Diffuse panbronchiolitis in East Asia

Pulmonary Hypertension Associated with Diffuse Panbronchiolitis That Improved with Erythromycin and Home Oxygen Therapy

Pulmonary hypertension (PH) often complicates chronic lung disease. However, there are few reports of PH associated with diffuse panbronchiolitis, and there is no effective treatment. We herein report a 64-year-old woman diagnosed with PH due to diffuse panbronchiolitis. She received erythromycin, carbocysteine, and home oxygen therapy (1 L O2/min). After 4 months of therapy, the respiratory function (diffusing capacity of the lungs for carbon monoxide: 23.3% to 76.1%) and PH (mean pulmonary arterial pressure: 50 to 28 mmHg; pulmonary vascular resistance: 680 to 518 dynes・sec・cm-5; pre- vs post-therapy, respectively) had improved markedly.

Prospects for macrolide therapy of asthma and COPD

Macrolide compounds, many of which are derived from natural sources, all share a lactone ring structure, but of varying sizes. Their biological activities differ with structure and size but tend to overlap. Marketed macrolide drugs include immunosuppressives and antibiotics. Some of the latter have been shown to exert anti-inflammatory activities, due to direct effects on inflammatory cells and processes when used for respiratory infections. Consequently, azithromycin is included in clinical guidelines for COPD and asthma treatment, though it has the disadvantage, as an antibiotic, of increasing bacterial resistance. COPD and asthma, however, like several chronic inflammatory diseases involving other organs, are driven to a large extent by epithelial barrier dysfunction. Recently, azithromycin was shown to directly enhance epithelial barrier function and a new class of derivatives, barriolides, is under development with the lead indication COPD. It is thus likely that by circumventing antibiosis and acting on a crucial etiological disease process, this type of agent will open up a new, safer approach to COPD and asthma therapy with macrolides.

Rheumatoid Arthritis Accompanying Diffuse Panbronchiolitis

A 58-year-old woman with rheumatoid arthritis (RA) visited our hospital complaining of a persistent cough and sputum for the past year. She had a high cold hemagglutinin titer and chronic sinusitis. Chest computed tomography revealed bilateral diffuse centrilobular nodules, bronchiectasis, and bronchial wall thickening. A surgical lung biopsy was performed that confirmed diffuse panbronchiolitis (DPB) because of the lymphocytic and plasmacytic infiltrates in the respiratory bronchioles. Her condition improved after the administration of clarithromycin. Several cases of RA complicating DPB have previously been reported, but only in Japan. We need to consider DPB as a bronchiolitis types accompanying RA among Japanese patients.

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.

Diffuse panbronchiolitis as parathymic syndrome in a Caucasian man previously treated for thymoma

Diffuse panbronchiolitis (DPB) is a rare disease characterized by bronchiolitis and chronic sinusitis. Being largely restricted to East Asia, its actual incidence in Caucasian patients is probably underestimated. DPB has been described in association with thymic neoplasms, mainly arising as a consequence of immune dysregulation. We present a rare case of DPB diagnosed in a 69-year-old Caucasian man who had undergone surgery for stage 2A thymoma a year before. The patient came to our hospital complaining of exertional dyspnea and productive cough, with a persistent lung consolidation described at chest X-rays. High resolution computed tomography (CT) showed diffuse centrilobular micronodules and solid nodules, tree-in-bud opacities, peripheral consolidations and cylindrical bronchiectasis. Sinus disease was also demonstrated by CT. Analysis of bronchoalveolar lavage showed marked granulocyte inflammation and allowed the isolation of Haemophilus Influenzae. Consequently, the diagnosis of DPB was reached by integrating clinical, and radiological data. Long-term therapy with azithromycin was prescribed, and was found to be effective in controlling symptoms and reducing radiological abnormalities at 6-month clinical and CT follow-up. Confidence with the radiological presentation and clinical significance of DPB is necessary, since the condition is responsive and reversible to long-term macrolide treatment, the effect of which is mainly attributed to an anti-inflammatory, and immunoregulatory action.

Azithromycin treats diffuse panbronchiolitis by targeting T cells via inhibition of mTOR pathway

Azithromycin (AZM), that is a macrolide antibiotic, has been found to treat diffuse panbronchiolitis (DPB) effectively. However, the mechanism of action underlying the therapeutic effects remains unclear. We selected 64 patients with DPB from 305 patients who were diagnosed with DPB at the outpatient clinic in Shanghai Pulmonary Hospital from Jan 2010 to Oct 2014. The primary PBLs, CD4 + T cells, and Jurkat T cells were treated with AZM or erythromycin (EM), and the effects of AZM and EM on IL-17A and CXCL-2 production, proliferation, apoptosis and autophagy were evaluated. AZM and EM significantly inhibited IL-17A and CXCL-2 production in patients' PBLs (all P < 0.05). AZM significantly inhibited proliferation and promoted apoptosis of T cells from DPB patients. AZM can enhance autophagosome formation of T cells by suppressing S6RP phosphorylation, which is a downstream target of mTOR pathway (all P < 0.05). AZM and EM significantly decreased secreted IL-17A levels (P < 0.05) in the primary CD4 + T cells of patients with DPB. AZM may treat DPB patients by targeting cytokine production, proliferation, apoptosis and autophagy of T cell. The mechanism of therapeutic effects of AZM on DPB may be associated with a specific inhibition of mTOR pathway in the T lymphocytes.

