Macrolides inhibit cytokine production by alveolar macrophages in bronchiolitis obliterans organizing pneumonia

Potential treatments of COVID-19: Drug repurposing and therapeutic interventions

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection is caused when Spike-protein (S-protein) present on the surface of SARS-CoV-2 interacts with human cell surface receptor, Angiotensin-converting enzyme 2 (ACE2). This binding facilitates SARS-CoV-2 genome entry into the human cells, which in turn causes infection. Since the beginning of the pandemic, many different therapies have been developed to combat COVID-19, including treatment and prevention. This review is focused on the currently adapted and certain other potential therapies for COVID-19 treatment, which include drug repurposing, vaccines and drug-free therapies. The efficacy of various treatment options is constantly being tested through clinical trials and in vivo studies before they are made medically available to the public.

Update on cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia (COP) is a form of idiopathic interstitial pneumonia that results from the pulmonary reaction to various unidentified injuries. Secondary organizing pneumonia is diagnosed when the triggering factor has been identified; it is mainly caused by infections, toxic substance exposure, drugs, connective tissue diseases, malignancies, autoimmune diseases, bone marrow, or organ transplantation, and radiotherapy. There has been an increase in the number of reports of drug-induced organizing pneumonia (OP). New biological therapies, interferon, monoclonal antibodies, anti-interleukin antibodies, and PD1/PDL-1 inhibitors may induce this specific pulmonary reaction. The classical form of COP is usually subacute and does not manifest as severe disease. Patients maintain sufficient respiratory function, and treatment with steroids is usually effective. Several specific forms of OP (e.g., the cicatricial variant or acute fibrinous type) have distinct clinical and histological features, require higher doses of immunosuppressive drugs, and have a worse prognosis. In the era of administering steroid-sparing therapies for the treatment of interstitial lung diseases, connective tissue dases, and other conditions, it is important to emphasize this type of therapy for patients with COP.

Systematic Review of Systemic Corticosteroids for Treatment of Organizing Pneumonia

Introduction

Regardless corticosteroids are recommended for the treatment of organizing pneumonia there is limited evidence supporting this practice. Thus, we performed a systematic review of the literature on systemic corticosteroid treatment for organizing pneumonia.

Methods

A search was implemented in the PubMed database (Medline) for articles published in the last 20 years. Those studies with incomplete or insufficient data and case reports were excluded. We collected data including: demographics, clinical data, diagnostic procedures, aetiology, treatment regimen (drug, posology, duration, response) and evolution.

Results

A total of 135 publications were selected and finally 13 studies with 849 patients were included in the review: 12 retrospective observational studies and a single prospective observational study. Most of the patients were started on treatment with systemic corticosteroids - a total of 627 (30-100% depending on the series), but there was a great heterogeneity regarding drug, doses and duration. On those that started treatment, 226 (36%) presented a relapse of the disease during follow-up. Only one study provided information regarding treatment side-effects.

Conclusion

The findings of this systematic review show the low quality data supporting the use of corticosteroids for the treatment of organizing pneumonia. This highlights a need to undertake appropriately designed studies to investigate which is the most appropriate treatment regimen that trades off benefits and risks of prolonged corticosteroid administration.

Significance of alveolar nitric oxide concentration in the airway of patients with organizing pneumonia after allogeneic hematopoietic stem cell transplantation

Organizing pneumonia (OP) is a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and a manifestation of peripheral airway/alveolar inflammation. Recently, alveolar nitric oxide concentration (Calv) has been revealed as a noninvasive marker of peripheral airway inflammation; however, whether Calv levels are associated with OP and peripheral airway in patients after allo-HSCT remains unclear. Herein, we evaluated whether Calv levels could reflect the presence of OP and structural airway changes in patients after allo-HSCT. We measured the eNO levels of 38 patients (6 with OP and 32 without OP) who underwent allo-HSCT. Three-dimensional computed tomography (CT) analysis of the airway was performed in 19 patients. We found that in patients with OP, Calv levels were significantly higher than in those without OP (10.6 vs. 5.5 ppb, p < 0.01). Receiver-operating characteristic analyses revealed a Calv cut-off value for OP detection of 10.2 ppb. No significant differences in the patient characteristics, except for the presence of OP (p < 0.01), were noted between the two groups stratified by the Calv cut-off value. Three-dimensional CT images of the airway revealed gradually increasing positive correlations between Calv levels and airway wall area of the third-, fourth-, and fifth-generation bronchi (r = 0.20, 0.31, 0.38; p = 0.42, 0.19, 0.038, respectively), indicating that Calv levels are strongly correlated with the wall thickness of the distal bronchi. Our results suggest that the Calv level may be a useful noninvasive detectable marker for OP after an allo-HSCT.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation is a major cause of morbidity and mortality in patients with idiopathic pulmonary fibrosis. Although the real nature of it is still not clear and there is no proven effective therapy, progress has been made since the consensus definition and diagnostic criteria were proposed. The trial results of several new innovative therapies in idiopathic pulmonary fibrosis have suggested a potential for benefit in acute exacerbation of idiopathic pulmonary fibrosis, leading to double blind randomized clinical trials in this area. This article reviews the present knowledge on acute exacerbation of idiopathic pulmonary fibrosis, focusing on the triggering factors and treatment.

