Organizing pneumonia is associated with molecular allograft injury and the development of antibody-mediated rejection

BACKGROUND

The association between organizing pneumonia (OP) after lung transplantation with the development of acute rejection (AR) remains undefined. In addition, molecular allograft injury, as measured by donor-derived cell-free DNA (dd-cfDNA), during episodes of OP and its relationship to episodes of AR, chronic lung allograft dysfunction (CLAD), or death is unknown.

METHODS

This multicenter, prospective cohort study collected serial plasma samples from 188 lung transplant recipients for dd-cfDNA at the time of bronchoscopy with biopsy. Multivariable Cox regression was used to analyze the association between OP with the development of AR (antibody-mediated rejection (AMR) and acute cellular rejection (ACR)), CLAD, and death. Multivariable models were performed to test the association of dd-cfDNA at OP with the risk of AR, CLAD, or death.

RESULTS

In multivariable analysis, OP was associated with increased risk of AMR (hazard ratio (HR) = 2.26, 95% confidence interval (CI) 1.04-4.92, p = 0.040) but not ACR (HR = 1.29, 95% CI: 0.66-2.5, p = 0.45) or the composite outcome of CLAD or death (HR = 0.88, 95% CI, 0.47-1.65, p = 0.69). Median levels of dd-cfDNA were higher in OP compared to stable controls (1.33% vs 0.43%, p = 0.0006). Multivariable analysis demonstrated that levels of dd-cfDNA at diagnosis of OP were associated with increased risk of both AMR (HR = 1.29, 95% CI 1.03-1.62, p = 0.030) and death (HR = 1.16, 95% CI, 1.02-1.31, p = 0.026).

CONCLUSIONS

OP is independently associated with an increased risk of AMR but not CLAD or death. The degree of molecular allograft injury at the diagnosis of OP may further predict the risk of AMR and death.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

COVID-19 organizing pneumonia with sudden dyspnea in an asymptomatic survivor

This case shows that COVID-19 survivors can develop delayed-type pneumonia with sudden respiratory distress that responds dramatically to steroid treatment after remaining asymptomatic for more than several weeks, although pulmonary involvement of post-COVID-19 syndrome is often accompanied by long-term and severe sequelae such as pulmonary fibrosis.

COVID-19-Associated Cognitive Biases on Pneumonia Differential Diagnosis

The coronavirus disease 2019 (COVID-19) pandemic favors cognitive biases such as anchoring and availability biases. The first refers to overvaluing some of the initial information and establishing a diagnosis too early, with resistance to future adjustments. The latter happens when diagnoses more frequently considered are regarded as more common in reality. This case, in which the correct diagnosis was delayed due to these biases, highlights the need to remain aware of them as a means toward timely diagnosis and therapeutic success of pneumonia cases. An 84-year-old woman presented with a mild non-productive cough for two months and fever. She had a history of breast carcinoma treated with radiotherapy in the previous year. Computerized tomography (CT) showed extensive bilateral consolidation foci with ground-glass-opacification areas and bilateral pleural effusion, CO-RADS 3. COVID-19 with bacterial superinfection was suspected and levofloxacin was initiated. Nasopharyngeal swab polymerase chain reaction (PCR) was carried out three times, always negative for SARS-CoV-2. As the patient remained with fever and cough, the antibiotic was escalated to piperacillin/tazobactam and then to meropenem/vancomycin. She underwent bronchofibroscopy and alveolar lavage, with negative SARS-CoV-2 PCR. The re-evaluation CT scan maintained bilateral consolidations, with an aerial bronchogram. The biopsy of pulmonary consolidation allowed the diagnosis of radiation-induced organizing pneumonia. Prednisolone was initiated and achieved clinical remission and radiological improvement. This case highlights the need to remain aware of cognitive biases both when COVID-19 is suspected or ruled out and to consider other diagnoses when there is a lack of therapeutic response.

Scleroderma Associated With Organising Pneumonia and Polyarthritis: A Report of a Rare Case

Cryptogenic organising pneumonia (COP) is a form of idiopathic diffuse interstitial lung disease (ILD) that develops in response to a variety of unknown irritants. An essential component of the development of organising pneumonia (OP) is damage to type II pneumocytes and the alveolar basement membrane. An autoimmune illness called systemic sclerosis (SSc) has a significant death rate from cardiopulmonary involvement such as pulmonary hypertension and ILD. Arthritis is an autoimmune disorder, in which the patients experience extra-articular symptoms such as ILD during the course of their disease, and COP frequently coexists with these conditions. It is exceedingly uncommon for OP to occur as the initial sign of arthritis, and its clinical characteristics are still unclear. Scleroderma and inflammatory polyarthritis related to COP are presented in this report.

Occult paraquat poisoning causing pneumomediastinum and organizing pneumonia

Pneumomediastinum is not an uncommon manifestation of lung toxicity in acute paraquat ingestion. The condition is almost invariably seen with other lung parenchymal abnormalities such as consolidations, ground-glass opacities and interlobular septal thickening. The diagnosis may be challenging in cases with no history of toxin exposure, presentation with a subacute illness and/or absence of typical local or systemic features of paraquat toxicity.

Lung Injury Induced by Crizotinib and Entrectinib in a Patient with ROS1-rearranged Non-small-cell Lung Cancer

We herein report the first case of c-ros oncogene 1 (ROS1)-rearranged advanced non-small-cell lung cancer (NSCLC) in which lung injury was induced by crizotinib and entrectinib. Crizotinib was administered as first-line chemotherapy in a woman in her early 70s with stage IV NSCLC showing ROS1 rearrangement. This resulted in the development of drug-induced organizing pneumonia, which was alleviated by discontinuing drug administration and giving corticosteroids. Following second-line chemotherapy with entrectinib, a similar lung injury was noted. In cases of crizotinib-induced lung injury, physicians must be alert for drug-induced lung injury in subsequent treatment with entrectinib.

Multimodality Appearances of Marginal Zone Lymphoma Masquerading as Cryptogenic Organizing Pneumonia-serial Chest Radiograph and High-resolution Computed Tomography Appearances: (18F) Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Staging Utility

Marginal zone lymphoma (MZL) is a group of low-grade, indolent, non-Hodgkin lymphomas rarely manifesting in the lungs. A 46-year-old man presenting with shortness of breath and cough was investigated and treated over 10 months for an atypical pattern of lung disease in keeping with cryptogenic organizing pneumonia (COP). Initial lung biopsies were nondiagnostic - repeat sampling eventually showed MZL. Staging whole-body (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) demonstrated multisystem stage IV disease with intensely avid widespread pulmonary changes resembling COP. The case elegantly illustrates that pulmonary MZL can present insidiously masquerading as COP and shows the value of (18F) FDG PET/CT to stage extranodal MZL.

