Erythromycin inhibits respiratory glycoconjugate secretion from human airways in vitro

Nonantimicrobial Actions of Macrolides: Overview and Perspectives for Future Development

Macrolides are among the most widely prescribed broad spectrum antibacterials, particularly for respiratory infections. It is now recognized that these drugs, in particular azithromycin, also exert time-dependent immunomodulatory actions that contribute to their therapeutic benefit in both infectious and other chronic inflammatory diseases. Their increased chronic use in airway inflammation and, more recently, of azithromycin in COVID-19, however, has led to a rise in bacterial resistance. An additional crucial aspect of chronic airway inflammation, such as chronic obstructive pulmonary disease, as well as other inflammatory disorders, is the loss of epithelial barrier protection against pathogens and pollutants. In recent years, azithromycin has been shown with time to enhance the barrier properties of airway epithelial cells, an action that makes an important contribution to its therapeutic efficacy. In this article, we review the background and evidence for various immunomodulatory and time-dependent actions of macrolides on inflammatory processes and on the epithelium and highlight novel nonantibacterial macrolides that are being studied for immunomodulatory and barrier-strengthening properties to circumvent the risk of bacterial resistance that occurs with macrolide antibacterials. We also briefly review the clinical effects of macrolides in respiratory and other inflammatory diseases associated with epithelial injury and propose that the beneficial epithelial effects of nonantibacterial azithromycin derivatives in chronic inflammation, even given prophylactically, are likely to gain increasing attention in the future. SIGNIFICANCE STATEMENT: Based on its immunomodulatory properties and ability to enhance the protective role of the lung epithelium against pathogens, azithromycin has proven superior to other macrolides in treating chronic respiratory inflammation. A nonantibiotic azithromycin derivative is likely to offer prophylactic benefits against inflammation and epithelial damage of differing causes while preserving the use of macrolides as antibiotics.

The development of diffuse panbronchiolitis during the treatment with long-term, low-dose clarithromycin for chronic sinusitis

Diffuse panbronchiolitis (DPB) is a progressive inflammatory airway disease characterized by a chronic cough, copious sputum expectation, dyspnea, and chronic sinusitis. Owing to the long-term treatment of low-dose macrolides, the prognosis has been remarkably improved. However, in some cases, patients are refractory to macrolides, and the subsequent treatment strategies are controversial. We herein present a patient with the onset of DPB during treatment with long-term, low-dose clarithromycin (CAM) for chronic sinusitis who was successfully treated by switching to long-term treatment with normal-dose CAM. We should recognize that DPB may develop in patients with chronic sinusitis despite treatment with a long-term, low-dose macrolide. We also propose that increasing the dose of macrolide may be a useful strategy for treating refractory patients.

Erythromycin Inhibits Adhesion of Pseudomonas Aeruginosa and Branhamella Catarrhalis to Human Nasal Epithelial Cells

Ciliated epithelial cells were obtained from nasal polyps. Bacterial adherence to these cells was compared for the ability to bind Hemophilus influenzae, Pseudomonas aeruginosa, and Branhamella catarrhalis in the presence of 10–5 M erythromycin, which was comparable with a physiologically attainable concentration in the nasal secretion and the maxillary sinus mucosa. Quantification of bacterial adherence showed the strongest ability of P. aeruginosa to the cells. Erythromycin has an inhibitory effect on adherence of P. aeruginose and B. catarrhalis to the nasal epithelial cell. Our findings suggest that the reduced adherence to the host cell is one of the underlying mechanisms to account for efficacy of erythromycin treatment in respiratory disorders.

Airway Gland Structure and Function

Submucosal glands contribute to airway surface liquid (ASL), a film that protects all airway surfaces. Glandular mucus comprises electrolytes, water, the gel-forming mucin MUC5B, and hundreds of different proteins with diverse protective functions. Gland volume per unit area of mucosal surface correlates positively with impaction rate of inhaled particles. In human main bronchi, the volume of the glands is ∼ 50 times that of surface goblet cells, but the glands diminish in size and frequency distally. ASL and its trapped particles are removed from the airways by mucociliary transport. Airway glands have a tubuloacinar structure, with a single terminal duct, a nonciliated collecting duct, then branching secretory tubules lined with mucous cells and ending in serous acini. They allow for a massive increase in numbers of mucus-producing cells without replacing surface ciliated cells. Active secretion of Cl(-) and HCO3 (-) by serous cells produces most of the fluid of gland secretions. Glands are densely innervated by tonically active, mutually excitatory airway intrinsic neurons. Most gland mucus is secreted constitutively in vivo, with large, transient increases produced by emergency reflex drive from the vagus. Elevations of [cAMP]i and [Ca(2+)]i coordinate electrolyte and macromolecular secretion and probably occur together for baseline activity in vivo, with cholinergic elevation of [Ca(2+)]i being mainly responsive for transient increases in secretion. Altered submucosal gland function contributes to the pathology of all obstructive diseases, but is an early stage of pathogenesis only in cystic fibrosis.

Effects of long-term use of macrolides in patients with non-cystic fibrosis bronchiectasis: a meta-analysis of randomized controlled trials

Background

The purpose of this study was to evaluate the clinical benefits and safety of the long-term use of macrolides in patients with non-cystic fibrosis (non-CF) bronchiectasis.

Methods

Embase, Pubmed, the Cochrane Library and Web of Science databases were searched from inception up to March 2014. The primary outcome was the improvement of exacerbations of bronchiectasis. Secondary endpoints included changes of microbiology, lung function, quality of life, sputum volume, adverse events and macrolide resistance.

Results

The literature search yielded 139 studies, ten of which containing 601 patients were included in this meta-analysis. Macrolides showed a statistically-significant improvement in reducing acute exacerbations per patient during follow-up treatment (RR = 0.55, 95% CI: 0.47, 0.64, P < 0.001), increasing the number of patients free from exacerbations (OR = 2.81, 95% CI: 1.85, 4.26, P < 0.001), and prolonging time to a first exacerbation (HR = 0.38, 95% CI: 0.28, 0.53, P < 0.001). Macrolides maintenance treatment was superior to control with respect to attenuating FEV1 decline (p = 0.02), improving sputum volume (p = 0.009) and SGRQ total scores (p = 0.02), but showed a higher risk of adverse events, especially diarrhea (OR = 5.36; 95% CI: 2.06, 13.98, P = 0.0006). Eradication of pathogens was improved in the macrolide group (OR = 1.76, 95% CI: 0.91, 3.41, P = 0.09), while pathogen resistance caused by macrolides dramatically increased (OR = 16.83, 95% CI: 7.26, 38.99, P < 0.001). The new appearance of a microbiologic profile or participant withdrawal due to adverse events showed no significant differences between the two groups.

