Organizing Pneumonia

The role of vasculature and angiogenesis in respiratory diseases

In European countries, nearly 10% of all hospital admissions are related to respiratory diseases, mainly chronic life-threatening diseases such as COPD, pulmonary hypertension, IPF or lung cancer. The contribution of blood vessels and angiogenesis to lung regeneration, remodeling and disease progression has been increasingly appreciated. The vascular supply of the lung shows the peculiarity of dual perfusion of the pulmonary circulation (vasa publica), which maintains a functional blood-gas barrier, and the bronchial circulation (vasa privata), which reveals a profiled capacity for angiogenesis (namely intussusceptive and sprouting angiogenesis) and alveolar-vascular remodeling by the recruitment of endothelial precursor cells. The aim of this review is to outline the importance of vascular remodeling and angiogenesis in a variety of non-neoplastic and neoplastic acute and chronic respiratory diseases such as lung infection, COPD, lung fibrosis, pulmonary hypertension and lung cancer.

Imaging of the Spectrum of Acute Lung Injury

Organizing pneumonia, acute fibrinous and organizing pneumonia, and diffuse alveolar damage, represent multi-compartment patterns of lung injury. The initial region of injury in all remains the same and is centered on the fused basement membrane (BM) between the capillary endothelium and type I pneumocyte. Injury leads to cellular death, BM denudation, increased cellular permeability, and BM structural damage, which leads to exudation, organization, and attempts at repair. When acute lung injury does lead to fibrosis, in some instances it can lead to histologic and/or radiologic usual interstitial pneumonia or nonspecific interstital pneumonia patterns suggesting that lung injury is the primary mechanism for the development of fibrosis.

Identification of kynurenine and quinolinic acid as promising serum biomarkers for drug-induced interstitial lung diseases

BACKGROUND

Drug-induced interstitial lung disease (DILD) is a lung injury caused by various types of drugs and is a serious problem in both clinical practice and drug development. Clinical management of the condition would be improved if there were DILD-specific biomarkers available; this study aimed to meet that need.

METHODS

Biomarker candidates were identified by non-targeted metabolomics focusing on hydrophilic molecules, and further validated by targeted approaches using the serum of acute DILD patients, DILD recovery patients, DILD-tolerant patients, patients with other related lung diseases, and healthy controls.

RESULTS

Serum levels of kynurenine and quinolinic acid (and kynurenine/tryptophan ratio) were elevated significantly and specifically in acute DILD patients. The diagnostic potentials of these biomarkers were superior to those of conventional lung injury biomarkers, Krebs von den Lungen-6 and surfactant protein-D, in discriminating between acute DILD patients and patients with other lung diseases, including idiopathic interstitial pneumonia and lung diseases associated with connective tissue diseases. In addition to identifying and evaluating the biomarkers, our data showed that kynurenine/tryptophan ratios (an indicator of kynurenine pathway activation) were positively correlated with serum C-reactive protein concentrations in patients with DILD, suggesting the potential association between the generation of these biomarkers and inflammation. Our in vitro experiments demonstrated that macrophage differentiation and inflammatory stimulations typified by interferon gamma could activate the kynurenine pathway, resulting in enhanced kynurenine levels in the extracellular space in macrophage-like cell lines or lung endothelial cells. Extracellular quinolinic acid levels were elevated only in macrophage-like cells but not endothelial cells owing to the lower expression levels of metabolic enzymes converting kynurenine to quinolinic acid. These findings provide clues about the molecular mechanisms behind their specific elevation in the serum of acute DILD patients.

CONCLUSIONS

The serum concentrations of kynurenine and quinolinic acid as well as kynurenine/tryptophan ratios are promising and specific biomarkers for detecting and monitoring DILD and its recovery, which could facilitate accurate decisions for appropriate clinical management of patients with DILD.

Migratory Pulmonary Infiltrates in a B-Cell-Depleted COVID-19 Patient

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still rampant around the world. Immunocompromised patients are prone to have long-term infection with coronavirus disease 2019 (COVID-19). However, it is difficult to decide on an appropriate treatment for persistent SARS-CoV-2 infection.

Case Presentation

We present a case of prolonged SARS-CoV-2 infection in a patient who had undergone B-cell depletion therapy. Chest computed tomography (CT) revealed notable migratory pulmonary infiltrates, and bronchoalveolar lavage fluid was positive for SARS-CoV-2 (day-120). The patient responded well to the combination treatment of antiviral medication, convalescent plasma, and corticosteroid.

