How I diagnose and treat organizing pneumonia in hematopoietic cell transplant recipients.

ABSTRACT: Organizing pneumonia (OP) is a known noninfectious pulmonary complication following allogeneic hematopoietic cell transplant (HCT) and represents a significant risk factor for nonrelapse mortality in HCT recipients. Unlike bronchiolitis obliterans syndrome, it is not universally acknowledged as a distinctive pulmonary manifestation of chronic graft-versus-host disease (cGVHD) and, therefore, its diagnostic criteria and management approach are lacking. Given its shared similar clinical features and radiological and histologic findings to OP in the non-HCT population, the diagnostic approach and treatment strategy for OP in HCT recipients is largely adapted from the non-HCT population. In this article, we aim to enhance the understanding of OP within the context of cGVHD following HCT and distinguish its clinical features and treatment strategy from non-HCT counterparts, thereby reinforcing its recognition as a pulmonary manifestation of graft-versus-host disease. We will propose the diagnostic criteria and outline our approach in diagnosis and treatment strategy, highlighting the potential challenges that may arise in each process. Finally, we will discuss knowledge gaps in this field and identify the area of need for future research.

A Case of Organizing Pneumonia Resembling Lung Cancer.

BACKGROUND: Organizing pneumonia (OP) is a pathologic diagnosis with clinical and imaging manifestations that often resemble other diseases, such as infections and cancers, which can lead to delays in diagnosis and inappropriate management of the underlying disease. In this article, we present a case of organized pneumonia that resembles lung cancer. METHODS: We report a case of initial suspicion of pulmonary malignancy, treated with anti-inflammatory medication and then reviewed with CT suggesting no improvement, and finally confirmed to be OP by pathological biopsy taken via transbronchoscopy. A joint literature analysis was performed to raise clinicians' awareness of the diagnosis and treatment of OP. RESULTS: Initially, because of the atypical auxiliary findings, we thought that the disease turned out to be a lung tumor, which was eventually confirmed as OP by pathological diagnosis. CONCLUSIONS: The diagnosis and treatment of OP requires a combination of clinical information and radiological expertise, as well as biopsy to obtain histopathological evidence. That is, clinical-imaging-pathological tripartite cooperation and comprehensive analysis.

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.

Properties of Pleural Mesothelial Cells in Idiopathic Pulmonary Fibrosis and Cryptogenic Organizing Pneumonia.

BACKGROUND: Profibrotic properties of pleural mesothelial cells may play an important role in the fibrosis activity in idiopathic pulmonary fibrosis (IPF). The purpose of this study was to compare the expression of pleural mesothelial cell markers in IPF and cryptogenic organizing pneumonia (COP), with an assumption that increased expression implies increase in fibrosis. METHODS: Twenty IPF lung samples were stained by immunohistochemistry for the pleural mesothelial cell markers: leucine rich repeat neuronal 4 (LRRN4), uroplakin 3B, CC-chemokine ligand 18, and laminin-5. Nine COP lung samples were used as controls. A semi-quantitative analysis was performed to compare markers expression in IPF and COP. RESULTS: LRRN4 expression was found in epithelial lining cells along the honeycombing and fibroblastic foci in IPF, but not in the fibrotic interstitial lesion and airspace filling fibrous tufts in COP. We found a significant decrease in baseline forced vital capacity when LRRN4 expression was increased in honeycombing epithelial cells and fibroblastic foci. CONCLUSION: LRRN4 expression patterns in IPF are distinct from those in COP. Our findings suggest that mesothelial cell profibrotic property may be an important player in IPF pathogenesis and may be a clue in the irreversibility of fibrosis in IPF.

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.

Scoping review: The state of research on cryptogenic organizing pneumonia therapeutics.

