Pleuroparenchymal fibroelastosis: a spectrum of histopathological and imaging phenotypes

Pleuroparenchymal fibroelastosis as a late complication of childhood cancer therapy: A case series

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial pneumonia with distinct clinicopathologic features. It has been associated with exposure to hematopoietic stem cell transplantation (HSCT) and classical alkylating agents. Here, we highlight PPFE as a late complication of childhood cancer therapy by describing the cases of four survivors of childhood cancer with a diagnosis of treatment-related PPFE. All patients received high-dose alkylating agents. PPFE should be considered in the differential diagnosis of restrictive lung disease in patients with history of exposure to alkylating agents or HSCT. Development of PPFE-specific, noninvasive diagnostic tools and disease-modifying therapies will clinically benefit these patients.

Central Role of CT in Management of Pulmonary Fibrosis

With the approval of antifibrotic medications to treat patients with idiopathic pulmonary fibrosis and progressive pulmonary fibrosis, radiologists have an integral role in diagnosing these entities and guiding treatment decisions. CT features of early pulmonary fibrosis include irregular thickening of interlobular septa, pleura, and intralobular linear structures, with subsequent progression to reticular abnormality, traction bronchiectasis or bronchiolectasis, and honeycombing. CT patterns of fibrotic lung disease can often be reliably classified on the basis of the CT features and distribution of the condition. Accurate identification of usual interstitial pneumonia (UIP) or probable UIP patterns by radiologists can obviate the need for a tissue sample-based diagnosis. Other entities that can appear as a UIP pattern must be excluded in multidisciplinary discussion before a diagnosis of idiopathic pulmonary fibrosis is made. Although the imaging findings of nonspecific interstitial pneumonia and fibrotic hypersensitivity pneumonitis can overlap with those of a radiologic UIP pattern, these entities can often be distinguished by paying careful attention to the radiologic signs. Diagnostic challenges may include misdiagnosis of fibrotic lung disease due to pitfalls such as airspace enlargement with fibrosis, paraseptal emphysema, recurrent aspiration, and postinfectious fibrosis. The radiologist also plays an important role in identifying complications of pulmonary fibrosis-pulmonary hypertension, acute exacerbation, infection, and lung cancer in particular. In cases in which there is uncertainty regarding the clinical and radiologic diagnoses, surgical biopsy is recommended, and a multidisciplinary discussion among clinicians, radiologists, and pathologists can be used to address diagnosis and management strategies. This review is intended to help radiologists diagnose and manage pulmonary fibrosis more accurately, ultimately aiding in the clinical management of affected patients. ©RSNA, 2024 Supplemental material is available for this article.

Genetic Testing Goes Beyond Imaging and Histological Evaluation in Pleuroparenchymal Fibroelastosis

BACKGROUND

Lung biopsy remains the gold standard in the diagnosis of fibrotic interstitial lung disease (F-ILD), but there is a growing appreciation of the role of pathogenic gene variants in telomere and surfactant protein genes, especially in familial pulmonary fibrosis (FPF). Pleuroparenchymal fibroelastosis (PPFE) is a rare disease that can coexist with different patterns of F-ILD, including FPF. It can be progressive and often leads to respiratory failure and death. This study tested the hypothesis that genetic testing goes beyond radiological and histological findings in PPFE and other F-ILD further informing clinical decision-making for patients and affected family members by identifying pathological gene variants in telomere and surfactant protein genes.

METHODS

This is a retrospective review of 70 patients with F-ILD in the setting of FPF or premature lung fibrosis. Six out of 70 patients were diagnosed with PPFE based on radiological or histological characteristics. All patients underwent telomere length evaluation in peripheral blood by Flow-FISH or genetic testing using a customized exome-based panel that included telomere and surfactant protein genes associated with lung fibrosis.

RESULTS

Herein, we identified six individuals where radiographic or histopathological analyses of PPFE were linked with telomere biology disorders (TBD) or variants in surfactant protein genes. Each case involved individuals with either personal early-onset lung fibrosis or a family history of the disease. Assessments of telomere length and genetic testing offered insights beyond traditional radiological and histopathological evaluations.

CONCLUSION

Detecting anomalies in TBD-related or surfactant protein genes can significantly refine the diagnosis and treatment strategies for individuals with PPFE and other F-ILD.

Similarities and differences of interstitial lung disease associated with pathogenic variants in SFTPC and ABCA3 in adults

BACKGROUND AND OBJECTIVE

Variants in surfactant genes SFTPC or ABCA3 are responsible for interstitial lung disease (ILD) in children and adults, with few studies in adults.

METHODS

We conducted a multicentre retrospective study of all consecutive adult patients diagnosed with ILD associated with variants in SFTPC or ABCA3 in the French rare pulmonary diseases network, OrphaLung. Variants and chest computed tomography (CT) features were centrally reviewed.

RESULTS

We included 36 patients (median age: 34 years, 20 males), 22 in the SFTPC group and 14 in the ABCA3 group. Clinical characteristics were similar between groups. Baseline median FVC was 59% ([52-72]) and DLco was 44% ([35-50]). An unclassifiable pattern of fibrosing ILD was the most frequent on chest CT, found in 85% of patients, however with a distinct phenotype with ground-glass opacities and/or cysts. Nonspecific interstitial pneumonia and usual interstitial pneumonia were the most common histological patterns in the ABCA3 group and in the SFTPC group, respectively. Annually, FVC and DLCO declined by 1.87% and 2.43% in the SFTPC group, respectively, and by 0.72% and 0.95% in the ABCA3 group, respectively (FVC, p = 0.014 and DLCO , p = 0.004 for comparison between groups). Median time to death or lung transplantation was 10 years in the SFTPC group and was not reached at the end of follow-up in the ABCA3 group.

CONCLUSION

SFTPC and ABCA3-associated ILD present with a distinct phenotype and prognosis. A radiologic pattern of fibrosing ILD with ground-glass opacities and/or cysts is frequently found in these rare conditions.

Pictorial Review of Fibrotic Interstitial Lung Disease on High-Resolution CT Scan and Updated Classification

TOPIC IMPORTANCE

Given the recently expanded approval of antifibrotics for various fibrotic interstitial lung diseases (ILDs), early and correct recognition of these diseases is imperative for physicians. Because high-resolution chest CT scan forms the backbone of diagnosis for ILD, this review will discuss evidence-based imaging findings of key fibrotic ILDs and an approach for differentiating these diseases.