Conclusion

When chest CT shows migratory pulmonary infiltrates in patients with recent COVID-19, it is necessary to be alert to the possibility of persistent SARS-CoV-2 infection, especially in B-cell-depleted immunocompromised patients. Once the diagnosis is confirmed, repeated antiviral therapy and intravenous convalescent plasma should be considered.

Resolution of an insidious and migratory Mycobacterium tuberculosis-associated secondary organizing pneumonia: a case report and literature review

BACKGROUND

Organizing pneumonia (OP) is a rare interstitial lung disease. Secondary organizing pneumonia (SOP) caused by Mycobacterium tuberculosis (MTB) is extremely rare. Migratory MTB-associated SOP is more deceptive and dangerous. When insidious tuberculosis (TB) is not recognized, SOP would be misdiagnosed as cryptogenic organizing pneumonia (COP). Use of steroid hormone alone leads to the progression of TB foci or even death. Clues of distinguishing atypical TB at the background of OP is urgently needed.

CASE PRESENTATION

A 56-year-old female patient was hospitalized into the local hospital because of cough and expectoration for more than half a month. Her medical history and family history showed no relation to TB or other lung diseases. Community-acquired pneumonia was diagnosed and anti-infection therapy was initialized but invalid. The patient suffered from continuous weigh loss. More puzzling, the lesions were migratory based on the chest computed tomography (CT) images. The patient was then transferred to our hospital. The immunological indexes of infection in blood and pathogenic tests in sputum and the bronchoalveolar lavage fluid were negative. The percutaneous lung puncture biopsy and pathological observation confirmed OP, but without granulomatous lesions. Additionally, pathogen detection of the punctured lung tissues by metagenomics next generation sequencing test (mNGS) were all negative. COP was highly suspected. Fortunately, the targeted next-generation sequencing (tNGS) detected MTB in the punctured lung tissues and MTB-associated SOP was definitely diagnosed. The combined therapy of anti-TB and prednisone was administrated. After treatment for 10 days, the partial lesions were significantly resorbed and the patient was discharged. In the follow-up of half a year, the patient was healthy.

CONCLUSIONS

It is difficult to distinguish SOP from COP in clinical practice. Diagnosis of COP must be very cautious. Transient small nodules and cavities in the early lung image are a clue to consider TB, even though all pathogen tests are negative. tNGS is also a powerful tool to detect pathogen, ensuring prompt diagnosis of TB-related SOP. For clinicians in TB high burden countries, we encourage them to keep TB in mind before making a final diagnosis of COP.

COVID-19 Pneumonia with Migratory Pattern in Agammaglobulinemic Patients: A Report of Two Cases and Review of Literature

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by marked reduction in serum immunoglobulins and early-onset infections. Coronavirus Disease-2019 (COVID-19) pneumonia in immunocompromised patients presents clinical and radiological peculiarities which have not yet been completely understood. Very few cases of agammaglobulinemic patients with COVID-19 have been reported since the beginning of the pandemic in February 2020. We report two cases of migrant COVID-19 pneumonia in XLA patients.

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.

Can Ultrasound and Contrast-Enhanced Ultrasound Help Differentiate between Subpleural Focal Organizing Pneumonia and Primary Lung Malignancy?

Background: Subpleural focal organizing pneumonia (FOP) and primary lung malignancy (PLM) are usually confused. The aim of this study was to explore the value of ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the differential diagnosis of FOP and PLM. Methods: A total of 23 patients (mean age: 64.57 ± 11.86 years) with FOP and 100 (mean age: 66.29 ± 11.05 years) with subpleural lesions diagnosed as PLM, confirmed by pathological diagnosis and clinical follow-up, were retrospectively enrolled. The largest lesion diameter, angle between the lesion border and thoracic wall, air bronchial sign, internal blood supply, blood supply form, and pleural effusion examined using conventional US were retrospectively analyzed. The indicators of CEUS included the arrival time of contrast agent in the lesion, lesion−lung arrival time difference, degree of enhancement, distribution uniformity of contrast medium, presence of non-enhancing region, and arterial filling mode in the lesion. A p < 0.05 was considered statistically significant. Results: Presence of air bronchial sign (odds ratio [OR] = 6.18, p = 0.025), acute angle between the lesion border and thoracic wall (OR = 7.124, p = 0.033), and homogeneous enhancement (OR = 35.26, p = 0.01) showed predictive value for the diagnosis of FOP. According to the results of the logistic regression analysis, the area under the receiver operating curve of the above features combined was 0.960, and the sensitivity and specificity were 95.0% and 82.6%, respectively. Conclusions: US combined with CEUS has the potential to differentiate between FOP and PLM.