Cryptogenic organizing pneumonia is a diffuse interstitial lung disease that starts in the alveolar wall and subsequently expands to the alveolar ducts and respiratory bronchioles. Randomized controlled trials are lacking to guide the treatment of cryptogenic organizing pneumonia, so treatment decisions and practice guidelines are often based upon observations from case series or expert clinical opinions. The backbone of treatment involves immunosuppression via corticosteroids. In refractory cases, cytotoxic therapy is considered. The evidence that supports the use of these regimens are limited. The goal of this scoping review is to conduct a systematic search of the literature to determine what regimens have been utilized to treat steroid refractory organizing pneumonia and to characterize the evidence supporting their use.

Bronchiolitis obliterans organizing pneumonia as the pulmonary manifestation of lupus: A review of three cases.

OBJECTIVE: Bronchiolitis obliterans organizing pneumonia (BOOP) is a clinico-patho-radiological diagnosis which rarely presents as a pulmonary manifestation of lupus. In this concise report, organizing pneumonia was found as the sole pulmonary manifestation of SLE in different age groups. METHOD: All three patients diagnosed with SLE according to SLICC 2012 classification criteria, were admitted in rheumatology ward of NIMS hospital, Hyderabad, India from May to November, 2018. Their diagnosis of BOOP was either biopsy proven or imaging guided. Review of literature was done with MeSH terms (SLE, BOOP) in PubMed and approximately 10 articles were reviewed including latest of 2019 published in Scientific Reports. RESULT: There were three patients - one juvenile lupus and two adults. Two patients were male and one female. All three patients had SLE with high disease activity. They all had organising pneumonia as pulmonary manifestation with other organ involvement. Juvenile patient had a fatal outcome while the others had a good recovery with steroid and immunosuppressive. CONCLUSION: BOOP is a rare pulmonary manifestation in lupus. It can be diagnosed early with more precision using computerised tomography of lung without waiting for biopsy report. This will result in a better prognosis by rapid initiation of corticosteroid and immunosuppressive treatment.

Diagnostic procedures and clinico-radiological findings of acute fibrinous and organizing pneumonia: a systematic review and pooled analysis.

OBJECTIVES: To evaluate the clinico-radiological findings of acute fibrinous and organizing pneumonia (AFOP) in the literature according to whether a surgical or non-surgical biopsy was performed, as well as to identify prognostic predictors. METHODS: We searched the Embase and OVID-MEDLINE databases to identify studies that presented CT findings of AFOP and had extractable individual patient data. We compared the clinical and CT findings of the patients depending on whether a surgical or non-surgical biopsy was performed and identified survival predictors using a multivariate logistic regression analysis. RESULTS: Eighty-one patients (surgical biopsy, n = 52; non-surgical biopsy, n = 29) from 63 studies were included. The surgical biopsy group frequently experienced an acute fulminant presentation (p = .011) and dyspnea (p = .001) and less frequently had a fever (p = .006) than the non-surgical biopsy group. The surgical biopsy group had a worse prognosis than the non-surgical biopsy group in terms of mechanical ventilation and mortality (both, p = .023). For survival analysis, the patients with the predominant CT finding of patchy or mass-like air-space consolidation survived more frequently (p < .001) than those with other CT findings. For prognostic predictors, subacute indolent presentation (p = .001) and patchy or mass-like air-space consolidation on CT images (p = .002) were independently associated with good survival. CONCLUSIONS: Approximately one-third of alleged AFOP cases in the literature were diagnosed via non-surgical biopsy, but those cases had different symptomatic presentations and prognosis from surgically proven AFOP. Subacute indolent presentation and patchy or mass-like air-space consolidation at the presentation on CT images indicated a good prognosis in patients with AFOP. KEY POINTS: • Acute fibrinous and organizing pneumonia (AFOP) cases diagnosed via non-surgical biopsy had different symptomatic presentations and prognosis from surgically proven AFOP. • Subacute indolent presentation and patchy or mass-like air-space consolidation on CT images indicated a good prognosis in patients with acute fibrinous and organizing pneumonia.

Comparison of Chest CT Findings of COVID-19, Influenza, and Organizing Pneumonia: A Multireader Study.

