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

Platythorax increases residual volume/total lung capacity in idiopathic pleuroparenchymal fibroelastosis

Platythorax significantly contributes to the increase in residual volume/total lung capacity ratio in patients with idiopathic pleuroparenchymal fibroelastosis https://bit.ly/3uZ0rmP.

Proposed Clinical Algorithm for Pleuroparenchymal Fibroelastosis (PPFE)

Pleuroparenchymal fibroelastosis (PPFE) is characterized by fibrosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobes. As PPFE appears to occur in patients with heterogeneous etiologies, the disease course is thus also heterogenous, with some patients showing rapid progression while others have slow progression. Therefore, it is very difficult to predict prognosis with PPFE. Needless to say, this problematic matter has influenced the treatment strategy of PPFE patients. In fact, until now no evidence has been shown for use in creating an appropriate management algorithm for PPFE. We speculate that "uncoordinated breathing" is the most important reason for dyspnea in PPFE patients. Because monitoring of physique and not just pulmonary function and radiological evaluation is also very important, particularly in PPFE patients, this review focused on the characteristics of PPFE through an overview of previous studies in this field, and we proposed an algorithm as precision medicine based on the current evidence. Multiple views by the pulmonologist are needed to standardize a clinical algorithm that is necessary to correctly assess PPFE patients under the premise of maintenance of physique by providing appropriate nutritional care and pulmonary rehabilitation.

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.

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.

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

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.

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.

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.

A case of thoracic air leak syndrome with pleural parenchymal fibroelastosis after treatment for hematologic malignancy while awaiting lung transplantation: Imaging and pathological findings of rapid loss in lung volume

We report the case of a 29-year-old man who underwent umbilical cord blood transplantation for chronic myelogenous leukemia 14 years previously. He was diagnosed with secondary pleuroparenchymal fibroelastosis (sPPFE) following treatment for hematologic malignancies (sPPFE after HM-Tx) 2.5 years ago. On computed tomography, pleural thickening in the upper lobe, lung volume loss, and recurrent bilateral pneumothorax were detected. Although he waited for cadaveric lung transplantation (LTx) for 1.5 years, his respiratory failure worsened, and he died. Pathological autopsy and clinical course indicated sPPFE. After diagnosing sPPFE after HM-Tx, the timing for deciding LTx is critical, especially when pneumothorax recurs.

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.

Pulmonary rehabilitation for idiopathic pleuroparenchymal fibroelastosis: A retrospective study on its efficacy, feasibility, and safety

BACKGROUND

The beneficial effects of pulmonary rehabilitation (PR) for patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) remain unknown. This study aimed to examine the efficacy, feasibility, and safety of PR for IPPFE.

METHODS

We retrospectively investigated 25 patients with IPPFE referred for PR between April 2007 and March 2017. The PR mainly consisted of a 10-week exercise training program. The primary outcome was a change in 6-min walk distance (6MWD). Secondary outcomes included changes in dyspnea (transition dyspnea index [TDI]), anxiety and depression (hospital anxiety and depression scale [HADS]), and health-related quality of life (HRQoL) (St George's respiratory questionnaire [SGRQ]).

RESULTS

Thirteen patients participated in the PR program (PRP). Recurrent pneumothorax was the most common reason for patients not participating in the PRP. Four patients discontinued the PRP due to the recurrence of pneumothorax, new onset of pneumomediastinum, stroke, and another reason, respectively. Nine patients completed the PRP. Significant improvement was observed in 6MWD (median [interquartile range], 90 m [55-116 m]; P = 0.033). Clinically important improvements in the 6MWD, and TDI, HADS-anxiety, HADS-depression, and SGRQ total domain scores were observed in seven (78%), five (56%), four (44%), four (44%), and five (56%) of the nine patients, respectively.

CONCLUSIONS

Patients with IPPFE benefited from PR in terms of exercise capacity, dyspnea, anxiety, depression, and HRQoL. Pneumothorax and pneumomediastinum may impede the implementation of a PRP for patients with IPPFE. While careful patient selection is required, PR may be an efficacious non-pharmacological approach for managing disabilities in patients with IPPFE.

