The thoracic cage becomes flattened in the progression of pleuroparenchymal fibroelastosis

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.

Vocal cord paralysis associated with pleuroparenchymal fibroelastosis: A case report and literature review

Here, we report a case of idiopathic pleuroparenchymal fibroelastosis (PPFE) that progressed to pulmonary aspergilloma, aspiration pneumonia, and left vocal cord paralysis (VCP). To date, five cases of PPFE with VCP have been reported, including the present case. Aspiration pneumonia occurred in three cases, leading to death in two cases. Four cases had left-sided paralysis, in two of which, the paralysis occurred on side opposite to the predominant side (right side) of PPFE. Structural mechanisms underlying the recurrent laryngeal nerve could be involved. This report may further highlight the existence of hoarseness and dysphagia in PPFE.

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.

Partial pressure of carbon dioxide levels reflect disease severity in idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

Hypercapnia can cause a disturbance of consciousness and adversely affect a patient's general condition. Patients with interstitial lung disease seldom experience hypercapnia. Hypercapnia is a typical phenomenon in patients with pleuroparenchymal fibroelastosis (PPFE), especially in advanced stages. However, the clinical significance of hypercapnia in patients with idiopathic PPFE (iPPFE) has not been studied in detail.

METHODS

We retrospectively selected patients with iPPFE who had undergone blood gas analysis. The first blood gas data obtained after iPPFE diagnosis were examined. The partial pressure of carbon dioxide (PCO₂) levels and their association with characteristic iPPFE parameters, including the flat chest index (the ratio of the anteroposterior diameter of the thoracic cage to the transverse diameter of the thoracic cage), were investigated.

RESULTS

A total of 47 patients with iPPFE were included in this study. The PCO₂ level was moderately and inversely correlated with the forced vital capacity. (r = -0.431, P = 0.014), flat chest index (r = -0.497, P < 0.001), and body mass index (r = -0.313, P = 0.038) and was positively correlated with residual volume/total lung capacity. (r = 0.514, P < 0.01). A higher PCO₂ level was also significantly associated with poorer prognosis in patients with iPPFE.

CONCLUSIONS

PCO₂ levels could be used as an indicator of disease severity in patients with iPPFE.

Determinants of Six-Minute Walk Distance in Idiopathic Pulmonary Fibrosis and Idiopathic Pleuroparenchymal Fibroelastosis

Background: In idiopathic pulmonary fibrosis (IPF), 6-minute walking distance (6MWD) is an independent factor for mortality. Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare disease with physical features such as emaciation, but the relationship between IPPFE and 6MWD is unclear. In this study, we investigated the factors that cause a decrease in the percent of the predicted value of a 6-minute walk distance (%6MWD), including the disease entities, IPF and IPPFE. Methods: This study included 100 patients (IPF: 75 patients, IPPFE: 25 patients, age: 73.5 ± 7.2 years, sex: 73 males) who visited the rehabilitation department. Patients with a %6MWD ≥ 80% were assigned to the normal group (n = 54), and patients with a %6MWD < 80% were assigned to the decreased group (n = 46). The items showing a significant difference between groups were used as independent variables, after the consideration of multicollinearity, for a logistic analysis where %6MWD < 80% was used as the dependent variable. Results: The 6MWD results show that there was no significant difference between IPF and IPPFE in the absolute value of 6MWD and in the number of people with 6MWD ≥ 250 m, but when 6MWD was compared with %6MWD, the IPPFE group showed a significantly lower value than the IPF group (p = 0.013). Logistic regression analysis showed that only BMI (p = 0.032), GAP index (p = 0.043), and mMRC (p = 0.026) were factors that caused a decrease in %6MWD in 100 patients. Conclusion: The results suggest that leanness, shortness of breath and severity of illness are the most important factors that determine exercise tolerance, regardless of disease entity in IPF and IPPFE.

Impact of sleep-related hypoventilation in patients with pleuroparenchymal fibroelastosis

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare fibrosing lung disease with a predilection for the upper lobe and its progression causes hypoventilation, resulting in hypercapnia. Even though the association between sleep-related hypoventilation (SRH) and chronic obstructive pulmonary disease was well documented, its impact in patients with PPFE was not evaluated. The aim of this study is to clarify the impact of SRH on prognosis in PPFE.

METHODS

A retrospective review of the medical records of 52 patients with PPFE who underwent transcutaneous carbon dioxide monitoring during sleep was done. Patients were stratified into SRH (n = 28) and non-SRH (n = 24) groups based on American Academy of Sleep Medicine criteria. The impact of SRH on the prognosis of PPFE, as well as the clinical factors and comorbidities of PPFE associated with SRH, were evaluated.

RESULTS

Forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), total lung capacity (TLC), and carbon monoxide diffusing capacity (DLco) in the SRH group were significantly lower than the non-SRH group (P < .01). Chronic pulmonary aspergillosis (CPA) was found at a higher rate in the SRH group (P = .02). The median survival time for SRH patients was 330 days, whereas roughly 80% of non-SRH patients were alive during the 3-year observation period (P < .01). Body mass index was a significant prognostic factor in PPFE patients with SRH (HR .78; 95% CI; .64-.94; P < .01). Home oxygen therapy (HOT) during the day and noninvasive positive pressure ventilation (NPPV) at night while sleeping tended to improve prognosis in the SRH group, as indicated by HR of .25 (P = .07).

CONCLUSIONS

SRH may be a poor prognostic factor for PPFE. Additionally, SRH may modify susceptibility to Aspergillosis in patients with PPFE. HOT plus NPPV may improve the disease outcomes in patients with SRH.

Clinical, radiological, and pathological features of idiopathic and secondary interstitial pneumonia cases with pleuroparenchymal fibroelastosis undergoing lung transplantation

AIMS

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare type of idiopathic interstitial pneumonia, and pathological PPFE is also observed in secondary interstitial pneumonia. This study aimed to evaluate the pathological findings associated with radiological PPFE-like lesions and the clinical and morphological features of patients with pathological PPFE.

METHODS AND RESULTS

We retrospectively reviewed the pathology of the explanted lungs from 59 lung transplant recipients with radiological PPFE-like lesions. Pathological PPFE lesions were identified in 14 patients with idiopathic cases and 12 patients with secondary cases. Pathological PPFE was associated with previous pneumothorax, a volume loss in the upper lobes and a flattened chest. Patients with idiopathic and secondary cases with pathological PPFE had similar clinical, radiological, and pathological findings, while fibroblastic foci were more common in patients with idiopathic cases, and patients with secondary cases more frequently showed alveolar septal thickening with elastosis or fibrosis. Post-transplantation survival did not differ between patients with idiopathic and secondary cases with pathological PPFE (log-rank; P=0.57) and was similar between patients with idiopathic cases with pathological PPFE and patients with idiopathic pulmonary fibrosis (IPF) (log-rank; P = 0.62).

