic fibrosis, of which there have been six randomised controlled trials showing evidence of benefit. However, most of the studies were limited by small numbers of patients and short follow-up. More recently, landmark studies have demonstrated the efficacy of azithromycin in reducing the risk of acute exacerbations in patients with chronic obstructive pulmonary disease, but the optimal duration and dosing of macrolide treatment remain uncertain. With the exception of patients with DPB and cystic fibrosis, until clear evidence of efficacy is available, the long-term use of macrolides should be limited to highly selected patients after careful evaluation of benefit and harm, or in the context of randomised controlled clinical trials.

Immunomodulatory and Clinical Effects of Long-Term Low-Dose Macrolide Treatment of Chronic Rhinosinusitis with Nasal Polyposis

Immunomodulatory and Clinical Effects of Long-Term Low-Dose Macrolide Treatment of Chronic Rhinosinusitis with Nasal PolyposisImmunomodulatory treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP) by macrolide antibiotics represents a challenging alternative to conventional therapy and surgery, still being at the very beginning. Immune and inflammatory processes in nasal and paranasal sinus mucosa, crucial in the etiopathogenesis of nasal polyps (NPs) are reflected in levels of various local mediators, found both in mucosa and nasal fluid. In this prospective study, we assessed the immunomodulatory and clinical effects of longterm low-dose oral macrolide treatment in the management of CRSwNP. Twenty-two (n = 22) nonasthmatic, nonallergic patients with CRSwNP were administered clarithromycin (CAM) 500 mg/day single oral dose for eight weeks. We measured the levels of proinflammatory cytokines TNF-α, TNF-β, and IL-1β, Th1 cytokines IL-2, IL-12, and IFN-γ, Th2 cytokines IL-4, IL-5, IL-6, and IL-10, and chemokine IL-8 in the nasal fluid samples, before and after treatment, using a flow cytometric method. We also scored each of the 22 patients before and after therapy according to Tsicopoulos' global nasal symptom score and Malm's endoscopic score. Following treatment, we found significantly reduced levels of IL-8 (p&lt;0.01) and TNF-α (p&lt;0.01) in nasal secretions. Macrolide therapy decreased the size of polyps in 45.45% of the patients. We concluded that long-term low-dose treatment with CAM was effective in the management of CRSwNP. We suggest that macrolides can be an alternative to topical and systemic corticosteroids in the management of CRSwNP.

INFLUENCE OF ALLERGY ON THE IMMUNOMODULATORY AND CLINICAL EFFECTS OF LONG-TERM LOW-DOSE MACROLIDE TREATMENT OF NASAL POLYPOSIS

Cytokine levels in nasal secretions reflect the inflammatory status of the nasal and paranasal sinus mucosa and the development of mucosal disease. The results of previous investigations suggest that macrolide antibiotics can be effective in treatment of chronic rhinosinusitis and nasal polyposis. The aim of this prospective study was to compare the immunomodulatory and clinical effects of long-term low-dose macrolide treatment of nonatopic and atopic patients with nasal polyposis. Forty (n = 40) patients with nasal polyposis, 22 allergic and 18 nonallergic were administered clarithromycin (CAM) 500 mg/day single oral dose for eight weeks. We measured the levels of proinflammatory Th1 cytokines TNF-α and IL-1β, Th2 cytokines IL-4, IL-5 and IL-6, and chemokine IL-8 in the nasal fluid samples, before and after treatment, using flow cytometric method. We also scored each of the 40 patients before and after therapy according to nasal symptom score and endoscopic score. Following treatment, we found significantly reduced levels of IL-8 (p<0.01) and TNF-α (p<0.01) in nasal secretions in nonallergic patients. In subjects with nasal polyposis and allergy, we found decreased levels of IL-8 (p<0.01), IL-6 (p<0.05) and IL-1β (p<0.01). Macrolide therapy decreased the size of polyps in 45.45% of nonatopic and in 50% of atopic patients. After macrolide treatment, we found 67.83% patients in nonallergic group and 55.55% patients in allergic group with improved nasal symptoms. Long-term low-dose treatment with CAM was effective in the management of nasal polyposis. Our results showed that macrolide treatment of nasal polyposis have different immunomodulatory and similar clinical effects in allergic and nonallergic patients.