BACKGROUND. Previous studies compared CT findings of COVID-19 pneumonia with those of other infections; however, to our knowledge, no studies to date have included noninfectious organizing pneumonia (OP) for comparison. OBJECTIVE. The objectives of this study were to compare chest CT features of COVID-19, influenza, and OP using a multireader design and to assess the performance of radiologists in distinguishing between these conditions. METHODS. This retrospective study included 150 chest CT examinations in 150 patients (mean [± SD] age, 58 ± 16 years) with a diagnosis of COVID-19, influenza, or non-infectious OP (50 randomly selected abnormal CT examinations per diagnosis). Six thoracic radiologists independently assessed CT examinations for 14 individual CT findings and for Radiological Society of North America (RSNA) COVID-19 category and recorded a favored diagnosis. The CT characteristics of the three diagnoses were compared using random-effects models; the diagnostic performance of the readers was assessed. RESULTS. COVID-19 pneumonia was significantly different (p < .05) from influenza pneumonia for seven of 14 chest CT findings, although it was different (p < .05) from OP for four of 14 findings (central or diffuse distribution was seen in 10% and 7% of COVID-19 cases, respectively, vs 20% and 21% of OP cases, respectively; unilateral distribution was seen in 1% of COVID-19 cases vs 7% of OP cases; non-tree-in-bud nodules was seen in 32% of COVID-19 cases vs 53% of OP cases; tree-in-bud nodules were seen in 6% of COVID-19 cases vs 14% of OP cases). A total of 70% of cases of COVID-19, 33% of influenza cases, and 47% of OP cases had typical findings according to RSNA COVID-19 category assessment (p < .001). The mean percentage of correct favored diagnoses compared with actual diagnoses was 44% for COVID-19, 29% for influenza, and 39% for OP. The mean diagnostic accuracy of favored diagnoses was 70% for COVID-19 pneumonia and 68% for both influenza and OP. CONCLUSION. CT findings of COVID-19 substantially overlap with those of influenza and, to a greater extent, those of OP. The diagnostic accuracy of the radiologists was low in a study sample that contained equal proportions of these three types of pneumonia. CLINICAL IMPACT. Recognized challenges in diagnosing COVID-19 by CT are furthered by the strong overlap observed between the appearances of COVID-19 and OP on CT. This challenge may be particularly evident in clinical settings in which there are substantial proportions of patients with potential causes of OP such as ongoing cancer therapy or autoimmune conditions.

Comparison of clinical features and prognosis in patients with cryptogenic and secondary organizing pneumonia.

BACKGROUND: Organizing pneumonia (OP) can be diagnosed pathologically, and cryptogenic OP (COP) and secondary OP (SOP) have been classified by cause and particular underlying context. Because it is clinically difficult to differentiate between COP and SOP, this study investigated characteristics that could distinguish between COP and SOP. METHODS: The medical records of patients who underwent lung biopsy for a diagnosis of OP at a single tertiary hospital from January 2016 to December 2018 were retrospectively reviewed. RESULTS: Eighty-five patients had pathologically proven OP, including 16 diagnosed with COP and 69 diagnosed with SOP. The most common cause of SOP was infectious pneumonia, observed in 57 (82.6%) of the 69 patients, followed by cancer and radiation pneumonitis. The pathogens causing infectious pneumonia were identified in 45 (65.2%) patients. There were no differences in age, sex, and lung function between the COP and SOP groups. Median body mass index was significantly lower (P = 0.030), and median time from symptom onset to hospital admission significantly shorter (P = 0.006), in the SOP than in the COP group. Fever was more common in the SOP group (P = 0.024), and CURB 65, an index of pneumonia severity, tended to be higher in the SOP group (P = 0.017). Some laboratory results differed significantly between the two groups. Lymphocyte counts in bronchoalveolar lavage (BAL) fluid were significantly higher in the COP than in the SOP group (P = 0.012). Radiologic findings showed that effusion was more common in the SOP group (P = 0.036). There were no between-group differences in steroid use, 30 day and in-hospital mortality rates, and rates of OP outcomes and recurrences. Pneumonia recurrence rate was significantly higher in SOP patients who were than were not treated with steroids (P = 0.035). CONCLUSIONS: Infection is the main cause of SOP. Symptom onset is more rapid in patients with SOP than with COP. Some blood and BAL fluid test results differed significantly in the COP and SOP groups. Pleural effusion was more common in the SOP group but there were no differences in clinical course. Recurrence in patients with SOP was more common in those who were than were not treated with steroids.