REVIEW FINDINGS

(1) Imaging findings of nonspecific interstitial pneumonia may evolve over time and become indistinguishable from usual interstitial pneumonia. Therefore, if remote imaging can be reviewed, this would increase the likelihood of an accurate imaging diagnosis, particularly if findings appear to represent a usual interstitial pneumonia pattern on the recent examination. (2) Given the difficulty and lack of objectivity in classifying patients with hypersensitivity pneumonitis into acute, subacute, and chronic categories and that prognosis depends primarily on presence or absence of fibrosis, the new set of guidelines released in 2020 categorizes patients with hypersensitivity pneumonitis as either nonfibrotic (purely inflammatory) or fibrotic (either purely fibrotic or mixed fibrotic/inflammatory) based on imaging and/or histologic findings, and the prior temporal terms are no longer used. (3) Interstitial lung abnormalities are incidental CT scan findings that may suggest early ILD in patients without clinical suspicion for ILD. Patients with high-risk features should undergo clinical evaluation for ILD and be actively monitored for disease progression.

SUMMARY

Fibrotic ILD on high-resolution chest CT scan is a complex topic, but with use of an evidence-based analysis and algorithm as provided in this article, the probability of a correct imaging diagnosis increases.

A Rare Case of Idiopathic Pleuro-Parenchymal Fibroelastosis Presenting With Bilateral Spontaneous Pneumothoraces

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease (ILD), characterized by predominantly upper lobe pleural and subjacent sub-pleural parenchymal fibrosis. Its name refers to a combination of fibrosis involving the visceral pleura with fibroelastotic changes, predominantly in the subpleural lung parenchyma. We describe the case of a 67-year-old lady who presented to the accident and emergency department of Weston General Hospital with worsening shortness of breath (SOB) and cachexia of six to eight months' duration. The initial imaging studies showed bilateral spontaneous pneumothoraces on a background of pleural-based consolidation and fibrotic changes. A subsequent high-resolution CT (HRCT) chest showed evidence of pleuroparenchymal fibroelastosis in the background. She was not considered for anti-fibrotic medications due to the advanced stage of the disease and was managed with supportive measures, including oxygen support, oral steroids and antibiotics to cover for any infections. After initial management of symptoms and long discussions with the patient, family and the palliative team, she was discharged home with community follow-up.

Development of microscopic polyangiitis following idiopathic pleuroparenchymal l fibroelastosis: A case report

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare type of idiopathic interstitial pneumonia, which is characterised by pleural fibrosis and subjacent parenchymal fibroelastosis of the upper lobes. Herein, we present a case of microscopic polyangiitis (MPA) following PPFE. The patient had abnormal shadows on chest radiographs 15 years before the onset of MPA, and the patient was diagnosed with PPFE. Four years after the PPFE diagnosis, the patient was diagnosed with MPA based on persistent fever, purpura, mononeuritis multiplex, myeloperoxidase-antineutrophil cytoplasmic antibody positivity, and pathological findings of peritubular capillaritis on kidney biopsy. The patient was treated with glucocorticoids, including methylprednisolone pulse therapy and rituximab, followed by maintenance therapy with rituximab. One year after treatment, the PPFE had not worsened. PPFE occasionally occurs secondary to connective tissue disease, including MPA; however, to the best of our knowledge, this is the first report of PPFE preceding MPA. Our case suggests that PPFE, as other interstitial lung diseases, may be associated with MPA and precede the onset of MPA. The accumulation of more cases is needed to clarify the characteristics of MPA-associated PPFE.

Neutrophil-lymphocyte ratio in patients with idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (iPPFE), a progressive fibrotic disease, is characterised by upper lobe-dominant lung fibrosis involving the pleura and subpleural lung parenchyma. However, no prognostic markers have been established for this condition. Associations between blood leucocyte levels and mortality have been reported in patients with idiopathic pulmonary fibrosis; therefore, we hypothesised that peripheral leucocyte levels are associated with mortality risk in patients with iPPFE.

METHODS

This retrospective study longitudinally assessed peripheral leucocyte counts at the time of diagnosis and 1 year after diagnosis in two cohorts of 127 patients with iPPFE (69 and 58 patients in Seirei and Hamamatsu cohorts, respectively).

RESULTS

A comprehensive assessment of peripheral leucocytes revealed that the neutrophil-lymphocyte ratio (NLR) was associated with mortality in patients with iPPFE after adjusting for age, sex and forced vital capacity in multivariate analyses (adjusted HR, 1.131; 95% CI, 1.032 to 1.227). When the patients were classified based on the median NLR, those with a high NLR had shorter survival than those with a low NLR (median, 32.2 vs 79.8 months; HR, 2.270; 95% CI, 1.416 to 3.696). Interestingly, the results of the NLR classification by median were longitudinally preserved in >70% of patients, and patients with consistently high NLR were at a higher risk of mortality than others (median, 24.8 vs 79.6 months; HR, 3.079; 95% CI, 1.878 to 5.031). Compared with the gender-age-physiology model, a composite model comprising age, sex and NLR could successfully stratify patients with iPPFE into three groups according to mortality risk.

CONCLUSION

The assessment of peripheral leucocyte counts is easy and might be useful in evaluating disease severity and mortality risk in patients with iPPFE. Our study suggests the importance of focusing on peripheral leucocyte levels in daily practice.

Variation in information needs of patients with interstitial lung disease and their family caregivers according to long-term oxygen therapy: a descriptive study

BACKGROUND

The information needs of patients and their families regarding interstitial lung disease (ILD) have yet to be studied in detail, and few reports have examined the differences in information needs according to patient status. This study aimed to determine whether there are differences in information needs between outpatients with ILD and their family caregivers and whether these differences depend on long-term oxygen therapy use.

METHODS

Patients with fibrotic ILDs and their families who visited Kyoto University Hospital between February 2020 and March 2022 were recruited for this descriptive study. Fibrotic ILDs included idiopathic pulmonary fibrosis (IPF), other idiopathic interstitial pneumonias (IIPs) than IPF, connective tissue disease-associated ILD (CTD-ILD), and fibrotic hypersensitivity pneumonia. Data were obtained from electronic patient records and questionnaires. Descriptive data analyses were performed.

RESULTS

Sixty-five patients and their family caregivers were analyzed. Twenty-seven (41.5%) patients had IIPs (IPF 9 and other IIPs 18), 34 (52.3%) had CTD-ILD, and 4 (6.2%) had fibrotic hypersensitivity pneumonia. The most common relationship between the patient and their family was a spouse (67.7%), with 80% living together. The primary information needs among patients and their family caregivers were common up to the third rank but differed from the rest. Patients were interested in "when and where to contact health care providers" and "end-of-life care and advanced directives," while family caregivers were interested in "diet and nutrition" and "care and support at home." Patients with long-term oxygen therapy had higher needs for "end-of-life care and advanced directives" and "how to manage breathlessness, cough, and fatigue," while the needs for "drugs for ILD" and "acute exacerbation of ILD" were relatively low. Family caregivers were interested in "diet and nutrition" in the long-term oxygen therapy group and "acute exacerbation of ILD" in the no long-term oxygen therapy group.