Conclusion

In patients with non-CF bronchiectasis, macrolide maintenance treatment can effectively reduce frequency of exacerbations, attenuate lung function decline, decrease sputum volume, improve quality of life, but may be accompanied with increased adverse events (especially diarrhea) and pathogen resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-0872-5) contains supplementary material, which is available to authorized users.

Combination therapy for airflow limitation in COPD

Abstract

Background and the purpose of the study

Existing evidence confirms that no pharmacologic agent ameliorates the decline in the lung function or changes the prognosis of chronic obstructive pulmonary disease (COPD). We tried a critical combination therapy for management of COPD.

Methods

Current or past smoker (passive or active) COPD patients with moderate to severe COPD who did not respond to primitive therapy (i.e., oral prednisolone (50 mg in the morning) for 5 days; with Beclomethasone Fort (3 puff q12h, totally 1500 micrograms/day), Salmeterol (2 puffs q12h, 50 micrograms/puff) and ipratropium bromide (4 puffs q8h) for two months, enrolled to study. Furthermore they were received N-Acetylcysteine (1200 mg/daily), Azithromycin (tablet 250 mg/every other day) and Theophylline (100 mg BD).

Results

The study group consisted of 44 men and 4 women, with a mean age and standard deviation of 63.6 ± 12.7 years (range 22–86 years). Thirteen of 48 patients (27.0%) was responder based on 15% increasing in FEV 1 (27.7 ± 7.9) after 6.7 ± 6.1 months (57.9 ± 12.9 year old). There were statistically significant differences in age and smoking between responders and non-responders (P value was 0.05 and 0.04 respectively). There was no difference in emphysema and air trapping between two groups (p = 0.13).

Conclusion

Interestingly considerable proportion of patients with COPD can be reversible using combination drug therapy and patients will greatly benefit from different and synergic action of the drugs. The treatment was more effective in younger patients who smoke less.

Diffuse Panbronchiolitis

Diffuse panbronchiolitis (DPB) is characterized by chronic sinobronchial infection and diffuse bilateral micronodular pulmonary lesions consisting of inflammatory cells. Studies on disease etiology point to a genetic predisposition unique to Asians. Early therapy for DPB was largely symptomatic. The advent of macrolide antibiotics, including erythromycin, roxithromycin and clarithromycin, has strikingly changed disease prognosis. Low-dose, long-term macrolide therapy for DPB originated from detailed observations of response to therapy in a single patient. The bactericidal activity of macrolides, particularly erythromycin, is not a significant factor for their clinical efficacy in DPB. Firstly, irrespective of bacterial clearance, clinical improvement is observed in patients treated with erythromycin. Secondly, even in cases with bacterial superinfection with Pseudomonas aeruginosa resistant to macrolides, treatment has proved effective. Thirdly, the recommended dosage of macrolides produces peak levels in tissue that are below the minimum inhibitory concentrations for major pathogenic bacteria that colonize the airway. In the last two decades, the possible mechanism underlying the effectiveness of macrolide therapy has been extensively studied. The proposed mechanism of action includes inhibition of excessive mucus and water secretion from the airway epithelium, inhibition of neutrophil accumulation in the large airway, inhibition of lymphocyte and macrophage accumulation around the small airway, and modulation of bacterial virulence. The great success of macrolide therapy in diffuse panbronchiolitis may extend its application to the treatment of other chronic inflammatory disorders. If the anti-inflammatory activity of macrolides is independent of their bactericidal effect, new anti-inflammatory macrolides without antimicrobial activity should be developed to minimize emergence of macrolide-resistant micro-organisms.

A case of refractory chronic respiratory tract infection due to Pseudomonas aeruginosa successfully controlled by combination of clarithromycin and azithromycin

The prognosis of patients with chronic respiratory tract infections, especially diffuse panbronchiolitis, is remarkably improved by long-term administration of low-dose macrolides. However, in some cases, patients are refractory to macrolide treatment and show a low or no response; therefore, new treatment strategies are required. Here we present a patient refractory to either single low-dose clarithromycin or azithromycin but responded remarkably to the combination usage of both macrolides.

Clarithromycin inhibits interleukin-13-induced goblet cell hyperplasia in human airway cells

IL-13 is a T-helper class 2 cytokine that induces goblet cell hyperplasia and mucus production in airway epithelial cells. Because macrolide antibiotics are known to have immunomodulatory and mucoregulatory properties, the aim of this study was to examine the effect of clarithromycin on IL-13-induced goblet cell hyperplasia and mucin hypersecretion in normal human bronchial epithelial (NHBE) cells. NHBE cells were cultured to differentiation at an air-liquid interface with IL-13 plus clarithromycin or vehicle. Histochemical analysis was performed using H&E staining, periodic acid-Schiff (PAS) staining, and MUC5AC immunostaining. MUC5AC synthesis was assayed using RT-PCR and ELISA. Western blotting was used to evaluate signaling pathways. IL-13 significantly increased the number of PAS-positive, MUC5AC-positive goblet cells, and this was significantly attenuated by clarithromycin at concentrations greater than 8 μg/ml (P < 0.01). Clarithromycin also dose-dependently decreased MUC5AC mRNA expression induced by IL-13 (P < 0.001), and, at 24 μg/ml, clarithromycin significantly attenuated the amount of MUC5AC protein in cell supernatants (P < 0.01). Western blotting showed that clarithromycin affected IL-13 receptor janus kinase signal transducers, activators of transcription6 (STAT6), and epidermal growth factor receptor mitogen-activated protein kinase signaling and that inhibition of these pathways by clarithromycin decreased goblet cell hyperplasia via nuclear factor-κB inactivation. We conclude that clarithromycin inhibits goblet cell hyperplasia and may directly regulate mucus secretion by IL-13 in NHBE cells.

Mechanisms of action and clinical application of macrolides as immunomodulatory medications

Macrolides have diverse biological activities and an ability to modulate inflammation and immunity in eukaryotes without affecting homeostatic immunity. These properties have led to their long-term use in treating neutrophil-dominated inflammation in diffuse panbronchiolitis, bronchiectasis, rhinosinusitis, and cystic fibrosis. These immunomodulatory activities appear to be polymodal, but evidence suggests that many of these effects are due to inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and nuclear factor kappa B (NF-kappaB) activation. Macrolides accumulate within cells, suggesting that they may associate with receptors or carriers responsible for the regulation of cell cycle and immunity. A concern is that long-term use of macrolides increases the emergence of antimicrobial resistance. Nonantimicrobial macrolides are now in development as potential immunomodulatory therapies.