Delayed-onset Organizing Pneumonia Emerging after Recovery from Coronavirus Disease 2019: A Report of Three Cases Diagnosed Using Transbronchial Cryobiopsy and a Review of the Literature

We present three cases with an atypical clinical course of organizing pneumonia (OP) secondary to coronavirus disease 2019 (COVID-19). Three patients were discharged with satisfactory improvement after standard steroid therapy for COVID-19. Shortly after the completion of treatment, the patients experienced a flare-up of symptoms. Imaging results showed new lesions in the lungs. Transbronchial lung cryobiopsy showed histological findings consistent with OP in all cases. Steroids were administered, and a good therapeutic response was observed. This report is the first to describe pathologically confirmed OP that developed after recovery from COVID-19. Careful follow-up is advisable for patients who have recovered from COVID-19.

Chest CT Imaging Features of the Pulmonary Sequelae in Four Patients with COVID-19

With the ongoing coronavirus disease 2019 (COVID-19) pandemic, there is an increasing interest in the sequelae and care in recovered patients. Although the long-term sequelae of COVID-19 are still unknown, recently published reports suggest that some of the patients have persistent symptoms and show radiologic abnormalities after discharge. Herein, we present cases of four patients with previous COVID-19 infection manifesting pulmonary sequelae, including pulmonary fibrosis or organizing pneumonia pattern with persistent dyspnea after recovery.

Organizing Pneumonia Secondary to Pulmonary Actinomycosis: A Case Report and Literature Review

Pulmonary actinomycosis is a common clinical infection caused by Actinomyces species. Although its treatment is very effective with Intravenous (IV) antibiotics, its diagnosis is challenging and easily missed. Organizing Pneumonia (OP) can be cryptogenic or secondary to different clinical diseases. Herein, we discuss a case of acute hypoxemic respiratory failure that was found to be due to OP, secondary to pulmonary actinomycosis, with a brief review of the literature. A 64-year-old male presented with acute hypoxemic respiratory failure two days after undergoing elective right total hip arthroplasty. Chest imaging with CT scan showed symmetric bilateral ground-glass opacities most pronounced within the upper lung lobes. The patient was treated initially with IV diuresis, steroids, and broad-spectrum antibiotics. However, his clinical status continued to worsen and his chest imaging showed worsening lung opacities. Video-assisted thoracoscopic lung biopsy (VATS) was done, and pathology results showed features of organizing pneumonia. Tissue culture confirmed Actinomyces species. The patient had clinical improvement after treatment with IV methylprednisolone and IV penicillin G.

Pulmonary actinomycosis is very rarely associated with OP but this bacterial infection should always be in the differential diagnosis when OP is confirmed as the treatment is effective with IV antibiotics.

Post COVID-19 Organizing Pneumonia: The Right Time to Interfere

The COVID-19 pandemic dramatically changed medical care. Healthcare professionals are faced with new issues. Patients who survived COVID-19 have plenty of different continuing symptoms, of which the most common are fatigue and breathlessness. It is not well known how to care for patients with persistent or worsening respiratory symptoms and changes on chest X-ray following COVID-19 pneumonia. In this article, we talk about a subgroup of patients with organizing pneumonia following COVID-19 pneumonia that could be effectively treated with systemic glucocorticoids. It is important that patients with COVID-19 pneumonia be followed-up at least three weeks after diagnosis, in order to recognize early lung damage. We are providing a management algorithm for early diagnosis of lung diseases after COVID-19 pneumonia.

An Uncommon Case of Secondary Organizing Pneumonia Due to Influenza Type B

Secondary organizing pneumonia refers to a disease process caused by pulmonary tissue injury. Various insults can cause secondary organizing pneumonia, including multiple types of infections and cancer. The mainstay of diagnosis is a combination of imaging and lung biopsy showing inflammatory changes, specifically plugs with granulated tissue and fibrosis. Clinical suspicion needs to be raised for secondary organizing pneumonia when a patient is requiring increasing amounts of oxygen in the presence of treatment for pneumonia or another underlying lung disease. Here, we present the case of a 65-year-old male who presented with acute hypoxemic respiratory failure in the setting of previously having been tested positive for influenza B. Aggressive steroids with eventual tapering of his O₂ requirements led to a successful outcome. While influenza has been reported as a cause of secondary organizing pneumonia after proceeding infection, these cases are usually represented by type A, rather than B.

Severe organising pneumonia following COVID-19

Various forms of diffuse parenchymal lung disease have been proposed as potential consequences of severe COVID‑19. We describe the clinical, radiological and histological findings of patients with COVID‑19-associated acute respiratory distress syndrome who later developed severe organising pneumonia including longitudinal follow-up. Our findings may have important implications for the therapeutic modalities in the late-phase of severe COVID‑19 and might partially explain why a subgroup of COVID‑19 patients benefits from systemic corticosteroids.