Secondary organizing pneumonia following occupational acute nitrogen oxide poisoning: a case report

Secondary organizing pneumonia (SOP) is a nonspecific inflammatory response towards acute lung injuries caused by various diseases. However, organizing pneumonia (OP) secondary to occupational acute nitrogen oxide poisoning has been reported rarely. We report a 49-year-old man who suffered from nitrogen oxide poisoning after inhaling mixed gas at work. After pathological examination, he was diagnosed with OP. In the absence of other underlying factors causing OP, he was diagnosed with SOP owing to acute nitrogen oxide poisoning. After systematic treatment, the patient recovered and was discharged in better health. In patients with lung injury caused by acute nitrogen oxide poisoning, physicians should be alert to the risk of patients subsequently developing SOP, and timely diagnosis and treatment are essential for complete recovery.

Low-Dose Radiotherapy for Late-Stage COVID-19 Pneumonia?

Low dose radiotherapy has been used in the pre-antibiotic era for the treatment of all kind of pneumonia, with relative success. The unimaginable daily death toll of thousands of victims dying from COVID-19 pneumonia and the marginal therapeutic value of agents tested, brings forward the re-evaluation of the position of radiotherapy in the treatment of late stage lethal COVID-induced respiratory failure. A sound biological rationale supports this idea. Immunopathology studies show that excessive inflammation and infiltration of the lung parenchyma by immune cells is the cause of death. Mice lacking IFNαβ receptors remain unaffected by the virus. Radiotherapy at doses of 50-200cG may exert an intense anti-inflammatory effect and reduce the burden of inflammatory cells infiltrating the lungs. Whether radiotherapy, in conjunction with remdesivir and/or macrolides can reduce the dramatic death rates related to COVID-19 is an open challenge, under the absence of an alternative solution.

Possible mechanisms of action of clarithromycin and its clinical application as a repurposing drug for treating multiple myeloma

Clarithromycin (CAM), a semisynthetic macrolide antibiotic, is a widely used antibacterial drug. Recently, the efficacy of CAM as an add-on drug for treating multiple myeloma (MM) has been noted. Its effect on treating MM has been confirmed in combination chemotherapies that include CAM. However, a single treatment of CAM has no efficacy for treating MM. Many myeloma growth factors (MGFs) including interleukin (IL)-6 are known to be closely involved in the development of MM. CAM has been shown to suppress many MGFs, particularly IL-6. The possible mechanisms of action of CAM in treating MM have been suggested to include its immunomodulatory effect, autophagy inhibition, reversibility of drug resistance, steroid-sparing/enhancing effect and suppression of MGFs. In addition, MM is characterised by uncontrolled cell growth of monoclonal immunoglobulin (Ig)-producing neoplastic plasma cells. Large quantities of unfolded or misfolded Ig production may trigger considerable endoplasmic reticulum stress. Thus, MM is originally a fragile neoplasm particularly susceptible to autophagy-, proteasome- and histone deacetylase 6-inhibitors. Taken together, CAM plays an important role in MM treatments through its synergistic mechanisms. In addition, CAM with its pleiotropic effects on cytokines including IL-6 and indirect antiviral effects might be worth a try for treating COVID-19.

A long-term retrospective study of patients with biopsy-proven cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia (COP) is characterized by good response to corticosteroids, but frequent relapses after reduction or cessation of treatment are noted. The incidence, risk factors of relapse, and long-term outcomes of patients with COP remain undetermined. Patients with COP from September 2010 to December 2017 were enrolled. Hospital and office records were used as data sources. Clinical information, lab examinations, chest radiographs, treatment courses, and follow-up data were collected. Relapse group was defined as worsening of clinical manifestations in combination with progression of radiographic abnormalities in the absence of identified causes. Eighty-seven patients with COP were enrolled. Of them, 73 patients were treated with corticosteroids with relapse rate yielding 31.5% (23 of 73). Eleven patients were treated with macrolides and none of them relapsed. Fever was more common (65.2% vs. 32.0%, p = 0.004), C-reactive protein (CRP) was higher (31.5 ± 39.4 mg/L vs. 17.5 ± 32.2 mg/L, p = 0.038), and diffusion capacity for carbon monoxide (DLCO) % predicted was lower (45.9 ± 14.2% vs. 57.6 ± 18.5%, p = 0.050) in relapse group compared to nonrelapse group. Four patients who presented with organizing pneumonia (OP) as the first manifestation were ultimately diagnosed with OP secondary to autoimmune disease in follow-up. We showed relapse was common in COP patients treated with corticosteroids, but the prognosis was favorable. Fever, elevated CRP, and a reduced DLCO were related to relapse. As OP may not always be cryptogenic, a careful follow-up should be programmed to diagnose the underlying systemic disease.