Diffuse panbronchiolitis research in MEDLINE (1969-2017): Report of a bibliometric analysis

BACKGROUND

Given the well documented and undesired impact of diffuse panbronchiolitis (DPB), there is a need to create a statistical inventory of research output on DPB. The aim of this study was to identify and analyze different trends in publication over time, with technological additions.

METHODS

Articles indexed in MEDLINE regarding DPB were retrieved using PubMed. Citation results were categorized by article type, year of publication, language, and country.

RESULTS

A total of 657 publications, published between 1969 and 2017 were retrieved from PubMed; the year with the highest number of articles published was 1992 (n = 32). Japan accounted for 68.34% (n = 449) publications, followed by the United States of America (USA; 6.70%, n = 44) and China (5.48%, n = 36). English (n = 401) was the most commonly used language in the publications, followed by Japanese (n = 223) and Chinese (n = 16). Articles were published in 218 different journals; The Japanese Journal of Thoracic Diseases published the maximum number of articles, accounting for 13.7% (n = 90) citations. Sugiyama Y was the most productive author and contributed to 12 publications.

CONCLUSIONS

This was the first bibliometric analysis of DPB. Between 1991 and 2000, the number of publications on DPB literature reached a peak, and although the frequency of publication has decreased recently, the quantity of DPB research during the past 48 years is adequate and satisfactory. Overall, the publications on DPB have undergone exponential growth over the last 30 years.

Macrolides in Children With Community-Acquired Pneumonia: Panacea or Placebo?

Pneumonia, most often caused by a respiratory virus, is common in childhood. Mycoplasma pneumoniae also is detected frequently, particularly in older children in the era of pneumococcal conjugate vaccination. Despite recommendations for β-lactam antibiotics, macrolide antibiotics, including erythromycin, clarithromycin, and azithromycin, are prescribed frequently to children with acute lower respiratory infection. However, the significance of detecting "atypical" pathogens, including M pneumoniae, in children remains contentious. Considering the potential for antibacterial and anti-inflammatory activities of macrolides, our understanding of the role of these drugs in acute and chronic infections and in inflammatory conditions is changing. Some observational data have revealed improved outcomes in adults and children with pneumonia who are prescribed macrolides, although its widespread use has led to increases in macrolide resistance in Streptococcus pneumoniae and M pneumoniae. Clinical trials to define the role of macrolides in pediatric acute respiratory infection must be prioritized.

Diffuse panbronchiolitis-The response and recurrence after erythromycin therapy

BACKGROUND/PURPOSE

Diffuse panbronchiolitis (DPB) is a rare clinicopathological entity. To date, no cohort study of DPB has been conducted in Taiwan. Erythromycin treatment improves the clinical outcome of DPB; however, whether relapse will occur or not is unclear. Herein, we report the first retrospective cohort of DPB patients in one medical center in Taiwan, including their clinical presentation and outcomes of erythromycin treatment.

METHODS

The study comprised a retrospective cohort analysis of 27 patients with a confirmed diagnosis of DPB. Clinical, radiological, and laboratory parameters were analyzed, and the course and outcome of erythromycin treatment were examined.

RESULTS

The mean age at symptom onset was 56.6 ± 18.5 years, and the time between symptom onset and a correct diagnosis was 4.3 ± 4.2 years. The percentages of patients with centrilobular micronodules on chest computed tomography, obstructive ventilator impairment with hypoxemia, and an elevated cold agglutinin titer were 72%, 37%, and 78%, respectively. After erythromycin treatment, 22 of the 27 (81.5%) patients showed clinical improvement, of whom six suffered a relapse. Four of these six patients clinically improved after a second course of erythromycin treatment.

CONCLUSION

Erythromycin therapy was suitable for DPB in our experience. In this study cohort, 27% experienced a relapse, of which two-thirds of the patients improved after a second course of erythromycin treatment.