CONCLUSIONS

This study found that the information needs of patients and their family caregivers were not the same and that the aspect of information needs differed by long-term oxygen therapy status. Healthcare providers should consider the position of the recipient of information, the appropriate time based on the patient's condition, and the necessary information.

Pulmonary fibroelastosis - A review

Elastin is a long-lived fibrous protein that is abundant in the extracellular matrix of the lung. Elastic fibers provide the lung the characteristic elasticity during inhalation with recoil during exhalation thereby ensuring efficient gas exchange. Excessive deposition of elastin and other extracellular matrix proteins reduces lung compliance by impairing ventilation and compromising gas exchange. Notably, the degree of elastosis is associated with the progressive decline in lung function and survival in patients with interstitial lung diseases. Currently there are no proven therapies which effectively reduce the elastin burden in the lung nor prevent dysregulated elastosis. This review describes elastin's role in the healthy lung, summarizes elastosis in pulmonary diseases, and evaluates the current understanding of elastin regulation and dysregulation with the goal of guiding future research efforts to develop novel and effective therapies.

High prevalence of upper lung field pulmonary fibrosis radiologically consistent with pleuroparenchymal fibroelastosis in patients with round atelectasis

BACKGROUND

Upper-lung field pulmonary fibrosis (upper-PF), radiologically consistent with pleuroparenchymal fibroelastosis (PPFE), was reported to develop in patients with a history of asbestos exposure and tuberculous pleurisy, indicating that chronic pleuritis is correlated with upper-PF development. Round atelectasis reportedly emerges after chronic pleuritis. This study aimed to clarify the association between round atelectasis and upper-PF.

METHODS

We examined the radiological reports of all consecutive patients with round atelectasis between 2006 and 2018 and investigated the incidence of upper-PF development.

RESULTS

Among 85 patients with round atelectasis, 21 patients (24.7%) were confirmed to finally develop upper-PF lesions. Upper-PF was diagnosed after round atelectasis recognition in more than half of the patients (13/21, 61.9%), whereas upper-PF and round atelectasis were simultaneously detected in the remaining 8 patients. At the time of round atelectasis detection, almost all patients (19/21, 90.5%) had diffuse pleural thickening and round atelectasis was commonly observed in non-upper lobes of 19 patients (90.5%). Fourteen patients had round atelectasis in unilateral lung, and the remaining 7 patients had round atelectasis in bilateral lungs. Among all 14 patients with unilateral round atelectasis, upper-PF developed on the same (n = 11) or both sides (n = 3). Thus, upper-PF emerged on the same side where round atelectasis was present (14/14, 100%). The autopsy of one patient revealed a thickened parietal-visceral pleura suggestive of chronic pleuritis. Subpleural fibroelastosis was also observed.

CONCLUSIONS

Upper-PF occasionally develops on the same side of round atelectasis. Upper-PF may develop as a sequela of chronic pleuritis.

Establishing quantitative radiographic criteria for the diagnosis of pleuroparenchymal fibroelastosis

PURPOSE

Pleuroparenchymal Fibroelastosis (PPFE) is a type of pulmonary fibrosis most commonly occurring at the apices. Patients with PPFE have an increased risk of adverse effects from lung biopsy and in the post-surgical setting. Here, we investigated simple and reproducible measurements on chest CT to evaluate their predictive value in diagnosing PPFE.

METHODS

We analyzed a cohort of patients with histologically-proven PPFE and compared them to a cohort of patients diagnosed with "biapical scarring" (BAS) on chest CT. We measured plueuroparenchymal thickness using several independent parameters on chest CT. We also assessed other radiologic and clinical characteristics to identify if any were predictive of PPFF.

RESULTS

Our analysis demonstrated the average greatest apical thickness with a cut off of 4.5 mm yielded a sensitivity of 94.4% and a specificity of 88.9%, and an area under the curve of 97.2%. Single greatest apical thickness with a cut off of 7.5 mm had a sensitivity of 100% and a specificity of 88.9%, with the area under the curve of 97.8%. Average greatest upper lobe thickness with a cut off of 8.0 mm had a sensitivity of 88.9% and a specificity of 100%, with an area under the curve of 98.2%. Single greatest upper lobe thickness with a cut off of 8.5 yielded both a sensitivity and specificity of 94.4% and an area under the curve of 94.3%.

CONCLUSION

Measurements described above are highly sensitive and specific for the diagnosis of PPFE and warrant investigation with a larger cohort of patients.

Imaging Features of Idiopathic Interstitial Lung Diseases

Idiopathic interstitial pneumonias (IIPs) are a group of diffuse parenchymal lung diseases of unclear etiology and are distinguished from diffuse parenchymal lung diseases of known cause, such as connective tissue disease-related interstitial lung diseases or hypersensitivity pneumonitis by history, physical exam, imaging, serologic testing, and, when necessary, histopathology. The 2013 American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines are the most widely accepted classification of IIPs and include the following diagnoses: idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, idiopathic lymphocytic interstitial pneumonia, idiopathic pleuro-parenchymal fibroelastosis, respiratory bronchiolitis-interstitial lung disease, and desquamative interstitial pneumonia. The gold standard for diagnosis of IIP involves multidisciplinary discussion among pulmonologists, radiologists, and pathologists. The focus of this review will be to discuss the imaging features of the most common IIPs and the role of multidisciplinary discussion as the gold standard for diagnosis.

CT Patterns of Interstitial Lung Disease in Patients with Plaque Psoriasis: A Retrospective Case Series Study

Background and Objectives: Recently published articles reported an association between psoriasis and interstitial lung diseases (ILDs). The aim of this study is to evaluate the differences in ILD computed tomography (CT) patterns between smoker and never smoker plaque psoriasis (PP) patients under topical treatment without psoriatic arthritis (PA), inflammatory bowel disease (IBD) or connective tissue diseases (CTDs). Matherials and Methods: Two radiologists evaluated chest CT examinations of 65 patients (33 smokers, 32 never smokers) with PP. Results: Usual interstitial pneumonia (UIP) pattern was diagnosed in 36 patients, nonspecific interstitial pneumonia pattern in 19, hypersensitivity pneumonitis in 7 and pleuropulmonary fibroelastosis (PPFE) in 3 patients. UIP pattern showed a statistically significant higher frequency in smoker patients (p = 0.0351). Respiratory symptoms were reported in 80% of patients. Conclusions: ILDs seems to represent a new comorbidity associated with psoriasis. Moreover, a statistically significant association between smokers and UIP pattern in PP patients is found. Respiratory symptoms should be evaluated in PP patients, in collaboration with a radiologist and a pneumologist. However, further studies are required to better understand the epidemiology of ILDs in PP patients.