Nasopharyngeal flora and drug susceptibility in children with macrolide therapy

OBJECTIVES/HYPOTHESIS

Low-dose, long-term administration of macrolides (macrolide therapy) has been used as an effective treatment for chronic respiratory tract diseases. The authors reported on the nasopharyngeal flora in children treated with macrolide therapy.

STUDY DESIGN

Prospective study.

METHODS

Nasopharyngeal cultures were obtained from 73 children with chronic rhinosinusitis and/or otitis media with effusion at the end of the low-dose administration of clarithromycin (macrolide group). As control subjects, 98 children with chronic rhinosinusitis and/or otitis media with effusion who were not given macrolides were also included in the study. The culture results were evaluated with respect to antimicrobial susceptibility patterns, risk factors for carriage of erythromycin-resistant Streptococcus pneumoniae, and the clinical efficacy of the therapy.

RESULTS

The macrolide therapy did not have a significant effect on the incidence or the susceptibility patterns of potential pathogens except for Moraxella catarrhalis. Most of children in the macrolide group possessed a normal flora compared with the control children. The risk factors for carriage of erythromycin-resistant S pneumoniae were male gender in the macrolide group and age under 6 years and use of antimicrobial drugs other than macrolides in the control group. The clinical efficacy of the therapy was independent of carriage of erythromycin-resistant S pneumoniae.

CONCLUSION

Macrolide therapy has little effect on carriage of drug-resistant pathogens, and the efficacy of the therapy depends on the anti-inflammatory effect of the drugs, which is independent of their antimicrobial effect.

[Usefulness of macrolides as anti-inflammatories in respiratory diseases]

The macrolides are antibiotics that, besides their anti-bacterial action, have an anti-inflammatory effect, by decreasing the activity of the immune cells and bacteria cell changes. An increase the survival of patients suffering from diffuse panbronchiolitis was already seen in the 1980s, after being treated with erythromycin. Currently, the use of macrolides in various chronic inflammatory diseases has increased significantly. Clinical improvements associated to the administration of macrolides have been observed in diseases such as, cystic fibrosis, asthma, and bronchiectasis. However, despite the apparent clinical benefit they seem to provide, the published results up until now are controversial and conclusive results are unable to be obtained. This means that further clinical trials are necessary to confirm or refute the long-term use of these drugs, which are not free of adverse effects, mainly the appearance of resistant bacteria.

Rokitamycin induces a mitochondrial defect and caspase-dependent apoptosis in human T-cell leukemia Jurkat cells

Macrolides are a well-known family of oral antibiotics whose antibacterial spectrum of activity covers most relevant bacterial species responsible for respiratory infectious disease. In recent years, it has been reported that macrolides have not only bactericidal activity but also direct immunomodulating activity in mammals. In this study, we observed new physiological activity of macrolides and examined whether various macrolides induce apoptosis in human leukemia cell lines. We investigated the effects of 13 different macrolides on the viability of Jurkat and HL-60 cells. Among all the macrolides used in this study, rokitamycin, a semisynthetic macrolide with a 16-member ring, effectively induced cell death. Rokitamycin induced DNA fragmentation and caspase activation, resembling the progression of apoptosis. Moreover, rokitamycin reduced the mitochondrial transmembrane potential and released cytochrome c from mitochondria to the cytosol, suggesting that mitochondrial perturbation is involved in rokitamycin-induced apoptosis. These results suggest that rokitamycin possesses not only bactericidal activity but also pro-apoptotic activity in human leukemia cells.

Concentrated ambient ultrafine particle exposure induces cardiac changes in young healthy volunteers

RATIONALE

Exposure to ambient ultrafine particles has been associated with cardiopulmonary toxicity and mortality. Adverse effects specifically linked to ultrafine particles include loss of sympathovagal balance and altered hemostasis.

OBJECTIVES

To characterize the effects of acute exposure to ambient ultrafine particles in young healthy humans.

METHODS

Nineteen healthy nonsmoking male and female subjects between the ages of 18 and 35 were exposed to filtered air or to an atmosphere in which captured ultrafine (<0.16 microm) particles were concentrated by a factor of up to 20-fold over ambient levels with the use of particle concentrators fitted with size-selective outlets (ultrafine concentrated ambient particles [UFCAPs]). Subjects underwent bronchoalveolar lavage 18 hours after each exposure. Cardiovascular endpoints measured included pulmonary function, clinical chemistry, and hematological parameters, as well as heart rate variability and repolarization indices.

MEASUREMENTS AND MAIN RESULTS

Exposure to UFCAPs was statistically associated with an increase in frequency domain markers of heart rate variability, specifically indicative of elevated vagal input to the heart. Consistent with this finding were increases in the variance associated with the duration of the QT interval. In addition, UFCAP exposure resulted in a significant increase in blood levels of the fibrin degradation product D-dimer as well as a modest elevation in the inflammatory chemokine IL-8 recovered in the lavage fluid.

CONCLUSIONS

These findings show mild inflammatory and prothrombic responses and are suggestive of alterations in cardiac repolarization induced by UFCAP inhalation.

Macrolide antibiotics as immunomodulatory medications: proposed mechanisms of action

Macrolide antibiotics administered in sub-antimicrobial doses improve pulmonary function and decrease exacerbation frequency for persons with diffuse panbronchiolitis or cystic fibrosis. Data also suggest a beneficial effect of macrolide antibiotics in the treatment of steroid dependent asthma. Many potential immunomodulatory effects of macrolide antibiotics have been reported including the ability to down-regulate prolonged inflammation, decreasing airway mucus secretion, inhibiting bacterial biofilm, decreasing the production of reactive oxygen species, inhibiting neutrophil activation and mobilization, accelerating neutrophil apoptosis, and blocking the activation of nuclear transcription factors. Macrolides initially decrease, then increase, and have finally a sustained suppression of cytokine secretions from normal human bronchial epithelial cells through inhibition and activation of extracellular signal-regulated kinases (ERK) and then reversibly retard cell proliferation probably through ERK. Consistent with this, macrolide antibiotics possibly reduce mucin production as well as neutrophil migration by interfering with ERK signal transduction.

Is there a role for inhaled corticosteroids and macrolide therapy in bronchiectasis?