Bitter Taste Receptors (TAS2Rs) in Human Lung Macrophages: Receptor Expression and Inhibitory Effects of TAS2R Agonists

BACKGROUND

Bitter-taste receptors (TAS2Rs) are involved in airway relaxation but are also expressed in human blood leukocytes. We studied TAS2R expression and the effects of TAS2R agonists on the lipopolysaccharide (LPS)-induced cytokine release in human lung macrophages (LMs).

METHODS

Lung macrophages were isolated from patients undergoing surgery for carcinoma. We used RT-qPCR to measure transcripts of 16 TAS2Rs (TAS2Rs 3/4/5/7/8/9/10/14/19/20/31/38/39/43/45 and 46) in unstimulated and LPS-stimulated (10 ng.mL-1) LMs. The macrophages were also incubated with TAS2R agonists for 24 h. Supernatant levels of the cytokines TNF-α, CCL3, CXCL8 and IL-10 were measured using ELISAs.

RESULTS

The transcripts of all 16 TAS2Rs were detected in macrophages. The addition of LPS led to an increase in the expression of most TAS2Rs, which was significant for TAS2R7 and 38. Although the promiscuous TAS2R agonists, quinine and denatonium, inhibited the LPS-induced release of TNF-α, CCL3 and CXCL8, diphenidol was inactive. Partially selective agonists (dapsone, colchicine, strychnine, and chloroquine) and selective agonists [erythromycin (TAS2R10), phenanthroline (TAS2R5), ofloxacin (TAS2R9), and carisoprodol (TAS2R14)] also suppressed the LPS-induced cytokine release. In contrast, two other agonists [sodium cromoglycate (TAS2R20) and saccharin (TAS2R31 and 43)] were inactive. TAS2R agonists suppressed IL-10 production - suggesting that this anti-inflammatory cytokine is not involved in the inhibition of cytokine production.

CONCLUSION

Human LMs expressed TAS2Rs. Experiments with TAS2R agonists' suggested the involvement of TAS2Rs 3, 4, 5, 9, 10, 14, 30, 39 and 40 in the inhibition of cytokine production. TAS2Rs may constitute new drug targets in inflammatory obstructive lung disease.

Acute fibrinous organising pneumonia presenting as a cavitary lung lesion and treatment response to azithromycin

Acute fibrinous organising pneumonia is distinct from the classic diffuse alveolar damage, organising pneumonia and eosinophilic pneumonia. A 52-year-old woman presented with fever, productive cough, night sweats and left-sided pleuritic chest pain for a week. Physical examination was significant only for decreased breath sounds in the left infraclavicular area laterally. Imaging studies revealed a peripheral thick-walled left upper lobe cavitary lesion, left lower lobe consolidation and an enlarged subcarinal lymph node. She was treated with doxycycline for 10 days without improvement. Pertinent laboratory tests, microbiologic workup and fibre-optic bronchoscopy were non-diagnostic and a CT-guided left upper lobe lung biopsy revealed acute fibrinous organising pneumonia. She was treated with azithromycin with complete resolution of symptoms. To our knowledge, this is the first reported case of acute fibrinous organising pneumonia presenting as a cavitary lung lesion and the first with treatment response to azithromycin.

Increased neutrophils and IL-17A in a rare organizing pneumonia secondary to extrapulmonary operation

Organizing pneumonia (OP) is a clinical syndrome caused by various diseases. The most common causes are infection, connective tissue disease, radiation therapy, drug reaction and thoracic operation. Herein, we describe the case of a patient that developed OP after fracture internal fixation. The case was confirmed to be OP by computer tomographic (CT)-guided percutaneous needle lung biopsy, and other causes of OP were excluded. After the initiation of corticosteroid therapy, marked clinical and radiographic improvements occurred. In addition, we discovered increased neutrophils and IL-17A in the lung tissue of the patient. To the best of our knowledge, this is the first case report about OP secondary to extrapulmonary operation.

Surgical management of organizing pneumonia: a retrospective study of 24 cases in a single Centre

Background

Organizing pneumonia (OP) is a rare disease that is often easily misdiagnosed as a malignancy. The diagnosis of OP can prove quite challenging. Patients typically receive treatment with high-dose corticosteroids. Relapse is common if corticosteroid treatment is reduced or stopped. However, given that long-term corticosteroid treatment often results in significant side-effects, the aim of this study was to discuss the diagnosis and surgical treatment of OP.