Extremely late-onset chronic graft-versus-host disease presenting with bronchiolitis obliterans and pleuroparenchymal fibroelastosis

A 35-year-old woman experienced left back pain after a 2-h flight. She reported coughing and left back pain 1 day later when she presented to our hospital. Chest computed tomography showed pneumothorax of the left lung, bronchiectasis, thickening of the bronchial wall, nodules, and cavity lesions in both lungs. A pulmonary function test revealed obstructive ventilation disorder with normal lung diffusing capacity. She had a history of haematopoietic stem cell transplantation (HSCT) at 2 years and 3 months of age during the second disease remission of acute myeloid leukaemia. She was diagnosed with chronic graft-versus-host disease (cGVHD) presenting with bronchiolitis obliterans (BO) and pleuroparenchymal fibroelastosis (PPFE). To our knowledge, this is the first reported case of BO and PPFE diagnosed more than 30 years after HSCT.

Overcoming the challenges of a misdiagnosed rare lung disease - Idiopathic pleuroparenchymal fibroelastosis

Pleuroparenchymal fibroelastosis (PPFE) is a rare condition characterized by pleural and subpleural lung fibroelastosis with an upper lobe predominance. We present the third case of idiopathic pleuroparenchymal fibroelastosis (IPPFE) from India, as well as the second antemortem diagnosis. A 27-year-old man presented with a one-year history of mMRC class II dry cough and shortness of breath. He described a fifteen-kilogram weight loss. After a clinico-radiological diagnosis, he was given anti-tubercular treatment and referred because he showed no improvement. A high-resolution computed tomography of the chest revealed bilateral upper lobe bullae, parenchymal and subpleural fibrosis, and irregular pleural thickening. PPFE was found in surgical lung and pleural biopsies. He was given systemic glucocorticoids but did not respond clinically or radiologically. Pirfenidone and a lung transplant were out of reach for him. He died nine months after being diagnosed with his condition. Finally, IPPFE is an extremely rare entity, with only three cases reported from our subcontinent. As a result, it is easily underdiagnosed or misdiagnosed; clinician awareness of this condition is critical for better diagnosis and management.

Lung Transplantation for Pleuroparenchymal Fibroelastosis: A Single-Center Experience with Revision of Literature

Pleuroparenchymal fibroelastosis (PPFE) is a rare condition characterized by fibrosis involving the pleura and the upper lobes which can be idiopathic or secondary to chemotherapy, transplantations and occupational exposure. For the end-stage form, lung transplantation (LT) is the treatment of choice. The aim of this study was to report our single-center experience for patients subjected to LT for PPFE and comparing it with the already published evidence on this topic. At our center, we have performed 6 bilateral LTs for patients with PPFE (3 males and 3 females) with a median age of 52 years. Median ICU and in-hospital length of stay were 8 and 30 days, respectively. To date, two patients are alive and four are dead, with a median overall survival of 10 months. In addition, after a formal search using the terms "pleuroparenchymal fibroelastosis AND lung transplantation", we collected 14 studies focused on outcomes after LT. LT for PPFE is technically challenging and its post-operative course could also be complicated. Current available data on LT outcomes are extremely poor and mostly limited to case reports. Further studies need to be published to improve knowledge of this disease and to achieve best outcomes for LT.

Pleuroparenchymal Fibroelastosis-like Lesions in Clinical Practice: A Rare Entity? Review of a Radiological Database

Background: Pleuroparenchymal Fibroelastosis (PPFE) is a rare disease that consists of elastofibrosis that involves the pleura and subpleural lung parenchyma; it is an unusual pulmonary disease with unique clinical, radiological and pathological characteristics. According to recent studies, PPFE may not be a definite disease but a form of chronic lung injury. The aim of this retrospective study is to determine the incidence and to evaluate the distribution, severity and progression of this radiological entity on high-resolution CT (HRCT) exams of the chest, performed in routine clinical practice. In total, 1514 HRCT exams performed in the period January 2016-June 2018 were analyzed. For each exam, the presence of PPFE was evaluated and a quantitative score was assigned (from 0 to 7 points, based on the maximum depth of fibrotic involvement of the parenchyma). When available, two exams with a time interval of at least 6 months were compared for each patient in order to evaluate progression (defined as the increase in the disease score). Patients were divided into different groups according to exposure and their associated diseases. Statistical analysis was performed by using the Wilcoxon test and Kruskal-Wallis test. Results: PPFE was detected in 174 out of 1514 patients (11.6%), with a mean score of 6.1 ± 3.9 (range 1-14). In 106 out of 174 patients (60.9%), a previous CT scan was available and an evolution of PPFE was detected in 19 of these (11.5%). Among these 19 patients with worsening PPFE, 4 had isolated PPFE that was associated with chronic exposure or connective tissue disorders, and the other 15 had an associated lung disease and/or a chronic exposure. In this group, it was found that the ventral segments of the upper lobes, fissures and apical segments of the lower lobes had a greater statistically significant involvement in the progression of the disease compared to the non-progressive group. In 16 of 174 patients (9.2%, 7 of which belonged to the radiological progression group) a biopsy through video-assisted thoracoscopic surgery or apicoectomy confirmed PPFE. Conclusion: PPFE-like lesions are not uncommon on HRCT exams in routine clinical practice, and are frequently found in patients with different forms of chronic lung injury. Further studies are necessary to explain why the disease progresses in some cases, while in most, it remains stationary over time.

Pulmonary nodular elastosis: The intraparenchymal counterpart of pulmonary apical caps?