Single center experience of five diffuse panbronchiolitis patients clinically presenting as severe asthma

Diffuse panbronchiolitis (DPB) is a bronchiolitis affecting the whole lung fields which can be treated by macrolide. Especially East Asian patients are more susceptible to diffuse panbronchiolitis. As asthma and DPB both can cause airway obstruction, differential diagnosis is important for the 2 diseases. Here we report 5 patients with DPB clinically presenting as severe asthma in Korea, who were well treated by macrolide. Among the 5 patients, 2 could stop their asthma inhalers and the other 3 could reduce asthma medications after diagnosis and treatment of DPB. In conclusion, considering DPB as differential diagnosis for asthmatics in Asian ethnic groups is important.

Macrolides for diffuse panbronchiolitis

BACKGROUND

Diffuse panbronchiolitis (DPB) is a chronic airways disease predominantly affecting East Asians. Macrolides, a class of antibiotics, have been used as the main treatment for DPB, based on evidence from retrospective and non-randomised studies.

OBJECTIVES

To assess the efficacy and safety of macrolides for DPB.

SEARCH METHODS

We searched CENTRAL (2014, Issue 6), MEDLINE (1966 to July week 1, 2014), EMBASE (1974 to July 2014), Chinese Biomedical Literature Database (CBM) (1978 to July 2014), China National Knowledge Infrastructure (CNKI) (1974 to July 2014), KoreaMed (1997 to July 2014) and Database of Japana Centra Revuo Medicina (1983 to July 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs assessing the effect of macrolides for DPB.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and subsequent risk of bias according to The Cochrane Collaboration's tool for assessing risk of bias. The primary outcomes were five-year survival rate, lung function and clinical response. We used risk ratios (RR) for individual trial results in the data analysis and measured all outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Only one RCT (19 participants) with significant methodological limitations was included in this review. It found that the computerised tomography images of all participants treated with a long-term, low-dose macrolide (erythromycin) improved from baseline, while the images of 71.4% of participants in the control group (with no treatment) worsened and 28.6% remained unchanged. Adverse effects were not reported. This review was previously published in 2010 and 2013. For this 2014 update, we identified no new trials for inclusion or exclusion.

AUTHORS' CONCLUSIONS

There is little evidence for macrolides in the treatment of DPB. We are therefore unable to make any new recommendations. It may be reasonable to use low-dose macrolides soon after diagnosis is made and to continue this treatment for at least six months, according to current guidelines.

The formulation, chemical and physical characterisation of clarithromycin-based macrolide solution pressurised metered dose inhaler

Objectives

The formulation of a clarithromycin (CLA) pressurised metered dose inhalers (pMDIs) solution formulation opens up exciting therapeutic opportunities for the treatment of inflammation in chronic obstructive lung diseases. In this study, we have formulated and tested a low dose macrolide formulation of CLA for treatment of inflammation and studied its physicochemical and aerosol properties.

Methods

The system was characterised for in-vitro aerosol performance using an Andersen cascade impactor. Short-term chemical and physical stability was assessed by dose content uniformity over a range of temperatures. Standard physicochemical characteristics were also investigated using scanning electron microscopy, thermo analysis and laser diffraction techniques.

Key findings

The formulation had a relatively high fine particle fraction (47%) and produced a particle size distribution suitable for inhalation drug delivery. Particles had an irregular morphology and were predominately amorphous. Furthermore, the short-term stability showed the formulation to be stable from 4 to 37°C.

Conclusions

This study demonstrated the feasibility of formulating a solution-based pMDI containing CLA for the treatment of lung inflammatory diseases.

The effects of azithromycin on patients with diffuse panbronchiolitis: a retrospective study of 29 cases

BACKGROUND

Diffuse panbronchiolitis (DPB), a chronic inflammatory disease of the airway, is treated with macrolide antibiotics. The ability of azithromycin to improve DPB prognosis, as detected by high-resolution computed tomography (HRCT) scans and lung function tests, has not been studied in a large retrospective of patients. Our study aims to investigate the effects of azithromycin on patients with DPB using lung function tests and radiologic images.

METHODS

Twenty-nine patients with DPB were studied; their medical records were collected and analyzed retrospectively. Patients studied were hospitalized in the respiratory department of the Yixing Hospital, affiliated with Jiangsu University. Azithromycin was administered for 6-17 months. Changes in lung function and HRCT scans after treatment with azithromycin for six months were compared with pre-treatment values and images respectively.

RESULTS

Azithromycin therapy for six months resulted in rapid improvements in lung function, demonstrated by forced expiratory volume in one second (FEV1.0%), forced expiratory volume in one second over the forced vital capacity (FEV1.0/FVC), and forced expiratory volume with 75% vital capacity (FEF75%) values. In addition, improvements were seen in small nodular shadows, dilated peripheral bronchi, bronchial wall thickening, and tree-in-bud pattern, as detected by chest HRCT scans.

CONCLUSIONS

Long-term therapy with azithromycin is effective for patients with DPB.