Clinical Similarities and Differences Between Human T-Cell Lymphotropic Virus Type 1-Associated Bronchiolitis and Diffuse Panbronchiolitis

Human T-cell lymphotropic virus type 1 (HTLV-1)-associated bronchiolitis and diffuse panbronchiolitis might overlap. We examined whether these conditions can be differentiated by comparing their clinical features and the effect of long-term macrolide treatment. Fifty-eight Japanese patients, including 15 with HTLV-1-associated bronchiolitis and 43 with diffuse panbronchiolitis. Both conditions were clinically compared using the clinical criteria for diffuse panbronchiolitis, including findings from CT scans and BAL fluid testing. Pulmonary function, blood gas levels, and cold hemagglutinin (CHA) levels were assessed before and after long-term treatment with macrolides. Interleukin-2 receptor (IL-2R) expression in T cells obtained from the BAL fluid of patients with HTLV-1-associated bronchiolitis or diffuse panbronchiolitis was analyzed by flow cytometry. Clinical, laboratory, radiologic, and bacterial features were strikingly similar in both groups, except for the fact that patients with HTLV-1-associated bronchiolitis had a higher ratio of IL-2R-positive cells in the BAL fluid. The histopathologic features were also similar. Long-term treatment with macrolides improved PaO(2), FEV(1), and CHA in patients with HTLV-1-associated bronchiolitis to a lesser extent than in those with diffuse panbronchiolitis, and PaO(2) and FEV(1) in the group of patients with HTLV-1-associated bronchiolitis who had high IL-2R levels did not respond after therapy. These findings showed that the clinicopathologic features of the two conditions are quite similar, suggesting that diffuse panbronchiolitis is a chronic pulmonary manifestation of HTLV-1 infection. However, HTLV-1-associated bronchiolitis might be associated with conditions that are distinct from those of diffuse panbronchiolitis based on the different responses to macrolide treatment and the difference in the number of activated T cells bearing IL-2R in the lungs.

Effects of macrolides on interleukin-8 secretion from human nasal epithelial cells.

Low-dose, long-term macrolide treatment has recently been reported to be very effective in patients with chronic airway diseases. We examined the in vivo and in vitro effects of 14-membered macrolide antibiotics erythromycin (EM) and clarithromycin (CAM) on interleukin (IL)-8 secretion from human nasal epithelial cells. Fifteen patients with chronic sinusitis received macrolide treatment (CAM 400 mg/day) for 1 to 3 months. The number of infiltrated neutrophils and IL-8 concentrations in the nasal discharges of these patients decreased significantly at 1 to 2 months after the treatment. In vitro effects of EM and CAM on IL-8 secretion were examined in nasal epithelial cells cultured at the air-liquid interface. After 14-day culture in the air-liquid interface, macrolide antibiotics were added in medium for 24 h. EM and CAM at concentrations of 10(-4) M did not affect spontaneous secretions or IL-1 beta-induced secretions of IL-8 either apically or basolaterally. When cells were preincubated with 10(-4) M CAM for 7 days, the IL-1 beta-induced secretion of IL-8 decreased significantly. However, no difference was observed between the effects of 10(-4) M CAM and 10(-4) M josamycin, a 16-membered macrolide. These results suggest that macrolide treatment inhibits neutrophil infiltration and IL-8 secretion in nasal epithelium in vivo and that these clinical effects depend on a mechanism other than the direct action of macrolide on nasal epithelial cells.

耳管狭窄に対するマクロライドの効果

The efficacy of low-dose long-term macrolide for treatment of intractable eustachian tube (ET) stenosis in 20 patients (21 ears) with otitis media with effusion or chronic suppurative otitis media was evaluated. A single daily dose (400-500mg) of erythromycin or clarithromycin was administered for 2-7 months, and ET function was assessed by a modified inflation-deflation test or catheter inflation before and after the course of medication. ET stenosis improved in 10 of the 21 ears (47.6%). The rate of improvement was higher in patients with chronic sinusitis than in those without chronic sinusitis. These results indicate that low-dose long-term macrolide treatment may be useful for treatment of intractable ET stenosis.

Effect of New Macrolide Roxithromycin upon Nasal Polyps Associated with Chronic Sinusitis

We often observe shrinkage of nasal polyps with low-dose long-term macrolide treatment, which was recently developed in Japan for the treatment of intractable chronic sinusitis. In order to assess the efficacy of this treatment for nasal polyps, we administered the new macrolide roxithromycin (RXM) (1 tablet: 150 mg a day) for at least 8 weeks to 20 patients with nasal polyps associated with chronic sinusitis. It was competent in controlling nasal polyp with the overall incidence of improvement being 52%. The combination of RXM with azelastine (1 mg twice/day), an inhibitor of mediator release, was examined in 20 other patients. It augmented the rate of improvement to 68%, but the increase was not significant. The incidence of improvement increased with time after the start of medication in both groups. Smaller polyps were more likely to decrease in size, but some larger polyps also markedly decreased in size. Associated allergic conditions and the extent of eosinophilic infiltration had no relation to the treatment result. We speculate that the mechanism of effectiveness of RXM is through its suppressive potency in cytokine production from inflammatory cells.