Bronchiectasis is characterised by permanent dilatation of the bronchi that arises from chronic inflammation predominantly caused by bacterial infection. This condition remains a major cause of excess respiratory morbidity and treatment is generally only partly successful. There is an urgent need for improved anti-inflammatory medication to treat bronchiectasis. Two potentially useful therapies are inhaled corticosteroids (ICS) and macrolides. The clinical trials that have been performed in bronchiectasis with these two medications can be considered to be preliminary data. This article reviews the anti-inflammatory properties, clinical efficacy and adverse effects of ICS and macrolides.ICS have a large number of potent anti-inflammatory properties. ICS remain the first-line treatment in asthma, reduce exacerbations in chronic obstructive pulmonary disease, and may improve lung function and symptoms in cystic fibrosis (CF). Four small clinical trials have assessed the effect of high-dose ICS on bronchiectasis. The main reported effect of these trials was a reduction in sputum volume and this may be a marker of decreased airway inflammation. Other possible benefits included decreased cough and sputum inflammatory cells/biomarkers. ICS have a relatively high prevalence of local adverse effects, and may be associated with ocular complications and osteoporosis. These adverse effects can be minimised by prescribing low doses of the medication. Macrolides have both antibacterial and immunomodulatory properties. Macrolides have less marked immunosuppressive properties than corticosteroids, and effects include decreasing mucous production, inhibiting virulence factors and biofilm formation of Pseudomonas aeruginosa, decreasing leukocyte numbers and altering inflammatory mediator release. Macrolides have been shown to be extremely effective in the treatment of diffuse panbronchiolitis, improve lung function and symptoms in asthma and CF, and reduce nasal polyps and secretions in sinusitis. Five small clinical trials have assessed the effect of macrolides on bronchiectasis. Reported benefits include reduced sputum volume, improved lung function and better symptom control. Macrolides are generally well tolerated, although they do have a number of drug interactions. There are concerns about the development of resistance, especially to non-tuberculous mycobacteria, with prolonged macrolide use. The evidence available suggests that both medications have a role in the management of bronchiectasis. More definitive trials of ICS and macrolides in bronchiectasis will clarify the likely benefit of these therapies.

Mycoplasma pneumoniae and its role in asthma

Mycoplasma pneumoniae (M pneumoniae), primarily recognised as a causative agent of community-acquired pneumonia has recently been linked to asthma. An infection with M pneumoniae may precede the onset of asthma or exacerbate asthma symptoms. Chronic infection with M pneumoniae has been suspected to play a part in some patients with asthma. The role of immunoglobulin E-related hypersensitivity and induction of T helper type 2 immune response leading to inflammatory response in M pneumoniae-infected patients with asthma have also been proposed. Use of macrolides in reducing asthma symptoms only in M pneumoniae-infected patients supports the use of macrolides in patients with asthma having M pneumoniae infection. As macrolides are both antimicrobial and anti-inflammatory drugs, the therapeutic role of their biphasic nature in reducing asthma symptoms needs further attention in clinical research.

The role of airway secretions in COPD--clinical applications

It has been established that mucus hypersecretion and decreased mucus clearance contribute to the morbidity of chronic obstructive pulmonary disease (COPD). Indeed, the classic definition of chronic bronchitis relies on determining the frequency and duration of sputum expectoration. Despite the well recognized importance of this symptom, there are few therapies routinely used to decrease the sputum production or to improve clearance. There are fewer well conducted clinical trials of existing medications and this has led many regulatory agencies, notably the Food and Drug Administration (FDA), to refuse to register these medications or approve their sale. Similarly, airway clearance devices and chest physical therapy have not been well studied in COPD. Carefully conducted studies of interventions to improve airway clearance, similar to those done in cystic fibrosis (CF), may help us to identify effective therapies and possibly novel diagnostic tests for the management of COPD.

Diffuse panbronchiolitis in East Asia

Diffuse panbronchiolitis is characterized by chronic sinobronchial infection and diffuse bilateral centrilobular lesions consisting of peribronchial infiltration of inflammatory cells. At present, it is known that diffuse panbronchiolitis is relatively restricted to East Asia. This uneven distribution is suspected to be highly associated with genetic predisposition located between human leucocyte antigen-A and -B loci. Low-dose, long-term macrolide therapy for the disease was suggested from a detailed observation of a single case that significantly improved by erythromycin therapy. Otherwise simple bactericidal activity of macrolides has been assumed as a candidate because of their clinical effect on the pathogenesis. In the last 10 years, the possible mechanism underlying the effectiveness of macrolide therapy has been dynamically investigated. To understand the pathological features and potential targets for macrolides in diffuse panbronchiolitis, the authors introduce the incidence of diffuse panbronchiolitis in East Asia, the profile of the disease and then trace the history of macrolide therapy in this review. The proposed mechanism of action includes the inhibition of excessive mucus and water secretion from the airway, the inhibition of neutrophil, and sometimes of lymphocyte and macrophage accumulating in the airway, the inhibition of transcription factors expressing several cytokines and the attenuation of bacterial virulence. Intracellular mechanisms of the action of macrolide are a hot topic of interest in research. The anti-inflammatory activity of macrolides is independent of their bactericidal effect, and a new anti-inflammatory analogue without antimicrobial activity should be developed to minimize the emergence of macrolide-resistant microorganisms and to maintain the safety of this treatment.

Effects of claritromycin on inflammatory parameters and clinical conditions in children with bronchiectasis1

BACKGROUND

The effects of the macrolides cannot be ascribed to their antibacterial action alone. Their immunoregulatory and anti-inflammatory functions are significant too. They are frequently used in the treatment of diffuse panbronchiolitis and cystic fibrosis (CF).

AIM

To evaluate the effects of a macrolide antibiotic [clarithromycin (CAM)] on the process of inflammation [by measuring IL-8, TNF-alpha, IL-10 levels and cell profiles in bronchoalveolar lavage (BAL) fluid], pulmonary function and sputum production in children with steady-state bronchiectasis, secondary to causes other than CF or primary immunodeficiencies.

METHODS

Seventeen patients randomized to the treatment group received CAM and supportive therapies for 3 months and 17 patients in the control group were given supportive therapies only.

RESULTS

Compared with the control group, the treatment group showed a significant decrease in IL-8 levels, total cell count, neutrophil ratios in BAL fluid and daily sputum production at the end of the third month. There was also a significant increase in the treatment group's BAL fluid macrophage ratios. The differences in pulmonary function test parameters were not significant.

CONCLUSION

Use of CAM in children with steady-state bronchiectasis results in laboratory improvement by reducing the inflammatory processes in the lungs. No corresponding clinical improvement could be shown but although this is possible with long-term use, trial validation is necessary.

Therapeutic approaches to mucus hypersecretion

Mucolytic and related agents have been in use since prehistoric times. Although widely prescribed and used extensively in over-the-counter preparations, their efficacy and mechanisms of action remain in doubt. These agents belong to several distinct chemical classes. Mucolytic agents such as N-acetyl-cysteine are thiols with a free-sulfhydryl group. They are assumed to break disulfide bonds between gel-forming mucins and thus reduce mucus viscosity. Mucokinetic agents are thiols with a blocked sulfhydryl group. Expectorants such as guaifenesin increase mucus secretion. They may act as irritants to gastric vagal receptors, and recruit efferent parasympathetic reflexes that cause glandular exocytosis of a less viscous mucus mixture. Cough may be provoked. This combination may flush tenacious, congealed mucopurulent material from obstructed small airways and lead to a temporary improvement in dyspnea or the work of breathing. The roles of anticholinergic agents, DNase, and other drugs are also discussed with regard to their roles in reducing mucus production in rhinitis and other airway diseases.