Macrolides for diffuse panbronchiolitis

BACKGROUND

Diffuse panbronchiolitis (DPB) is a chronic airways disease predominantly affecting East Asians. Macrolides, a class of antibiotics, have been used as the main treatment for DPB, based on evidence from retrospective and non-randomised studies.

OBJECTIVES

To assess the efficacy and safety of macrolides for DPB.

SEARCH METHODS

We searched CENTRAL 2012, Issue 7, MEDLINE (1966 to July week 2, 2012), EMBASE (1974 to July 2012), Chinese Biomedical Literature Database (CBM) (1978 to July 2012), China National Knowledge Infrastructure (CNKI) (1974 to July 2012), KoreaMed (1997 to July 2012) and Database of Japana Centra Revuo Medicina (1983 to July 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs assessing the effect of macrolides for DPB.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and subsequent risk of bias according to the Cochrane Collaboration's tool for assessing risk of bias. The primary outcomes were five-year survival rate, lung function and clinical response. We used risk ratios (RR) for individual trial results in the data analysis and measured all outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Only one RCT (19 participants) with significant methodological limitations was included in this review. It found that the computerised tomography images of all participants treated with a long-term, low-dose macrolide (erythromycin) improved from baseline, while the images of 71.4% of participants in the control group (with no treatment) worsened and 28.6% remained unchanged. Adverse effects were not reported.

AUTHORS' CONCLUSIONS

There is little evidence for macrolides in the treatment of DPB. We are therefore unable to make any new recommendations. It may be reasonable to use low-dose macrolides soon after diagnosis is made and to continue this treatment for at least six months, according to current guidelines.

Pathogen- and host-directed anti-inflammatory activities of macrolide antibiotics

Macrolide antibiotics possess several, beneficial, secondary properties which complement their primary antimicrobial activity. In addition to high levels of tissue penetration, which may counteract seemingly macrolide-resistant bacterial pathogens, these agents also possess anti-inflammatory properties, unrelated to their primary antimicrobial activity. Macrolides target cells of both the innate and adaptive immune systems, as well as structural cells, and are beneficial in controlling harmful inflammatory responses during acute and chronic bacterial infection. These secondary anti-inflammatory activities of macrolides appear to be particularly effective in attenuating neutrophil-mediated inflammation. This, in turn, may contribute to the usefulness of these agents in the treatment of acute and chronic inflammatory disorders of both microbial and nonmicrobial origin, predominantly of the airways. This paper is focused on the various mechanisms of macrolide-mediated anti-inflammatory activity which target both microbial pathogens and the cells of the innate and adaptive immune systems, with emphasis on their clinical relevance.

Erythromycin enhances CD4+Foxp3+ regulatory T-cell responses in a rat model of smoke-induced lung inflammation

Heavy smoking can induce airway inflammation and emphysema. Macrolides can modulate inflammation and effector T-cell response in the lungs. However, there is no information on whether erythromycin can modulate regulatory T-cell (Treg) response. This study is aimed at examining the impact of erythromycin on Treg response in the lungs in a rat model of smoking-induced emphysema. Male Wistar rats were exposed to normal air or cigarette smoking daily for 12 weeks and treated by gavage with 100 mg/kg of erythromycin or saline daily beginning at the forth week for nine weeks. The lung inflammation and the numbers of inflammatory infiltrates in bronchoalveolar lavage fluid (BALF) were characterized. The frequency, the number of Tregs, and the levels of Foxp3 expression in the lungs and IL-8, IL-35, and TNF-α in BALF were determined by flow cytometry, RT-PCR and ELISA, respectively. Treatment with erythromycin reduced smoking-induced inflammatory infiltrates, the levels of IL-8 and TNF-α in the BALF and lung damages but increased the numbers of CD4⁺Foxp3⁺ Tregs and the levels of Foxp3 transcription in the lungs, accompanied by increased levels of IL-35 in the BALF of rats. Our novel data indicated that erythromycin enhanced Treg responses, associated with the inhibition of smoking-induced inflammation in the lungs of rats.

Differential association between HLA and diffuse panbronchiolitis in Northern and Southern Chinese

BACKGROUND

Diffuse panbronchiolitis (DPB) is a progressive inflammatory pulmonary disease that predominately affects East Asians. Genetic susceptibility to DPB is correlated with the human leukocyte antigens HLA-B54 in Japanese and HLA-A11 in Koreans. However, no systematic genetic study of DPB pathogenesis has been conducted in the Chinese population. The aim of this study was to investigate the possible association between HLA and disease susceptibility in Chinese patients with DPB.

METHODS

A literature review of both Chinese and English language studies on Chinese DPB patients, published between 1983 and 2010, was conducted. Seventy subjects met the inclusion criteria and were retrospectively analyzed for HLA gene frequency according to geographic region.