CONCLUSIONS

Not all patients with interstitial pneumonia with radiological PPFE-like lesions have pathological PPFE. Characteristic clinical features can suggest the presence of pathological PPFE, and idiopathic and secondary cases with pathological PPFE are similar except for fibroblastic foci in idiopathic cases and alveolar septal thickening with elastosis or fibrosis in secondary cases. Patients with pathological PPFE have a similar prognosis to those with IPF after transplantation.

Platythorax progresses with lung involvement in pleuroparenchymal fibroelastosis

BACKGROUND

Patients diagnosed with pleuroparenchymal fibroelastosis (PPFE) exhibit unique clinical features, including upper lobe-dominant lung involvement and platythorax (or flattened thoracic cage). Although platythorax have been shown to be a sign of disease progression, the temporal relationship between the progression of platythorax and the extent of lung involvement has not been closely investigated.

METHODS

We retrospectively investigated patients diagnosed with PPFE, who did not exhibit fibrotic lesions other than PPFE in the lower lobes. We estimated the fibrosis score, which is a visual score indicating the percentage of lung parenchyma occupied by the disease on computed tomography images selected every 2 cm from the lung apex to the lung base, and the flat chest index (the ratio of the anteroposterior diameter of the thoracic cage to the transverse diameter of the thoracic cage). Additionally, we investigated serial changes in the flat chest index and fibrosis score.

RESULTS

A total of 29 patients were included in this study. The fibrosis score was found to be weakly and inversely correlated with forced vital capacity %predicted at the diagnosis (r = -0.40, p = 0.038). Furthermore, the annual changes in the flat chest index and fibrosis score was found to be moderately and inversely correlated (r = -0.663, p = 0.0037).

CONCLUSIONS

These results indicate that there is a causal relationship between the progression of fibroelastosis and that of platythorax in patients with PPFE.

Nintedanib in idiopathic and secondary pleuroparenchymal fibroelastosis

Background

Pleuroparenchymal fibroelastosis (PPFE) has a variable disease course with dismal prognosis in the majority of patients with no validated drug therapy. This study is to evaluate the effect of nintedanib in patients with idiopathic and secondary PPFE. Patients admitted to a tertiary care center (2010–2019) were included into this retrospective analysis if they had a multidisciplinary diagnosis of PPFE, had been followed-up for 3 months or more, and had lung function tests and chest CTs available for review. Changes in pulmonary function tests were assessed using non-parametric tests and linear mixed effect model. Lung volumes were measured with lobar segmentation using chest CT.

Results

Out of 21 patients with PPFE, nine had received nintedanib, six had received another treatment and another six patients were monitored without drug therapy. Annual FVC (% of predicted) relative decline was − 13.6 ± 13.4%/year before nintedanib and − 1.6 ± 6.02%/year during nintedanib treatment (p = 0.014), whereas no significant change in FVC% relative decline was found in patients receiving another treatment (− 13.25 ± 34 before vs − 16.61 ± 36.2%/year during treatment; p = 0.343). Using linear mixed effect model, the slope in FVC was − 0.97%/month (95% CI: − 1.42; − 0.52) before treatment and − 0.50%/month (95% CI: − 0.88; 0.13) on nintedanib, with a difference between groups of + 0.47%/month (95% CI: 0.16; 0.78), p = 0.004. The decline in the upper lung volumes measured by CT was − 233 mL/year ± 387 mL/year before nintedanib and − 149 mL/year ± 173 mL/year on nintedanib (p = 0.327). Nintedanib tolerability was unremarkable.

Conclusion

In patients with PPFE, nintedanib treatment might be associated with slower decline in lung function, paving the way for prospective, controlled studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02043-5.

A proposed prognostic prediction score for pleuroparenchymal fibroelastosis

BACKGROUND

Clinical course of pleuroparenchymal fibroelastosis (PPFE) shows considerable variation among patients, but there is no established prognostic prediction model for PPFE.

METHODS

The prediction model was developed using retrospective data from two cohorts: our single-center cohort and a nationwide multicenter cohort involving 21 institutions. Cox regression analyses were used to identify prognostic factors. The total score was defined as the weighted sum of values for the selected variables. The performance of the prediction models was evaluated by Harrell's concordance index (C-index). We also examined the usefulness of the gender-age-physiology (GAP) model for predicting the prognosis of PPFE patients.

RESULTS

We examined 104 patients with PPFE (52 cases from each cohort). In a multivariate Cox analysis, a lower forced vital capacity (FVC [defined as FVC < 65%]; hazard ratio [HR], 2.23), a history of pneumothorax (HR, 3.27), the presence of a lower lobe interstitial lung disease (ILD) (HR, 2.31), and higher serum Krebs von den Lungen-6 (KL-6) levels (> 550 U/mL, HR, 2.56) were significantly associated with a poor prognosis. The total score was calculated as 1 × (FVC, < 65%) + 1 × (history of pneumothorax) + 1 × (presence of lower lobe ILD) + 1 × (KL-6, > 550 U/mL). PPFE patients were divided into three groups based on the prognostic score: stage I (0-1 points), stage II (2 points), and stage III (3-4 points). The survival rates were significantly different in each stage. The GAP stage was significantly associated with the prognosis of PPFE, but no difference was found between moderate (stage II) and severe (stage III) disease. Our new model for PPFE patients (PPFE Prognosis Score) showed better performance in the prediction of mortality in comparison to the GAP model (C-index of 0.713 vs. 0.649).

CONCLUSIONS

Our new model for PPFE patients could be useful for predicting their prognosis.

Pleuroparenchymal fibroelastosis: Clinical, radiological and histopathological features

Pleuroparenchymal fibroelastosis (PPFE) is a rare, generally idiopathic form of interstitial pneumonia with unique clinical, radiological and histopathological features. It is named after the presence of upper lobe pleural and subjacent parenchymal fibrosis, with accompanying elastic fibers. Although it is usually an idiopathic disease, it has been linked to other co-existent diseases. Diagnostic suspicion of PPFE is based on the identification of typical abnormalities on chest CT scan, which are prevailingly located in the upper lobes, adjacent to the apex of the lungs. Diagnosis can be confirmed by histological analysis, although biopsy is not always feasible. The disease is generally progressive, but not uniformly. The course of the disease is frequently slow and involves a progressive loss of upper lobe volume, which results in platythorax, associated with a significant reduction of body mass. PPFE concomitant to other interstitial lung diseases is associated with a poorer prognosis. The disease occasionally progresses rapidly causing irreversible respiratory insufficiency, which leads to death. Currently, there is no effective pharmacological therapy available, and lung transplantation is the best therapeutic option. The purpose of this review is to draw the attention to PPFE, describe its clinical, radiological and histopathological features, analyze its diagnostic criteria, and provide an update on the management of the disease.