Macrolides and airway inflammation in children

For more than 20 years macrolide antibiotics have been used to treat chronic inflammatory airway diseases based on their immunomodulatory activity. Macrolide antibiotics down-regulate damaging prolonged inflammation as well as increase mucus clearance, decrease bacterial virulence and prevent biofilm formation. Initially shown to decrease morbidity and mortality in diffuse panbronchiolitis and in steroid-dependent asthma, long-term macrolide therapy has now been shown to significantly reduce exacerbations and improve lung function and quality of life in children with cystic fibrosis. They have also proven beneficial in Japanese children and adults with chronic sinobronchitis especially when there is nasal polyposis. Long-term macrolides have also proven clinically beneficial in some patients with plastic bronchitis. Adverse reactions are few and generally self-limited when used at the recommended dosage for immunomodulation.

Mediators of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem that is now a leading cause of death. COPD is associated with a chronic inflammatory response, predominantly in small airways and lung parenchyma, which is characterized by increased numbers of macrophages, neutrophils, and T lymphocytes. The inflammatory mediators involved in COPD have not been clearly defined, in contrast to asthma, but it is now apparent that many lipid mediators, inflammatory peptides, reactive oxygen and nitrogen species, chemokines, cytokines, and growth factors are involved in orchestrating the complex inflammatory process that results in small airway fibrosis and alveolar destruction. Many proteases are also involved in the inflammatory process and are responsible for the destruction of elastin fibers in the lung parenchyma, which is the hallmark of emphysema. The identification of inflammatory mediators and understanding their interactions is important for the development of anti-inflammatory treatments for this important disease.

Long-term macrolide antibiotic therapy in the treatment of chronic small airway disease clinically mimicking diffuse panbronchiolitis

OBJECTIVE

In the current studies, we investigated the clinical effects of long-term macrolide antibiotic therapy for patients with chronic small airway disease (CAD) that clinically and radiologically mimics but is pathologically distinct from diffuse panbronchiolitis (DPB).

PATIENTS AND METHODS

Twenty-one Japanese patients were selected on the basis of clinical criteria for DPB and were categorized as DPB or CAD following histological evaluation of surgical lung biopsies. All patients received long-term macrolide therapy, and therapeutic results were compared for the DPB and CAD groups.

RESULTS

Clinical, laboratory, radiological, and bacterial features, as well as neutrophilia in bronchoalveolar lavage fluid were strikingly similar in both groups. Long-term treatment with macrolides improved the clinical symptoms and PaO(2) in both groups. There was a significant improvement in forced expiratory volume in one second (FEV(1)), vital capacity (VC), and %VC in patients with DPB but not in patients with CAD. Neutrophilia in bronchoalveolar lavage fluid was also reduced following therapy in DPB patients but was refractory in CAD patients.

CONCLUSION

Based on the different responses to macrolides, CAD might be associated with conditions distinct from those of DPB. Nevertheless, low-dose macrolide therapy may be applied in CAD to achieve clinical improvement, such as in respiratory symptoms and PaO(2).

Antibiotic-induced apoptosis in human activated peripheral lymphocytes

Long-term administration of macrolide antibiotics reduced the number of lymphocytes in bronchoalveolar lavage fluid in patients with chronic airway inflammatory disease. To evaluate the inflammatory activity of macrolides, their effect on apoptosis of activated lymphocytes isolated from human peripheral blood was compared with that of other antibiotics. Macrolides, including clarithromycin and azithromycin, at a final concentration of 100 microg/ml accelerated apoptosis of activated lymphocytes, while other antibiotics such as fosfomycin sodium, beta-lactams--ceftazidime, piperacillin sodium and biapenem, and a quinolone, ofloxacin, did not cause significant induction of apoptosis. Our results suggest that 14- or 15-membered ring macrolides are specifically involved in the augmentation of apoptosis of activated lymphocytes, and this may be of value therapeutically for chronic airway diseases.

Macrolide antibiotics induce apoptosis of human peripheral lymphocytes in vitro

We previously reported that long-term administration of macrolides (MCL) reduced the number of lymphocytes in bronchoalveolar lavage fluid (BALF) of patients with chronic lower respiratory tract disease. To investigate the anti-inflammatory activity of macrolides, we evaluated their effect on apoptosis of lymphocytes isolated from human peripheral blood. Lymphocytes treated with clarithromycin, azithromycin and josamycin at a final concentration of 200 microg/ml showed positive staining for Annexin V, Fas and Fas ligand using flow cytometry with time at 12-72 h, while other antibiotics did not. Our results suggest that macrolides induce apoptosis of lymphocytes through Fas-Fas ligand pathway and could potentially reduce the number of lymphocytes in the lungs of patients with chronic lower respiratory tract disease.

Anti-inflammatory effects of macrolides—an underappreciated benefit in the treatment of community-acquired respiratory tract infections and chronic inflammatory pulmonary conditions?

BACKGROUND

It has been recognized for more than 20 years that the macrolides have immunomodulatory effects that are beneficial for those suffering from chronic pulmonary inflammatory syndromes, such as diffuse panbronchiolitis, cystic fibrosis, asthma and bronchiectasis. The macrolides have consistently been associated with decreased length of stay and mortality when used alone or in combination with beta-lactam antibiotics. This effect can be demonstrated against combinations consisting of beta-lactams and other antibiotics active against 'atypical chest pathogens' when treating community-acquired pneumonia (CAP) in hospitalized patients. As such, it appears that the macrolides' effects in CAP patients are more than just antibacterial in nature. AIMS OF THIS REVIEW: This review aims: to give the reader information on the background areas described, as well as related areas; to review the CAP benefits with macrolides and how they may be related to the immunomodulatory properties they demonstrate, albeit in a shorter period of time than previously demonstrated with chronic pulmonary disorders; to use ex vivo data to support these extrapolations.

LITERATURE SEARCH

A literature search using Medline was conducted from 1966 onwards, searching for articles with relevant key words such as macrolide, diffuse panbronchiolitis, community-acquired pneumonia, biofilm, immunomodulation, cystic fibrosis, erythromycin, clarithromycin, roxithromycin and azithromycin, bronchiectasis and asthma. When appropriate, additional references were found from the bibliographies of identified papers of interest. Any relevant scientific conference proceedings or medical texts were checked when necessary.