RESULTS

HLA-B54 frequency was significantly greater in DPB patients than in controls in the Northern Chinese group (35.7% vs. 4.6%, p=7.5×10(-7)). Although the HLA-B54 frequency was slightly increased in the Southern Chinese patients, the difference was not significant compared with control subjects (14.3% vs. 5.7%, p=0.28). The HLA-A11 frequency was significantly greater in DPB patients than controls in the Southern Chinese group (54.8% vs. 26.4%, p=0.009). Despite an increase of HLA-A11 frequency in the Northern Chinese group, no significant variation in HLA-A11 frequency was found compared with control subjects (42.9% vs. 30.8%, p=0.535). The HLA-A2 frequency was significantly decreased in DPB patients than in controls in the Southern Chinese group (22.9% vs. 66.0%, p=0.001). However, no significant difference in HLA-A2 frequency was found in the Northern Chinese group (50.0% vs. 46.9%, p=0.872).

CONCLUSION

HLA-B54 and HLA-A11 were positively associated with DPB in Northern and Southern Chinese, respectively. Population substructure may impact the genetic predisposition of DPB in China.

Optimal management of severe/refractory asthma

Asthma is a chronic inflammatory disease of the airways, affecting approximately 300 million people worldwide. Asthma results in airway hyperresponsiveness, leading to paroxysmal symptoms of wheeze, cough, shortness of breath, and chest tightness. When these symptoms remain uncontrolled, despite treatment with high doses of inhaled and ingested corticosteroids, asthmatic patients are predisposed to greater morbidity and require more health care support. Treating patients with severe asthma can be difficult and often poses a challenge to physicians when providing ongoing management. This clinical review aims to discuss the definition, prevalence and evaluation of severe asthmatics, and provides a review of the existing pharmacologic and non-pharmacologic treatment options.

Macrolide antibiotics broadly and distinctively inhibit cytokine and chemokine production by COPD sputum cells in vitro

Macrolide antibiotics are known to exert anti-inflammatory actions in vivo, including certain effects in COPD patients. In order to investigate the immunomodulatory profile of activity of macrolide antibiotics, we have studied the effects of azithromycin, clarithromycin, erythromycin and roxithromycin on the in vitro production of a panel of inflammatory mediators from cells isolated from human, steroid-naïve, COPD sputum samples. Macrolide effects were compared to three other commonly used anti-inflammatory compounds, the corticosteroid dexamethasone, the PDE4 inhibitor, roflumilast and the p38 kinase inhibitor, SB203580. Three of the four tested macrolides, azithromycin, clarithromycin and roxithromycin, exhibited pronounced, concentration-related reduction of IL-1β, IL-6, IL-10, TNF-α, CCL3, CCL5, CCL20, CCL22, CXCL1, CXCL5, and G-CSF release. Further slight inhibitory effects on IL-1α, CXCL8, GM-CSF, and PAI-1 production were also observed. Erythromycin was very weakly active. Qualitatively and quantitatively, macrolides exerted distinctive and, compared to other tested classes of compounds, more pronounced immunomodulatory effects, particularly in terms of chemokine (CCL3, CCL5, CCL20, CCL22, and CXCL5), IL-1β, G-CSF and PAI-1 release. The described modulation of inflammatory mediators could potentially contribute to further definition of biomarkers of macrolide anti-inflammatory activity in COPD.

Effect of azithromycin on patients with diffuse panbronchiolitis: retrospective study of 51 cases

BACKGROUND

Patients with diffuse panbronchiolitis (DPB) are routinely treated with erythromycin, clarithromycin, and roxithromycin. The clinical effect of azithromycin on DPB has not been confirmed in a large cohort.

OBJECTIVE

The present study was undertaken to investigate the clinical effects of azithromycin on patients with DPB.

METHODS

Fifty-one patients with DPB treated with azithromycin in Shanghai Pulmonary Hospital, China, from July 2001 to April 2007 were analyzed retrospectively. Azithromycin (500 mg a day) was administrated intravenously in the first 1-2 weeks, taken orally (500 mg, once a day) for 3 months, and tapered to 3 times a week for 6-12 months. The patients were followed up until September 1, 2009. The therapeutic effect, according to their clinical and radiological findings, arterial gas analysis, lung function, and sputum bacterium before and after the therapy, was categorized into the following five grades: 1) cured; 2) improved; 3) no response; 4) aggravation, and 5) relapse.

RESULTS

With azithromycin therapy, 14 (27.5%) patients with DPB were completely cured. The symptoms were eliminated to certain degrees for the other 36 cases (70.6%) of DPB. Five-year survival in this cohort was 94.1%.

CONCLUSION

Azithromycin is effective and well tolerated for patients with diffuse panbronchiolitis.

Macrolides for diffuse panbronchiolitis

BACKGROUND

Diffuse panbronchiolitis (DPB) is a chronic airways disease predominantly affecting East Asians. Macrolides, a class of antibiotics, have been used as the main treatment for DPB, based on evidence from retrospective and non-randomised studies.