Diagnostic yield, safety, and impact of transbronchial lung biopsy in mechanically ventilated, critically ill patients: a retrospective study.

BACKGROUND: Pulmonary infiltrates of variable etiology are one of the main reasons for hypoxemic respiratory failure leading to invasive mechanical ventilation. If pulmonary infiltrates remain unexplained or progress despite treatment, the histopathological result of a lung biopsy could have significant impact on change in therapy. Surgical lung biopsy is the commonly used technique, but due to its considerable morbidity and mortality, less invasive bronchoscopic transbronchial lung biopsy (TBLB) may be a valuable alternative. METHODS: Retrospective, monocentric, observational study in mechanically ventilated, critically ill patients, subjected to TBLB due to unexplained pulmonary infiltrates in the period January 2014 to July 2019. Patients' medical records were reviewed to obtain data on baseline clinical characteristics, modality and adverse events (AE) of the TBLB, and impact of the histopathological results on treatment decisions. A multivariable binary logistic regression analysis was performed to identify predictors of AE and hospital mortality, and survival curves were generated using the Kaplan-Meier method. RESULTS: Forty-two patients with in total 42 TBLB procedures after a median of 12 days of mechanical ventilation were analyzed, of which 16.7% were immunosuppressed, but there was no patient with prior lung transplantation. Diagnostic yield of TBLB was 88.1%, with AE occurring in 11.9% (most common pneumothorax and minor bleeding). 92.9% of the procedures were performed as a forceps biopsy, with organizing pneumonia (OP) as the most common histological diagnosis (54.8%). Variables independently associated with hospital mortality were age (odds ratio 1.070, 95%CI 1.006-1.138; p = 0.031) and the presence of OP (0.182, [0.036-0.926]; p = 0.040), the latter being confirmed in the survival analysis (log-rank p = 0.040). In contrast, a change in therapy based on histopathology alone occurred in 40.5%, and there was no evidence of improved survival in those patients. CONCLUSIONS: Transbronchial lung biopsy remains a valuable alternative to surgical lung biopsy in mechanically ventilated critically ill patients. However, the high diagnostic yield must be weighed against potential adverse events and limited consequence of the histopathological result regarding treatment decisions in such patients.

[Cryptogenic organizing pneumonia versus secondary organizing pneumonia]. / Kryptogen organisierende Pneumonie versus sekundäre organisierende Pneumonie.

Organizing pneumonia (OP) describes a histological pattern of acute or subacute lung damage. Clinically, patients present with cough, fever, and dyspnea. A distinction is made between idiopathic or cryptogenic organizing pneumonia (COP) and secondary organizing pneumonia (OP). In COP, neither clinical/radiological nor histological causes can be determined. It is classified as an interstitial idiopathic pneumonia (IIP) according to the criteria of the American Thoracic Society (ATS) and the European Respiratory Society (ERS). Secondary organizing pneumonia has a known triggering mechanism, such as infectious agents, certain medications, or concomitant symptoms of other primary pulmonary diseases and diseases of other organ systems. Common to both forms is the histological picture of intra-alveolar mesenchymal buds. These are myofibroblast proliferates that branch out along the alveolar spaces. They are usually accompanied by a moderate interstitial and alveolar, chronic, and macrophage-rich inflammatory cell infiltrate. The most important differential diagnosis is common interstitial pneumonia (UIP). It also shows fibroblast proliferates, which are, however, located in the interstitium. The correct classification of an IIP as a COP by means of clinical, radiological, and histological findings is essential, since the COP, in contrast to the UIP, responds very well to corticosteroids and therefore has an excellent prognosis compared to the UIP. The course of secondary organizing pneumonia depends on the respective underlying disease. Here it is important for the pathologist to correctly identify potential accompanying histological characteristics in order to be able to provide clues to a possible cause of OP.