CONCLUSIONS

(1) Research into macrolide immunomodulation for chronic pulmonary disorders demonstrates consistent positive effects, although of types other than seen with diffuse panbronchiolitis. These effects, together with their inhibitory activity on biofilms, have the potential to make them a useful option. (2) The benefits for CAP are consistent, and higher when a macrolide is given with another atypical agent than if the other atypical agent is given alone, suggesting a non-antibacterial benefit. (3) Recent research of the immunomodulatory properties of azithromycin imply that azithromycin may have a previously unknown short-term biphasic effect on inflammation modulation: enhancement of host defence mechanisms shortly after initial administration followed by curtailment of local infection/inflammation in the following period. (4) Additional in vivo research is needed prior to developing any firm conclusions.

Clinical implications of the immunomodulatory effects of macrolides

Macrolide antibiotics are known for their efficacy in treating acute airway infections, but just as importantly, they are also effective anti-inflammatory agents. Their anti-inflammatory properties have been studied most thoroughly in chronic inflammatory airway diseases, particularly diffuse panbronchiolitis (DPB). Erythromycin, azithromycin, clarithromycin, and roxithromycin inhibit chemotaxis and infiltration of neutrophils into the airway and, subsequently, decrease mucus secretion. Mucus formation, a significant cause of morbidity and mortality in patients with chronic airway inflammation, is directly inhibited by macrolides and suppressed by decreased inflammation in the airway. The mechanisms of action for the anti-inflammatory properties of the macrolides are still being investigated, but they are clearly multifactorial. Macrolides inhibit the production of many proinflammatory cytokines, such as interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor-alpha, perhaps by suppressing the transcription factor nuclear factor-kappaB or activator protein-1. Inhibition of cytokine production has been seen in vitro and also in bronchoalveolar lavage fluid, which contains less IL-8 and fewer neutrophils after treatment with macrolides. Macrolides also inhibit formation of leukotriene B4, which attracts neutrophils, and inhibit the release of superoxide anion by neutrophils that may be present in the airway. An important aspect of inflammation is extravasation of neutrophils into the tissues. Macrolides block formation of adhesion molecules necessary for neutrophil migration. Together, these anti-inflammatory effects result in improved pulmonary functions and fewer airway infections. In patients with DPB, the anti-inflammatory effects lead to a significant increase in survival. Further work is needed to characterize the clinical benefits of macrolides in patients with other chronic inflammatory airway diseases.

Clinical implications of the immunomodulatory effects of macrolides on sinusitis

This article reviews the treatment of chronic sinusitis with macrolides. Chronic sinusitis is often the result of bacterial infections that lead to chronic inflammation with thickening of the sinus mucosa and hypersecretion of mucus. In addition to their anti-infective properties, some macrolides possess immunomodulatory effects. These macrolides have been used successfully to treat diffuse panbronchiolitis, a progressive inflammatory lung disease, and may be useful for treatment of asthma, chronic bronchitis, chronic sinusitis, cystic fibrosis, and bronchiectasis. The clinical benefits of macrolides in patients with chronic sinusitis include decreased nasal secretions and postnasal drip, with improvement in nasal obstruction. In vivo and in vitro studies show that some macrolides affect neutrophil chemotaxis and infiltration, inflammatory cytokine production, mucus production, and the transportability of airway secretions. These findings indicate that macrolides are promising agents for treating chronic inflammation of the airways.

Azithromycin inhibits MUC5AC production induced by the Pseudomonas aeruginosa autoinducer N-(3-Oxododecanoyl) homoserine lactone in NCI-H292 Cells

The features of chronic airway diseases, including chronic bronchitis, cystic fibrosis, bronchiectasis, and diffuse panbronchiolitis, include chronic bacterial infection and airway obstruction by mucus. Pseudomonas aeruginosa is one of the most common pathogens in chronic lung infection, and quorum-sensing systems contribute to the pathogenesis of this disease. The quorum-sensing signal molecule [N-(3-oxododecanoyl) homoserine lactone (3O-C(12)-HSL)] not only regulates bacterial virulence but also is associated with the immune response. In this study, we investigated whether 3O-C(12)-HSL could stimulate the production of a major mucin core protein, MUC5AC. The effect of a macrolide on MUC5AC production was also studied. 3O-C(12)-HSL induced NCI-H292 cells to express MUC5AC at both the mRNA and the protein levels in time- and dose-dependent manners. A 15-membered macrolide, azithromycin, inhibited MUC5AC production that was activated by 3O-C(12)-HSL. 3O-C(12)-HSL induced extracellular signal-regulated kinase (ERK) 1/2 and I-kappa B phosphorylation in cells, and this induction was suppressed by azithromycin. 3O-C(12)-HSL-induced MUC5AC production was blocked by the ERK pathway inhibitor PD98059. Our findings suggest that the P. aeruginosa autoinducer 3O-C(12)-HSL contributes to excessive mucin production in chronic bacterial infection. Azithromycin seems to reduce this mucin production by interfering with intracellular signal transduction.

The Effect of Clarithromycin on Inflammatory Markers in Chronic Obstructive Pulmonary Disease: Preliminary Data

BACKGROUND:

Clarithromycin is an antimicrobial agent that can be used for treatment of chronic obstructive pulmonary disease (COPD) exacerbations with bronchodilator therapy. However, it has also been shown that clarithromycin has antiinflammatory effects by the inhibition of cytokine production.

OBJECTIVE:

To evaluate the antiinflammatory effect of clarithromycin on serum and sputum interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and leukotriene B4 levels in patients with COPD.

METHODS:

Thirty men with mild to moderate COPD were enrolled in this prospective, single-center, double-blind, placebo-controlled study. None of the patients was receiving systemic or inhaled corticosteroids during the study. Subjects received either clarithromycin or placebo for 14 days. Before and after this treatment period, spirometric tests and arterial blood gas analysis were performed, blood was drawn for measurement of serum inflammatory markers, and sputum was induced.

RESULTS:

There were no statistically significant differences in baseline clinical or laboratory parameters between the groups. After the treatment, the induced sputum total cell counts, and IL-8 and TNF-α levels decreased significantly in the clarithromycin group compared with pretreatment levels (mean ± SD IL-8 1606 ± 367.3 vs 882 ± 143.6 pg/mL, p = 0.001; TNF-α 638.2 ± 287.5 vs 390 ± 235 pg/mL, p = 0.001). Similarly, decreases in serum inflammatory markers were found in the clarithromycin group while there was no significant change in the placebo group.

CONCLUSIONS:

This study demonstrated that the decrease in IL-8 and TNF-α levels might be related to the antiinflammatory effect of clarithromycin. Thus, we suggest that the use of clarithromycin in COPD exacerbations may either treat the infection or help control the inflammation. Future studies are needed to determine the clinical significance of these findings.