Material and methods

The medical records of 24 patients with pathologically diagnosed OP between October 2007 and January 2019 were retrospectively reviewed. All patients underwent thoracic computed tomography (CT) and transbronchial biopsy or CT-guided percutaneous needle aspiration. We analysed the clinical manifestations, radiological findings, diagnostic methods, treatment, and follow-up outcomes of all patients.

Results

In total, 24 patients with OP were identified. The study included 17 (70.8%) men and 7 (29.2%) women, and the mean age was 61.25 ± 11.33 years (range: 31–82). The most common symptom was cough (n = 16; 66.6%), and the most common radiological finding was consolidation (n = 13; 54.2%) on thoracic CT. The diagnosis of OP was made by transbronchial biopsy in 11 patients (45.8%), and percutaneous needle aspiration biopsy in 13 (54.2%). We performed 11 wedge resections, 9 segmentectomy, and 4 lobectomies. Twenty patients underwent video-assisted thoracoscopic surgery (VATS), and 4 underwent thoracotomy. Complete lesion resection was obtained in all patients, and all patients were discharged from the hospital between 5 and 11 days after surgery. The mean follow-up period was 59.1 ± 34.5 (range: 2–134) months. Residual lesions or local or distant recurrence were not observed.

Conclusions

OP is a rare disease, and the exact aetiology remains unclear. Preoperative diagnosis is difficult to achieve despite the use of transbronchial biopsy or CT-guided percutaneous needle aspiration. Complete surgical resection represents an effective method for the treatment of OP.

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.

Seven patients with cryptogenic organizing pneumonia succesfully treated with clarithromycin

Cryptogenic organizing pneumonia is a type of idiopathic interstitial pneumonia with a subacute presentation characterized by variable degrees of cough and dyspnea. As a consequence of the upregulation of inflammatory mediators in cryptogenic organizing pneumonia, it typically responds to anti-inflammatory therapy. Although the majority of patients recover completely with long term oral corticosteroids, relapse is common and their long term use is associated with many adverse effects. Macrolides antiinflammatory agents that appear effective and safe for the treatment of cryptogenic organizing pneumonia. Herein, we analyzed the clinical properties of seven cryptogenic organizing pneumonia patients without severe functional loss who were treated with clarithromycin. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 165-170).

Organizing pneumonia revisited: insights and uncertainties from a series of 67 patients

Background: Organizing pneumonia (OP) is classified as an acute/subacute pneumonia according to the American Thoracic Society/European Respiratory Society statement (2013 update). Although its clinical presentation, radiologic and histologic features are well established, data on the relevance of potential causes, corticosteroid doses and length, or management of relapses are based on heterogeneous series of patients. Objectives: The aims of this study were to describe clinical presentation, diagnosis and treatment of OP, explore potential causes, discuss strategies for managing relapses, and analyze prognostic factors. We also discuss our findings in relation to relevant data in the literature. Methods: We performed a cross-sectional study of all patients diagnosed with OP at a tertiary referral center in northern Portugal between 2008 and 2015. Results: Sixty-seven patients were diagnosed with OP over the 7-year study period. Dyspnea and cough were the most common presenting symptoms and approximately 30% of patients were hospitalized at the time of diagnosis. Approximately half of the patients were receiving drugs described as potential causes of OP. Microorganisms were isolated in approximately one-third of patients. Other potential causes identified were hematologic disorders, neoplasms, connective tissue diseases, myelodysplastic syndromes, immunodeficiencies, radiotherapy, and bird exposure. Cryptogenic OP was diagnosed in just 16 patients (23.8%). Corticosteroids were the most common treatment and 11 patients (16.4%) experienced relapse. Conclusions: The findings for this series of patients confirm the extreme variability of the contexts in which OP can occur and suggest that rather than a distinct, homogeneous clinicopathologic entity, OP is a non-specific reaction whose outcomes are dependent on the cause. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 129-138).

A 12-week combination of clarithromycin and prednisone compared to a 24-week prednisone alone treatment in cryptogenic and radiation-induced organizing pneumonia

Background: Some data suggest that anti-inflammatory macrolides may be effective to treat organizing pneumonia (OP) and prevent relapses, but no formal comparison with prednisone alone is available. To explore this issue, we retrospectively compared the efficacy of a 12-week combined regimen of clarithromycin and prednisone with a 24-week prednisone alone regimen in OP. Methods: A standard 12-week regimen of combined clarithromycin and prednisone was designed for the treatment of cryptogenic or radiation-induced OP, aiming at reducing the cumulated prednisone dose and the relapse rate. Its use was left to the discretion of the treating physicians, members of the Groupe d'Etudes et de Recherche sur les Maladies Orphelines Pulmonaires. Data were compared to a historical control group treated with a standard 24-week prednisone alone regimen. Results: 16 patients were treated with combined therapy and 21 with prednisone alone. Complete radiological remission was achieved in 63% of the combined therapy group and 81% of the prednisone alone group (p=0.38). Symptomatic relapses occurred in 81% of the combined therapy group, and 52% of the prednisone alone group (p=0.14). No side effect of clarithromycin was reported. Conclusions: In patients with cryptogenic or radiation-induced OP, a 12-week regimen of clarithromycin and prednisone showed no benefit on remission rate and relapse rate as compared to a 24-week prednisone only regimen. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 230-238).