Severe and progressive platythorax disproportionate to lung fibrosis: A rare variant of idiopathic pleuroparenchymal fibroelastosis

A 57-year-old man was referred to our department because of progressive shortness of breath and emaciation. He had experienced pneumothorax three times in the past five years. The patient radiologically showed mild upper-lobe predominant airspace consolidation and severe platythorax and was clinically diagnosed with idiopathic pleuroparenchymal fibroelastosis (PPFE). Although the wedge-shaped shadows in the bilateral lung apexes did not significantly progress, his platythorax gradually worsened during the clinical course. He ultimately died of chronic respiratory failure 1.2 years after the diagnosis. This case demonstrates a rare variant of idiopathic PPFE with progressive platythorax disproportionate to the extent of upper-lobe fibroelastosis.

Lung Transplantation for Pleuroparenchymal Fibroelastosis

Pleuroparenchymal fibroelastosis (PPFE), a new disease entity associated with interstitial pneumonia, is characterized by fibrosis and elastosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobe. As the awareness of this disease entity has increased, many studies have revealed the prevalence and incidence, clinical and pathological characteristics, and disease course of PPFE. Patients with PPFE reportedly have several unique clinical characteristics—including an extremely low body mass index with a slender body and chest wall deformity, known as “flat chest”. As this disease progresses, shrinking of the lungs often causes life-threatening complications, such as pneumothorax, and associated air leak syndrome. Lung transplantation is considered the only effective treatment for patients with advanced PPFE; however, little is known about the influences of the characteristics of PPFE on the outcome of lung transplantation. This review focuses on the unique clinicopathologic characteristics of PPFE and associated outcomes of lung transplantation for these patients.

Pleuroparenchymal fibroelastosis in Mycobacterium avium complex pulmonary disease: clinical characteristics and prognostic impact

The association between Mycobacterium avium complex pulmonary disease (MAC-PD) and pleuroparenchymal fibroelastosis (PPFE) has been reported previously, and interstitial pneumonia as a comorbidity is associated with a worse prognosis. However, no study has thoroughly reported on PPFE associated with MAC-PD. The present study investigated the prevalence, clinical characteristics, and prognostic impact of PPFE in patients with MAC-PD. A total of 224 patients, newly diagnosed with MAC-PD, were retrospectively reviewed. At the time of diagnosis, chest high-resolution computed tomography (HRCT), sputum examination, and clinical characteristics were collected. The extent of PPFE and MAC-PD was evaluated semi-quantitatively using HRCT scores. Risk factor analysis for clinical or radiological deterioration necessitating multidrug antimicrobial treatment within 3 years, and all-cause mortality within 5 years, from the initial diagnosis was performed based on the PPFE score. PPFE was observed in 59 out of 224 patients (26.3%). A higher PPFE score was a risk factor for dyspnoea, fatigue, and lower body mass index (BMI) (p<0.05). Although PPFE score did not correlate with clinical or radiological deterioration within 3 years (p=0.576), a higher PPFE score (adjusted OR 1.66, 95% CI 1.06-2.60, p=0.028) and lower BMI (adjusted OR 0.61, 95% CI 0.39-0.94, p=0.028) increased the risk of 5-year mortality. PPFE is a relatively common complication and an independent poor prognostic factor of MAC-PD. This study highlights the need for further studies investigating whether the presence of PPFE can be a clinical indicator for initiating treatment of MAC-PD.

Outcomes of lung transplantation for idiopathic pleuroparenchymal fibroelastosis

PURPOSE

This study was performed to compare the outcome of lung transplantation (LT) for idiopathic pleuroparenchymal fibroelastosis (IPPFE) with that of LT for idiopathic pulmonary fibrosis (IPF).

METHODS

We reviewed, retrospectively, all adult patients who underwent LT for IPPFE or IPF in Japan between 1998 and 2018.

RESULTS

There were 100 patients eligible for this study (31 with IPPFE and 69 with IPF). Patients with IPPFE tended to have a significantly lower body mass index (BMI) than those with IPF (median, 16.7 vs. 22.6 kg/m², respectively; P < 0.01). However, Kaplan-Meier survival curves showed no significant difference in overall survival between the groups. The BMI did not increase in patients with IPPFE, even 1 year after LT (pretransplant, 16.5 ± 3.2 kg/m² vs. 1 year post-transplant, 15.6 ± 2.5 kg/m²; P = 0.08). The percent predicted forced vital capacity (%FVC) 1 year after LT was significantly lower in the IPPFE group than in the IPF group (48.4% ± 19.5% vs. 68.6% ± 15.5%, respectively; P < 0.01).

CONCLUSIONS

Despite extrapulmonary problems such as a flat chest, low BMI, and associated restrictive impairment persisting in patients with IPPFE, patient survival after LT for IPPFE or IPF was equivalent.

The pathogenesis and pathology of idiopathic pleuroparenchymal fibroelastosis

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare subtype of idiopathic interstitial pneumonias that consists of elastofibrosis involving the lung parenchyma and pleural collagenous fibrosis predominantly located in the upper lobes. IPPFE has various distinct clinical and physiological characteristics, including platythorax and a marked decrease of forced vital capacity with an increased residual volume on a respiratory function test. The concept of IPPFE is now widely recognized and some diagnostic criteria have been proposed. In addition, the accumulation of cases has revealed the pathological features of IPPFE. However, little is known about the pathogenesis or the process of disease formation in IPPFE. This review article will provide a summary of the pathological features and previously reported hypotheses on disease formation in IPPFE, to discuss the potential etiologies and pathogenesis of IPPFE.

Pleuroparenchymal fibroelastosis (PPFE)-like finding on CT in daily practice -prevalence and serial changes

Objective

To characterize the prevalence of PPFE (pleuroparenchymal fibroelastosis)-like finding on CT in daily practice and to identify the risk factors for its progression.

Matelials & methods

2416 consecutive daily CT examinations were screened for PPFE-like finding. CT images with PPFE-like finding were retrospectively reviewed for the extent, maximum height, presence or absence of intraalveolar fibroelastosis (IAFE), emphysema, interstitial lung disease (ILD), suprasternal depression at the level of clavicle end, and bronchiectasis in upper lobe, and anterior-posterior/transverse diameter ratio (AT ratio) of thoracic cage. Serial CT scans more than 3 years before the baseline scan were also reviewed and compared when available.

Results

380 patients (median age of 65, M:F = 153:227) were recognized as having PPFE-like finding. The lowest level of PPFE-like finding was T5 in median, horizontal extent was 0–25 % in 229/380, 25–50 % in 66 and >50 % in 24. Median height was 8.0 mm. IAFE was seen in 75, emphysema in 71, ILD in 59, chronic bronchial disorder in 71, suprasternal depression in 148, upper-lobe bronchial dilatation in 124. Mean AT ratio was 0.63. Serial images were available in 131 patients. 11 showed significant progression, 57 showed mild progression. Existing ILD lesion and >25 % horizontal extent were significantly related to significant progression.

Conclusions

PPFE-like finding was seen relatively in high proportion. Extensive lesion in axial plane and co-existing ILD might be risk factors of progression.