Assessment score for the diagnosis of a case with pleuroparenchymal fibroelastosis

Idiopathic pleuropulmonary fibroelastosis is an extremely rare lung disease characterized by the combination of fibrosis of the visceral pleura and the fibroelastotic changes transcending in the subpleural lung parenchyma that predominantly affects the upper lobes with accompanying volume loss. It is mostly idiopathic while infection, autoimmunity, bone marrow or lung transplantation and genetic predisposition may be associated with the development of PPFE. The disease is exceptionally rare as approximately ninety cases have been reported in the literature currently. A 35-year-old female presented with exertional dyspnea, dry cough and weight loss. Physical examination demonstrated platythorax, suprasternal notch deepening and fine rales over the upper lobes. Blood count, serum biochemistry, autoimmunity and serologic markers for collagen vascular diseases were within normal limits. Arterial blood gases demonstrated a low pO2 (48 mm Hg) and a high pCO2 (54 mm Hg) values. Chest x-ray showed bilateral parenchymal fibrotic lesions, left pneumothorax, bronchiectasis in the middle and pleural thickening in the upper lung zones while HRCT revealed bilateral apical pleural thickening, traction bronchiectasis, subpleural reticulations, ground-glass opacities and honeycombing in the upper lobes. Bronchoscopy, BAL cytology, smear and culture did not reveal any pathologic findings. Relevant with the clinical, laboratory, radiologic manifestations and the differential diagnosis with other interstitial lung diseases, PPFE was the final diagnosis. The aim of this case report was to present the clinical manifestations of our case. The second crucial objective was to establish a diagnostic scoring system relevant with the literature and the clinical manifestations of the patient.

Prognostic and Clinical Value of Cluster Analysis in Idiopathic Pleuroparenchymal Fibroelastosis Phenotypes

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a distinctive interstitial pneumonia with upper lobe predominance that shows unique morphological features among idiopathic interstitial pneumonias (IIPs). Affected patients have a variety of clinical presentations with heterogeneous clinical courses. Cluster analysis is a valuable tool for identifying distinct clinical phenotypes under heterogeneous conditions. This study aimed to identify the phenotypes of patients with idiopathic PPFE. Using cluster analysis, novel PPFE phenotypes were identified among subjects from our multicenter cohort, and outcomes were stratified according to phenotypic clusters. Among the subjects with baseline data (N = 84), four clusters were identified. Cluster 1 included younger male subjects with coexisting non-UIP-like patterns. Cluster 2 included elderly female nonsmokers with low body mass index (BMI). Cluster 3 included elderly male smokers with a coexisting IP-like pattern. Cluster 4 included younger male smokers without lower lobe lesions. Patients in cluster 3 had significantly worse survival outcomes than those in clusters 1, 2, and 4 (p < 0.001, p = 0.0041, and p = 0.0155, respectively). Among idiopathic PPFE patients, cluster analysis using baseline characteristics identified four distinct clinical phenotypes that might predict survival outcomes.

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 Korean patients: clinico-radiologic-pathologic features and 2-year follow-up

BACKGROUND/AIMS

Pleuroparenchymal fibroelastosis (PPFE) is a type of rare idiopathic interstitial pneumonia that is characterized by predominantly upper lobe involvement with pleural fibrosis and subjacent parenchymal fibrosis. This study aimed to determine the clinico-radiologic-pathologic features and prognosis of Korean patients with PPFE.

METHODS

A total of 26 patients who were confirmed to have PPFE by lung biopsy, were included, and their clinico-radiologic-pathologic findings were retrospectively analyzed.

RESULTS

The mean follow-up period was 23.8 months, and the mean age of the patients was 62.5 years; 61.5% were men and 50% were smokers. Cough and dyspnea were the most frequent presenting symptoms, and restrictive pattern was the most common observation in lung function. In 84.6% of the subjects, lower lobe involvement was found on chest computed tomography, and the usual interstitial pneumonia (UIP) pattern was the most common (59.1%). Among patients whose lower lobe was biopsied (n = 13), the UIP pattern was the most common (46.2%). Patients with lower lobe involvement were older and walked a shorter distance during the 6-minute walk test, compared to those without. Spontaneous pneumothorax was a common complication (26.9%), and 15.4% of the patients died mostly due to pneumonia (100%). The 1- and 3-year survival rates were 90.2% and 84.5%, respectively.