Long-term macrolides in diffuse interstitial lung diseases

In the present review we provide currently available evidence for the use of macrolides in the treatment of diffuse interstitial lung diseases (ILDs). Up to now, research on macrolides has mainly focused on three areas. First, macrolides have shown some promising results in cellular models and case reports as antifibrotic agents, by promoting autophagy and clearance of intracellular protein aggregates and acting as regulators of surfactant homeostasis. Secondly, macrolides have an immunomodulatory effect, which has been applied in some organising pneumonia cases. In particular, macrolides have been tested in association with systemic corticosteroids as steroid-sparing agents and alone as either first-line agents in mild cases or second-line agents where steroids were poorly tolerated or had failed. Thirdly, a recent area of research concerns the possible role of macrolides as modulators of lung microbiota and the host–microbiota interaction. This function has been particularly studied in idiopathic pulmonary fibrosis patients, in whom changes in microbiota have been proved to be associated with disease progression. However, the lack of high-quality studies makes the application of macrolide therapy in ILDs a field in which research should be conducted on a large scale.

Managing the oncologic patient with suspected pneumonia in the intensive care unit

INTRODUCTION

Solid cancer patients are frequently admitted in intensive care units for critical events. Improving survival rates in this setting is considered an achievable goal today. Respiratory failure is the main reason for admission, representing a primary target for research.

AREAS COVERED

This review presents a diagnostic and therapeutic algorithm for pneumonia and other severe respiratory events in the solid cancer population. It aims to increase awareness of the risk factors and the different etiologies in this changing scenario in which neutropenia no longer seems to be a decisive factor in poor outcome. Bacterial pneumonia is the leading cause, but opportunistic diseases and non-infectious etiologies, especially unexpected adverse effects of radiation, biological drugs and monoclonal antibodies, are becoming increasingly frequent. Options for respiratory support and diagnostics are discussed and indications for antibiotics in the management of pneumonia are detailed. Expert commentary: Prompt initiation of critical care to facilitate optimal decision-making in the management of respiratory failure, early etiological assessment and appropriate antibiotic therapy are cornerstones in management of severe pneumonia in oncologic patients.

Cryptogenic organizing pneumonia-Results of treatment with clarithromycin versus corticosteroids-Observational study

Background

Cryptogenic organizing pneumonia (COP) is a clinicopathological syndrome of unknown origin. Corticosteroids are the standard treatment, but clarithromycin (CAM) is also effective. The aim of this observational retrospective study was to compare the results of CAM versus prednisone (PRE) treatment in patients with biopsy-proven OP without respiratory insufficiency.

Material and methods

In a 15-year period, 40 patients were treated with CAM (500 mg twice daily orally for 3 months) and 22 with PRE (mean initial dose of 0.67 ± 0.24 mg/kg/d for a mean of 8.59 ± 3.05 months).

Results

The clinical presentation, laboratory, and radiological findings did not differ markedly between patients treated with CAM and PRE, with the exception of a higher frequency of sweats (55% vs. 23%; p < 0.015), ground glass opacities (95% vs. 50%; p <0.0001) and nodular lesions (45% vs. 18%; p = 0.036) in the CAM group. A complete response was achieved in 35(88%) patients treated with CAM and in all treated with PRE. Patients treated with PRE relapsed more frequently than those treated with CAM (54.5% vs. 10%; p < 0.0001). Corticosteroid-related adverse events were noticed in 8(6.5%) patients (with one death), but CAM caused only one (2.5%) allergic reaction. A FVC >80% identified patients who might be successfully treated with CAM with a sensitivity of 60% and a specificity of 88.57% (AUC 0.869; 95% CI 0.684–1; p = 0.008); the figures for the FEV1 were >70%, a sensitivity of 60%, and a specificity of 91.43% (AUC 0.809; 95%CI 0.609–1; p = 0.027).

Conclusions

CAM can be used to treat COP patients in whom the pulmonary function parameters are within normal limits. Such therapy is shorter, better tolerated, and associated with fewer adverse events and relapses than is PRE. However, the therapy is ineffective in some patients.