Physiological Criteria Are Useful for the Diagnosis of Idiopathic Pleuroparenchymal Fibroelastosis

BACKGROUND

Diagnostic criteria of idiopathic pleuroparenchymal fibroelastosis (IPPFE) were recently proposed, including physiological criteria of the body mass index (BMI) and percentage of the predicted values of residual volume (RV)/total lung capacity (TLC) (RV/TLC %pred.). The aim of this study was to evaluate (i) whether the physiologic criteria are useful for the diagnosis and (ii) whether the flat chest index, defined as the ratio of the anteroposterior diameter to the transverse diameter of the thoracic cage, could be an alternative parameter to RV/TLC %pred.

METHODS

We selected consecutive IPPFE patients and idiopathic pulmonary fibrosis (IPF) patients. We examined the diagnostic sensitivity and specificity of the physiological criteria and flat chest index for differentiating IPPFE patients from IPF patients.

RESULTS

This study included 37 IPPFE patients and 89 IPF patients. The physiological criteria distinguished IPPFE patients from IPF patients with a sensitivity of 78.6% and specificity of 88.0%. The combination of the flat chest index and BMI was also effective for differentiation (sensitivity of 82.1% and specificity of 89.3%).

CONCLUSION

We verified the good performance of the physiologic criteria in a different cohort. When the RV/TLC is not measured, using the flat chest index instead of RV/TLC %pred. may be reasonable.

Exacerbation of Secondary Pulmonary Hypertension by Flat Chest after Lung Transplantation

A 40-year-old woman with idiopathic pleuroparenchymal fibroelastosis (IPPFE) and flat chest underwent left single lung transplantation (SLT). Although she had developed over-systemic pulmonary arterial pressure (PAP) at transplantation, it was alleviated. However, her PAP gradually increased again. Her transplanted lung was well-inflated, but progression of fibrosis in her right native lung appeared to have caused a mediastinal shift, and her flat chest caused obstruction of the outflow tract of the pulmonary vein. She died of heart failure and associated infection 1.5 years after transplantation. An autopsy confirmed irreversible pulmonary arterial and venous changes in the transplanted lung, suggestive of chronic pressure overload. The flat chest associated with IPPFE can affect pulmonary circulation after SLT.

Extent of pulmonary fibrosis on high-resolution computed tomography is a prognostic factor in patients with pleuroparenchymal fibroelastosis

BACKGROUND

Several prognostic factors for pleuroparenchymal fibroelastosis (PPFE) have recently been reported. However, detailed high-resolution computed tomography (HRCT) findings have not yet been evaluated as prognostic factors. This study retrospectively investigated whether HRCT findings are prognostic factors in patients with PPFE compared to those with idiopathic pulmonary fibrosis (IPF).

METHODS

Patients with PPFE and IPF diagnosed at our hospital between January 2008 and December 2016 were enrolled. Clinical and HRCT characteristics were obtained. In addition to our patients, we also analyzed data of PPFE patients whose cause of death had been identified in previous studies.

RESULTS

We enrolled 15 patients with PPFE and 75 patients with IPF. Consolidation and maximum pleural thickening were significantly higher in patients with PPFE than in those with IPF (both P < .001). Fibrosis score, honeycomb area, and traction bronchiectasis were not significantly different between these patient groups but were significant prognostic factors in patients with PPFE in univariate analysis (P = .021, P = .017, and P = .014, respectively). The proportions of deaths by acute exacerbation or lung cancer were significantly lower in patients with PPFE than in those with IPF (P < .001 and P = .001, respectively), whereas death by respiratory failure was significantly more frequent in PPFE patients (P < .001).

CONCLUSIONS

HRCT findings, such as fibrosis score, honeycomb area, and traction bronchiectasis, were independent prognostic factors in patients with PPFE. Respiratory failure, but not acute exacerbation and lung cancer, was the main cause of death in patients with PPFE.

The similarities and differences between pleuroparenchymal fibroelastosis and idiopathic pulmonary fibrosis

The idiopathic form of pleuroparenchymal fibroelastosis (PPFE) is categorized as a rare idiopathic interstitial pneumonia in the current classification. The majority of PPFE cases are idiopathic, but many predisposing factors or comorbidities have been reported. Although histological PPFE is predominantly located in the upper lobes, which are less often affected by fibrosis in patients with idiopathic pulmonary fibrosis (IPF), the clinical course of PPFE is seemingly similar to that of IPF. However, upper lobe fibroelastosis has various clinical and physiological characteristics that differ from those of IPF, including a flattened thoracic cage and a marked decrease in the forced vital capacity (FVC) but with a preserved residual volume. Compared with IPF, the decrease in the walking distance is mild despite the markedly decreased FVC in PPFE, and chest radiograph more frequently shows the elevation of bilateral hilar opacities with or without tracheal deviation. The prognosis may be related to the development of fibrosing interstitial pneumonia in the lower lobes with elevated levels of serum Krebs von den Lungen-6; however, there is marked variation in the pathogenesis and clinical features in PPFE. A proposal of the diagnostic criteria for idiopathic PPFE with and without surgical lung biopsy, which has recently been published, may be useful.

Chronic Progressive Dyspnea in a 71-Year-Old Man: A Diagnostic Ithaca After 8 Years of Consultation

CASE PRESENTATION

A 71-year-old ex-bus driver (ex-smoker, 20 pack-years) was admitted for the first time to the respiratory department because of chronic dry cough and progressive exertional dyspnea with insidious onset 8 years ago. The patient also reported weight loss of about 20 kg in 3 years and proximal muscle weakness. A decade ago, he was diagnosed with gastric adenocarcinoma and subjected to partial gastrectomy and splenectomy, followed by an unspecified chemotherapy regimen. Additionally, the patient has coronary disease and underwent coronary bypass graft surgery 7 years ago. In the course of his disease, many diagnostic procedures have been performed including Mantoux tests, five CT scans, a CT-guided biopsy, two bronchoscopies, and an 18F-fluorodeoxyglucose PET scan with inconclusive results. The patient was referred to the hospital to have his long-lasting condition diagnosed and treated.

Role of alveolar collapse in idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

Zonal aggregates of elastic fibres (zonal elastosis) and intraalveolar collagenosis with septal elastosis are histologic components of subpleural fibroelastosis of idiopathic pleuroparenchymal fibroelastosis (IPPFE). Zonal elastosis is considered to result from alveolar collapse, but this mechanism has not been fully justified.

METHODS

We immunohistochemically attempted to identify epithelial cells in zonal elastosis of 10 patients with IPPFE. The thickness of the zonal elastosis in relation to the total thickness of the fibroelastosis was examined to estimate the influence of zonal elastosis on the occurrence and development of IPPFE.

RESULTS

In 9 of the 10 patients, multi-cytokeratin-positive cells were found lining the inner surface of slit-like spaces embedded in the zonal elastosis. Zonal elastosis was predominant when fibroelastosis was < 1 mm thick but less predominant when it was ≥1 mm.

CONCLUSION

The zonal elastosis was proven to result from alveolar collapse, which might be an initial lesion in IPPFE. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (2): 212-217).