We have studied six cases in which focal consolidative pulmonary opacities observed on imaging studies led to surgical resection due to the suspicion of malignancy and showed on histopathologic examination a benign process characterized by an expansile tumor-like nodular accumulation of elastotic material. The patients were five women and one man aged 46 to 67 years (mean: 61 years). All lesions were found incidentally on imaging studies done for a variety of reasons, including surveillance for metastatic carcinoma in four patients. The lesions presented as solid nodules within lung parenchyma with irregular borders and spiculated margins and measured between 0.6 and 4.6 cm in diameter. Histological examination showed dense deposits of elastic tissue without evidence of malignancy, similar to those seen in pulmonary apical caps. Clinical follow-up between 5 and 16 years (mean: 10 years) showed that all patients were alive and well without evidence of disease. Pulmonary nodular elastosis is a localized intraparenchymatous process that may be confused clinically and radiographically for a malignant neoplasm and needs to be distinguished from other nodular lesions of the lung. To the best of our knowledge, tumor-forming lesions within lung parenchyma that are predominantly or almost exclusively composed of accumulation of elastic fibers have not been previously described.

The world of rare interstitial lung diseases

The world of rare interstitial lung diseases (ILDs) is diverse and complex. Diagnosis and therapy usually pose challenges. This review describes a selection of rare and ultrarare ILDs including pulmonary alveolar proteinosis, pulmonary alveolar microlithiasis and pleuroparenchymal fibroelastosis. In addition, monogenic ILDs or ILDs in congenital syndromes and various multiple cystic lung diseases will be discussed. All these conditions are part of the scope of the European Reference Network on rare respiratory diseases (ERN-LUNG). Epidemiology, pathogenesis, diagnostics and treatment of each disease are presented.

Pleuroparenchymal Fibroelastosis: A Review with a Focus on a Non-Infectious Complications after Hematopoietic Stem Cell Transplant

Pleuroparenchymal fibroelastosis (PPFE) is a rare disease that is currently classified as an idiopathic interstitial pneumonia. Although originally described as an idiopathic disease, PPFE has now been identified as a rare complication following hematopoietic stem cell transplant (HSCT). Unlike other pulmonary complications after HSCT, PPFE occurs very late after transplant. Etiologies for PPFE after HSCT remain to be fully established. Infections and adverse effects to alkylating chemotherapy have been suggested as possible causes. In several cases, there is an association of PPFE with bronchiolitis obliterans syndrome after HSCT, suggesting that PPFE may be another manifestation of pulmonary chronic graft versus host disease after HSCT. Algorithms have been designed to assist in confirming a diagnosis of PPFE without the need for a surgical lung biopsy, however at present, no biomarker is established for the diagnosis or to predict the progression of disease. Presently, there is no current therapy for PPFE, but fortunately the disease progresses slowly in most patients.

Pleuroparenchymal fibroelastosis after hematopoietic stem cell transplantation in children: a propensity score-matched analysis

OBJECTIVES

To investigate the incidence, risk factors, and clinical outcomes of pleuroparenchymal fibroelastosis (PPFE) in pediatric hematopoietic stem cell transplantation (HSCT) recipients.

METHODS

This single-center, retrospective, case-control study included 738 consecutive patients who underwent chest CT more than 3 months after HSCT. We identified patients who fulfilled the diagnostic criteria for PPFE and assessed their clinical characteristics and radiologic findings. Propensity score-matched analysis was performed using four covariates (age, sex, HSCT type, and primary disease). The risk factors and clinical outcomes of PPFE were analyzed using the Fine and Gray regression model and stratified log-rank test in the matched groups.

RESULTS

PPFE was identified in 4% (31/738, 8.3 ± 3.1 years, 15 males) of the pediatric HSCT recipients with a median time of 2.7 years after HSCT, and it occurred following allogeneic (5%, 15/317), autologous (4%, 15/379), or both (2%, 1/42). Matching yielded 30 and 130 cases in the PPFE and control groups, respectively. The PPFE group showed more frequent late-onset noninfectious pulmonary complications (LONIPCs) and pneumonia more than 3 months after HSCT (p < 0.05). Multivariable analysis showed a significantly higher risk of PPFE in HSCT recipients who had pneumonia more than 3 months after HSCT (hazard ratio = 10.78 [95% confidence interval: 4.29, 27.13], p < 0.001). The PPFE group showed higher mortality (73%, 22/30) and poorer median overall survival (6.8 years [95% confidence interval: 4.1, 9.5]) than the control group (p < 0.001).

CONCLUSIONS

PPFE represents a severe type of LONIPC after HSCT. HSCT recipients with pneumonia after HSCT may have an increased risk of PPFE.

KEY POINTS

• The incidence of pleuroparenchymal fibroelastosis is not negligible (4%), and it can occur after either allogeneic or autologous hematopoietic stem cell transplantation. • Pleuroparenchymal fibroelastosis after hematopoietic stem cell transplantation showed poor outcome with a high mortality rate of 73% and median overall survival of 6.8 years. • After hematopoietic stem cell transplantation, pneumonia may increase the risk of pleuroparenchymal fibroelastosis development in children. • Lung biopsy should not be indicated in patients with pleuroparenchymal fibroelastosis findings on chest CT as it can cause refractory pneumothorax without helping the diagnosis.

Clinical features of idiopathic pleuroparenchymal fibroelastosis with progressive phenotype showing a decline in forced vital capacity

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is heterogeneous, with some patients showing a progressive decline in forced vital capacity (FVC). However, the clinical features of these cases with progressive phenotypes remain unknown.

METHODS

This retrospective study included 48 patients diagnosed with IPPFE who underwent longitudinal pulmonary function tests at our institution from 2005 to 2021. The progressive phenotype was defined as a relative decline of ≥10% in %FVC within two years from diagnosis of IPPFE, and its clinical features were evaluated.

RESULTS

Of the 48 patients, 23 (47.9%) were classified as progressive IPPFE. They were significantly older with a higher rate of dyspnea, fine crackles on chest auscultation, lower-lobe usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography, and lower %FVC at diagnosis than non-progressive IPPFE. Additionally, progressive IPPFE had a significantly higher rate of long-term oxygen therapy requirement, the incidence of pneumothorax, and weight loss after diagnosis, which showed worse survival than non-progressive IPPFE. The relative decline in %FVC and weight loss showed a significant positive correlation. Multivariate analysis revealed that lower body mass index tended to predict early progression, and the coexistence of lower-lobe UIP pattern was significantly associated with early progression. A decline in %FVC was an independent poor prognostic factor in IPPFE.

CONCLUSIONS

With a progressive decline in %FVC, IPPFE often has an advanced stage at diagnosis and lower-lobe UIP pattern and is associated with weight loss and worse survival.