Organizing Pneumonia in an Adult With Chronic Recurrent Noninfectious Osteomyelitis: A Case Report and Literature Review

Chronic recurrent multifocal osteomyelitis (CRMO) is an idiopathic inflammatory disorder primarily of children and adolescents that is characterized by multifocal nonpyogenic relapsing and remitting inflammatory bone lesions. Pulmonary abnormalities are rarely associated with CRMO, with two reported cases of consolidation on chest CT that occurred in children. We present a case of organizing pneumonia in an adult patient with CRMO. The concurrent worsening of pulmonary and bone disease suggests that CRMO may be a rare cause of organizing pneumonia.

Azithromycin for idiopathic acute exacerbation of idiopathic pulmonary fibrosis: a retrospective single-center study

Background

Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is a fatal condition without an established pharmaceutical treatment. Most patients are treated with high-dose corticosteroids and broad-spectrum antibiotics. Azithromycin is a macrolide with immunomodulatory activity and may be beneficial for treatment of acute lung injury. The objective of this study was to determine the effect of azithromycin on survival of patients with idiopathic AE of IPF.

Methods

We evaluated 85 consecutive patients hospitalized in our department for idiopathic AE of IPF from April 2005 to August 2016. The initial 47 patients were treated with a fluoroquinolone-based regimen (control group), and the following 38 consecutive patients were treated with azithromycin (500 mg/day) for 5 days. Idiopathic AE of IPF was defined using the criteria established by the 2016 International Working Group.

Results

Mortality in patients treated with azithromycin was significantly lower than in those treated with fluoroquinolones (azithromycin, 26% vs. control, 70%; p < 0.001). Multivariate analysis revealed that the two variables were independently correlated with 60-day mortality as determined by the Acute Physiology and Chronic Health Evaluation II score (p = 0.002) and azithromycin use (p < 0.001).

Conclusion

Azithromycin may improve survival in patients with idiopathic AE of IPF.

Nonantibiotic macrolides restore airway macrophage phagocytic function with potential anti-inflammatory effects in chronic lung diseases

We reported defective efferocytosis associated with cigarette smoking and/or airway inflammation in chronic lung diseases, including chronic obstructive pulmonary disease, severe asthma, and childhood bronchiectasis. We also showed defects in phagocytosis of nontypeable Haemophilus influenzae (NTHi), a common colonizer of the lower airway in these diseases. These defects could be substantially overcome with low-dose azithromycin; however, chronic use may induce bacterial resistance. The aim of the present study was therefore to investigate two novel macrolides-2'-desoxy-9-(S)-erythromycylamine (GS-459755) and azithromycin-based 2'-desoxy molecule (GS-560660)-with significantly diminished antibiotic activity against Staphylococcus aureus, Streptococcus pneumonia, Moraxella catarrhalis, and H. influenzae We tested their effects on efferocytosis, phagocytosis of NTHi, cell viability, receptors involved in recognition of apoptotic cells and/or NTHi (flow cytometry), secreted and cleaved intracellular IL-1β (cytometric bead array, immunofluorescence/confocal microscopy), and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) using primary alveolar macrophages and THP-1 macrophages ± 10% cigarette smoke extract. Dose-response experiments showed optimal prophagocytic effects of GS-459755 and GS-560660 at concentrations of 0.5-1 µg/ml compared with our findings with azithromycin. Both macrolides significantly improved phagocytosis of apoptotic cells and NTHi (e.g., increases in efferocytosis and phagocytosis of NTHi: GS-459755, 23 and 22.5%, P = 0.043; GS-560660, 23.5 and 22%, P = 0.043, respectively). Macrophage viability remained >85% following 24 h exposure to either macrolide at concentrations up to 20 µg/ml. Secreted and intracellular-cleaved IL-1β was decreased with both macrolides with no significant changes in recognition molecules c-mer proto-oncogene tyrosine kinase; scavenger receptor class A, member 1; Toll-like receptor 2/4; or CD36. Particulate cytoplasmic immunofluorescence of NLRP3 inflammasome was also reduced significantly. We conclude that GS-459755 and GS-560660 may be useful for reducing airway inflammation in chronic lung diseases without inducing bacterial resistance.

Organizing pneumonia in mice and men

BACKGROUND

Organizing pneumonia is a reaction pattern and an inflammatory response to acute lung injuries, and is characterized by intraluminal plugs of granulation tissue in distal airspaces. In contrast to other fibrotic pulmonary diseases, organizing pneumonia is generally responsive to corticosteroids. However, some patients do not respond to treatment, leading to respiratory failure and potentially death (up to 15 % of patients). In order to devise new therapeutic strategies, a better understanding of the disease's pathomechanisms is warranted. We previously generated a mouse model overexpressing CCL2, which generates organizing pneumonia-like changes, morphologically comparable to human patients. In this study, we investigated whether the histopathological similarities of human and murine pulmonary organizing pneumonia lesions also involve similar molecular pathways.