Pleuroparenchymal Fibroelastosis. A Review of Clinical, Radiological, and Pathological Characteristics

Pleuroparenchymal fibroelastosis (PPFE) is an unusual pulmonary disease with unique clinical, radiological, and pathological characteristics. Designated a rare idiopathic interstitial pneumonia in 2013, its name refers to a combination of fibrosis involving the visceral pleura and fibroelastotic changes predominating in the subpleural lung parenchyma. Although a number of disease associations have been described, no single cause of PPFE has been unequivocally identified. A diagnosis of PPFE is most commonly achieved by identifying characteristic abnormalities on computed tomographic scans. The earliest changes are consistently located in the upper lobes close to the lung apices, the same locations where subsequent disease progression is also most conspicuous. When sufficiently severe, the disease leads to progressive volume loss of the upper lobes, which, in combination with decreased body mass, produces platythorax. Once regarded as a slowly progressing entity, it is now acknowledged that some patients with PPFE follow an inexorably progressive course that culminates in irreversible respiratory failure and early death. In the absence of effective medical drug treatment, lung transplant remains the only therapeutic option for this disorder. This review focuses on improving early disease recognition and evaluating its pathophysiological impact and discusses working approaches for its management.

Differences Between Patients With Idiopathic Pleuroparenchymal Fibroelastosis and Those With Other Types of Idiopathic Interstitial Pneumonia in Candidates for Lung Transplants

INTRODUCTION

The prognostic implications of having patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) on lung transplantation waiting lists have been unclear. In Japan, where a severe shortage of brain-dead donors remains a major limitation for organ transplantation, it is particularly important to predict the prognoses of patients when they are listed for transplantation. The purpose of this study was to investigate the characteristics of lung transplantation candidates with IPPFE and the influence of those characteristics on prognosis.

METHODS

This was a retrospective review of 29 consecutive adult lung transplant candidates with idiopathic interstitial pneumonia between January 2014 and April 2018.

RESULTS

Eight patients with IPPFE and 21 with other types of idiopathic interstitial pneumonia were included. Body mass index (median 17.1 kg/m² vs 23.5 kg/m², P < .01) and ratio of anteroposterior to transverse diameter of the thoracic cage were significantly lower (0.530 vs 0.583, P = .02) in the IPPFE group. Patients with a body mass index <20.0 kg/m² (P = .02), 6-minute walk distance <250.0 m (P < .01), ratio of PaO₂ to fraction of inspiratory oxygen <300.0 mm Hg (P < .01), and an inability to perform the diffusing capacity of carbon monoxide test (P < .01) had significantly shorter survival times in the other idiopathic interstitial pneumonia, but not in the IPPFE, group. Some patients with IPPFE survived for long enough to undergo transplantation.

CONCLUSIONS

Patients with IPPFE waiting for transplantation have some distinctive characteristics and should be retained on waiting lists to receive transplants.

Criteria for the diagnosis of idiopathic pleuroparenchymal fibroelastosis: A proposal

BACKGROUND

Physicians have few opportunities to perform surgical lung biopsy (SLB) to diagnose idiopathic pleuroparenchymal fibroelastosis (IPPFE). Therefore, diagnostic criteria for IPPFE that do not require SLB must be established. Herein, we propose diagnostic criteria for IPPFE with and without SLB.

METHODS AND RESULTS

The diagnostic criteria for IPPFE with SLB are histological, based on computed tomography (CT) lesions compatible with PPFE, predominantly in the upper lobes. The three diagnostic criteria for IPPFE without SLB are as follows: (1) radiologically possible IPPFE (a radiological criterion confirming CT lesions in both lung apexes, regardless of the lower lobe lesions); (2) radiologically probable IPPFE (also a radiological criterion, but mandatory to confirm chest radiograph findings of bilateral upward shift of the hilar structures and/or CT findings of volume loss of the upper lobes); (3) radiologically and physiologically probable IPPFE. Our data from 41 patients with IPPFE and 97 with idiopathic pulmonary fibrosis (IPF) showed that the percentage of the predicted values of the ratio of residual volume to total lung capacity (RV/TLC %pred.) ≥115% and body mass index (BMI) ≤20 kg/m² plus RV/TLC %pred. ≥80% performed well for discriminating IPPFE from IPF. These parameters were thus added to criterion (3).

CONCLUSIONS

We have proposed diagnostic criteria for IPPFE in patients with and without SLB. Both imaging criteria and physiological criteria using RV/TLC and BMI successfully discriminate IPPFE from chronic IIPs when SLB cannot be performed.

Clinical significance of lower-lobe interstitial lung disease on high-resolution computed tomography in patients with idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare form of idiopathic interstitial pneumonias (IIP) and may have other patterns of interstitial lung disease (ILD) in the lower lobe, such as usual interstitial pneumonia (UIP). However, the clinical significance of lower-lobe ILD in patients with IPPFE is unclear.

METHODS

A retrospective review of 40 consecutive patients with clinically diagnosed IPPFE in our institution from 2005 to 2016 was conducted. The presence of lower-lobe ILD on high-resolution computed tomography (HRCT) was assessed and classified into UIP or non-UIP pattern according to a modification of diagnostic criteria for idiopathic pulmonary fibrosis. Clinical characteristics and prognostic factors were evaluated.

RESULTS

Among the 40 patients with IPPFE, 21 (53%) had lower-lobe ILD, including 13 with UIP pattern and 8 with non-UIP pattern. Patients with IPPFE who had lower-lobe ILD had significantly older age, higher frequency of fine crackles, higher serum KL-6 level, lower residual volume (RV), and lower total lung capacity (TLC) than those without lower-lobe ILD. In addition, those with lower-lobe ILD, especially UIP pattern, had a significantly poorer survival than those without lower-lobe ILD (log-rank test; p = 0.014, p < 0.001, respectively). Multivariate Cox proportional hazards regression analysis revealed that low %forced vital capacity (%FVC) at baseline and coexistence of UIP pattern were significantly associated with poor prognosis in patients with IPPFE.

CONCLUSIONS

The coexistence of lower-lobe ILD on HRCT, especially the UIP pattern, may predict poor survival in patients with IPPFE.

Differential diagnoses of fibrosing lung diseases

OBJECTIVES

To describe the challenges inherent in diagnosing fibrosing lung diseases (FLD) on CT imaging and methodologies by which the diagnostic process may be simplified.

METHODS

Extensive searches in online scientific databases were performed to provide relevant and contemporary evidence that describe the current state of knowledge related to FLD diagnosis. This includes descriptions of the utility of a working diagnosis for an individual case discussed in a multidisciplinary team (MDT) setting and challenges associated with the lack of consensus guidelines for diagnosing chronic hypersensitivity pneumonitis.

RESULTS

As well as describing imaging features that indicate the presence of a fibrosing lung disease, those CT characteristics that nuance a diagnosis of the various FLDs are considered. The review also explains the essential information that a radiologist needs to convey to an MDT when reading a CT scan. Lastly, we provide some insights as to the future directions the field make take in the upcoming years.