Efficacy of Additional Corticosteroids After Dexamethasone Treatment for Moderate to Severe COVID-19: An Observational Study

Background Previous studies have demonstrated dexamethasone (DEX)'s efficacy for coronavirus disease 2019 (COVID-19). In contrast, patients with residual lung field shading and symptoms after DEX treatment have been observed, and the efficacy of additional corticosteroids (AC) is unknown. Objectives We aimed to investigate the efficacy of AC in patients with COVID-19 with residual respiratory symptoms or who required oxygen therapy or invasive mechanical ventilation after DEX treatment. Methods This was a single-center, retrospective observational study including 261 patients with community-onset COVID-19, aged ≥ 18 years, admitted to our hospital between March 1, 2020, and May 31, 2021. Finally, 34 patients were included in the study who met all four of the following criteria: (1) required oxygen therapy or invasive ventilation, (2) were treated with DEX, (3) had residual shading on chest imaging after DEX treatment, or (4) had unimproved respiratory symptoms or oxygen saturation < 90%. We reviewed the medical records and clinical courses of 14 patients who received AC therapy (AC group) and 20 patients who did not (non-additional corticosteroids or NC group). Results The 90-day mortality rate was 35.7% in the AC group and 25.0% in the NC group. There was no statistically significant difference between the two groups (p = 0.797). In addition, there was no difference between groups in the proportion of patients who required oxygen therapy at discharge (64% vs. 35%, p = 0.162). The time from the end of DEX therapy to discharge was significantly longer in the AC group (median 7.5 vs. 33 days, p = 0.019). Regarding serious adverse events, infection was statistically more common in the AC group than in the NC group (p = 0.005). Conclusions AC after DEX treatment does not improve clinical outcomes and may prolong hospital stay.

Molecular and immune signatures, and pathological trajectories of fatal COVID-19 lungs defined by in situ spatial single-cell transcriptome analysis

Despite intensive studies during the last 3 years, the pathology and underlying molecular mechanism of coronavirus disease 2019 (COVID-19) remain poorly defined. In this study, we investigated the spatial single-cell molecular and cellular features of postmortem COVID-19 lung tissues using in situ sequencing (ISS). We detected 10 414 863 transcripts of 221 genes in whole-slide tissues and segmented them into 1 719 459 cells that were mapped to 18 major parenchymal and immune cell types, all of which were infected by SARS-CoV-2. Compared with the non-COVID-19 control, COVID-19 lungs exhibited reduced alveolar cells (ACs) and increased innate and adaptive immune cells. We also identified 19 differentially expressed genes in both infected and uninfected cells across the tissues, which reflected the altered cellular compositions. Spatial analysis of local infection rates revealed regions with high infection rates that were correlated with high cell densities (HIHD). The HIHD regions expressed high levels of SARS-CoV-2 entry-related factors including ACE2, FURIN, TMPRSS2 and NRP1, and co-localized with organizing pneumonia (OP) and lymphocytic and immune infiltration, which exhibited increased ACs and fibroblasts but decreased vascular endothelial cells and epithelial cells, mirroring the tissue damage and wound healing processes. Sparse nonnegative matrix factorization (SNMF) analysis of niche features identified seven signatures that captured structure and immune niches in COVID-19 tissues. Trajectory inference based on immune niche signatures defined two pathological routes. Trajectory A primarily progressed with increased NK cells and granulocytes, likely reflecting the complication of microbial infections. Trajectory B was marked by increased HIHD and OP, possibly accounting for the increased immune infiltration. The OP regions were marked by high numbers of fibroblasts expressing extremely high levels of COL1A1 and COL1A2. Examination of single-cell RNA-seq data (scRNA-seq) from COVID-19 lung tissues and idiopathic pulmonary fibrosis (IPF) identified similar cell populations consisting mainly of myofibroblasts. Immunofluorescence staining revealed the activation of IL6-STAT3 and TGF-β-SMAD2/3 pathways in these cells, likely mediating the upregulation of COL1A1 and COL1A2 and excessive fibrosis in the lung tissues. Together, this study provides a spatial single-cell atlas of cellular and molecular signatures of fatal COVID-19 lungs, which reveals the complex spatial cellular heterogeneity, organization, and interactions that characterized the COVID-19 lung pathology.

A Case Report of Squamous Cell Carcinoma Misdiagnosed as Cryptogenic Organizing Pneumonia

After adenocarcinoma, squamous cell lung cancer is the most common type of non-small cell lung cancer (NSCLC) among non-smokers. A tissue biopsy followed by imaging (chest X-ray, computed tomography (CT) lung, and positron emission tomography (PET) scan) is the best modality for confirmation and staging of the disease. Sometimes, the histopathological appearance of squamous cell lung carcinoma (SCLC) can be confused with organizing pneumonia. Such findings can delay the diagnosis of SCLC, which can affect the treatment and course of the disease. Any lung mass that is highly suspicious for carcinoma should be closely monitored with imaging, and a repeat tissue biopsy should be done for a confirmation of the diagnosis to start appropriate therapy as soon as possible.

Dominant CT Patterns and Immune Responses during the Early Infection Phases of Different SARS-CoV-2 Variants

Ground-glass opacity (GGO) and organizing pneumonia (OP) are dominant pulmonary CT lesions associated with COVID-19. However, the role of different immune responses in these CT patterns remains unclear, particularly following the emergence of the Omicron variant. In this prospective observational study, we recruited patients hospitalized with COVID-19, before and after the emergence of Omicron variants. Semi-quantitative CT scores and dominant CT patterns were retrospectively determined for all patients within five days of symptom onset. Serum levels of IFN-α, IL-6, CXCL10, and VEGF were assessed using ELISA. Serum-neutralizing activity was measured using a pseudovirus assay. We enrolled 48 patients with Omicron variants and 137 with precedent variants. While the frequency of GGO patterns was similar between the two groups, the OP pattern was significantly more frequent in patients with precedent variants. In patients with precedent variants, IFN-α and CXCL10 levels were strongly correlated with GGO, whereas neutralizing activity and VEGF were correlated with OP. The correlation between IFN-α levels and CT scores was lower in patients with Omicron than in those with precedent variants. Compared to preceding variants, infection with the Omicron variant is characterized by a less frequent OP pattern and a weaker correlation between serum IFN-α and CT scores.

Nivolumab-Induced Organizing Pneumonia in Management of Non-small Cell Lung Carcinoma: A Case Report

Nivolumab is an immune checkpoint inhibitor (ICI) that has proven efficacy in managing certain malignancies, including non-small lung carcinoma. In this case, we present a 53-year-old female patient diagnosed with metastatic non-small lung carcinoma. After management with radiation (both external beam and brachytherapy) and tumor debulking by bronchoscopic cryotherapy, she developed an initial pneumonitis attributed to nivolumab and ipilimumab. This was successfully managed with steroid therapy and allowed nivolumab monotherapy to restart. However, several months later, she developed organizing pneumonia, prompting immunotherapy discontinuation and initiation of corticosteroid therapy. This case serves as a reminder to clinicians that although ICIs constitute a novel, effective therapy for certain malignancies, immunological side effects can be debilitating and prevent continued immunotherapy. Through this case, we aim to review the literature about this rare side effect of nivolumab-induced pneumonitis, risk factors, diagnosis, and management.