Organizing pneumonia and COVID-19: A report of two cases

Organizing pneumonia (OP) is a sub-acute process of pulmonary tissue repair secondary to lung injury, defined histopathologically by intra-alveolar buds of granulation tissue within the lumen of distal pulmonary airspaces. It can be either cryptogenic or secondary (SOP) to different clinical conditions, namely infections. Despite being nonspecific, its diagnosis can be made by the association of clinical and imaging criteria. We report two cases of OP associated to SARS-CoV-2 pneumonia, admitted at a Portuguese tertiary hospital unit dedicated to COVID-19. Both patients presented with severe respiratory failure with need of invasive mechanical ventilation. After initial recovery, there was worsening of dyspnea and hypoxemic respiratory failure with increase in inflammatory markers. Chest CT revealed an OP pattern. Other conditions such as superinfection, auto-immune disease and iatrogenic etiology, were excluded and corticotherapy at a dose of 1 mg/kg/day was administered. Chest CT follow up of both our patients showed complete resolution of OP pattern, with mild to moderate residual pulmonary fibrosis without honeycombing. There is no OP to SARS-CoV-2 case series yet published describing the progress of patients after corticotherapy, although the association between systemic corticosteroids and lower all-cause mortality in patients with COVID-19 has been recently established. It is possible that, as has been described with other viruses, OP secondary to SARS-CoV-2 represents an immunological process after initial infection, presenting with elevation of inflammatory markers and cytokines storm in the bloodstream and lung tissue, which may explain the favorable response to corticosteroids.

Rapidly progressive organizing pneumonia associated with COVID-19

We report a case of clinically diagnosed secondary organizing pneumonia (SOP) associated with coronavirus disease 2019 (COVID-19). A 70-year-old woman who had been diagnosed with COVID-19 was admitted to Hokkaido University Hospital. Although her fever, cough, dyspnea, and serum C-reactive protein levels improved, she developed rapidly progressive respiratory failure and computed tomography revealed the development of bilateral lung consolidation. Her dyspnea was relieved, and her oxygenation levels and radiological findings improved after commencing corticosteroid treatment. Blood biomarkers for interstitial lung disease, Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D), showed different responses during the clinical course of her disease. Evaluation of serial changes in levels of KL-6 and SP-D may help diagnose and monitor COVID-19-associated organizing pneumonia (OP). Clinicians should be aware that SOP can develop in response to COVID-19 and that these patients may benefit from the use of steroids.

Pulmonary tuberculosis presenting secondary organizing pneumonia with organized polypoid granulation tissue: case series and review of the literature

Background

Secondary organizing pneumonia (SOP) is difficult to distinguish from cryptogenic organizing pneumonia (COP) considering various clinical situations. SOP caused by Mycobacterium tuberculosis is rare; indeed, it has not been reported as a sequela of disseminated tuberculosis.

Methods

From January 2016 to December 2018, we identified six cases of tuberculosis-associated SOP in which Mycobacterium tuberculosis was revealed by microbiological examination; one of the cases was miliary tuberculosis.

Results

Of the six cases, 17% were positive for acid fast bacillus (AFB) stain, but 100% were positive for M. tuberculosis polymerase chain reaction (MTB PCR) and AFB culture. In all cases, transbronchial lung biopsy was performed and organizing pneumonia was confirmed pathologically. All survived after treatment with anti-tuberculosis therapy.

Conclusions

Pulmonary tuberculosis, which shows OP in lung biopsy, is diagnosed through MTB PCR and AFB culture, and the prognosis is thought to be good.

Airway invasive aspergillosis with organizing pneumonia: a case report and review of literature

Organizing pneumonia (OP) is a distinct clinical and pathologic entity. This condition can be cryptogenic (COP) or secondary to other known causes (secondary OP, SOP). Concomitant occurrence of invasive pulmonary aspergillosis (IPA) with SOP is unusual. Here, we report a case where SOP was a presenting feature in a patient with diagnosed IPA. A previously healthy 62-year-old man presented to the hospital with a month of intermittent fever accompanied by cough and expectoration. According to computed tomography (CT), sputum culture, and transbronchial lung biopsy, he was diagnosed as IPA. Despite undergoing voriconazole and dexamethasone therapy, the patient's condition did not improve after three weeks of therapy. CT-guided percutaneous lung biopsy performed in the left upper lung showed invasive airway aspergillosis with organizing pneumonia. Two months after the combination therapy of voriconazole and methylprednisolone, the CT scan indicated the pulmonary consolidations were almost entirely resolved. To the best of our knowledge, this is the first case of successful non-surgical treatment of IPA with SOP. In a review of the literature, we aimed to highlight the possibility of invasive airway aspergillosis concurrent with secondary organizing pneumonia. Physicians should be aware of the possibility of SOP in the case of IPA.