OBJECTIVES

To assess the efficacy and safety of macrolides for DPB.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, issue 1), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to April 2010), EMBASE (1974 to April 2010), Chinese Biomedical Literature Database (CBM) (1978 to April 2010), China National Knowledge Infrastructure (CNKI) (1974 to April 2010), KoreaMed (1997 to April 2010) and Database of Japana Centra Revuo Medicina (1983 to April 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs assessing the effect of macrolides for DPB.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and subsequent risk of bias according to the Cochrane Collaboration's tool for assessing risk of bias. The primary outcomes were five-year survival rate, lung function and clinical response. We used risk ratios (RR) for individual trial results in the data analysis and measured all outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Only one RCT (19 participants) with significant methodological limitations was included in this review. It found that the computerised tomography images of all participants treated with a long-term, low-dose macrolide (erythromycin) improved from baseline, while the images of 71.4% of participants in the control group (with no treatment) worsened and 28.6% remained unchanged. Adverse effects were not reported.

AUTHORS' CONCLUSIONS

There is little evidence for macrolides in the treatment of DPB. We are therefore unable to make any new recommendations. It may be reasonable to use low-dose macrolides soon after diagnosis is made and to continue this treatment for at least six months, according to current guidelines.

Pseudomonas aeruginosa: host defence in lung diseases

Lung infections caused by the opportunistic pathogen Pseudomonas aeruginosa can present as a spectrum of clinical entities from a rapidly fatal pneumonia in a neutropenic patient to a multi-decade bronchitis in patients with cystic fibrosis. P. aeruginosa is ubiquitous in our environment, and one of the most versatile pathogens studied, capable of infecting a number of diverse life forms and surviving harsh environmental factors. It is also able to quickly adapt to new environments, including the lung, where it orchestrates virulence factors to acquire necessary nutrients, and if necessary, turn them off to prevent immune recognition. Despite these capabilities, P. aeruginosa rarely infects healthy human lungs. This is secondary to a highly evolved host defence mechanism that efficiently removes inhaled or aspirated pseudomonads. Many arms of the respiratory host defence have been elucidated using P. aeruginosa as a model pathogen. Human infections with P. aeruginosa have demonstrated the importance of the mechanical barrier functions including mucus clearance, and the innate immune system, including the critical role of the neutrophilic response. As more models of persistent or biofilm P. aeruginosa infections are developed, the role of the adaptive immune response will likely become more evident. Understanding the pathogenesis of P. aeruginosa, and the respiratory host defence response to it has, and will continue to, lead to novel therapeutic strategies to help patients.

Deterioration of asthma in a patient with diffuse panbronchiolitis (DPB) after macrolide therapy

Diffuse panbronchiolitis (DPB), an important cause of progressive obstructive lung disease in the Far East, is a distinctive sinobronchial syndrome with characteristic radiologic and histologic features. Asthma is a chronic inflammatory disease characterized by airway narrowing. The major inflammatory cells involved in the pathogenesis of asthma are type 2 helper T (Th2) cells, eosinophils, and mast cells. The authors' patient was diagnosed with DPB and asthma. Although macrolide therapy led to the disappearance of the radiologic abnormalities indicating centrilobular nodular lesions, the respiratory symptoms and pulmonary function worsened. Administration of inhaled corticosteroids improved the respiratory symptoms and pulmonary function. To the authors' knowledge, no case of DPB with asthma has been reported in the English-language literature.

Pathology of small airways disease

CONTEXT

The term small airways disease encompasses a generally poorly understood group of lung diseases that may arise primarily within the small airways or secondarily from diseases primarily affecting the bronchi or lung parenchyma. Their histology may be confusing; however, because treatments and prognoses vary, correct pathologic diagnosis is important.

OBJECTIVE

To present a nonexhaustive review of the pathology of primary and secondary small airways diseases, including small airways disease related to tobacco; to various other exposures, including mineral dusts; to diseases involving other areas of the lung with secondary bronchiolar involvement; and to recently described bronchiolitic disorders.

DATA SOURCES

Current literature is reviewed.

CONCLUSIONS

Small airways diseases include a wide variety of diseases of which the pathologist must consider. Uncommon conditions such as diffuse idiopathic neuroendocrine cell hyperplasia and diffuse panbronchiolitis may show relatively specific diagnostic features histologically; however, most small airways diseases exhibit nonspecific histologic features. Conditions not considered primary pulmonary diseases, such as collagen vascular diseases, bone marrow transplantation, and inflammatory bowel disease, must also be considered in patients with small airways changes histologically. Clinical and radiologic correlation is important for obtaining the best possible diagnosis.