CONCLUSIONS

This review outlines the current state of FLD diagnosis and emphasizes areas where knowledge is limited, and more evidence is required. Fundamentally, however, it provides a guide for radiologists when tackling CT imaging in a patient with FLD.

ADVANCES IN KNOWLEDGE

This review encompasses advice from recent guideline statements and evidence from the latest studies in FLD to provide an up-to-date manual for radiologists to aid the diagnosis of FLD on CT imaging in an MDT setting.

Various Bronchiolar Lesions Accompanied by Idiopathic Pleuroparenchymal Fibroelastosis with a Usual Interstitial Pneumonia Pattern Demonstrating Acute Exacerbation

A 63-year-old man presented with persistent cough and progressive dyspnea. Computed tomography showed irregular pleural thickening and fibrotic changes with volume loss in the upper lobes, and subtle reticulation in the lower lobes. Pleuroparenchymal fibroelastosis (PPFE) was diagnosed based on the findings of a surgical lung biopsy. Bronchiolar lesions, including proliferative bronchiolitis, constrictive bronchiolitis obliterans, and peribronchiolar metaplasia were evident on pathology. A usual interstitial pneumonia (UIP) pattern was also observed in the lower lobes. Three weeks after the biopsy, an acute exacerbation occurred. We herein describe a rare case of idiopathic PPFE with various bronchiolar lesions and a UIP pattern in which an acute exacerbation developed.

Pleuroparenchymal fibroelastosis (PPFE) treated with lung transplantation and review of the literature

A 26-year-old woman presented with a 15-year history of non-progressive dyspnoea. Chest imaging showed bilateral apical pleural and parenchymal scarring, pleural thickening and bronchiectasis. Pulmonary function tests showed a moderate restrictive defect. Non-invasive workup was non-revealing; therefore, the patient was referred for video-assisted thoracic surgery and lung biopsy. Histopathology revealed pleural thickening and, subpleural parenchymal fibrosis and elastic tissue deposition. Lung parenchyma further away from the pleura was well preserved. Based on these findings, the patient was diagnosed with pleuroparenchymal fibroelastosis (PPFE). Since PPFE is a progressive disorder without effective medical therapies, and given our patient's worsening symptoms, she underwent bilateral lung transplantation. It has been almost 4 years since the lung transplantation, our patient continues to do well. To the best of our knowledge, to date, this is the longest follow-up reported for a PPFE patient undergoing lung transplantation.

The upward shift of hilar structures and tracheal deviation in pleuroparenchymal fibroelastosis

The upward shift of hilar structures is a characteristic finding on chest radiographs in pleuroparenchymal fibroelastosis (PPFE). However, the relationship between the hilar shift and clinical parameters is unclear. In this study, the ratio of the length of the lung apex to the hilum and the length of the apex to the base of the right lung was measured using chest computed tomography (CT) at the time of the diagnosis, and the relationship with clinical parameters was investigated. We also examined the deviations of the trachea on chest radiographs and compared them with those in idiopathic pulmonary fibrosis (IPF) and early-stage lung cancer. Thirty-eight PPFE patients in a previous study included 20 patients who simultaneously showed the lower lobe lesions. The median ratio of the length of the apex to the hilum/apex to the base was 0.32 (range: 0.10–0.41) in PPFE, and this value was significantly lower than that in IPF (0.39; 0.32–0.45, n = 38) and in lung cancer (0.41; 0.33 to 0.45, n = 38) (p < 0.001, respectively). However, the ratio of the length of the apex to the hilum/apex to the base did not correlate with the dyspnea scale, body mass index or pulmonary function in PPFE. Tracheal deviations were observed in 41 out of 52 PPFE patients (36 with rightward deviations, 5 with leftward deviations) and in 30 out of 52 IPF patients (30 with rightward deviations) (p = 0.01). Although the existence of the upward shift of hilar structures on chest images might lead to a diagnosis of PPFE, the extent of hilar elevation does not necessarily reflect disease progression. Tracheal deviation is not a specific finding for PPFE.

Clinical significance of radiological pleuroparenchymal fibroelastosis pattern in interstitial lung disease patients registered for lung transplantation: a retrospective cohort study

BACKGROUND

Radiological pleuroparenchymal fibroelastosis (PPFE) lesion is characterized by pleural thickening with associated signs of subpleural fibrosis on high-resolution computed tomography (HRCT). This study evaluated the clinical significance of radiological PPFE as an isolated finding or associated with other interstitial lung diseases (ILDs) in patients having fibrotic ILDs and registered for cadaveric lung transplantation (LT).

METHODS

This retrospective study included 118 fibrotic ILD patients registered for LT. Radiological PPFE on HRCT was assessed. The impact of radiological PPFE on clinical features and transplantation-censored survival were evaluated.

RESULTS

Radiological PPFE was observed in 30/118 cases (25%): definite PPFE (PPFE concentrated in the upper lobes, with involvement of lower lobes being less marked) in 12 (10%) and consistent PPFE (PPFE not concentrated in the upper lobes, or PPFE with features of coexistent disease present elsewhere) in 18 (15%). Of these, 12 had late-onset non-infectious pulmonary complications after hematopoietic stem-cell transplantation and/or chemotherapy (LONIPCs), 9 idiopathic PPFE, and 9 other fibrotic ILDs (idiopathic pulmonary fibrosis, IPF; other idiopathic interstitial pneumonias, other IIPs; connective tissue disease-associated ILD, CTD-ILD, and hypersensitivity pneumonia, HP). Radiological PPFE was associated with previous history of pneumothorax, lower body mass index, lower percentage of predicted forced vital capacity (%FVC), higher percentage of predicted diffusion capacity of carbon monoxide, less desaturation on six-minute walk test, and hypercapnia. The median survival time of all study cases was 449 days. Thirty-seven (28%) received LTs: cadaveric in 31 and living-donor lobar in six. Of 93 patients who did not receive LT, 66 (71%) died. Radiological PPFE was marginally associated with better survival after adjustment for age, sex, %FVC, and six-minute walk distance < 250 m (hazard ratio 0.51 [0.25-1.05], p = 0.07). After adjustment for covariates, idiopathic PPFE and LONIPC with radiological PPFE was associated with better survival than fibrotic ILDs without radiological PPFE (hazard ratio 0.38 [0.16-0.90], p = 0.03), and marginally better survival than other fibrotic ILDs with radiological PPFE (hazard ratio, 0.20 [0.04-1.11], p = 0.07).

CONCLUSIONS

idiopathic PPFE and LONIPC with radiological PPFE has better survival on the wait list for LT than fibrotic ILDs without radiological PPFE, after adjustment for age, sex, %FVC, and six-minute walk distance.

Poorer Prognosis of Idiopathic Pleuroparenchymal Fibroelastosis Compared with Idiopathic Pulmonary Fibrosis in Advanced Stage

Objective

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare disease characterized by predominant upper lobe pulmonary fibrosis of unknown etiology. However, the prognosis of IPPFE has not been discussed. We investigated the clinical characteristics and prognostic factors of IPPFE and idiopathic pulmonary fibrosis (IPF).