A retrospective clinical research of relapsed organizing pneumonia

BACKGROUND

Organizing pneumonia (OP) usually responds spectacularly well to initial treatment, but relapses can occur and some cases run a fatal course. Still, the issue of relapse has been addressed in relatively few studies, and predictors have not been clarified. The purpose of this study was to examine the pattern of relapses in OP, to determine whether relapse affects morbidity and mortality, and to identify possible predictors of relapse.

METHODS

Blood sampling, pulmonary function testing, computed tomography (CT) of the chest, and bronchofiberscopy were performed for all patients and were retrospectively reviewed along with clinical information. Periodical chest CT was conducted and additional chest CT was performed when relapse of OP was clinically suspected. All patients were followed regarding treatment response, treatment duration, and presence of relapse. Results were compared between two groups based on serum concentrations of surfactant protein (SP)-D: normal SP-D and high SP-D.

RESULTS

Twenty-two patients were analyzed in this study. SP-D showed a negative correlation with percutaneous oxygen saturation and positive correlations with serum lactate dehydrogenase, Krebs von den Lungen (KL)-6, and percentage of lymphocytes in bronchoalveolar lavage (BAL). Prognosis was good for all patients, but relapse was significantly more frequent in the high SP-D group (6 cases) than in the normal SP-D group (0 cases; P = 0.049). Serum KL-6 and percentage of monocytes in BAL were significantly higher, and pulmonary vital capacity and forced expiratory volume in 1 s were significantly lower in the high SP-D group than in the low SP-D group.

CONCLUSIONS

When treating cases of OP with high serum concentrations of SP-D, attention should be paid to the possibility of relapse.

Pathology of Idiopathic Interstitial Pneumonias

This review discusses diagnostic pathology in idiopathic interstitial pneumonias (IIPs). Accurate understanding of basic structure of lung lobules is critical because the location of abnormalities inside the lobule is an important effector of pathology diagnosis. Depending on the method of obtaining tissue, recognition of the location may be difficult or impossible. Cryobiopsy is a new technology and its coverage of lung lobules is limited. This article discusses fundamental anatomy and approach to interstitial pneumonia. In addition, most histologic types of IIPs are covered, but the focus is on diagnosis of usual interstitial pneumonia because of its clinical importance.

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.

Radiofrequency spectral analysis of EBUS for peripheral pulmonary lesions

BACKGROUND AND OBJECTIVE

We previously reported that histogram-based quantitative evaluation for endobronchial ultrasonography (EBUS) B-mode images could differentiate between benign and malignant lesions. However, these images were generated from reconstructed raw radiofrequency (RF) signals and had some limitations. Currently, there are no reports on raw RF signal data to quantitatively differentiate ultrasound information for peripheral pulmonary lesions.

METHODS

We prospectively hypothesized that RF spectral analysis from EBUS images could reveal sonographic features of peripheral pulmonary diseases. RF data were imported into a frequency spectral analysis software programme, comparing four parameters: mean frequency (MHz); slope; mid-band fit (dB); and y-intercept (dB), to differentiate between benign and malignant lesions. Furthermore, we compared subgroup analysis within benign and malignant lesions.

RESULTS

RF data from EBUS images were obtained in 146 cases, of which, 106 lung cancers and 40 inflammatory diseases were present. Significant differences were observed for three parameters in benign and malignant lesions (mean frequency: P < 0.05, slope: P < 0.05, y-intercept: P < 0.01) with diagnostic accuracy of 61%, 57.5%, 63%, respectively. In subgroup analysis, the acute pneumonia group showed higher mean frequency, higher slope and lower y-intercept patterns compared to mycobacterial and fibrotic diseases (P < 0.05). In malignant lesions, small cell carcinoma showed higher mean frequency, higher slope and lower y-intercept pattern compared to other histopathological lung cancers (P < 0.01).

CONCLUSION

RF analysis might be capable of demonstrating aspects of the lesion's pathological heterogeneity rather than precisely differentiating between benign and malignant lesions.