Organizing pneumonia as an initial presentation in a male lupus: A rare case report

Organizing pneumonia (OP) is one of the rare pulmonary manifestations of systemic lupus erythematosus (SLE) which is infrequently reported as a presenting manifestation. Early diagnosis of lupus-related OP with the help of imaging, can drive to prompt initiation of immunosuppressive therapy leading to a better prognosis. We present a case of a 34-year-old young male who presented with fever, myalgia, and a dry cough for 1 month and was later diagnosed as SLE-related organizing pneumonia.

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.

Anti-synthetase syndrome associated interstitial lung disease after combination dual immune checkpoint inhibition

Immune checkpoint inhibitors (ICIs) unleash potent anti-tumour responses but with frequent off-target immune-mediated adverse events (irAE). ICIs can induce a spectrum of rheumatologic manifestations including inflammatory arthritis, Sjögren's syndrome, scleroderma and systemic lupus erythematosus. Here, we describe a case of antisynthetase syndrome associated interstitial lung disease (ILD) following dual Programmed Cell Death 1 and Cytotoxic T Lymphocyte-Associated Protein 4 checkpoint inhibition in a patient with metastatic melanoma. Initial treatment course was complicated by a number of irAEs including pneumonitis, colitis and thyroiditis. Suspicion of an underlying systemic rheumatic disease was heightened by the severe, relapsing and fibrosing nature of the interstitial pneumonitis. A diagnosis of amyopathic antisynthetase syndrome was made upon detection of circulating aminoacyl-tRNA synthetase (anti-EJ) autoantibodies. Intensification of induction immunosuppression followed by maintenance mycophenolate, prednisone and monthly intravenous immunoglobulin achieved long-term disease control. Detection of de novo ICI-induced inflammatory myositis ILD requires a high index of suspicion and carries important prognostic and treatment implications.

Organizing Pneumonia and Ulcerative Colitis: A Relationship To Remember

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterised by relapsing and remitting mucosal inflammation of the colon. Despite primarily affecting the gastrointestinal tract, UC has various extraintestinal manifestations that often affect other organs and systems. Although pulmonary involvement is uncommon, organising pneumonia (OP), which affects the lung parenchyma, is one of the potential extraintestinal manifestations of UC. We report a case of OP in a 35-year-old male with a longstanding history of UC, well-medicated with sulfasalazine (SSZ). He presented to the emergency department (ED) with complaints of fatigue, coughing, myalgia, thoracalgia and dyspnoea. A chest X-ray showed parenchymal infiltrates and computed tomography revealed bilateral consolidation. Under a preliminary diagnosis of atypical pneumonia, he was treated with an empirical broad-spectrum antimicrobial agent, which did not lead to any clinical, laboratory or imaging improvement. Furthermore, the diagnostic work-up excluded any malignancy or infectious cause. A probable diagnostic hypothesis was OP as an extraintestinal manifestation of UC or as an adverse effect of SSZ therapy. Hence, SSZ was discontinued, and he was successfully treated with corticosteroids, exhibiting significant improvements and recovering completely during the follow-up period. Despite lung involvement in UC being rare, we present this case to emphasise the importance of a thorough differential diagnosis when treating acute respiratory illness in patients with UC, including extraintestinal manifestations of UC, especially OP, even during a period of remission. We also emphasise the importance of early initiation of corticosteroid therapy to prevent major complications and promote recovery.

Organizing pneumonia following ocrelizumab use in a patient with multiple sclerosis: A case report

Ocrelizumab is an anti-CD20 monoclonal antibody used in the treatment of primary progressive and relapsing multiple sclerosis (MS). Although cases of organizing pneumonia have been reported in association with other antiCD20 agents such as rituximab, there is insufficient data in the literature on Ocrelizumab-associated lung involvement. Herein, we present a case of organizing pneumonia in a 37-year-old female patient with multiple sclerosis following Ocrelizumab use.

Pleuropulmonary Manifestations of Vacuoles, E1 Enzyme, X-Linked, Autoinflammatory, Somatic (VEXAS) Syndrome

BACKGROUND

The vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a newly identified autoinflammatory disorder related to somatic UBA1 mutations. Up to 72% of patients may show lung involvement.

RESEARCH QUESTION

What are the pleuropulmonary manifestations in VEXAS syndrome?

STUDY DESIGN AND METHODS

One hundred fourteen patients were included in the French cohort of VEXAS syndrome between November 2020 and May 2021. Each patient included in the study who had an available chest CT scan was discussed in an adjudication multidisciplinary team and classified as showing potentially pleuropulmonary-specific involvement of VEXAS syndrome or others.

RESULTS

Fifty-one patients had a CT scan available for review and 45 patients (39%) showed pleuropulmonary abnormalities on chest CT scan that were considered related to VEXAS syndrome after adjudication. Most patients were men (95%) with a median age 67.0 years at the onset of symptoms. Among these 45 patients, 44% reported dyspnea and 40% reported cough. All 45 patients showed lung opacities on chest CT scan (including ground-glass opacities [87%], consolidations [49%], reticulation [38%], and septal lines [51%]) and 53% of patients showed pleural effusion. Most patients showed improvement with prednisone, but usually required > 20 mg/d. The main clinical and biological features as well the median survival did not differ between the 45 patients with pleuropulmonary involvement and the rest of the cohort, suggesting that the prevalence of pleuropulmonary involvement might have been underdiagnosed in the rest of the cohort.

INTERPRETATION

Pulmonary manifestations are frequent in VEXAS syndrome, but rarely are at the forefront. The initial outcome is favorable with prednisone and does not seem to lead to pulmonary fibrosis.

[Organizing Pneumonia in A Patient Double-positive for ANCA and anti-GBM Antibodies: A Case Report]

Both anti-glomerular basement membrane (GBM) disease and the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are common causes of pulmonary-renal syndrome. Organizing pneumonia (OP), a special pattern of interstitial lung disease, is extremely rare either in AAV or anti-GBM disease. We report an old woman presented with OP on a background of co-presentation with both ANCA and anti-GBM antibodies.

Late Onset of Organizing Pneumonia Following SARS-CoV-2 Infection: A Case Report of Successful Management and Review Literature

A late consequence of COVID-19, organizing pneumonia is characterized by significant imaging and pathological abnormalities. The goals of this study are to better understand these abnormalities. The use of corticoid continues to be the recommended course of treatment for COVID-19. On the other hand, it is not clear whether or not corticoid has the same impact on organizing pneumonia after COVID-19. A 53-year-old male patient was identified with organized pneumonia following COVID-19 infection. He was diagnosed after experiencing severe respiratory symptoms several days with no improvement. We initiated a high dose of corticoid based on imaging and pathological findings and observed a significant response. In addition, we looked into the research that has been done concerning the diagnosis and treatment of this peculiar ailment. Patients who have been diagnosed with pneumonia after COVID 19 are required to undergo a reevaluation that includes a chest CT scan, and some of these patients may be candidates for an early lung biopsy. The most effective and convincing therapy for COVID-19-induced organizing pneumonia is corticoid treatment at a dose equivalent to 0.5 mg/kg/day of prednisone.