Influence of daily low-dose 14-membered-ring macrolide therapy on Helicobacter pylori infection in patients with chronic inflammatory disease of the airway

Our aim was to evaluate the effects of eradication and the incidence of secondary resistance by long-term low-dose daily 14-membered-ring macrolide therapy on Helicobacter pylori ( H. pylori) infection in patients with chronic lower respiratory tract inflammatory disease. In a retrospective analysis, we studied the seroprevalence of H. pylori IgG in 90 patients with inflammation of the lower respiratory tract (68 had been treated with macrolide and 22 served as controls). Then, in a prospective analysis, we evaluated the eradication effect of macrolide therapy by the decline of IgG values and the (13)C-urea breath test. Only long-term macrolide use significantly affected the seroprevalence of H. pylori IgG. However, macrolide therapy did not reduce the H. pylori IgG values in 24 patients and did not eradicate H. pylori in (13)C-urea breath tests. Chemosensitivity testing was performed on three H. pylori strains obtained by gastric biopsy from patients in whom the disease could not be eradicated. Only one strain demonstrated a resistant character. Daily long-term low-dose 14-membered-ring macrolide therapy for patients with lower respiratory inflammatory disease may not be sufficient to eradicate H. pylori, but some strains do not acquire a resistant nature.

Macrolides inhibit epithelial cell-mediated neutrophil survival by modulating granulocyte macrophage colony-stimulating factor release

Macrolides have been shown to be effective in treating diffuse panbronchiolitis (DPB), although the precise modes of action remain unclear. At sites of airway inflammation, respiratory epithelium is considered an active participant in regulating neutrophil survival. We therefore examined the effect of erythromycin, clarithromycin, azithromycin, and josamycin on both neutrophil survival and on epithelial-derived factors, which influence neutrophil longevity. Media conditioned with transiently tumor necrosis factor (TNF)-alpha-stimulated A549 human airway epithelial cells prolonged neutrophil survival compared with control media. The presence of dexamethasone during neutrophil culture led to further prolongation of neutrophil survival. In contrast, none of the tested macrolides modulated neutrophil survival, suggesting a lack of direct effect of these drugs. On the other hand, pretreatment of TNF-alpha-stimulated A549 cells by erythromycin, clarithromycin, azithromycin, or dexamethasone, but not josamycin, decreased the neutrophil survival-enhancing effects in a dose-dependent manner. Neutralizing antibodies to granulocyte macrophage colony-stimulating factor (GM-CSF) dampened the prolonged neutrophil survival observed in TNF-alpha-stimulated A549 conditioned media. Erythromycin, clarithromycin, azithromycin, and dexamethasone inhibited TNF-alpha-induced GM-CSF expression in A549 cells at both the protein and messenger RNA levels. These results suggest that macrolides inhibit epithelial cell-mediated neutrophil survival by modulating GM-CSF release, which may, at least in part, explain the effectiveness of this family of drugs on DPB.

Clarithromycin inhibits overproduction of muc5ac core protein in murine model of diffuse panbronchiolitis

Long-term treatment of macrolide antibiotics is considered an effective treatment for diffuse panbronchiolitis (DPB). Although hypersecretion is a common feature of this disease, and it is known that macrolides inhibit mucin production, the mechanism of the effect on mucin production is unclear. The aim of our study was to determine the production of muc5ac core protein, a major core protein of mucin in airway secretion, and the effect of clarithromycin treatment on such production in a mouse model mimicking DPB. Alcian blue-periodic acid-Schiff-positive cells were detected in the lungs of Pseudomonas aeruginosa-infected mice. Western blots of these mice showed muc5ac glycoprotein at day 1 and increased progressively from day 4 to day 14 after inoculation of bacteria. Clarithromycin (10 mg. kg-1. day-1 for 7 days) significantly reduced the muc5ac expression at both the mRNA and protein levels. To investigate the role of molecules upstream in muc5ac regulation, we examined the role of mitogen-activated protein kinase. Extracellular signal-regulated kinase 1/2 phosphorylation increased in the infected lung and decreased after treatment. Our results suggest that overproduction of muc5ac plays an important role in the pathogenesis of DPB and that clinical improvement following macrolide therapy seems to involve, at least in part, its inhibition of mucin overproduction, through modulation of intracellular signal transduction.

In vivo and in vitro effects of macrolide antibiotics on mucus secretion in airway epithelial cells

To examine the in vivo effects of macrolide antibiotics on mucus hypersecretion, we induced hypertrophic and metaplastic changes of goblet cells in rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats and by intranasal LPS instillation. Oral administration of clarithromycin (CAM) (5-10 mg/kg) significantly inhibited OVA- and LPS-induced mucus production and neutrophil infiltration, whereas josamycin and ampicillin showed no effect. In vitro effects of macrolide antibiotics on airway epithelial cells were examined using NCI-H292 cells and human nasal epithelial cells cultured in air-liquid interface. Mucus secretion was evaluated by ELISA using anti-mucin monoclonal antibodies (anti-MUC5AC and HCS18). CAM and erythromycin significantly inhibited spontaneous and tumor necrosis factor-alpha (20 ng/ml)-induced mucus secretion from NCI-H292 cells at 10-6 to 10-7 M and from human nasal epithelial cells at 10-4 to 10-5 M. MUC5AC messenger RNA expression was also significantly inhibited. These results indicate that the 14-member macrolide antibiotics, CAM and erythromycin, exert direct inhibitory effects on mucus secretion from airway epithelial cells and that they may be useful for the treatment of mucus hypersecretion caused by allergic inflammation and LPS stimulation.

Pulmonary mucus: Pediatric perspective

Airway mucus hypersecretion is a clinical feature of a number of childhood diseases, including asthma and bronchitis-associated conditions. However, compared with adults, there is relatively scarce information concerning mucus pathophysiology in respiratory diseases in children. The available evidence indicates many similarities between adult and childhood respiratory hypersecretory conditions, including goblet-cell hyperplasia and submucosal gland hypertrophy, and airway mucus plugging in asthma. Consequently, it is likely that treatments that are effective in adults would be effective in children. Numerous therapeutic targets are linked to the pathophysiology of airway mucus hypersecretion in experimental models and adults with respiratory disease. Whether or not these same targets are relevant in children is for the most part unclear. These targets include the inflammatory cells mediating the inflammatory response that generates the hypersecretory phenotype, and highly specific cellular elements such as epidermal growth factor receptor tyrosine kinase and calcium-activated chloride (CACL) channels. Identification of these factors is linked with the development of different classes of pharmacotherapeutic molecules directed at these targets. Compounds with a broader spectrum of anti-inflammatory activity are likely to be more effective than compounds with restricted activity. However, certain highly specific targets, such as human CACL1 channels, appear to be strongly associated with the development of an airway hypersecretory phenotype. Data from current clinical trials in adults with blockers of these specific targets are awaited with great interest. The hope is that, if effective, pediatric trials with these compounds could be initiated with a view to alleviation of the clinical impact of airway mucus hypersecretion in children. A significant challenge to the therapeutic progression of these new compounds is effective delivery to the airways in children, with the research effort into development of new compounds matched by advances in inhaler design.