Cryptogenic and Secondary Organizing Pneumonia: Clinical Presentation, Radiological and Laboratory Findings, Treatment, and Prognosis in 56 Cases

OBJECTIVES

Organizing pneumonia is an important disease that is associated with non-specific clinical findings and radiographic appearance. Our aim was to examine the clinical and radiological features, laboratory findings, diagnostic approach, and response to therapy in subjects with cryptogenic (COP) and secondary organizing pneumonia (SOP).

MATERIALS AND METHODS

Patients' medical records were retrospectively reviewed between 2010 and 2016 in our hospital. We analyzed the symptoms, radiological features, pulmonary function tests, laboratory data, bronchoalveolar lavage findings, treatment, and prognosis.

RESULTS

Thirty-seven patients were diagnosed with COP and 19 patients with SOP. The most common causes of SOP were determined as rheumatologic diseases. The most common symptoms were cough (71.4%) and dyspnea (66.1%). Bilateral symmetrical consolidations were the most prominent radiological appearance in both COP and SOP. The general radiographic findings were not different in COP and SOP. However, pulmonary lesions were located rather in the central (p=0.023) and middle (p=0.001) zones in patients with SOP. Corticosteroid (CS) therapy was administered to 34 (60.7%) patients. Two patients showed deterioration despite CS therapy.

CONCLUSION

The clinical and radiographic findings, treatment response, prognosis were similar in patients with COP and SOP.

Successful treatment of suspected organizing pneumonia in a patient without typical imaging and pathological characteristic: A case report

Introduction

Organizing pneumonia (OP) is a clinicopathological entity characterized by granulation tissue plugs in the lumen of small airways, alveolar ducts, and alveoli. Diagnosis of OP needs the combination of clinical features, imaging and pathology. But it occurs often that there are no typical pathological features to support the diagnosis, which poses a challenge for clinicians' diagnosis and treatment. We diagnosed a case of OP without typical imaging and pathological characteristic and treated successfully. Finally we confirmed the pathological diagnosis.

Conclusions

Not every OP case is supported by pathological evidence and typical imaging changes. It is important for us to judge and decide the diagnosis according to clinical experience.

Clinical characteristics of autoimmune rheumatic disease-related organizing pneumonia

To study the clinical characteristics of autoimmune rheumatic disease-related organizing pneumonia (AIRD-OP), the clinical presentation, radiological findings, treatment, and outcome of AIRD-OP patients were analyzed, in comparison with patients with cryptogenic organizing pneumonia (COP). A total of 131 OP patients were identified, including 57 cases of AIRD-OP, 35 cases of COP, and 39 cases of other disease-related OPs. Among AIRD-OP patients, 36 (63%) presented the symptoms of OP at onset. The primary disease of AIRDs included Sjogren's syndrome (38%), polymyositis/dermatomyositis (23%), rheumatoid arthritis (23%), and undifferentiated AIRD. Compared with COP patients, the prevalence of patients having cough and malaise at baseline was significantly lower (54.4 vs 82.9%, P < 0.05; 49.1 vs 70.6%, P < 0.05), and the signs of moist rales and crackles were more common in AIRD-OP patients (54.4 vs 32.4%, P < 0.05; 49.1 vs 26.5%, P < 0.05). Lung function (TLC%, FVC%) was more significantly reduced in AIRD-OP patients (72 vs 97%, P < 0.05;75 vs 96%, P < 0.05). The dosage of corticosteroids prescribed was significantly higher in AIRD-OP patients (44 vs 37 mg/day, P < 0.05). The complete recovery rate was slightly lower in AIRD-OP patients (22.2 vs 29%, P > 0.05) with a tendency towards higher recurrence rate in AIRD-OP patients (32.7 vs 14.3%, P < 0.05). AIRD-OP may be the most common cause of OP. OP can be the initial presentation of AIRD. Compared with COP patients, AIRD-OP patients are characterized with occult onset but more severe lung involvement and higher recurrence rate.

Is there any superiority among diagnostic methods in organizing pneumonia in terms of clinical features of the patients?

Background

Organizing pneumonia (OP) can be idiopathic or secondary to some clinical situations. If an etiological cause is not present, this phenomenon is called cryptogenic OP. Secondary OP is associated with various diseases that are known to induce the OP.

Objectives

The aim of this study was to evaluate the clinical features of the cases with OP and compare the patients diagnosed by bronchoscopic transbronchial biopsy with patients diagnosed by surgical lung biopsy.

Patients and methods

Medical records of 41 patients diagnosed with OP between 2004 and 2014 were reviewed retrospectively.