Clinical features and outcomes of patients with myositis associated-interstitial lung disease

Introduction

Myositis associated interstitial lung disease (ILD) seems to be an under-recognized entity.

Methods

In this multicenter, retrospective study, we recorded between 9/12/2019 and 30/9/2021 consecutive patients who presented in five different ILD centers from two European countries (Greece, France) and received a multidisciplinary diagnosis of myositis associated-ILD. The primary outcome was all-cause mortality over 1 year in specific subgroups of patients. Secondary outcomes included comparison of disease characteristics between patients diagnosed with the amyopathic subtype and patients with evidence of myopathy at diagnosis.

Results

We identified 75 patients with myositis associated-ILD. Median age (95% CI) at the time of diagnosis was 64.0 (61.0-65.0) years. Antinuclear antibody testing was positive in 40% of the cohort (n = 30/75). Myopathy onset occurred first in 40.0% of cases (n = 30), ILD without evidence of myopathy occurred in 29 patients (38.7%), while 16 patients (21.3%) were diagnosed concomitantly with ILD and myopathy. The commonest radiographic pattern was cellular non-specific interstitial pneumonia (NSIP) and was observed in 29 patients (38.7%). The radiographic pattern of organizing pneumonia was significantly more common in patients diagnosed with the amyopathic subtype compared to patients that presented with myopathy [24.1% (n = 7/29) vs. 6.5% (n = 3/46), p = 0.03]. One year survival was 86.7% in the overall population. Kaplan-Meier analysis demonstrated significantly higher all-cause 1-year mortality in patients with the amyopathic subtype compared to patients with evidence of myopathy [H R 4.24 (95% CI: 1.16-15.54), p = 0.03]. Patients diagnosed following hospitalization due to acute respiratory failure experienced increased risk of 1-year all-cause mortality compared to patients diagnosed in outpatient setting [HR 6.70 (95% CI: 1.19-37.81), p = 0.03]. Finally, patients with positive anti-MDA5 presented with higher 1-year all-cause mortality compared to anti-MDA5 negative patients [HR 28.37 (95% CI: 5.13-157.01), p = 0.0001].

Conclusion

Specific ILD radiographic patterns such as NSIP and organizing pneumonia may herald underlying inflammatory myopathies. Hospitalized patients presenting with bilateral organizing pneumonia refractory to antibiotics should be meticulously evaluated for myositis associated-ILD even if there is no overt muscular involvement. Incorporation of ILD radiological patterns in the diagnostic criteria of inflammatory myopathies may lead to timely therapeutic interventions and positively impact patients' survival.

Does cryptogenic organizing pneumonia change seasonal?

BACKGROUND AND AIM

Meteorological factors affect the respiratory system, and the most important factor is the change in ambient temperature and humidity. We aimed to investigate the seasonal characteristics of patients diagnosed with cryptogenic organizing pneumonia.

METHODS

The study included 84 cryptogenic organizing pneumonia, 55 chronic obstructive pulmonary disease, and 42 asthma patients. To determine the characteristics of the disease according to the seasons, the number of attacks and admissions was grouped according to the seasonal characteristics and analyzed for three groups.

RESULTS

Among cryptogenic organizing pneumonia and chronic obstructive pulmonary disease patients, males significantly predominated (p<0.001). The hospitalization rate was highest in chronic obstructive pulmonary disease patients but similar to cryptogenic organizing pneumonia and asthma patients (p<0.001). The highest admission rate in cryptogenic organizing pneumonia patients was observed in spring (39.3% in spring, 26.2% in fall, 22.6% in winter, and 11.9% in summer). In winter, cryptogenic organizing pneumonia patients were admitted less frequently than chronic obstructive pulmonary disease and asthma patients. The neutrophil-to-lymphocyte ratio was higher in cryptogenic organizing pneumonia patients than in asthma patients and similar to chronic obstructive pulmonary disease patients.

CONCLUSION

As a result of our study, the high rate of diagnosis and admission in the spring in cryptogenic organizing pneumonia suggested that the effect of allergens on the formation of cryptogenic organizing pneumonia should be investigated. In contrast, it should be kept in mind that cryptogenic organizing pneumonia may develop as a prolonged finding of involvement that may occur in the lung parenchyma due to lung infections and/or cold weather triggering during the winter months. In this regard, further studies can be conducted in which allergens and/or the history of infection in patients and meteorological variables are also evaluated.

Glucocorticoid Therapy in COVID-19-Induced Organizing Pneumonia: A Rare Occurrence

Background Although the incidence of post-COVID-19 organizing pneumonia (OP) is low, the mortality and morbidity in select patients appear to be high. Anticipating specific populations who may be at higher risk and initiating treatment earlier could reduce mortality. Research question Does treatment with high dose, standard dose, or no glucocorticoids for COVID-19 infection impact the incidence and clinical outcome in COVID-19-induced OP? Study design and methods This was a single-center, retrospective, observational cohort study conducted from 03/01/2020 to 06/30/2021 in hospitalized patients over the age of 18 with confirmed COVID-19 infection and computed tomography (CT) scan evidence of OP. Institutional review board (IRB) approval was obtained from the institution (STUDY00002241). Patients' demographics and oxygen requirements at the time of diagnosis, at the time of discharge, and at one, three, six, 10, and 12 months post-discharge were obtained. The dose, duration, and choice of glucocorticoid therapy were recorded for each subject, as well as oxygen requirements during hospitalization. Despite radiological evidence of OP, patients on minimal supplemental oxygen requirements did not receive high-dose or long-duration glucocorticoid therapy. Results A total of 881 patients were admitted with COVID-19, of which 42 met the study criteria. Three patients underwent a lung biopsy to confirm the diagnosis of organizing pneumonia. All other patients were diagnosed based on CT imaging and clinical presentation. Of the patients, 17% did not receive any steroid treatment, while 36% received dexamethasone and 43% received prednisone. The most common oxygen requirement at the time of discharge for steroid-treated patients was nasal cannula (55%) and room air (29%). The incidence of OP in this patient population was 0.05 with a mortality rate of 14%. Interpretation and relevance The incidence of post-COVID-19 OP appears to be lower than anticipated. Steroids for patients on lower supplemental oxygen requirements were discontinued although they had radiological evidence of OP. Patients who were on higher supplemental oxygen requirements at 10 days were continued on steroids regardless of imaging. The decision to continue steroids should be based on individual patient characteristics such as oxygen requirements. In the future, larger multicenter cohort studies would help understand further treatment of post-COVID-19-associated OP. Anticipating specific populations who may be at higher risk and starting treatment earlier could help reduce mortality.