CONCLUSION

Clinical features of Korean patients with PPFE were similar to those reported previously; however, lower lobe involvement was more frequent. During follow-up, one-fourth of the patients experienced pneumothorax and one-fifth died from pneumonia.

Pleuroparenchymal fibroelastosis in rheumatic autoimmune diseases: a systematic literature review

OBJECTIVES

Pleuroparenchymal fibroelastosis (PPFE) is characterized by predominantly upper lobe pleural and subjacent parenchymal fibrosis; PPFE features were described in patients with rheumatic autoimmune diseases (RAID). A systematic literature review was performed to investigate the prevalence, prognosis and potential association of PPFE with previous immunosuppression in RAID.

METHODS

EMBASE, Web of Science and PubMed databases were questioned from inception to 1 September 2019. Articles published in English and addressing PPFE in patients with RAID were selected.

RESULTS

Twenty out of 794 papers were selected with a total of 76 cases of RAID-PPFE patients (20 SSc, 9 RA, 6 IIM6 primary SS, 5 overlap syndromes, 3 ANCA-associated vasculitides, 2 granulomatosis with polyangiitis, 1 microscopic polyangiitis, 1 UCTD, 1 SLE, 1 GCA and 21 patients with non-specified RAID). Dyspnoea was the most frequently reported symptom (37/48 patients, 77%). Patients frequently presented with a restrictive pattern and decline in diffusing lung capacity for carbon monoxide. During the follow-up, 7/12 patients had progression at imaging, 22/39 presented a generic clinical worsening, 19/38 had a functional deterioration and 15/43 remained stable.

CONCLUSION

The present systematic literature review confirms that PPFE features are present in RAID. Rheumatologists should be aware of this new radiological pattern that holds a bad prognosis.

Pneumothorax in Patients with Idiopathic Pleuroparenchymal Fibroelastosis: Incidence, Clinical Features, and Risk Factors

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare form of idiopathic interstitial pneumonia that is characterized by predominantly upper lobe pleural and subpleural lung parenchymal fibrosis. Pneumothorax is one of the major respiratory complications in PPFE patients; however, its clinical features are poorly understood.

OBJECTIVE

We aimed to investigate the complication of pneumothorax in patients with idiopathic PPFE.

METHODS

A retrospective multicenter study involving 89 patients who had been diagnosed with idiopathic PPFE was conducted. We investigated the cumulative incidence, clinical features, and risk factors of pneumothorax after the diagnosis of idiopathic PPFE.

RESULTS

Pneumothorax developed in 53 patients (59.6%) with 120 events during the observation period (41.8 ± 35.0 months). The cumulative incidence of pneumothorax was 24.8, 44.9, and 53.9% at 1, 2, and 3 years, respectively. Most events of pneumothorax were asymptomatic (n = 85; 70.8%) and small in size (n = 92; 76.7%); 30 patients (56.6%) had recurrent pneumothorax. Chest drainage was required in 23 pneumothorax events (19.2%), and a persistent air leak was observed in 13 (56.5%). Patients with pneumothorax were predominantly male and frequently had pathological diagnoses of PPFE and prior history of pneumothorax and corticosteroid use; they also had significantly poorer survival than those without pneumothorax (log-rank test; p = 0.001). Multivariate analysis revealed that a higher residual volume/total lung capacity ratio was significantly associated with the development of pneumothorax after the diagnosis.

CONCLUSION

Pneumothorax is often asymptomatic and recurrent in patients with idiopathic PPFE, leading to poor outcomes in some cases.

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.

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.

A case report of idiopathic pleuroparenchymal fibroelastosis with severe respiratory failure in pregnancy

Background

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare lung disease that manifests as parenchymal fibrosis of the upper lung lobe and pleura. There have been no reports of IPPFE complicating pregnancy. Here, we report a case of IPPFE that deteriorated rapidly during pregnancy.