METHODS

We analyzed the similarities and differences of fibrosis-associated gene expression in individual compartments from patients with organizing pneumonia and transgenic (CCL2) mice using laser-assisted microdissection, real-time PCR and immunohistochemistry.

RESULTS

Gene expression profiling of human and murine organizing pneumonia lesions showed in part comparable expression levels of pivotal genes, notably of TGFB1/Tgfb1, TIMP1/Timp1, TIMP2/Timp2, COL3A1/Col3a1, CXCL12/Cxcl12, MMP2/Mmp2 and IL6/Il6. Hence, the transgenic CCL2 mouse model shows not only pathogenomic and morphological features of human organizing pneumonia but also a similar inflammatory profile.

CONCLUSIONS

We suggest that the CCL2-overexpressing transgenic mouse model (CCL2 Tg mice) is suitable for further investigation of fibrotic pulmonary remodeling, particularly of organizing pneumonia pathogenesis and for the search for novel therapeutic strategies.

Clinical Characteristics and Cytokine Profiles of Organizing Pneumonia in Patients with Rheumatoid Arthritis Treated with or without Biologics

OBJECTIVE

It has been reported that organizing pneumonia (OP) develops when patients with rheumatoid arthritis (RA) are treated with biologic disease-modifying antirheumatic drugs (bDMARD). However, the clinical characteristics and pathophysiology of OP in RA remain unknown in patients treated with bDMARD. We investigated the clinical characteristics and cytokine profiles of patients with RA-OP treated with bDMARD or conventional synthetic DMARD (csDMARD).

METHODS

Twenty-four patients with RA who had developed OP were enrolled. These patients included 12 treated with bDMARD (bDMARD-OP subset) and 12 treated with csDMARD (csDMARD-OP subset). We compared the clinical characteristics and cytokine profiles between the patients with OP (OP subset, n = 24) and non-OP patients (non-OP subset, n = 29).

RESULTS

There was no significant difference in clinical characteristics between the OP subset and the non-OP subset. Four patients developed OP within 2 months of bDMARD administration. In the other 8 patients, OP developed more than 1 year after the initiation of bDMARD. OP improved with corticosteroid treatment in all bDMARD-OP patients. After OP improved, bDMARD were readministered in 6 patients, and no OP recurrence was observed in any of these patients. Our multivariate analysis revealed that serum levels of interferon-α (IFN-α), interleukin (IL)-1β, IL-6, IL-8, and interferon-γ-inducible protein 10 were significantly associated with the development of OP, although these cytokines tended to be lower in the bDMARD-OP subset than in the csDMARD-OP subset.

CONCLUSION

OP is unlikely to be fatal in patients treated with bDMARD or csDMARD. IFN-α and proinflammatory cytokines are associated with the pathophysiology of OP in RA.

Clarithromycin Synergistically Enhances Thalidomide Cytotoxicity in Myeloma Cells

Clarithromycin (CAM) is a macrolide antibiotic that is widely used in the treatment of respiratory tract infections, sexually transmitted diseases and infections caused by the Helicobacter pylori and Mycobacterium avium complex. Recent studies showed that CAM was highly effective against multiple myeloma (MM) when used in combination with immunomodulatory drugs and dexamethasone. However, the related mechanism is still unknown. As 3 immunomodulatory agents are all effective in the respective regimen, we postulated that CAM might enhance the effect of immunomodulatory drugs. We evaluated the interaction effects of CAM and thalidomide on myeloma cells. Taking into consideration that thalidomide did not affect the proliferation of myeloma cells in vitro, we cocultured myeloma cells with peripheral blood monocytes and evaluated the effects of CAM and thalidomide on the cocultured cell model. Data showed that thalidomide and CAM synergistically inhibited the proliferation of the cells. On this same model, we also found that thalidomide and CAM synergistically decreased the secretion of tumor necrosis factor-α and interleukin-6. This might be caused by the effect of the 2 drugs on inhibiting the activation of ERK1/2 and AKT. These data suggest that the efficacy of CAM against MM was partly due to its synergistic action with the immunomodulatory agents.

A case of bronchiolitis obliterans organizing pneumonia in an HIV-infected Korean patient successfully treated with clarithromycin

Background

Bronchiolitis obliterans organizing pneumonia (BOOP) is a type of diffuse interstitial lung disease characterized by the pathology of fibroblastic plugs in the lumens of the respiratory bronchioles, alveolar ducts, and alveoli. The occurrence of BOOP in human immunodeficiency virus (HIV)-infected patients has rarely been described, and there have been no clinical case reports in Korea.