Methods

We performed a retrospective cohort study on 375 consecutive idiopathic interstitial pneumonia patients between April 2004 and December 2014. Among them, we diagnosed IPPFE and IPF patients using high-resolution computed tomography radiological criteria.

Results

Twenty-nine IPPFE patients (9 males, 20 females) and 67 IPF patients (54 males, 13 females) were enrolled. IPPFE patients were significantly more likely to be females and nonsmokers and had lower body mass index, lower values of predicted percentage of forced vital capacity (%FVC), and a higher residual volume-to-total lung capacity ratio than IPF patients. Survival analysis revealed that they had significantly poorer prognosis than IPF patients in GAP (gender, age, and physiology) stages II + III. %FVC and GAP index independently predict mortality in patients with IPPFE.

Conclusions

Patients with IPPFE showed poorer prognosis in the advanced stage than patients with IPF. %FVC and GAP index are independent predictors of survival in patients with IPPFE.

Pleuroparenchymal fibroelastosis diagnosed by multidisciplinary discussions in Japan

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare subset of idiopathic interstitial pneumonias. No large-scale clinical studies of PPFE have been published. The aim of the study was to clarify the clinical and physiological characteristics of PPFE in Japan METHODS: This was a retrospective, nationwide, and multicenter study in Japan. We reviewed 52 patients with PPFE, diagnosed after multidisciplinary discussions.

RESULTS

Flat chest index, defined as the ratio of anteroposterior diameter to transverse diameter of thoracic cage at the level of 6th thoracic vertebra, correlated positively with body mass index (BMI) (r = 0.340, p = 0.013) and percentage of predicted value of forced vital capacity (FVC %pred) (r = 0.355, p = 0.012), and negatively with the ratio of residual volume to total lung capacity (RV/TLC) (r = -0.312, p = 0.042). RV/TLC correlated negatively with BMI (r = -0.746, p < 0.0001) and FVC %pred (r = -0.507, p = 0.0005), and positively with age, and physiological variables (GAP) scores (r = 0.332, p = 0.030). The median survival time and the cumulative 5-year survival rate were 96 months and 58%, respectively. Patients with KL-6 level >600 (U/mL) survived shorter than those with <600 (p < 0.001).

CONCLUSION

Low BMI, decreased FVC and increased RV/TLC in PPFE may be related to the progression of flattened chest cage which impairs distension of chest cage at inspiration. Elevated serum levels of KL-6 suggest a poor prognosis of PPFE.

Significant increases in the density and number of lymphatic vessels in pleuroparenchymal fibroelastosis

AIMS

Some investigators have detected fibrinous exudate or immature organisation in the alveolar spaces prior to the development of subpleural elastofibrosis in patients with pleuroparenchymal fibroelastosis (PPFE). We hypothesised that PPFE progress is associated with an impaired lymphatic drainage system, resulting in the failed resolution of intra-alveolar exudate. The aim of this study is to investigate the pulmonary lymphatic vessels in PPFE, histologically.

METHODS AND RESULTS

We retrospectively reviewed our medical records from 1995 to 2017, and selected autopsied or surgically biopsied patients with PPFE (n = 18), pulmonary apical cap (n = 18), and IPF (n = 26). We detected lymphatic endothelial cells by using immunostained specimens, calculating the percentage of lymphatic vessel area in the non-aerated area (lymphatic vessel density) and the number of lymphatic vessels per non-aerated area (per mm² ) (lymphatic vessel number). These parameters in PPFE were compared with those in apical cap, IPF, and normal lung tissue. The lymphatic vessel density in PPFE patients [2.97%; interquartile range (IQR) 2.61-3.86] was significantly higher than that in normal lung (0.91%; IQR 0.84-1.07), pulmonary apical cap (0.67%; IQR 0.58-0.83), and IPF (0.91%; IQR 0.68-1.25) (P < 0.01 in any comparison). The lymphatic vessel number in PPFE was also significantly higher than that in normal lung, pulmonary apical cap, and IPF. Among PPFE patients, the increase in lymphatic vessel density was found to be correlated with the characteristic physiology of PPFE, such as a flattened chest cage on computed tomography and high residual volume/total lung capacity ratio on spirometry.

CONCLUSIONS

Significant increase in the density and number of lymphatic vessels is a supportive characteristic that enables the differentiation of PPFE from IPF and apical cap.

Functional associations of pleuroparenchymal fibroelastosis and emphysema with hypersensitivity pneumonitis

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) has been described in hypersensitivity pneumonitis (HP) yet its functional implications are unclear. Combined pulmonary fibrosis and emphysema (CPFE) has occasionally been described in never-smokers with HP, but epidemiological data regarding its prevalence is sparse. CTs in a large HP cohort were therefore examined to identify the prevalence and effects of PPFE and emphysema.

Methods

233 HP patients had CT extents of interstitial lung disease (ILD) and emphysema quantified to the nearest 5%. Lobar percentage pleural involvement of PPFE was quantified on a 4-point categorical scale: 0 = absent, 1 = affecting <10%, 2 = affecting 10–33%, 3 = affecting >33%. Marked PPFE reflected a total lung score of ≥3/18. Results were evaluated against FVC, DLco and mortality.

RESULTS

Marked PPFE prevalence was 23% whilst 23% of never-smokers had emphysema. Following adjustment for patient age, gender, smoking status, and ILD and emphysema extents, marked PPFE independently linked to reduced baseline FVC (p = 0.0002) and DLco (p = 0.002) and when examined alongside the same covariates, independently linked to worsened survival (p = 0.01).

CPFE in HP demonstrated a characteristic functional profile of artificial lung volume preservation and disproportionate DLco reduction. CPFE did not demonstrate a worsened outcome when compared to HP patients without emphysema beyond that explained by CT extents of ILD and emphysema.

CONCLUSIONS

PPFE is not uncommon in HP, and is independently associated with impaired lung function and increased mortality. Emphysema was identified in 23% of HP never-smokers. CPFE appears not to link to a malignant microvascular phenotype as outcome is explained by ILD and emphysema extents.

•

In patients with HP, marked PPFE had a prevalence of 23% in our study cohort.

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23% of never-smokers with HP demonstrated emphysema on CT imaging.

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Outcome in HP patients with CPFE is explained by CT extents of ILD and emphysema.

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PPFE is independently associated with a worsened outcome in HP.

Pulmonary Apical Opacities on Thin-Section Computed Tomography: Relationship to Primary Spontaneous Pneumothorax in Young Male Patients and Corresponding Histopathologic Findings

OBJECTIVE

The purpose of this study was to test the hypothesis that apical opacities on computed tomography (CT) are related to occurrence of primary spontaneous pneumothorax (PSP) in young male patients.

METHODS

We compared the frequency of apical opacities on thin-section CT between 70 male patients with PSP (PSP group) and 74 male patients without a history of PSP (non-PSP group). We also evaluated histopathologic findings of 39 specimens from 37 surgical cases in the PSP group.