Chest CT imaging features for prediction of treatment response in cryptogenic and connective tissue disease-related organizing pneumonia.

OBJECTIVES: To investigate CT imaging features associated with poor clinical outcome after corticosteroid treatment in patients diagnosed with cryptogenic organizing pneumonia (COP) and connective tissue disease-related organizing pneumonia (CTD-OP) and to assess the difference in CT findings and treatment responses between COP and CTD-OP. METHODS: Chest CT images from 166 patients (COP, 131; CTD-OP, 35) with pathologically proven organizing pneumonia were reviewed by two thoracic radiologists. The type, distribution pattern, and extent of parenchymal abnormalities, along with other associated imaging features, were assessed for each patient. Logistic regression analyses were used to identify features associated with poor clinical outcomes such as residual disease (RD) and disease relapse. The differences between COP and CTD-OP were also analyzed. RESULTS: Consolidation involving more than 10% of parenchyma (hazard ratio [HR], 2.27), detectable bronchiectasis (HR, 3.59), and diagnosis of CTD-OP (HR, 4.31) were associated with a higher risk of RD after adjustments for patient age and sex. More than 10% consolidation involvement (HR, 2.54) and diagnosis of CTD-OP (HR, 6.42) were also associated with a higher risk of disease relapse. Compared with COP, CTD-OP demonstrated a greater extent of parenchymal abnormalities, especially consolidation, and was less likely to show a peribronchovascular distribution pattern. CONCLUSION: Bronchiectasis and a greater extent of consolidation were associated with RD, with the latter also being associated with disease relapse. Compared with COP, CTD-OP was associated with worse treatment outcomes and demonstrated a greater extent of parenchymal abnormalities, which were also less likely to show a peribronchovascular pattern. KEY POINTS: • The presence of bronchiectasis and a high parenchymal involvement of consolidation on initial chest CT were associated with a worse response to corticosteroids in patients with organizing pneumonia. • Connective tissue disease-related organizing pneumonia (CTD-OP) was associated with worse treatment outcomes than its idiopathic counterpart cryptogenic organizing pneumonia (COP). • Compared with COP, CTD-OP generally demonstrated a greater extent of parenchymal abnormalities, especially consolidation, and was less likely to show a peribronchovascular distribution pattern.

Familial Mediterranean fever is associated with a wide spectrum of inflammatory disorders: results from a large cohort study.

Familial Mediterranean fever (FMF) is characterized by recurrent short-lived/self-limiting inflammatory attacks. Besides these, a substantial number of patients with FMF present with a variety of other inflammatory diseases; however, this issue has not been systematically studied previously. Hence, we aimed to investigate the frequency of inflammatory comorbid diseases in a large FMF cohort. All patients were recruited from "FMF in Central Anatolia (FiCA) Cohort", comprising 971 (mean age 35.3 ± 12 years, 61.5% female) adult subjects. All patients fulfilled Tel Hashomer criteria. Demographic data, FMF disease characteristics, MEFV gene mutations, and comorbid inflammatory diseases were meticulously questioned, and laboratory features and genotype data were retrieved from hospital records. There were comorbid inflammatory diseases in 205 (21.1%) patients. The most common inflammatory disease was spondyloarthritis (12.9%). Other remarkable inflammatory disorders were psoriasis, immunoglobulin A vasculitis/Henoch-Schönlein purpura, Behçet's disease and inflammatory bowel diseases. Cryptogenic organizing pneumonia is a newly defined entity in our cohort which is seemed to be associated with FMF (0.3%). Number of patients with persistent inflammation was higher in those with comorbid diseases (p < 0.001). Our results suggest that FMF is commonly associated with other inflammatory diseases. Therefore, clinicians should be cautious about comorbid inflammatory diseases in FMF patients, particularly in those with persistent inflammation. Identification of pathogenic pathways linking FMF to these diseases warrants further investigations.

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.

Gross and Histopathological Findings in the First Reported Vaping-Induced Lung Injury Death in the United States.