Case presentation

A 29-year-old woman presented with dyspnea and dry cough at 19 weeks of gestation. IPPFE with acute exacerbation was suspected on chest computed tomography (CT). Despite steroid treatment, her condition progressed. A cesarean section was performed at 28 weeks of gestation. On postoperative day 26, she underwent living-donor lung transplantation. She was discharged a year after transplantation.

Conclusion

Our experience suggested that when pregnancy is complicated by PPFE, the disease may deteriorate rapidly. In this case, even though IPPFE with acute exacerbation was diagnosed during pregnancy, live birth was achieved, and the mother survived after lung transplantation. Lung transplantation should be considered in these patients because, once advanced, pulmonary lesions may be irreversible.

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.

Disease course and prognosis of pleuroparenchymal fibroelastosis compared with idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare interstitial lung disease characterized by unique radiological and pathological findings. However, pathological evaluations are available only in a limited number of patients. Therefore, several clinical diagnostic criteria have been proposed. Nevertheless, the applicability of these criteria has not yet been validated. Moreover, the clinical course of iPPFE and its prognosis have not yet been completely elucidated.

METHODS

The present study assessed previously proposed clinical diagnostic criteria by comparing the clinical features between pathologically diagnosed iPPFE (p-iPPFE) and clinically diagnosed iPPFE (c-iPPFE). Subsequently, the clinical features of iPPFE were characterized and compared with those of idiopathic pulmonary fibrosis (IPF, n = 323).

RESULTS

Clinical characteristics of c-iPPFE (n = 27) and p-iPPFE (n = 35) were similar. No significant difference was observed in terms of prognosis between c-iPPFE and p-iPPFE. The number of patients with iPPFE (both c-iPPFE and p-iPPFE) who developed lung cancer was significantly lower than that of patients with IPF. However, acute exacerbation (AE) showed similar incidence in patients with iPPFE and IPF. Survival of patients with iPPFE was significantly worse than that of patients with IPF (5-year survival rate: 38.5% vs. 63.5%, p < 0.0001), and the most common cause of death was chronic respiratory failure (73.8%), followed by AE (14.3%). Male gender was the only poor prognostic factor of iPPFE.

CONCLUSION

The present study demonstrated efficiency of clinical diagnosis and also revealed clinically important characteristics of iPPFE that should be considered for management of iPPFE.

Serum latent transforming growth factor-β binding protein 4 as a novel biomarker for idiopathic pleuroparenchymal fibroelastosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare idiopathic interstitial pneumonia characterized by an upper lobe-dominant interstitial increase in predominantly elastic fibers. The accumulation of cases has resulted in a refinement of the disease concept, but there are no blood biomarkers to aid in the diagnosis or prediction of a progressive phenotype among PPFE patients. Several organizers, including latent transforming growth factor-β binding protein 4 (LTBP-4), are known to be involved in elastogenesis. However, the potential of LTBP-4 as a blood biomarker for PPFE has not been investigated.

METHODS

We selected cases of clinically or histologically diagnosed IPPFE (n = 20) along with idiopathic pulmonary fibrosis (IPF) patients (n = 39) and healthy controls (n = 10). We quantified the protein levels of LTBP-4 in lung tissues and serum samples.

RESULTS

The LTBP-4 levels in lung tissue of PPFE patients were 2.16 times higher than those of IPF patients (p = 0.032). The serum concentration of LTBP-4 (pg/ml) in IPPFE was higher than that in healthy controls (1429 [154-3620] vs. 187 [56.4-490], p = 0.013). The serum concentration of LTBP-4 in IPPFE was markedly higher than that in IPF without a significant difference (1429 [154-3620] vs. 915 [491-1967], p = 0.671). In addition, a higher concentration of LTBP-4 was associated with a poor prognosis in IPPFE patients.

CONCLUSIONS

The serum concentration of LTBP-4 may aid in the diagnosis of IPPFE or the prediction of an aggressive phenotype.