RESULTS

Apical opacities were significantly more frequent in the PSP group than in the non-PSP group (right side, P = 0.01; left side, P = 0.005). Histopathologically, subpleural band-like alveolar collapse was seen in 35 specimens (89.7%), which was always accompanied by fibroelastosis and fibroblastic foci.

CONCLUSIONS

Apical opacities on CT were significantly associated with PSP in young male patients. These apical opacities histopathologically correspond to fibrotic pleural thickening with subpleural alveolar collapse.

Pleuroparenchymal fibroelastosis: the prevalence of secondary forms in hematopoietic stem cell and lung transplantation recipients

PURPOSE

Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonia, characterized by elastotic fibrosis involving the pleura and subpleural parenchyma, predominantly in the upper lobes. PPFE can be either idiopathic or secondary and mostly occurs as a late complication of lung or hematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate the prevalence of secondary forms in transplant recipients.

METHODS

An expert thoracic radiologist retrospectively reviewed high-resolution computed tomography exams of 700 HSCT recipients and 53 lung transplant recipients from the database of the Radiology Department of S. Orsola-Malpighi Hospital dating back from 2007. For each case that radiologically fulfilled PPFE criteria, the following details were retrieved: clinical characteristics, laboratory and functional data, pathologic findings (obtained from one patient) and metabolic data (obtained from three patients).

RESULTS

Six cases clinically and radiologically consistent with PPFE were identified: two HSCT recipients (0.28%) and four lung transplant recipients (7.54%).

CONCLUSION

In this study, PPFE was strongly associated with lung transplants as a late complication, with a prevalence of 7.54%.

[Idiopathic interstitial pneumonias in 2016]

Idiopathic interstitial pneumonias comprise 8 clinicopathological entities, most of them with a chronic course and various prognosis. Idiopathic pulmonary fibrosis is the most frequent and most severe of these. Computed tomography has an important role for its diagnosis. It can identify the corresponding pathological pattern of usual interstitial pneumonia in about 50 percent of cases. It can suggest differential diagnosis in other cases, most frequently fibrosing nonspecific interstitial pneumonia and chronic hypersensitivity pneumonitis. Imaging features should be integrated to clinical and available pathologic data during multidisciplinary team meetings involving physicians with a good knowledge of interstitial diseases. Some cases may be unclassifiable, but these could later be reclassified as new data may occur or imaging features may change. Surgical lung biopsy is being less frequently performed and an emerging less invasive technique, lung cryobiopsy, is under evaluation. Pleuroparenchymal fibroelastosis is a distinct entity only recently described, with uncertain prevalence and prognosis that seems being quite often associated to another pattern of interstitial pneumonia.

Idiopathic Pleuroparenchymal Fibroelastosis

Purpose of the review

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare fibrosing lung disease, affecting the visceral pleura and the subpleural parenchyma with an upper lobe predilection, included as a distinct clinicopathologic entity in the latest international multidisciplinary classification of the idiopathic interstitial pneumonias (IIP). We aim to summarize the current evidence on IPPFE, in terms of clinical features and potential treatments.

Recent findings

Overall, there is increasing awareness of PPFE in association with a separate ILD pattern. Although an agreed consensus on diagnosis has yet to be defined, a list of radiological and histopathological criteria has been proposed. Due to the unfavorable risk-benefit profile of surgical lung biopsy in a significant proportion of patients, a potential role for transbronchial lung cryobiopsy has been suggested. At present, lung transplantation remains the only curative option.

Summary

The increasing awareness of this condition among specialists has led to more frequent identification of IPPFE. Large international studies are needed to better characterize pathogenesis and pheno/endotypes of disease, a key step towards the development of effective treatments.

Two cases of pleuroparenchymal fibroelastosis diagnosed with transbronchial lung biopsy

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare subset of idiopathic interstitial pneumonias (IIPs). Here we present two patients with PPFE in which the histology was confirmed with transbronchial lung biopsy (TBLB). The 25-year-old and 64-year-old men were both slender with a long history of pulmonary upper lobe fibrosis and a marked restrictive impairment. Although the imaging findings supported the diagnosis of PPFE, surgical lung biopsy (SLB) seemed to be needed to identify fibroelastosis for the definite diagnosis. However, we selected TBLB instead of SLB because of their general condition and the risk such as prolonged pneumothorax after TBLB. TBLB specimens in both patients showed aggregates of elastic fibers in the submucosa that were essential clues for the histological diagnosis of PPFE. TBLB may be an alternative tool for the histological diagnosis of PPFE, although a multidisciplinary discussion is necessary for the final diagnosis of PPFE as a clinicopathological entity.

Heterogeneous clinical features in patients with pulmonary fibrosis showing histology of pleuroparenchymal fibroelastosis

BACKGROUND

The histological pattern of pleuroparenchymal fibroelastosis (PPFE) is well defined, but its clinical features remain unclear.

METHODS

We retrospectively examined the predominantly involved lung-fields (based on abnormal opacities on computed tomography [CT] images), and the initial value and annual decline of respiratory function in patients with pulmonary fibrosis presenting with histologically confirmed PPFE.

RESULTS

Thirteen female and nine male subjects were included. Eleven interpreters independently analyzed 231 CT image series. One-third of the CT series (78/231) was interpreted as demonstrating equal involvement of the upper and lower lung fields, i.e., six out of 21 patients had equal involvement of the upper and lower lung fields, based on a majority decision of the interpreters. The residual volume/total lung capacity (RV/TLC) was increased and correlated inversely with forced vital capacity (FVC) at the initial measurement. FVC followed two patterns of decline over time: a gradual decline over a follow-up period of more than 6 years (-55mL/year, R(2)=0.799), and a relatively rapid decline over a shorter period (-364mL/year, R(2)=0.855) as determined by mixed-effect linear regression.

CONCLUSIONS

The predominantly involved sites seen on CT images of PPFE were not limited to the upper lobes. In some cases, upper lung fields were predominantly involved, but in other cases, both upper and lower lung fields were equally involved. Two patterns of FVC decline exists: a rapid decline over a short period and a slow decline over a longer period, suggesting that the disease follows a heterogeneous clinical course.

A Patient with Idiopathic Pleuroparenchymal Fibroelastosis Showing a Sustained Pulmonary Function due to Treatment with Pirfenidone

The patient was a 68-year-old man presenting with body weight loss and exertional dyspnea. High-resolution computed tomography of the chest showed dense subpleural consolidation with traction bronchiectasis and volume loss predominantly in bilateral apical lesions and upper lobes. A histopathological analysis of a specimen of the right upper lobe showed histological patterns which were consistent with idiopathic pleuroparenchymal fibroelastotis (IPPFE). Treatment with pirfenidone was introduced with the expectation of its potential benefit. The effect of pirfenidone was satisfactory, and a decline in forced vital capacity was inhibited during treatment. This is the first case report suggesting the efficacy of pirfenidone for patients with IPPFE.