Acute exacerbation of pleuroparenchymal fibroelastosis with lower lobe usual interstitial pneumonia: An autopsy case

An 87-year-old man presented with dyspnea. Computed tomography revealed progressive subpleural consolidation in the apex, reticular shadows in the lower lobes, and bilateral ground glass opacifications. He died of respiratory failure on day 3. The post-mortem examination showed exudative stage diffuse alveolar damage and pulmonary edema. Intraalveolar collagenous fibrosis and subpleural elastosis were observed in the upper lobes, accompanied by interlobular septal and pleural thickening and lung architecture remodeling in the lower lobes. He was diagnosed with acute exacerbation of pleuroparenchymal fibroelastosis with lower lobe usual interstitial pneumonia, which can be fatal.

Idiopathic pleuroparenchymal fibroelastosis: three-dimensional computed tomography assessment of upper-lobe lung volume

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare interstitial lung disease characterised by predominant upper-lobe fibrosis involving the pleura and subpleural lung parenchyma. Despite its poor prognosis, there is no consensus on prognostic determinants of iPPFE to date. Because volume loss in the upper lobe is a distinct feature of iPPFE, we hypothesised that the lung volume of the bilateral upper lobes (upper-lobe volume) accurately indicates disease severity and mortality risk in iPPFE patients.

METHODS

This retrospective study assessed two cohorts of 132 patients with iPPFE (69 in Hamamatsu cohort; 63 in Seirei cohort) and 45 controls. Each lobe volume was quantitatively measured using three-dimensional computed tomography at the time of iPPFE diagnosis and standardised using predicted forced vital capacity.

RESULTS

The standardised upper-lobe volume in iPPFE patients was less than half that of controls, whereas the lower-lobe volume did not decrease. iPPFE patients with lower standardised upper-lobe volume had significantly shorter survival rates than those with higher volume (median survival: 6.08 versus 2.48 years, p<0.001). In multivariate analysis, the lower standardised upper-lobe volume was significantly associated with increased mortality adjusting for age, sex and forced vital capacity (HR 0.939). A composite scoring model, including age, sex and standardised upper-lobe volume, better predicted risk of death than the gender-age-physiology model.

CONCLUSION

Assessment of upper-lobe volume provides useful information for managing iPPFE by evaluating disease severity and mortality risk in clinical practice.

Idiopathic pleuroparenchymal fibroelastosis

The term idiopathic pleuroparenchymal fibroelastosis refers to a rare interstitial lung disease that predominantly involves the upper lobes. It has been considered a rare subtype of interstitial lung disease since 2013, when it was included in the joint consensus statement on the diagnosis of interstitial lung diseases published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS). Currently, two distinct types of pleuroparenchymal fibroelastosis are recognized: the idiopathic type for cases in which it has not been possible to establish a specific etiology and a secondary type associated with a variety of different causes. The diagnosis of pleuroparenchymal fibroelastosis must be managed from a combined clinical and radiological perspective. High-resolution computed tomography (HRCT) is the imaging method of choice for the evaluation and diagnosis of pleuroparenchymal fibroelastosis. In many cases, the diagnosis will be based exclusively on the HRCT findings and histologic confirmation will be unnecessary. This article describes the clinical, radiological, and histological characteristics of pleuroparenchymal fibroelastosis, discussing the different associations with this entity and its differential diagnosis.

High-Resolution Computed Tomography of Fibrotic Interstitial Lung Disease

While radiography is the first-line imaging technique for evaluation of pulmonary disease, high-resolution computed tomography (HRCT) provides detailed assessment of the lung parenchyma and interstitium, allowing normal anatomy to be differentiated from superimposed abnormal findings. The fibrotic interstitial lung diseases have HRCT features that include reticulation, traction bronchiectasis and bronchiolectasis, honeycombing, architectural distortion, and volume loss. The characterization and distribution of these features result in distinctive CT patterns. The CT pattern and its progression over time can be combined with clinical, serologic, and pathologic data during multidisciplinary discussion to establish a clinical diagnosis. Serial examinations identify progression, treatment response, complications, and can assist in determining prognosis. This article will describe the technique used to perform HRCT, the normal and abnormal appearance of the lung on HRCT, and the CT patterns identified in common fibrotic lung diseases.

Idiopathic Pulmonary Fibrosis and Telomeres

Idiopathic pulmonary fibrosis is an interstitial lung disease of unknown etiology with a highly compromised prognosis and a significant mortality rate within a few years of diagnosis. Despite being idiopathic, it has been shown that telomeric shortening could play an important role in its etiopathogenesis. Mutations in telomere-related genes have been identified, but they are not always present despite telomere shortening. On the other hand, this telomeric shortening has been linked to a worse prognosis of the disease independently of other clinical factors, implying it may serve as a biomarker.

Prognostic significance of radiological pleuroparenchymal fibroelastosis inMycobacterium aviumcomplex lung disease: a multicentre retrospective cohort study

Background

Mycobacterium aviumcomplex (MAC) causes chronic respiratory infectious diseases with diverse clinical features and prognoses. Pleuroparenchymal fibroelastosis (PPFE) is a rare disease characterised by pleural fibrosis with subjacent intra-alveolar fibrosis and alveolar septal elastosis, with unique chest high-resolution CT (HRCT) features (radiological PPFE). An association between recurrent respiratory infections and PPFE formation has been hypothesised; however, the clinical significance of PPFE in MAC lung disease remains unclear.

Methods

This retrospective, multicentre study investigated the prevalence of radiological PPFE in patients with MAC lung disease and its association with clinical features and outcomes. Radiological PPFE was diagnosed on the basis of HRCT findings. Prognostic factors were identified using Cox proportional hazards and Fine-Gray models.

Results

Of 850 consecutive patients with definite MAC lung disease, 101 (11.9%) exhibited radiological PPFE. Patients with radiological PPFE had unique characteristics, such as lower body mass index, lower survival rate (5-year cumulative survival rate, 63.1% vs 91.7%; p<0.001) and a higher incidence of respiratory-related death (5-year cumulative incidence, 31.1% vs 3.6%; p<0.001), than those without radiological PPFE. In the multivariable analysis, the presence of radiological PPFE was independently associated with all-cause mortality (adjusted HR, 4.78; 95% CI, 2.87 to 7.95; p<0.001) and respiratory-related death (adjusted HR, 3.88; 95% CI, 2.14 to 7.01; p<0.001).

Interpretation

This large-scale study demonstrated that in patients with MAC lung disease, radiological PPFE was common, a phenotype associated with unique clinical features and poor prognosis, particularly respiratory-related death. The specific management of this subgroup should be established.