An Autopsy Case of Idiopathic Pleuroparenchymal Fibroelastosis with Left Vocal Cord Paralysis and a Rapid Deterioration without an Acute Exacerbation

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a generally slow-progressing rare disorder of unknown etiology. The direct cause of death in cases of IPPFE is rarely investigated. We experienced an autopsy case of a Japanese man with IPPFE and found aspiration pneumonia to be the major trigger of death. The individual had left vocal cord paralysis at admission, which may have contributed to aspiration pneumonia, and which probably was affected by the fibrous adhesion of the left apex of the chest wall resulting from IPPFE. The prevention of aspiration pneumonia is important for maintaining the respiratory function, especially in IPPFE patients with repeated pneumothorax.

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.

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.

Squawks in interstitial lung disease prevalence and causes in a cohort of one thousand patients

Squawks are lung adventitious sounds with a mix of both musical and nonmusical components heard during the inspiratory phase. Small series have described squawks in interstitial lung diseases. Hypersensitivity pneumonitis and other diseases involving small airways can result in squawks, but new interstitial lung diseases (ILDs) involving peripheral airways are being described. A retrospective analysis was performed on 1000 consecutive patients from a database of ILD of a tertiary referral center. Squawks were recorded in 49 cases (4.9%), hypersensitivity pneumonitis (23 cases), connective tissue disease (7), microaspiration (4), pleuroparenchymal fibroelastosis (4), fibrosing cryptogenic organizing pneumonia (, 3), familial ILD (2), sarcoidosis (2), idiopathic pulmonary fibrosis (IPF; 1), bronchiolitis (2), and nonspecific interstitial pneumonia (1). One patient had a final diagnosis of IPF. There was a significant association between mosaic pattern and squawks: 20 cases with squawks (40.8%) had mosaic pattern compared with 140 (14.7%) cases without squawks (x = 23.6, P < .001).Findings indicative of fibrosis were described on high-resolution chest tomography (HRCT) in 715 cases (71.5%). Squawks were more common in patients with findings indicative of fibrosis on HRCT: 45 of 715 (6.3%) compared with 4 of 285 (1.4%) of those without findings indicative of fibrosis (x = 10.46, P = .001).In conclusion, squawks are an uncommon finding on physical examination in patients with ILD, but when present suggest fibrosing ILD associated with bronchiolar involvement. However, squawks are rare in IPF.

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.

Orphan Lung Diseases

There are hundreds of rare orphan lung diseases. We have highlighted five of them, one from each of the five major categories of pulmonary disorders: pleuroparenchymal fibroelastosis (a rare diffuse parenchymal lung disease), pulmonary alveolar proteinosis (a rare autoimmune and diffuse parenchymal lung disease), lymphangioleiomyomatosis (a rare cystic lung disease), yellow nail syndrome (a rare pleural disease), and Mounier-Kuhn syndrome (a rare airway disorder). The pathogenesis, clinical presentation, diagnostic criteria, treatment options, and prognosis of each disorder is discussed. This review is by no means exhaustive and further research is needed to improve our understanding of these disorders.

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.

Pleuroparenchymal fibroelastosis secondary to autologous hematopoietic stem cell transplantation: A case report

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease. Although an increased number of PPFE cases have been reported recently, the characteristics of this condition have not been well described. The present study reports on the case of a 34-year-old male patient who presented with unilateral lung abnormalities. The patient was admitted due to a 9-year history of progressive cough and exertional dyspnea, as well as a history of Hodgkin's lymphoma treated by autologous hematopoietic stem cell transplantation (HSCT). The patient had been initially diagnosed with tuberculosis and received regular anti-tuberculosis therapy for 18 months; however, the symptoms progressed. Serial chest computed tomography scans indicated a gradually worsening diffuse pleural thickening, dense subpleural opacification and volume loss, associated with evidence of fibrosis in the right lung. On physical examination the patient was cachectic, with a body mass index of 18.5 kg/m², and he had a flattened thoracic cage. Arterial blood gas analysis revealed hypoxia. Pulmonary function tests revealed restrictive ventilation dysfunction and decreased diffusion capacity. The microbiological and cytological examinations were negative. Lung biopsy revealed a thickened pleura consisting of large amounts of collagen and elastic fibers, coexisting with subpleural intra-alveolar fibrosis with alveolar septal elastosis, without inflammatory infiltrates. The patient was diagnosed with PPFE secondary to HSCT and eventually succumbed to respiratory failure and infection while waiting for a lung transplant. Physicians should be aware of the typical and atypical characteristics of this rare disease, as its clinical and radiological characteristics may lead to misdiagnosis, particularly as chronic infections. The prognosis remains poor without effective long-term treatment.