The popularity of e-cigarettes (vaping) has been on the rise in recent years, but the adverse effects of vaping have been greatly unknown. In 2019, the use of vaping products has been linked to an outbreak of severe lung disease, some cases of which have progressed to death. One death attributed to vaping is presented with emphasis on the gross and histopathological findings from the autopsy. These findings were correlated with the patient's clinical course and medicolegal investigation to determine the cause of death. To our knowledge, this is the first confirmed death in the United States that was directly attributed to the use of vaping.

[Analysis of clinical characteristics of 21 cases of acute fibrinous and organizing pneumonia].

Objective: To summarize the clinical features of 21 cases of acute fibrinous and organizing pneumonia (AFOP) confirmed by pathology, thereby improving clinicians' understanding of this disease and avoiding misdiagnosis in clinical practice. Methods: Twenty-one patients diagnosed pathologically with AFOP from January 2016 to April 2019 were analyzed retrospectively. The clinical symptoms, laboratory examination results, imaging features, treatments and outcomes were analyzed comprehensively. Results: There were 10 males and 11 females, with an average age of (58±10) years. All the cases presented subacute disease onset. The main symptoms were cough, expectoration and fever. The results from laboratory examination showed that the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were significantly higher than the normal levels. The total number of leukocytes, the percentage of neutrophils, and procalcitonin were also higher than the normal levels. Among these patients, 4 cases showed positive sputum bacteriology. Nine patients were found to have probable etiological factors (infections in 4, tumors in 4 cases, and connective tissue disease in 1 case). Twelve patients had no confirmed etiological factors. As to radiological findings, the patterns were multiple patchy infiltrates(16/21), solitary mass (3/21) and multiple nodules in both lungs (2/21). Most lesions were subpleural in distribution (15/21), with air bronchogram sign (11/21), pleural effusion (9/21), and cavity (4/21). Three patients received anti-infective therapy only. The infiltration in lung disappeared within 2 months in one patient, but the lesion still existed in one case after three years of follow-up. However, one patient were lost during the follow-up. Eighteen patients were treated with oral glucocorticoids, and about 50% of the patients showed significant improvement in symptoms and imaging findings within one month. The average follow-up time was (22±10) months, and there was no death. Conclusions: The clinical and imaging findings of AFOP are nonspecific. The exact mechanism of its pathogenesis is not clear. Infection and tumor may be related to the pathogenesis of AFOP. AFOP with subacute onset has a good response to glucocorticoid treatment with a better prognosis.

Utility of procalcitonin for differentiating cryptogenic organising pneumonia from community-acquired pneumonia.

Background This study aimed to investigate the usefulness of inflammatory biomarkers such as white blood cell (WBC) count, C-reactive protein (CRP) and procalcitonin (PCT) for differentiating cryptogenic organising pneumonia (COP) from community-acquired pneumonia (CAP). Methods COP patients hospitalised in Kurashiki Central Hospital between January 2010 and December 2017 whose WBC counts and CRP and PCT levels were measured were investigated retrospectively, and their results were compared with those of hospitalised CAP patients who were prospectively enrolled between October 2010 and November 2017. Definite COP was defined by specific histopathological findings, and possible COP was defined as a consolidation shadow on chest computed tomography and lymphocyte dominance in bronchoalveolar lavage fluid in the absence of specific histopathological findings or lung specimens. The discriminatory abilities of WBC counts, CRP and PCT were evaluated by receiver operating characteristic (ROC) curve analysis. Results There were 56 patients in the entire COP group, 35 (61.4%) with definite COP, and 914 CAP patients. All three biomarkers were significantly lower in COP than in CAP. The AUC value of PCT in all COP patients was 0.79, significantly higher than of both CRP (AUC 0.59, p < 0.001) and WBC (AUC 0.69, p = 0.048). In definite COP patients, the AUC value of PCT was 0.79, which was also significantly higher than of both WBC (AUC 0.64, p = 0.006) and CRP (AUC 0.64, p = 0.001). Conclusions PCT is a more useful biomarker for differentiating COP from CAP than WBC count or CRP. However, PCT should be used as an adjunct to clinical presentation and radiological findings.