The Hidden Pandemic of COVID-19-Induced Organizing Pneumonia

Since the beginning of the COVID-19 pandemic, clinical, radiological, and histopathological studies have provided evidence that organizing pneumonia is a possible consequence of the SARS-CoV2 infection. This post-COVID-19 organizing pneumonia (PCOP) causes persisting dyspnea, impaired pulmonary function, and produces radiological abnormalities for at least 5 weeks after onset of symptoms. While most patients with PCOP recover within a year after acute COVID-19, 5-25% of cases need specialized treatment. However, despite substantial resources allocated worldwide to finding a solution to this problem, there are no approved treatments for PCOP. Oral corticosteroids produce a therapeutic response in a majority of such PCOP patients, but their application is limited by the anticipated high-relapse frequency and the risk of severe adverse effects. Herein, we conduct a systematic comparison of the epidemiology, pathogenesis, and clinical presentation of the organizing pneumonias caused by COVID-19 as well as other viral infections. We also use the clinical efficacy of corticosteroids in other postinfection OPs (PIOPs) to predict the therapeutic response in the treatment of PCOP. Finally, we discuss the potential application of a candidate anti-inflammatory and antifibrotic therapy for the treatment of PCOP based on the analysis of the latest clinical trials data.

Timeline of Oxygen Demand in Patients with COVID-19 Pneumonia

Objective In patients with coronavirus disease 2019 (COVID-19), understanding the timeline of oxygen demand and severe respiratory failure, such as intensive care unit (ICU) admission, may clarify the therapeutic window when home-care treatment is possible and help determine the timing of treatment in hospitalized patients to improve the respiratory status. We examined the timeline of respiratory status in hospitalized patients with moderate-to-severe COVID-19 in terms of oxygen demand and ICU admission. Methods We retrospectively assessed all patients with COVID-19 who were admitted to our hospital between February 2020 and February 2021 and required supplemental oxygen. This study included 66 patients who were transferred to the ICU (ICU patients) and 144 patients who were not transferred to the ICU (non-ICU patients). Results In the total cohort, the median duration from symptom onset to the need for supplemental oxygen was 8 [interquartile range (IQR) 6-10] days. This duration was significantly shorter in ICU patients than in non-ICU patients [8 (IQR 6-9) vs. 9 (IQR 6-10) days, p=0.02]. The median duration from symptom onset to ICU admission was 9 (IQR 8-11) days in severely ill patients. The median duration from the initiation of supplemental oxygen to ICU admission was 1.0 (IQR 1-2.75) days. Only 2 of 66 patients (3.0%) were admitted to the ICU six days or later after the initiation of supplemental oxygen. Conclusion Physicians should carefully monitor each patient's condition after eight days from symptom onset. New therapies and their early administration are needed to reduce the frequency of respiratory failure in COVID-19 patients.

ALK-positive lung adenocarcinoma in a patient with rheumatoid arthritis with long-term treatment for organizing pneumonia: A case report

RATIONALE

Rheumatoid arthritis (RA) causes inflammation in various organs including the lungs. Pulmonary manifestations include inflammation of the pleura, vasculature, airway, and parenchyma, including interstitial lung disease (ILD). RA-organizing pneumonia (OP) is the third most common cause of RA-ILD. Cases of OP coexisting/complicated with lung cancer have been reported. Therefore, lung cancer can represent a diagnostic challenge, especially in patients with underlying pulmonary diseases including OP.

PATIENT CONCERNS

An 81-year-old woman with a 12-year history of RA-OP underwent multiple transbronchial lung biopsies (TBLBs), all of which resulted in no malignant findings. She was treated with prednisolone (PSL) depending on the deteriorated infiltrations. At admission, chest computed tomography (CT) images showed exacerbation of left S8 consolidation on chest CT. Additionally, her RA activity was exacerbated, and PSL dose was increased to 30 mg/day, which resulted in improved dyspnea and consolidation. Accordingly, PSL dose was gradually decreased. However, 6 months later, when PSL dose was 11 mg/d, due to a worsening of consolidation and the joint symptoms of RA, PSL dose was increased to 20 mg/d and tacrolimus 2 mg/d was administered. 3 months after the increase in PSL dose, dyspnea improved and PSL dose was reduced to 15 mg/d; however, she was admitted to our hospital because of low back pain.

DIAGNOSIS

Spinal magnetic resonance imaging showed bone metastases in the third and fifth lumbar vertebrae, and lung cancer was suspected as the primary tumor on CT.

INTERVENTIONS

TBLB was performed on the left B8 infiltrate, which showed no evidence of malignancy in the previous TBLB.

OUTCOMES

Pathological examination of TBLB on the left B8 revealed an adenocarcinoma that was positive for anaplastic lymphoma kinase.

LESSONS

Physicians should be aware of the development of lung cancer in regions with OP, even after a partial response to corticosteroid therapy.

Prognostic implications of and clinical risk factors for acute lung injury and organizing pneumonia after lung transplantation: Data from a multicenter prospective cohort study

We determined prognostic implications of acute lung injury (ALI) and organizing pneumonia (OP), including timing relative to transplantation, in a multicenter lung recipient cohort. We sought to understand clinical risks that contribute to development of ALI/OP. We analyzed prospective, histologic diagnoses of ALI and OP in 4786 lung biopsies from 803 adult lung recipients. Univariable Cox regression was used to evaluate the impact of early (≤90 days) or late (>90 days) posttransplant ALI or OP on risk for chronic lung allograft dysfunction (CLAD) or death/retransplantation. These analyses demonstrated late ALI/OP conferred a two- to threefold increase in the hazards of CLAD or death/retransplantation; there was no association between early ALI/OP and these outcomes. To determine risk factors for late ALI/OP, we used univariable Cox models considering donor/recipient characteristics and posttransplant events as candidate risks. Grade 3 primary graft dysfunction, higher degree of donor/recipient human leukocyte antigen mismatch, bacterial or viral respiratory infection, and an early ALI/OP event were significantly associated with increased late ALI/OP risk. These data from a contemporary, multicenter cohort underscore the prognostic implications of ALI/OP on lung recipient outcomes, clarify the importance of the timing of these events, and identify clinical risks to target for ALI/OP prevention.

Incidence, Characteristics, Clinical Course, and Risk Factors of Ulcerative Colitis-related Lung Diseases

BACKGROUND

Ulcerative colitis (UC) is a chronic GI inflammatory disorder involving various extraintestinal organs, including the lungs. Although UC-related lung diseases (UC-LDs) have been widely recognized, much remains unclear.

RESEARCH QUESTION

What are the incidence, characteristics, clinical course, and risk factors of UC-LD?

STUDY DESIGN AND METHODS

This study retrospectively identified and classified UC-LDs by reviewing the medical records of consecutive patients with UC. The incidence, characteristics, and clinical course of each UC-LD type were investigated, and the clinical characteristics of patients with and without each UC-LD type were compared.

RESULTS

Among 563 patients with UC, 28 (5.0%) developed UC-LD during a mean follow-up period of 77 months. A majority of them displayed airway disease (AD) (n = 13 [2.3%]) or organizing pneumonia (OP) (n = 10 [1.8%]); there were six cases of interstitial pneumonias other than OP (IP) (0.8%) and one of pleuritis (0.2%). All 13 patients with AD responded favorably to inhaled or systemic corticosteroids, although five experienced frequent exacerbations. Older age and a history of colectomy were identified as the risk factors for developing AD. Nine of the 10 cases of OP were possibly due to drug-induced pathogenesis. Only one case showed recurrence, and all cases of OP exhibited a favorable clinical course with discontinuation of the suspicious drug and/or initiation of corticosteroid. The clinical course of IP depended on the existence of fibrosis, and IP with fibrosis was associated with gradual deterioration. Older age was associated with the development of IP.