Diffuse panbronchiolitis: not just an Asian disease: Australian case series and review of the literature

Diffuse panbronchiolitis is a disease of obscure aetiology that is traditionally associated with Asian ethnicity. We propose that this disease also occurs in Caucasians and the incidence in this population is greater than currently recognised. We further propose that high resolution computed tomography (HRCT) and response to macrolide therapy should be relied upon to make this diagnosis without verification by lung biopsy. In most circumstances, obtaining a biopsy for histopathology is not practical, and the disease may then be mistaken for other more common airway diseases. Accuracy of diagnosis is important as untreated disease is associated with a poor prognosis, and effective treatment is available. We report four out of a series of cases as evidence that DPB is in fact more common in the Western population than is currently understood.

Comparison of clinical and radiographic characteristics between nodular bronchiectatic form of nontuberculous mycobacterial lung disease and diffuse panbronchiolitis

The nodular bronchiectatic form of nontuberculous mycobacterial (NTM) lung disease and diffuse panbronchiolits (DPB) show similar clinical and radiographic findings. The present study was performed to clarify the clinicoradiographic similarities as well as the differences between NTM lung disease and DPB. The initial clinicoradiographic features of 78 patients with the nodular bronchiectatic form of NTM lung disease (41 patients with Mycobacterium avium complex infection and 37 patients with Mycobacterium abscessus infection) were compared with those of 35 patients with DPB. Old age, female sex, a history of tuberculosis treatment, and hemoptysis were related to NTM lung disease while exertional dyspnea, coarse crackles, history of sinusitis, obstructive abnormalities in pulmonary function tests, and hypoxemia were related to DPB. The number of lobes involved with bronchiolitis and bronchiectasis on chest computed tomography were more numerous in DPB patients. There is considerable overlap in the clinical and radiographic appearances of the nodular bronchiectatic form of NTM lung disease and DPB, although some clinicoradiographic features differ between two diseases. The correct diagnosis, including aggressive microbiologic evaluation, should be made for the appropriate management of patients presenting with bilateral bronchiectasis and bronchiolitis.

Effect of long-term and low-dose administration of erythromycin on proliferation of T lymphocytes stimulated with mitogens

The aim of the study was to assess the effect of long-term low-dose erythromycin (EM) treatment for chronic airway inflammation on proliferation of T cell subsets when stimulated with concanavalin A (Con A) and phytohemagglutinin (PHA). CD8+ cells are much more responsive to Con A compared to PHA. Ten patients with bronchiectasis were administered EM at 400 mg daily for 6 months. The extent of proliferation was assayed by [(3)H] thymidine incorporation and expressed as a stimulation index (SI). The lymphocyte subsets were analyzed including CD3+, CD4+ and CD8+ cells. The SI stimulated with Con A in the last month of therapy was significantly lower compared with that before the start of therapy (p=0.015) and 3 months after the end of therapy (p=0.002). However, EM therapy did not make a significant difference to the SIs when stimulated with PHA. CD3+, CD4+ and CD8+ cells in absolute numbers and CD4+/CD8+ ratios were not different among those harvested at the three time points. Long-term administration of EM may decrease the transformation response of CD8+ cells in patients.

Anti-inflammatory treatment of chronic rhinosinusitis: a shifting paradigm

Treatment of chronic rhinosinusitis still represents an unmet medical need. Presently, the US Food and Drug Administration has not approved any drugs for the treatment of this common condition. Various inflammatory processes are involved in the pathogenesis of chronic rhinosinusitis. Treatment of infection and surgical intervention to correct anatomic abnormalities often are inadequate in management when singly employed. Anti-inflammatory therapy such as topical cortico-steroids and more recently long-term, low-dose macrolide therapy has been integrated into the treatment algorithm for chronic rhinosinusitis. Better classification and point-of-care identification of inflammatory features may improve choice of anti-inflammatory therapy and thus outcome.

Non-infectious bronchiolitis as an early pulmonary complication of hematopoietic stem cell transplantation

Pulmonary complications occur in up to 60% of patients after hematopoietic stem cell transplantation (HSCT), causing significant morbidity and mortality. Among them, non-infectious bronchiolitis is considered a late complication in the form of bronchiolitis obliterans. We report a patient who developed non-infectious bronchiolitis within four weeks after undergoing HSCT for biphenotypic leukemia. Chest CT revealed centrilobular nodules that were reminiscent of diffuse panbronchiolitis, and lymphocytic bronchiolitis was confirmed by biopsy. Infection and bronchiolitis obliterans were ruled out, and the bronchiolitis resolved when leukemia relapsed. This case suggests that bronchiolitis may be another early, non-infectious pulmonary complication of HSCT.