Results

Totally, 41 patients with OP were identified. In all, 39.02% of the cases were diagnosed by bronchoscopic methods, and 60.97% of the cases were diagnosed by surgical procedures. Although the frequency of ground glass opacities, consolidations, and micronodules was higher in the group diagnosed by bronchoscopy, mass-like lesions were more common in the cases diagnosed by surgery. Bronchoscopy, performed in 30 patients totally, had a diagnostic efficacy of 53.33%. Diagnostic value of bronchoscopy was significantly higher in cryptogenic OPs. Although diffuse radiological pattern was more common in “successful bronchoscopy” group, frequency of focal pattern was higher in “failed bronchoscopy” group. Ground glass opacity in successful bronchoscopy group and mass-like lesions in failed bronchoscopy group reached significant differences.

Conclusion

There were significant differences between the diagnostic procedures in terms of radiological patterns. This is the first study about the relationship between the diagnostic methods and the characteristics of OP.

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.

Organizing pneumonia: chest HRCT findings

OBJECTIVE:

To determine the frequency of HRCT findings and their distribution in the lung parenchyma of patients with organizing pneumonia.

METHODS:

This was a retrospective review of the HRCT scans of 36 adult patients (26 females and 10 males) with biopsy-proven organizing pneumonia. The patients were between 19 and 82 years of age (mean age, 56.2 years). The HRCT images were evaluated by two independent observers, discordant interpretations being resolved by consensus.

RESULTS:

The most common HRCT finding was that of ground-glass opacities, which were seen in 88.9% of the cases. The second most common finding was consolidation (in 83.3% of cases), followed by peribronchovascular opacities (in 52.8%), reticulation (in 38.9%), bronchiectasis (in 33.3%), interstitial nodules (in 27.8%), interlobular septal thickening (in 27.8%), perilobular pattern (in 22.2%), the reversed halo sign (in 16.7%), airspace nodules (in 11.1%), and the halo sign (in 8.3%). The lesions were predominantly bilateral, the middle and lower lung fields being the areas most commonly affected.

CONCLUSIONS:

Ground-glass opacities and consolidation were the most common findings, with a predominantly random distribution, although they were more common in the middle and lower thirds of the lungs.

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.

From the radiologic pathology archives: organization and fibrosis as a response to lung injury in diffuse alveolar damage, organizing pneumonia, and acute fibrinous and organizing pneumonia

Organization, characterized by fibroblast proliferation, is a common and nearly universal response to lung injury whether it is focal or diffuse. Despite the vast range of injurious agents, the lung's response to injury is quite limited, with a similar pattern of reaction seen radiologically and histologically regardless of the underlying cause. Although there is a tendency to divide organization into distinct entities, the underlying injury to the alveolar epithelial basement membrane is a uniting factor in these processes. This pattern of lung injury is seen in the organizing phase of diffuse alveolar damage, organizing pneumonia (OP), acute fibrinous and organizing pneumonia, and certain types of fibrotic lung disease. In addition, although organization can heal without significant injury, in some instances it progresses to fibrosis, which can be severe. When fibrosis due to organization is present, other histologic and imaging patterns, such as those seen in nonspecific interstitial pneumonia, can develop, reflecting that fibrosis can be a sequela of organization. This article reviews the histologic and radiologic findings of organization in lung injury due to diffuse alveolar damage, OP, and acute fibrinous and organizing pneumonia and helps radiologists understand that the histologic and radiologic findings depend on the degree of injury and the subsequent healing response.

Bronchoalveolar lavage fluid and blood natural killer and natural killer T-like cells in cryptogenic organizing pneumonia

BACKGROUND AND OBJECTIVE

Natural killer (NK) cells appear to be involved in the development of interstitial lung diseases (ILD). The purpose of this study was to investigate the involvement of NK and natural killer T (NKT)-like cells in two recognized cytotoxic ILD with systemic character, hypersensitivity pneumonitis (HP) and cryptogenic organizing pneumonia (COP), compared with idiopathic pulmonary fibrosis (IPF) and controls.

METHODS

Bronchoalveolar lavage fluid (BALF) and peripheral blood (PBL) cells and lymphocyte subsets of 83 patients (26 with COP, 19 with HP and 38 with IPF) and 10 controls were prospectively studied by flow cytometry.

RESULTS

The percentage of NK and NKT-like cells was lower in BALF than in PBL in all patient groups and controls. Patients with COP presented with statistically significantly higher NK and NKT-like cell counts in BALF compared with controls (P = 0.044 and P = 0.05 respectively) and IPF (P = 0.049 and P = 0.045 respectively). BALF NKT-like cell count correlated with PBL NKT-like cell count only in COP (r = 0.627, P = 0.002). In addition, a significant positive correlation between BALF NKT-like cell and PBL cytotoxic T CD8+ cell count was observed in COP (r = 0.562, P = 0.006) but not in HP, IPF or controls.