INTERPRETATION

A nonnegligible number of patients with UC may develop UC-LD. AD, OP, and IP without fibrosis show good prognosis following steroid therapy along with the specific management for each UC-LD type, whereas IP with fibrosis shows gradual deterioration with poor prognosis. Our results provide cues to establish better management of UC-LDs.

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.

Algorithmic Approach to the Diagnosis of Organizing Pneumonia: A Correlation of Clinical, Radiologic, and Pathologic Features

Organizing pneumonia (OP), characterized histopathologically by patchy filling of alveoli and bronchioles by loose plugs of connective tissue, may be seen in a variety of conditions. These include but are not limited to after an infection, drug reactions, radiation therapy, and collagen vascular diseases. When a specific cause is responsible for this entity, it is referred to as "secondary OP." When an extensive search fails to reveal a cause, it is referred to as "cryptogenic OP" (previously called "bronchiolitis obliterans with OP"), which is a clinical, radiologic, and pathologic entity classified as an interstitial lung disease. The clinical presentation of OP often mimics that of other disorders, such as infection and cancer, which can result in a delay in diagnosis and inappropriate management of the underlying disease. The radiographic presentation of OP is polymorphous but often has subpleural consolidations with air bronchograms or solitary or multiple nodules, which can wax and wane. Diagnosis of OP sometimes requires histopathologic confirmation and exclusion of other possible causes. Treatment usually requires a prolonged steroid course, and disease relapse is common. The aim of this article is to summarize the clinical, radiographic, and histologic presentations of this disease and to provide a practical diagnostic algorithmic approach incorporating clinical history and characteristic imaging patterns.

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.

Organizing pneumonia as a possible pulmonary manifestation of systemic lupus erythematosus: Three cases and a review of literature

Background: Organizing pneumonia (OP) is a rare manifestation of systemic lupus erythematosus (SLE). It has been described in very few case reports.Purpose and Methods: We encountered OP in three patients with SLE in 1 year; two manifested OP as an initial presentation of SLE, while the third manifested OP when SLE relapsed. To elucidate the clinical features and outcomes of OP in patients with SLE, we screened the PubMed database for cases diagnosed with OP either at or after the diagnosis of SLE; the search was restricted to articles that were published after 1990, when OP became widely recognized.Results: We identified 15 cases of OP in patients with SLE. Thus, we analyzed a total of 18 cases (including our three). OP developed at the initial diagnosis of SLE in 15 cases and at relapse of SLE in three cases. In most cases, the disease activity of SLE was moderate or high. In all cases, OP was accompanied by other extrapulmonary symptoms of SLE, namely, fever (77.8%), cutaneous manifestations (61.1%), arthralgia/arthritis (50%), and lupus nephritis (33.3%). Steroid monotherapy or increasing the dose of the steroids was effective in seven cases (38.8%); however, steroid monotherapy was ineffective and led to death due to respiratory failure in two cases (11.1%). Combination therapies of steroids with hydroxychloroquine, azathioprine, tacrolimus, mycophenolate mofetil, intravenous pulse cyclophosphamide therapy, and belimumab were effective in seven cases (38.8%).Conclusions: Based on the review of previously reported and our cases, we concluded that OP is an important pulmonary manifestation of SLE. Clinicians should be aware of it as it may require intensive immunosuppressive therapy either at or after the diagnosis of SLE.

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Characteristics and Follow-Up of Organizing Pneumonia Associated with Haematological Malignancies

Background

Organizing pneumonia (OP) is a secondary process in many diseases. Due to its low incidence and indistinct symptoms, there is limited information on OP associated with haematological malignancies. Therefore, the aim of this study was to discuss the characteristics and prognosis of OP associated with haematological malignancies.

Methods

We observed and analysed pathologically confirmed OP cases associated with haematological malignancies in a hospital record database and excluded cases of OP with known causes, including chemotherapy, radiotherapy, targeted therapy, transplantation and infection.

Results

There were five patients with OP underlying only haematological malignancies, including one case each of the following: myelodysplastic syndrome, acute myelogenous leukaemia, multiple myeloma, aplastic anaemia, and T cell lymphoma. Radiological findings did not show a distinct pattern, and two cases mimicked pulmonary aspergillosis with ground-glass opacity (GGO). The diagnosis of OP was confirmed by minimal invasive biopsy. Although all patients developed severe cases, steroids yielded favourable outcomes.

Conclusion

This study demonstrates that haematological malignancies may be a cause of OP and that minimal invasive biopsy may be an effective and safe method to confirm the diagnosis. Although OP associated with haematological malignancies may more frequently develop into severe cases, the OP lesions were steroid-responsive during follow-up.

Chemotherapy-Associated Pulmonary Toxicity-Case Series from a Single Center

Background Pulmonary toxicity due to chemotherapeutic agents can occur with many established and new drugs. Strong clinical suspicion is important as the clinical presentation is usually with nonspecific symptoms like cough, dyspnea, fever, and pulmonary infiltrates. Timely discontinuation of the offending agent alone can improve the condition. Methods A prospective observational study on patients receiving chemotherapy at an 800-bedded tertiary care hospital was performed from 2014 to 2016. Consecutive patients on chemotherapy, presenting with nonresolving respiratory symptoms were evaluated with contrast-enhanced computerized tomography of chest, diffusion lung capacity for carbon monoxide (DLCO), fiberoptic bronchoscopy with lavage, and biopsy, after excluding all causes for pulmonary infections. Descriptive data has been depicted. Results A total of 18 patients were evaluated for persistent symptoms of dry cough, dyspnea, and fever among 624 who received chemotherapy during the study period. Ground-glass opacities on high-resolution CT was the most common imaging finding, others being patchy subpleural consolidation and pleural effusion. Lymphocyte-predominant bronchoalveolar lavage was detected in nine. Eight of the 15 patients who underwent DLCO, had abnormal results. Seven had significant histopathological findings on bronchoscopic lung biopsy, which revealed organizing pneumonia as the most common pattern. Paclitaxel, fluorouracil, gemcitabine, and tyrosine kinase inhibitors were the common culprit drugs. Discontinuation alone of the culprit drug was effective in 15 and 3 needed oral corticosteroids for relief of symptoms. None of the patients died due to the toxicity. Conclusion An incidence of 2.8% for chemotherapy-induced lung injury was seen in our observational study of 3 years, with parenchymal, interstitial, and pleural involvement due to various chemotherapeutic agents. Oral steroids maybe required in a subset of patients not responding to discontinuation of the culprit agent.