Case presentation

A 24-year-old female who had been diagnosed with HIV ten years prior was admitted due to a 1-year history of cough and sputum production and a 3-day history of fever. She had poor adherence to anti-retroviral therapy (ART) due to gastrointestinal troubles. At the time of admission, her CD4 T-cell count was 5 cells/mm³. A high resolution computed tomography (CT) scan showed tiny centrilobular nodules with a tree-in-bud pattern in both lungs. Bacterial culture, Pneumocystis jirovecii polymerase chain reaction (PCR), Aspergillus galactomannan antigen (Ag) assay, and respiratory virus PCR were negative. Rapid chest x-ray improvement was seen after a 7-day treatment with anti-tuberculosis medication, ceftriaxone, and clarithromycin. Miliary tuberculosis seemed unlikely considering the rapid radiologic improvement and negative tuberculosis PCR results. Due to the unknown etiology, we performed video-assisted thoracoscopic surgery (VATS) to determine the cause of the diffuse lung infiltration. Pathologic findings were consistent with BOOP, while tissue acid-fast bacilli (AFB) stain and tuberculosis PCR results were negative. Tuberculosis medication and intravenous ceftriaxone were discontinued, while treatment with clarithromycin monotherapy was sustained. Five months after discharge, the patient was asymptomatic with a normal chest x-ray and as her adherence to ART improved, her CD4 T-cell count rose to 181 cells/mm³. Clarithromycin was discontinued at that time and the patient is currently receiving regular outpatient follow-up.

Conclusion

This case suggests that macrolides are a potential treatment option in HIV-infected patients with mild BOOP. In cases that are otherwise unexplained or unresponsive to treatment, BOOP should be taken into consideration and surgical biopsy performed to confirm a diagnosis of BOOP.

Macrolide therapy in cryptogenic organizing pneumonia: A case report and literature review

Cryptogenic organizing pneumonia (COP) is a pulmonary disorder associated with nonspecific clinical presentations. The macrolide class of antimicrobial agents is widely used to treat infectious and inflammatory respiratory diseases in humans. The present study reports a case of COP that was effectively treated with azithromycin in combination with glucocorticoid. A literature review of similar cases is also presented. It was found that all COP patients in the literature received macrolide treatment, including six cases with unknown clinical outcomes. For the remaining 29 patients, 20 patients initially received the macrolide as a single therapy and 4/5 of them (16 cases) were cured with a treatment time of 3–14 months, while 1/5 (4 cases) showed no improvement after treatment for 1 month and were switched to a glucocorticoid or combination treatment with a glucocorticoid, after which the disease was finally well-controlled. Side-effects of macrolide were rare. Based on this analysis, it is recommended that macrolides can be used as a first-line therapy in patients with mild COP. For patients with recurrent COP, it is suggested that macrolides should be used as an adjunctive therapy with other treatments, such as a glucocorticoid.

Macrolide use leads to clinical and radiological improvement in patients with cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia is an idiopathic form of organizing pneumonia (also known as bronchiolitis obliterans organizing pneumonia). Because cryptogenic organizing pneumonia is considered an inflammatory disease, it characteristically responds to the broad-spectrum antiinflammatory corticosteroids, although relapse is common on discontinued use. Additionally, long-term use of corticosteroids has many side effects. In severe cases in which corticosteroids have failed, either cytotoxic therapy or macrolide therapy is used. Because of the toxicity and adverse effects of cytotoxic therapy (e.g., cyclophosphamide), this therapy option cannot be used long term in refractory cases. Macrolide therapy has been shown to be an effective antiinflammatory agent that is relatively safe when used on a long-term basis in patients with cryptogenic organizing pneumonia.

Azithromycin is able to control Toxoplasma gondii infection in human villous explants

Background

Although Toxoplasma gondii infection is normally asymptomatic, severe cases of toxoplasmosis may occur in immunosuppressed patients or congenitally infected newborns. When a fetal infection is established, the recommended treatment is a combination of pyrimethamine, sulfadiazine and folinic acid (PSA). The aim of the present study was to evaluate the efficacy of azithromycin to control T. gondii infection in human villous explants.

Methods

Cultures of third trimester human villous explants were infected with T. gondii and simultaneously treated with either PSA or azithromycin. Proliferation of T. gondii, as well as production of cytokines and hormones by chorionic villous explants, was analyzed.

Results

Treatment with either azithromycin or PSA was able to control T. gondii infection in villous explants. After azithromycin or PSA treatment, TNF-α, IL-17A or TGF-β1 levels secreted by infected villous explants did not present significant differences. However, PSA-treated villous explants had decreased levels of IL-10 and increased IL-12 levels, while treatment with azithromycin increased production of IL-6. Additionally, T. gondii-infected villous explants increased secretion of estradiol, progesterone and HCG + β, while treatments with azithromycin or PSA reduced secretion of these hormones concurrently with decrease of parasite load.

Conclusions

In conclusion, these results suggest that azithromycin may be defined as an effective alternative drug to control T. gondii infection at the fetal-maternal interface.