Characteristics of pulmonary Mycobacterium avium-intracellulare complex (MAC) infection in comparison with those of tuberculosis

To clarify the clinical features of pulmonary Mycobacterium avium-intracellulare complex (MAC) infection, we retrospectively evaluated clinical manifestations, laboratory data, chest and maxillary sinus computed tomographic scans and induced sputum findings in 26 with MAC infection in comparison with 104 patients with tuberculosis (TB) infection. We found that carbohydrate antigen 19-9 (CA 19-9) and immunoglobulin A (IgA) in the serum and percentage of neutrophils in the sputum were significantly higher, and sinusitis was significantly more frequent in patients with MAC compared with patients with TB. MAC infection might be more strongly associated with impaired upper and lower airway defense mechanism in comparison with TB.

Airway hypersecretion in allergic rhinitis and asthma: new pharmacotherapy

Mucus hypersecretion is a prominent feature of allergic rhinitis and asthma. Biologic targets for suppression of hypersecretion range from the inflammatory cells that initiate airway inflammation, to specific cellular elements such as calcium-activated chloride (CLCA) channels, epidermal growth factor receptor tyrosine kinase, and antiapoptotic factors (eg, Bcl-2). Identification of these targets is driving development of new pharmacotherapeutic compounds. Aside from specific instances in which a single mediator has a major impact on hypersecretion--for example, histamine in rhinitis--it is likely that compounds with broad-spectrum anti-inflammatory activity are more effective than compounds with restricted activity. However, certain highly specific targets, such as CLCA channels, seem to be intimately associated with development of a hypersecretory phenotype. Data from clinical trials with blockers of these targets are awaited with great interest, not only for disease management but also to determine the clinical benefit of selective inhibition of airway hypersecretion.

Fourteen-member macrolides promote the phosphatidylserine receptor-dependent phagocytosis of apoptotic neutrophils by alveolar macrophages

An inflammation of the airway of patients with diffuse panbronchiolitis (DPB), is characterized by dense neutrophil infiltration. Resolution of the inflammation can be achieved by the removal of apoptotic neutrophils by human alveolar macrophages (AM) without liberating neutrophil proteases in the airway. To understand clinical efficacy for the treatment of DPB by 14- or 15-member macrolides, their effects on the phagocytosis of apoptotic neutrophils by AM were examined. Treatment of AM with erythromycin (ERY) or clarithromycin at clinically achievable levels significantly increased the levels of phagocytosis of apoptotic neutrophils. A serum factor was not essential for the enhancement by these 14-member macrolides. Of the antibiotics tested, these effects were specific for the 14-member macrolides and a 15-member macrolide, azithromycin, but not for the 16-member macrolides, clindamycin or beta-lactam antibiotics. The enhanced phagocytosis of apoptotic neutrophils by ERY had no effect on the levels of interleukin-8 or tumor necrosis factor alpha production by lipopolysaccharide-stimulated AM after phagocytosis of the apoptotic neutrophils. The increased phagocytosis of apoptotic neutrophils by ERY was also found to be phosphatidylserine receptor-dependent for AM. These data indicate a novel anti-inflammatory action of 14-member and 15-member macrolides, and suggest that such antibiotics achieve clinical efficacy for patients with DPB, in part, through enhancing the nonphlogistic phagocytosis of apoptotic neutrophils by AM.

Addition of a 2-month low-dose course of levofloxacin to long-term erythromycin therapy in sinobronchial syndrome

BACKGROUND

We previously reported that a 6-month low-dose course of ofloxacin combined with long-term low-dose erythromycin therapy (EM therapy) was superior to EM therapy alone for sinobronchial syndrome (SBS), especially during the initial 2 months of treatment. However, there was no data as to whether discontinuation of low-dose ofloxacin after 2 months results in symptom relapse. This study was designed to clarify this issue.

METHODOLOGY

Twenty-three patients with SBS received a 2-month course of levofloxacin (LVFX) therapy (100 mg once a day) concurrent with a 6-month course of EM therapy (200 mg three times a day) (group A). Eighteen other patients were given the EM therapy alone (group B). Clinical parameters, including quantity of morning sputum, were recorded in a daily symptom diary, and reviewed by each doctor in charge at 2-4 week intervals.

RESULTS

The quantity of morning sputum decreased more rapidly in group A than in group B. No relapse of symptoms was recognized after discontinuation of LVFX in group A.

CONCLUSIONS

A 2-month low-dose course of LVFX in conjunction with long-term EM therapy may be efficacious for the treatment of SBS, as evidenced by rapid improvement of expectoration without any relapse after LVFX discontinuation.

Diffuse panbronchiolitis: an underdiagnosed disease? Study of 4 cases in Brazil

BACKGROUND: Diffuse panbronchiolitis is a clinical pathologic condition characterized by chronic inflammation of respiratory bronchioles, with clinical features that position it as a differential diagnosis among the sinopulmonary syndromes. METHODS AND RESULTS: We present 4 cases (1 Black, 2 Japanese descendants, and 1 Japanese), living in Brazil, in which the diagnosis was made by the clinical and radiological features and confirmed by transbronchial biopsy. The clinical findings included chronic sinusitis, productive cough, rhonchi, and wheezes. The pulmonary function tests showed an obstructive pattern. High resolution computerized tomography showed a diffuse nodular pattern, airway ectasia, and airway wall thickening. The biopsy showed interstitial accumulation of foam cells and lymphoid cells in the walls of respiratory bronchioles: 2 of our cases had bronchus-associated lymphoid tissue hyperplasia. We searched for the HLA Bw54 in all of our patients, but only 1 was positive. A low dose macrolide treatment was introduced, resulting in with clinical and functional improvement. A score that rated the extent of nodules, airway ectasia, mucus plugging, and airway wall thickening was applied on pre- and post-treatment High resolution computerized tomography results, revealing an improvement in tomographic pattern related to that observed in the pulmonary function tests. CONCLUSION: We conclude that diffuse panbronchiolitis is a systemic disease that is not exclusive to the Asian population, whose clinical and radiological features should be better known by occidental pulmonary physicians.