Diagnosis of pleuroparenchymal fibroelastosis: A review

Pleuroparenchymal fibroelastosis (PPFE) is a rare lung disease with unprecedented features characterized by fibroelastotic changes in the subpleural lung parenchyma affecting the upper lobes. PPFE is usually idiopathic, but it can be caused by infection, autoimmunity, bone marrow or lung transplantation, or a genetic predisposition. Histopathologic examination of lung biopsy samples reveals homogenous subpleural fibrosis and abundant elastic fibers, allowing for a definitive diagnosis. As PPFE mimics many interstitial lung diseases, clinicians face significant difficulties in making a definitive final diagnosis. Since most disease-related comorbid conditions manifest at an advanced stage, invasive tissue sampling for histopathologic evaluation is consistently impossible. Such a patient presentation highlights the importance of an analysis based solely on clinical findings, which would provide a definitive diagnosis without the need for a biopsy. Because of its exceptional and inconceivable presentation, PPFE creates a diagnostic dilemma. In light of our two cases and the literature data, we present a diagnostic assessment score assay that relies solely on clinical manifestations without histopathological tissue verification to shed light on the diagnosis of PPFE. This review focuses on PPFE identification through the use of a diagnostic assessment analysis to improve early disease recognition without the use of invasive diagnostic interventions to obtain biopsy samples for histopathologic evaluation. This analytic approach, while not diagnostic in and of itself, may provide a useful pathway for differential diagnosis and may preclude redundant initiatives.

Pleuroparenchymal Fibroelastosis: A Case Report

Pleuroparenchymal fibroelastosis (PPFE) is a rare, idiopathic interstitial pneumonia. wherein the first symptom might be dyspnea or a dry cough. The condition can also be manifested with chest pain secondary to pneumothorax. While the definitive diagnosis is based on a histological evaluation (which is not often performed), a computed tomography scan shows findings, such as apical fibrosis and pleural thickening of the apical lobes, which help assess the diagnosis. We describe a case of PPFE diagnosed radiologically in a 69-year-old man. This case highlights that PPFE is a pathology that can go unnoticed for a long time, and patients might neglect the revealing symptoms such as coughing.

Röntgenbefunde bei diffusen parenchymatösen Lungenerkrankungen

Klinisches Problem

Empfehlungen für die Praxis

Pleuroparenchymal fibroelastosis

PURPOSE OF REVIEW

Pleuroparenchymal fibroelastosis (PPFE) is a clinico-radiologic-pathologic interstitial lung disease (ILD) characterized by fibrosis that has upper lobe and subpleural predominance, involving both the visceral pleura and the subjacent subpleural lung parenchyma, and comprises dense fibroelastic changes with prominent elastosis of the alveolar walls together with fibrous thickening of the visceral pleura. The goal of this review is to summarize the state-of-the-art understanding in PPFE.

RECENT FINDINGS

PPFE was described in an increasing number of conditions. The course of disease is heterogeneous. Idiopathic PPFE, cases associated with telomerase-related gene mutations, cases related to a history of chemotherapy, and cases combining PPFE with a pattern of usual interstitial pneumonia, may have a particularly poor prognosis. Well-conducted retrospective studies identified marked PPFE features in approximately 10% of patients with idiopathic pulmonary fibrosis, 11% of patients with systemic sclerosis-associated ILD, 6.5% of patients with rheumatoid arthritis-associated ILD, and 23% of patients with hypersensitivity pneumonitis. Drug therapy has not been evaluated prospectively. A small retrospective study suggests that nintedanib may slow disease progression. However, whether the efficacy of antifibrotics is comparable in PPFE and in other forms of progressive pulmonary fibrosis warrants further evaluation.

SUMMARY

Accumulating data indicate that PPFE features are associated with poor prognosis in fibrosing ILDs. Further research on the management of PPFE is warranted.

Late pulmonary complications related to cancer treatment in children

As the number of childhood cancer survivors increases, a heightened awareness and recognition of therapy-related late effects is becoming more important. Pulmonary complications are the third leading cause of late mortality in cancer survivors. Diagnosis of these complications on chest imaging helps facilitate prompt treatment to mitigate adverse outcomes. In this review, we summarize the imaging of late pulmonary complications of cancer therapy in children and highlight characteristic findings that should be recognized by radiologists.

Pulmonary hypertension or pulmonary arterial hypertension in idiopathic pleuroparenchymal fibroelastosis: An updated comprehensive review

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a little-known entity with unique clinical, radiological, and pathological features. iPPFE is chronic interstitial pneumonia characterized by the thickening of elastic fibers in the pleura and subpleural parenchyma involving the upper lobes. Computed tomography pulmonary angiography (CTPA) usually depicts bilateral pleural thickening, with a left scalloped appearance that conditions retraction of the structures of the superior mediastinum and both pulmonary hila, associated with pulmonary consolidations with bronchogram air and thickening of the peribronchovascular interstitium, in addition to areas of left apical air trapping. When severe enough, the disease leads to progressive loss of volume of the upper lobes, decreased body mass, and platythorax. Some patients with iPPFE follow an inexorably progressive course culminating in irreversible respiratory failure and premature death. Up to 20% of patients might develop pulmonary hypertension (PH); transthoracic echocardiography is used as a screening test for PH; right heart catheterization performed in a tertiary-care hospital will confirm the diagnosis. Because iPPFE can be easily confused and misdiagnosed with infectious pathologies, such as pulmonary tuberculosis, and easily confuse physicians with little expertise in diffuse interstitial lung diseases, knowing the differential diagnoses, clinical presentation, imaging, and complications of the iPPFE allows for an early diagnosis and gives patients who suffer from it a better quality of life. This report presents a comprehensive review of PPFEi, discussing severe precapillary pulmonary hypertension and the associated findings demonstrated by right heart catheterization (RHC), which be of interest for cardiopulmonologists.

Patient background and prognosis of chronic pulmonary aspergillosis in fibrosing interstitial lung disease

Several previous reports have shown interstitial lung disease (ILD) to be a predictor of poor prognosis in patients with chronic pulmonary aspergillosis (CPA). However, there is a lack of clarity regarding patient background and the prognostic factors in CPA associated with ILD (CPA-ILD). Therefore, we assessed these points to obtain valuable information for clinical practice. We retrospectively surveyed and collected data from 459 patients who had serum examination for anti-Aspergillus antibody. Of these patients, we extracted and investigated CPA-ILD patients. We ultimately analyzed 32 CPA-ILD patients. Patient background factors more frequently showed the patients to be older (mean: 74.9 years), male (75.0%), and to have a smoking history (71.9%). Median survival time from the diagnosis of ILD was 76.0 months, whereas that from the diagnosis of CPA-ILD was 25.5 months. No significant differences in survival were found in regard to each ILD pattern and the presence of idiopathic pulmonary fibrosis. A higher level of C-reactive protein was a significant predictor of mortality by Cox regression analysis. CPA complicating ILD is associated with poor prognosis. ILD patients with older age, male sex, and smoking history should be aware of the potential for the development of CPA in ILD. If such patients have elevated markers of inflammation, prompt induction of antifungal treatment may improve their prognosis. Clinicians should be aware of which complications of CPA may lead to a poor prognosis for any ILD not just those limited to idiopathic pulmonary fibrosis or usual interstitial pneumonia pattern.