Two cases of cryptogenic organizing pneumonia masquerading as tuberculosis (TB) in a TB endemic area

Before the era of COVID-19 pandemic, organizing pneumonia (OP) is often underdiagnosed while tuberculosis (TB) is overdiagnosed especially in an endemic area. We report two patients with cryptogenic OP mimicking TB. First, a 56-year-old lady with right upper lobe air space opacity and, second, a 37-year-old lady with left upper lobe cavitary lesion. They were treated empirically for pulmonary TB as they had chronic cough with typical chest imaging findings. As there were no improvements despite anti-TB and investigations for TB were negative, they underwent image-guided biopsy which confirmed OP. Both patients received 6 months of corticosteroids therapy and made complete recovery. These cases highlight the rare presentation of OP and serves as a reminder that patients tested negative for TB, despite typical history and chest imaging findings, warrant further investigations as many diseases may mimic TB and vice versa.

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-CMV Organizing Pneumonia - An Unusual Presentation 10 years after Kidney Transplantation

A 45-year-old gentleman underwent kidney transplantation in March 2010. He remained apparently healthy for the next 10 years when he developed anorexia and weight loss. Diagnostic workup revealed cytomegalovirus (CMV) pneumonia. While viremia resolved within 3 weeks of initiation of valganciclovir, he developed progressive breathlessness and hypoxia on exertion. Imaging of thorax revealed central peri-bronchovascular consolidation and fine reticulations with peripheral sparing. Computed tomography (CT)-guided percutaneous lung biopsy revealed organizing intra-alveolar exudates, suggestive of organizing pneumonia, with no evidence of active infection on biopsy as well as bronchoalveolar lavage (BAL) cytology. This atypical pattern of central distribution of opacities is not typical of organizing pneumonia where peripheral subpleural distribution is more common. Patient responded dramatically following escalation of steroids, with complete resolution of infiltrates on follow-up imaging.

Secondary organizing pneumonia after recovery of mild COVID-19 infection

A 36-year-old male with diffuse large B-cell lymphoma on maintenance rituximab therapy presented to the emergency department with high fever and fatigue. A chest X-ray showed a lobar infiltrate, 40 days before admission the patient suffered from a mild coronavirus disease 2019 (COVID-19) infection and fully recovered. PCR nasopharyngeal swab was negative for COVID-19. Comprehensive biochemical, radiological, and pathological evaluation including 18-fluorodeoxyglucose positron emission tomography with computed tomography and transbronchial lung biopsy found no pathogen or lymphoma recurrence. Treatment for pneumonia with antibiotic and antifungal agents was nonbeneficial. A diagnosis of secondary organizing pneumonia (OP) was made after pneumonia migration and a rapid response to corticosteroids. OP secondary to a viral respiratory infection has been well described. Raising awareness for post-COVID-19 OP has therapeutic and prognostic importance because those patients benefit from steroid therapy. We believe the condition described here is underdiagnosed and undertreated by doctors worldwide. Because of the ongoing global pandemic we are now encountering a new kind of patient, patients that have recovered from COVID-19. We hope that this case may contribute to gaining more knowledge about this growing patient population.

Idiopathic Pulmonary Fibrosis Complicated by Adenocarcinoma and Organizing Pneumonia

We describe a case of a 77-year-old male with idiopathic pulmonary fibrosis (IPF) complicated by lung adenocarcinoma and organizing pneumonia (OP). On initial examination, physical examination revealed fine crackles in both sides of his chest. There were no physical findings suggestive of collagen disease. Blood tests showed no elevation of C-reactive protein, and lactate dehydrogenase and Krebs von den Lungen-6 (KL-6) were within normal limits. A high-resolution CT (HRCT) of the chest showed multiple ground-glass opacities (GGOs) in both lungs, with consolidation and traction bronchiectasis in the left lower lobe. Although a bronchoscopy was performed, no diagnosis could be made. Bronchoalveolar lavage showed elevated lymphocytes, and treatment with prednisolone was started for the possibility of OP. Subsequent chest X-ray and chest CT showed worsening of the shadows over time, and shortness of breath on exertion progressed. Surgical lung biopsy revealed IPF complicated by adenocarcinoma and OP. Although the patient was treated with pemetrexed and carboplatin combination therapy, respiratory failure progressed, and palliative care was decided. There is no report of IPF complicated by adenocarcinoma and OP, and early surgical lung biopsy may be important for diagnosis.

Air-Leak Syndrome with Spontaneous Tension Pneumothorax and Pneumomediastinum Caused by Bleomycin-Induced Organizing Pneumonia

Teaching Point: The appearance of pneumatoceles in a patient with organizing pneumonia is an early sign of leak syndrome and is a significant finding as its rupture can lead to a life-threatening tension pneumothorax. Air leak syndrome (ALS), consisting of pneumothorax, subcutaneous emphysema and pneumomediastinum, is a rare complication of organizing pneumonia (OP). We report a case of a patient with bleomycin-induced OP who develops a tension pneumothorax due to a ruptured pneumatocele caused by ALS and correlate with histopathological analysis. This is the third case in the literature with these findings and the first with a tension pneumothorax.

Severe COVID-19 Pneumonia Treated by Intensive Immune Suppression Therapy With a Combination of Steroid Pulse and Tocilizumab Followed by a Tapering Dose of Steroid Therapy During the Delta (B.1.617.2) Variant Outbreak: A Successfully Treated Case

A 55-year-old man developed a low-grade fever (day 1). His wife had already been infected with COVID-19 four days previously and he had been isolated in his house as a close contact. Polymerase chain reaction for COVID-19 was positive. He had untreated diabetes mellitus. On day 7, his percutaneous saturated oxygen fell to <70% and he was transported to a hospital by ambulance. He underwent tracheal intubation, mechanical ventilation, and treatments with half steroid pulse, tocilizumab, remdesivir, and heparin. However, his ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) decreased to 120 under mechanical ventilation and he was transported to our hospital. On arrival, he did not synchronize with mechanical ventilation well. Initially, he was treated using a muscle relaxant and deep sedation to facilitate complete synchronization with mechanical ventilation and his P/F ratio improved to 247; thus, he was treated with mechanical ventilation alone with intermittent placement in the prone position. In addition, he was treated with steroid pulse therapy after steroid tapering therapy for nearly one month, glycyrrhizin, γ-globulin, azithromycin, and heparin. On day 20, the tracheal tube was removed after the improvement of the P/F ratio. We herein present the case of a patient with severe COVID-19 pneumonia who survived following treatment by intensive immune suppression therapy, including the combination of steroid pulse and tocilizumab, followed by a tapering dose of steroid therapy, after an outbreak of COVID-19 Delta variant. Further studies are needed to investigate the usefulness of this regimen.