CONCLUSIONS

Our study provides for the first time evidence for the implication of NKT-like cells in the pathogenesis of COP, as part of both localized and systemic cytotoxicity.

Organizing pneumonia presenting after ulcerative colitis remission

Ulcerative colitis (UC) is the most common form of inflammatory bowel disease worldwide, and extraintestinal manifestations (EIMs) involving various organs and systems occur in 10% to 30% of patients. Recently, although the pulmonary manifestation of UC is being increasingly recognized, these manifestations are described much less frequently than other EIMs. Furthermore, organizing pneumonia (OP) involving the lung parenchyma is a relatively uncommon pulmonary manifestation of UC, and to our knowledge, no case of OP after histologically confirmed UC remission has been previously reported in the English literature. Here, we present a case of OP after remission in an elderly female with a history of UC.

Focal Organizing Pneumonia Mimicking Lung Cancer: A Surgeon's View

Focal organizing pneumonia is a unique form of organizing pneumonia. Little is known regarding its clinical and radiological feature, diagnosis, management, and outcome. Twenty patients with focal organizing pneumonia were investigated and compared with 40 patients with bronchogenic carcinoma. There were 38 men (63.3%) and 22 women (36.7%). The mean age was 55 ± 9.9 years. No specific feature in clinical and radiological manifestation was found to distinguish between focal organizing pneumonia and bronchogenic carcinoma. In patients with focal organizing pneumonia, wedge resection was performed in 12 cases and lobectomy in eight cases. Follow-up was complete with a median period of 26 months (range, 6 to 104 months). All patients were free from recurrence of organizing pneumonia. Clinical and radiologic findings of focal organizing pneumonia are nonspecific, and this unique form of organizing pneumonia is difficult to differentiate from lung cancer. Surgical resection allows both diagnosis and cure. However, considering the benign nature of this disease, major pulmonary resections should be avoided.

Case of polycythemia vera with unusual organizing pneumonia mimicking the clinical features of military tuberculosis and possibly caused by the involvement of neoplastic megakaryocytes

Polycythemia vera (PV) is a clonal myeloproliferative neoplasm (MPN) of hematopoietic stem cells. Although the management of MPN patients generally focuses on the prevention of thromboembolic events caused by hypercoagulability, it is true that the patients with hematological malignancy often suffer from pulmonary diseases with atypical radiological patterns. We present here a 56-year-old woman with PV harboring a JAK2(V617F) mutation that had a diffuse reticulonodular pattern on chest radiography and was initially suspected of having military tuberculosis. Pathological assessment of a video-assisted thoracoscopic surgery lung biopsy revealed that the lesions were in fact organizing pneumonia (OP). Interestingly, pulmonary extramedullary hematopoiesis with a diffuse plugging of the alveolar blood capillaries by numerous atypical megakaryocytes was also observed around the granulation components. The histological findings of our case of unusual OP suggest that local activated neoplastic megakaryocytes and platelets played an important role in the development of spreading fibrotic lesions. JAK2 mutation or the preleukemic phase of MPN may accelerate the activation of megakaryocytes and result in the proliferative process of fibrosis.

[Azithromycin as an adjuvant therapy in cryptogenic organizing pneumonia]

There are literature data about the immunomodulatory properties of some macrolides in cryptogenic organizing pneumonia (COP) as an alternative to corticosteroids in mild disease or as adjuvant to standard therapy. A sixty-year-old female, with a controlled intrinsic asthma, presented with COP and recurrent respiratory exacerbations despite corticosteroid and immunossupressant therapy. Azithromycin (500mg, on alternate days) as an adjuvant to steroids was then started, with clinical and functional improvement and regression of lung infiltrates. Withdrawal of steroids was possible in one year, without evidence of relapse in the next six months. Azithromycin was maintained (three times per week) with no documentation of adverse side effects. This clinical case reinforces the potential role of macrolides anti-inflammatory properties in COP as corticosteroids adjuvant therapy.

Organising pneumonia as the first manifestation of rheumatoid arthritis

Organising pneumonia (OP) is an inflammatory lung disease with distinctive clinicopathological features. OP can be evident during the course of rheumatoid arthritis (RA) with increased disease activity. The authors report an OP associated with RA case in which pulmonary symptoms preceded the onset of joint symptoms. An OP patient with elevated serum anticyclic citrullinated peptide antibody is likely to manifest RA in the near future, reflecting its high disease activity. Thus, an early rheumatologic consultation should be taken into consideration to make an early decision to initiate disease-modifying antirheumatic drugs therapy.