Sclerosis as a predictive factor for failure after bulbar urethroplasty: a prospective single-centre study

OBJECTIVE

The aim of this study was to assess whether sclerosis in histology following bulbar urethroplasty is a predictive factor for failure of surgery.

MATERIALS AND METHODS

Resected stricture specimens from 45 patients undergoing open urethroplasty with excision and anastomosis were collected prospectively during 2011-2014. Histopathological characteristics, including fibrosis (grade I-III), inflammation and sclerosis, were evaluated using different routine staining. These specimens were compared to normal urethral resection specimens from patients undergoing sex-correction surgery. The uropathologist who conducted the analyses was blinded to the study design.

RESULTS

The outcomes of the histological classifications were as follows: 19 patients had grade I fibrosis, of whom three had failures; 13 patients had grade II fibrosis, without any failures; and the most severe fibrosis, grade III, including sclerosis, was found in 13 patients (11 with sclerosis), with failure in eight. Sclerosis was a significant risk factor for restricture when comparing patients with sclerosis and those without sclerosis, and likewise when adjusting for age, inflammation and stricture length.

CONCLUSION

Histological findings of sclerosis in the resected urethral stricture specimen indicate a significantly higher risk for restricture after urethroplasty surgery.

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.

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.

•

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.

•

PPFE is independently associated with a worsened outcome in HP.

Is hypothyroidism in idiopathic pleuroparenchymal fibroelastosis a novel lung-thyroid syndrome?

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare type of interstitial pneumonia characterized by fibroelastosis. Patients with IPPFE as well as idiopathic interstitial pneumonia often have autoimmune diseases, which sometimes coincide with hypothyroidism (HypoT). However, there have been no reports on the association between IPPFE and HypoT. The purpose of this study was to evaluate the correlation between IPPFE and HypoT. We also examined the pathological features of the thyroid glands from autopsied cases.

METHODS

Thirteen patients diagnosed with IPPFE from among 255 consecutive cases of idiopathic interstitial pneumonia were included in this study; pertinent data were obtained from our hospital's clinical library. We examined the prevalence of HypoT and compared the clinical, radiological, and pathological features between the patients with and those without HypoT. Histological analyses of the lungs and thyroid glands were performed in 4 and 3 cases, respectively.

RESULTS

HypoT was identified in 7 of 13 patients (53.8%). Sex, body mass index, survival time, and laboratory test results were not significantly different between patients with and those without HypoT. Radiological and pathological lung findings were similar between both groups of patients. Thyroid gland histology demonstrated perifollicular or interlobular fibrosis without inflammation in all three cases, including a euthyroid case.

CONCLUSIONS

Although we only analyzed a small number of IPPFE cases, HypoT was prevalent among all of them. Characteristic fibrosis in the thyroid gland was observed even in a euthyroid case. Therefore, patients with IPPFE may potentially have thyroid gland dysfunction through a common pathogenesis in both organs.

Pleuroparenchymal Fibroelastosis: A Review of Histopathologic Features and the Relationship Between Histologic Parameters and Survival