Clinical characteristics of pulmonary hypertension in patients with pleuroparenchymal fibroelastosis

BACKGROUND

This study aimed to investigate the clinical characteristics and prognosis of patients with pleuroparenchymal fibroelastosis (PPFE) and pulmonary hypertension (PH).

METHODS

We retrospectively analyzed the data of patients who were diagnosed with PPFE and underwent transthoracic echocardiography (TTE) for the evaluation of their right heart systems within 3 months of their first visit between 2011 and 2018. Patients were divided into the PH and non-PH groups based on their peak tricuspid regurgitation velocity (TRV) on TTE (cutoff, 2.8 m/s). The clinical characteristics of PH and association between PH and survival among patients with PPFE were investigated.

RESULTS

In total, 83 patients were enrolled. Sixteen (19.3%) patients were included in the PH group. The PH group had a lower body mass index, percent predicted forced vital capacity (FVC), 6-min walk distance, and partial pressure of arterial oxygen than the non-PH group. There was no significant difference in the presence of usual interstitial pneumonia patterns in the lower lobes between the two groups. The survival period was significantly shorter in the PH group than in the non-PH group (median survival 16.3 versus 50.2 months, log-rank p < 0.001). The multivariate Cox proportional hazard model showed that male sex (hazard ratio [HR] = 4.83, p < 0.001), Krebs von den Lungen-6 (KL-6) > 550 U/mL (HR = 3.48, p = 0.005), %FVC < 50% (HR = 3.04, p = 0.028), and peak TRV > 2.8 m/s (HR = 3.26, p = 0.038) were independently associated with poor survival.

CONCLUSIONS

PH was not rare in patients with PPFE. Male sex, increased KL-6, lower FVC, and PH were independently associated with poor survival in patients with PPFE.

Usual interstitial pneumonia: a review of the pathogenesis and discussion of elastin fibres, type II pneumocytes and proposed roles in the pathogenesis

The pathogenesis of idiopathic pulmonary fibrosis (IPF) and its histological counterpart, usual interstitial pneumonia (UIP) remains debated. IPF/UIP is a disease characterised by respiratory restriction, and while there have been recent advances in treatment, mortality remains high. Genetic and environmental factors predispose to its development and aberrant alveolar repair is thought to be central. Following alveolar injury, the type II pneumocyte (AEC2) replaces the damaged thin type I pneumocytes. Despite the interstitial fibroblast being considered instrumental in formation of the fibrosis, there has been little consideration for a role for AEC2 in the repair of the septal interstitium. Elastin is a complex protein that conveys flexibility and recoil to the lung. The fibroblast is presumed to produce elastin but there is evidence that the AEC2 may have a role in production or deposition. While the lung is an elastic organ, the role of elastin in repair of lung injury and its possible role in UIP has not been explored in depth. In this paper, pathogenetic mechanisms of UIP involving AEC2 and elastin are reviewed and the possible role of AEC2 in elastin generation is proposed.

Pleuroparenchymal fibroelastosis in rheumatoid arthritis-associated interstitial lung disease

Background

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease (ILD) featuring dense fibrosis of the visceral pleura and subpleural parenchyma, mostly in the upper lobes. PPFE can present in other ILDs, including rheumatoid arthritis-associated ILD (RA-ILD). The aim of this retrospective study was to investigate the prevalence and clinical implications of coexistent PPFE in RA-ILD.

Methods

Overall, 477 patients with RA-ILD were recruited from two cohorts; their clinical data and HRCT images were analysed. The criteria for diagnosing PPFE were (1) pleural thickening with bilateral subpleural dense fibrosis in the upper lobes, (2) evidence of disease progression, and (3) absence of other identifiable aetiologies.

Results

The median follow-up duration was 3.3 years. The mean age of the patients was 63.4 years, and 60.0% were women. PPFE was identified in 31 patients (6.5%). The PPFE group showed significantly lower body mass index and forced vital capacity (FVC) and more frequent usual interstitial pneumonia (UIP)-like pattern on HRCT than no-PPFE group. The risk factors for all-cause mortality were older age, lower FVC, and the presence of UIP-like pattern on HRCT; PPFE was not significantly associated with mortality in both all patients and a subgroup with a UIP-like pattern. The presence of PPFE was associated with a significantly increased risk of pneumothorax and greater decline in diffusing capacity.

Conclusions

PPFE was not rare in patients with RA-ILD and was significantly associated with an increased risk of pneumothorax and greater lung function decline, though we found no significant association with mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02064-z.

Limited efficacy of nintedanib for idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

The antifibrotic agent nintedanib has been reported to effectively prevent the decline in forced vital capacity (FVC) in a broad range of interstitial lung diseases. However, the efficacy of nintedanib against idiopathic pleuroparenchymal fibroelastosis (iPPFE) remains unclear.

METHODS

We retrospectively examined patients with idiopathic PPFE or idiopathic pulmonary fibrosis (IPF) who received nintedanib for more than 6 months. We evaluated annual changes in %FVC, radiological PPFE lesions, and body weight before and during nintedanib treatment. To investigate radiological PPFE lesions, we examined the fibrosis score, which was defined as the mean percentage of the high attenuation area in the whole lung parenchyma using three axial computed tomography images.

RESULTS

Overall, 15 patients with iPPFE and 27 patients with IPF were included in the present study. In patients with IPF, the annual rate of decline in %FVC was significantly lower during nintedanib treatment than that before treatment (-2.01%/year [-7.64 to 3.21] versus -7.64%/year [-10.8 to -4.44], p = 0.031). Meanwhile, in patients with iPPFE, the annual rate of decline in %FVC during nintedanib treatment was higher than that before treatment (-18.0%/year [-21.6 to -12.7] versus -9.40%/year [-12.3 to -8.23], p = 0.109). In addition, nintedanib treatment failed to inhibit the annual rate of increase in fibrosis score in patients with iPPFE (6.53/year [1.18-15.3] during treatment versus 2.70/year [0.27-12.2] before treatment, p = 0.175).

CONCLUSIONS

Nintedanib efficacy may be limited in patients with iPPFE.

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.