Post-coronavirus disease 2019 organizing pneumonia confirmed pathologically by video-assisted thoracoscopic surgery

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has become a global pandemic. Many survivors of serious COVID-19 pneumonia have long-term residual pulmonary disease. However, there is little documentation of the histopathological characteristics of lung sequelae post-COVID-19 and effective treatments. We present two Japanese cases of lung sequelae post-COVID-19. The patients were histopathologically diagnosed with organizing pneumonia (OP) or OP with fibrosis and no diffuse alveolar damage on video-assisted thoracoscopic surgery. Case 1, who had been diagnosed with OP, was successfully treated with corticosteroid and other immunosuppressive agents over a 6-month period. Although case 2, who had been diagnosed with OP with fibrosis, had a partial and unsatisfactory response to immunosuppressive agents, the patient responded to antifibrotic treatment including nintedanib.

Organizing pneumonia-like pattern in COVID-19

INTRODUCTION

Organizing pneumonia (OP) is a radio-histologic pattern that forms in response to lung damage in patients with focal or diffuse lung injury. OP is frequently observed subsequent to viral-induced lung damage and is associated with a diverse range of clinical outcomes.

MATERIAL AND METHODS

We included 210 patients (mean age: 55.8 ± 16.5 years old; 61% male) with mild Coronavirus disease 2019 (COVID-19) who underwent chest computed tomography (CT) from 25 February to 22 April, 2020. The patients were divided into two groups based on the presence (n = 103) or absence of typical OP-like pattern (n =107) on initial chest CT. The extent of lung involvement and final outcome was compared across the two groups. Serial changes in imaging were also evaluated in 36 patients in the OP-group with a second CT scan.

RESULTS

Duration from symptom onset to presentation was significantly higher in the OP group (7.07 ± 3.71 versus 6.13 ± 4.96 days, p = 0.008). A higher COVID-19-related mortality rate was observed among patients with OP-like pattern (17.5% vs 3.7%, p = 0.001).There was no significant difference in the overall involvement of the lungs (p = 0.358), but lower lobes were significantly more affected in the OP group (p < 0.001). Of the 36 patients with follow-up imaging (mean duration of follow-up = 8.3 ± 2.1 days), progression of infiltration was seen in more than 61% of patients while lesions had resolved in only 22.2% of cases.

CONCLUSIONS

Our observation indicates that physicians should carefully monitor for the presence of OP-like pattern on initial CT as it is associated with a poor outcome. Furthermore, we recommend interval CT to evaluate the progression of infiltrations in these patients.

Treatment of electronic cigarette or vaping product use-associated lung injury (EVALI) by corticosteroid and low-dose pirfenidone: Report of a case

Electronic (e)-cigarette or vaping product use-associated lung injury (EVALI) is a novel and potentially lethal disease first reported in the United States. We report the case of a 56-year-old man who presented to our hospital with dyspnoea and cough lasting for 2 months after using an e-cigarette for approximately 50 puffs over 2 weeks. Physical examination revealed crackles in the left lower lung. High-resolution computed tomography (HRCT) showed consolidation and ground-glass opacities in both lungs. The baseline forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DLCO) were 65.7% and 63.9% of the predicted, respectively. Lung biopsy revealed organizing pneumonia with focal fibrosis. In addition to prednisolone, he was treated with a low-dose pirfenidone (200 mg three times per day) due to the persistence of a mild cough, exertional dyspnoea and basal crackles after discharge. His symptoms and FVC significantly improved, but the recovery of the DLCO was slow. The follow-up HRCT demonstrated only minimal fibrotic changes. To our knowledge, this was the first reported case of EVALI successfully treated with a combination of corticosteroid and antifibrotic agents.

Case Report: Potential Role of Corticosteroids in the Management of Post-COVID-19 Pneumonia

Certain patients who recover from severe pneumonia due to coronavirus disease 2019 (COVID-19) remain symptomatic in the post-infectious period, either clinically, radiologically, or respiratory. The post-COVID-19 period is characterized by clinical symptoms of varying duration from one subject to another and does not seem to depend on the severity of initial pneumonia. The persisting inflammatory and/or immune reactions in the post-COVID-19 period may play a role in the development of pulmonary lesions. Here, we report the case of a 61-year-old man with severe COVID-19 pneumonia, complicated by acute respiratory distress syndrome and pulmonary embolism, which required the patient's admission to the intensive care unit and high-flow oxygen therapy. The patient was hospitalized for 23 days for the management of his severe COVID-19 pneumonia. Afterwards, he was discharged home following a negative SARS-CoV-2 PCR test. The post-COVID-19 period was characterized by a complex respiratory symptomatology associating cough, resting dyspnea, and exertional dyspnea requiring oxygen therapy for several weeks. Surprisingly, the follow-up chest CT scan performed 4 weeks after discharge revealed bilateral interstitial lung lesions. After ruling out pulmonary superinfection, the patient was treated with oral corticosteroid for 3 months at a digressive dose. In our case, the use of corticosteroid therapy in the post-COVID19 phase had improved the outcome of the lung disease. These benefits are characterized by a rapid symptomatic improvement, accelerated repair of pulmonary images, rapid oxygen withdrawal, and rapid return to daily activities.

Extracorporeal Membrane Oxygenation for Secondary Organizing Pneumonia after Severe SARS-CoV-2 Infection: A Case Report

(Background) COVID-19 is caused by SARS-CoV-2 infection and may result in unfavorable outcomes. A recent large-scale study showed that treatment with dexamethasone leads to favorable outcomes in patients with severe COVID-19, and the use of extracorporeal membrane oxygenation (ECMO) has also been shown to improve outcomes. Recently, secondary organizing pneumonia (SOP) has been reported after SARS-CoV-2 infection, but the diagnostic and treatment strategies are still unclear. (Case presentation) Here, we report a patient with severe COVID-19 who developed SOP even after the use of dexamethasone, for whom the introduction of ECMO on the 19th day after hospitalization led to a favorable outcome. (Conclusions) Life-threatening SOP may evolve even after the use of dexamethasone, and the late-phase introduction of ECMO may save such patients with COVID-19.

Idiopathic Interstitial Pneumonias and COVID-19 Pneumonia: Review of the Main Radiological Features and Differential Diagnosis

COVID-19 pneumonia represents a challenging health emergency, due to the disproportion between the high transmissibility, morbidity, and mortality of the virus and healthcare systems possibilities. Literature has mainly focused on COVID-19 pneumonia clinical-radiological diagnosis and therapy, and on the most common differential diagnoses, while few papers investigated rare COVID-19 pneumonia differential diagnoses or the overlapping of COVID-19 pneumonia on pre-existing lung pathologies. This article presents the main radiological characteristics of COVID-19 pneumonia and Idiopathic Interstitial Pneumonias (IIPs) to identify key radiological features for a differential diagnosis among IIPs, and between IIPs and COVID-19 pneumonia. COVID-19 pneumonia differential diagnosis with IIPs is challenging, since these entities may share common radiological findings as ground glass opacities, crazy paving patterns, and consolidations. Multidisciplinary discussion is crucial to reach a final and correct diagnosis. Radiologists have a pivotal role in identifying COVID-19 pneumonia patterns, reporting possible overlapping with long-lasting lung diseases, and suggesting potential differential diagnoses. An optimal evaluation of HRTC may help in containing the disease, in promoting better treatment for patients, and in providing an efficient allocation of human and economic resources.