Pleuroparenchymal fibroelastosis (PPFE) is now a defined clinicopathologic entity in the updated 2013 ATS/ERS classification of idiopathic interstitial pneumonias (IIPs), which has led to a significant increase in cases being diagnosed at our institution. We have therefore reviewed 43 PPFE cases (58 biopsies in total) to assess whether any clinical or histopathologic features provide prognostic information. A semiquantatitive grading system was used to assess extent of fibroblastic foci, intra-alveolar fibroelastosis, visceral pleural fibrosis, chronic inflammation in areas of fibrosis, vascular fibrointimal thickening, and presence of granulomas. Other patterns of interstitial lung disease were also noted, if present. All biopsies showed intra-alveolar fibroelastosis, fibroblastic foci at the leading edge of fibrosis and chronic inflammation within areas of fibrosis, 91% showed vascular fibrointimal thickening of vessels, 73% showed pleural fibrosis, and 35% showed granulomas. Ten cases showed a coexistent IIP (5 showed usual interstitial pneumonia, 5 showed features of hypersensitivity pneumonitis). There was no significant correlation with mortality and severity of histologic parameters, other than a significant decrease in mortality in PPFE with coexistent granulomas, after adjusting for age and gender (hazard ratio, 0.27; P=0.049). Male gender was also associated with an increased risk of mortality, after adjusting for age (hazard ratio, 4.8; P=0.045). PPFE is more common than previously thought, not infrequently showing coexistent pathology, specifically usual interstitial pneumonia and granulomatous lung disease, our data suggesting the latter may have prognostic significance.

Proliferation of elastic fibres in idiopathic pulmonary fibrosis: a whole-slide image analysis and comparison with pleuroparenchymal fibroelastosis

AIMS

We occasionally encounter patients with idiopathic pulmonary fibrosis (IPF) who have similar imaging patterns to those of pleuroparenchymal fibroelastosis (PPFE) in the upper lung fields but are not diagnosed as having PPFE clinically. The aim of this study is to identify the clinicopathological features and intrapulmonary distribution of elastic fibres and collagen fibres in these patients.

METHODS AND RESULTS

We retrospectively reviewed the medical records of patients with a clinical diagnosis of IPF, and selected consecutive patients who underwent autopsy or pneumonectomy for lung transplantation. Patients with histologically confirmed PPFE were also reviewed for comparison. We quantified the collagen fibres and elastic fibres in each lobe as a percentage of the non-aerated lung area (collagen fibre score and elastic fibre score, respectively) in histological specimens by using whole-slide image analysis, and compared these scores between IPF and PPFE patients. In a total of 55 patients (IPF, 48; PPFE, 7), there were no significant differences in the collagen fibre scores between IPF and PPFE patients. The elastic fibre scores in the upper lobe in PPFE patients were significantly higher than those in IPF patients (23.5 versus 10.3, P = 0.005). However, it is of note that, in 12 of 48 IPF patients, the elastic fibre scores of the upper lobes were above the first quartile of those in PPFE patients.

CONCLUSIONS

IPF occasionally shows intense elastosis in the upper lobes, and such cases are histologically indistinguishable from PPFE. There seem to be histologically borderline cases between PPFE and IPF.

A CARE-compliant case report: Lung transplantation for a Chinese young man with idiopathic pleuroparenchymal fibroelastosis

RATIONAL

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease that is characterized radiologically by apical pleural thickening and histologically by elastic fibrosis of the visceral pleura. Although PPFE cases have been reported occasionally since this disease was initially described, most such cases have involved secondary PPFE. Idiopathic PPFE (iPPFE) cases have been less thoroughly studied. There are no effective medications for patients with iPPFE.

PATIENT CONCERNS

A 34-year-old man with no asbestos or cigarette exposure was admitted to our ward due to worsening cough and exertional dyspnea for 10 years. He had a "flattened thoracic cage" and bibasilar inspiratory crackles without finger clubbing. A series of chest computed tomography scans during the preceding 10 years revealed the presence of gradual, exaggerated, upper lung-predominant, diffuse pleural thickening and dense subpleural opacification with traction bronchiectasis.

DIAGNOSIS

He was performed with video-assisted thoracic surgical (VATS) lung biopsy. The pulmonary histopathologic examination showed thickened visceral pleura and prominent subpleural fibroelastosis, confirming the diagnosis of iPPFE.

INTERVENTION

After the failure of treatment with prednisone plus cyclophosphamide and sequential pirfenidone administration, he was arranged with bilateral lung transplantation two years later.

OUTCOMES

The patient did not require supplemental oxygenation anymore after he recovered from lung transplantation.

LESSONS

Bilateral lung transplantation might be tried for the end-stage iPPFE cases.

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.