Prolongation of neutrophil survival by the culture supernatant of Pseudomonas aeruginosa

BACKGROUND AND OBJECTIVES

The pathogenesis of airway inflammation in diffuse panbronchiolitis (DPB) is unknown. Neutrophil survival-enhancing activity, partially mediated by granulocyte-macrophage colony-stimulating factor (GM-CSF), has been shown in the sputum from DPB patients. This study investigated the mechanisms of GM-CSF expression in the airways of DPB patients. This involved examining the effects of mucoid Pseudomonas aeruginosa strains derived from chronically colonized patients with DPB on neutrophil survival and GM-CSF expression.

METHODS

Neutrophils from healthy subjects were cultured with the culture supernatants of P. aeruginosa isolated from sputum of DPB patients in the presence or absence of anti-GM-CSF and anti-GM-CSF receptor (alpha chain) antibodies, and viable neutrophils were counted daily. GM-CSF gene expression in neutrophils was evaluated by RT-PCR.

RESULTS

Neutrophils cultured with the culture supernatants showed significantly prolonged survival, compared with neutrophils cultured with the control broth. The neutrophil survival-enhancing activity in the culture supernatants was lost by heating. The enhanced survival of neutrophils was abolished in the presence of anti-GM-CSF and anti-GM-CSF receptor (alpha chain) antibodies. GM-CSF mRNA was detected in neutrophils cultured with the bacterial supernatants, but not in those with the control broth.

CONCLUSION

P. aeruginosa-derived factors (rich in proteins) stimulated neutrophils to synthesize GM-CSF, which enhanced neutrophil survival in an autocrine/paracrine fashion.

Anti-inflammatory treatment of chronic rhinosinusitis: A shifting paradigm

Treatment of chronic rhinosinusitis still represents an unmet medical need. Presently, the US Food and Drug Administration has not approved any drugs for the treatment of this common condition. Various inflammatory processes are involved in the pathogenesis of chronic rhinosinusitis. Treatment of infection and surgical intervention for correction of anatomical abnormalities often are inadequate in management when singly employed. Anti-inflammatory therapy such as topical cortico-steroids and more recently long-term, low-dose macrolide therapy have been integrated into the treatment algorithm for chronic rhinosinusitis. Better classification and point-of-care identification of inflammatory features may improve choice of anti-inflammatory therapy and thus outcome.

Association of HLA genes with diffuse panbronchiolitis in Chinese patients

Diffuse panbronchiolitis (DPB) is a pulmonary disease of unknown etiology that predominantly affects East Asians, particularly Japanese with a prevalence of 0.00028. Research has shown that HLA-B54 and HLA-A11 are positively associated with this disease. HLA-A, -B, and -DR loci were analyzed using an oligonucleotide microarray in both Chinese patients with DPB and normal control subjects. The most marked difference between the patients and the controls was the decreased frequency of HLA-A2 (p=0.001, OR=0.12), which showed a negative association with the disease; however, there was no significant contribution of HLA-B loci. Interestingly, the frequency of HLA-A11 was increased (p=0.007, OR=3.9), in accordance with previous reports on Japanese and Koreans. In addition, the frequency of HLA-DRB5*010/020 slightly increased (p=0.049). The HLA-associated genes for DPB are located between the HLA-A and HLA-B loci. Differences in HLA-associated genes may partially explain differences in the incidence of DPB among different populations.

Geography and cough aetiology

Cough is the most common complaint that leads patients to seek medical attention. Especially chronic persistent cough is annoying, and requires appropriate diagnosis and treatment. Recent cough guidelines and original papers on cough epidemiology from various countries show remarkable differences in the aetiology of chronic cough among countries, especially between US, UK and Japan. Entities associated with rhinosinus disease (post-nasal drip/upper airway cough syndrome reported from the US, rhinitis or rhinosinusitis from the UK, and sinobronchial syndrome from Japan), and eosinophilic lower airway disorders (cough variant asthma, non-asthmatic eosinophilic bronchitis and atopic cough) are most confusing and might involve significant overlap. In this article, issues related to chronic cough aetiology are discussed, including geographic issues, e.g. 'simple' geography or difference in race, and difference in patient characteristics possibly arising from difference in the medical system.

Macrolide immunomodulatory effects and symptom resolution in acute exacerbation of chronic bronchitis and acute maxillary sinusitis: a focus on clarithromycin

Bacterial respiratory tract infections are common in the primary care setting and patients often seek the assistance of a healthcare professional in order to achieve resolution of their symptoms. Antibiotic agents that offer rapid symptom relief, in addition to excellent bacteriological and clinical cure, are highly desired. Macrolides have proven to be highly effective in treating acute bacterial exacerbations of chronic bronchitis and acute maxillary sinusitis. In addition, immunomodulatory effects that may contribute to symptom resolution have been reported. This article reviews current literature on symptom resolution in acute bacterial exacerbations of chronic bronchitis and acute maxillary sinusitis, with a focus on clarithromycin, and explores the potential mechanisms that may contribute to this action.