Pleuroparenchymal fibroelastosis in heterogeneous clinical conditions: Clinicopathologic analysis of 7 cases

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.

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.

Acute Exacerbation of Pleuroparenchymal Fibroelastosis Secondary to Allogenic Hematopoietic Stem Cell Transplantation

In this article, we report a case with pleuroparenchymal fibroelastosis (PPFE) following hematopoietic stem cell transplantation (HSCT) that developed acute respiratory failure with new bilateral ground glass opacity, which could not be explained by either a pulmonary infection, drug toxicity or extraparenchymal causes. Although combination therapy with multiple immunosuppressants was transiently effective, the patient died from a recurrent exacerbation. Autopsied lungs demonstrated diffuse alveolar damage superimposed on PPFE. There was no evidence of any coexisting interstitial pneumonia with the usual interstitial pneumonia (UIP) pattern. Our case suggests that acute exacerbation can occur in patients with post-HSCT PPFE, even when a coexisting UIP pattern is absent.

Unilateral pleuroparenchymal fibroelastosis as a rare form of idiopathic interstitial pneumonia: A case report

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia characterized by predominantly upper lobe involvement with pleural fibrosis and subjacent parenchymal fibrosis. Recently, there have been increasing reports of PPFE, and PPFE might coexist with other interstitial lung diseases in the lower lobe and upper lobe. However, cases of unilateral PPFE are scarce.

CASE SUMMARY

A 75-year-old Korean male presented to our hospital with chronic dry cough and exertional dyspnea. The patient’s symptoms started 6 mo previously and had been gradually worsening. At the time of presentation, he felt dyspnea when walking at his own pace. Radiologic findings suggested PPFE, but the lesion was localized in the upper lobe of the right lung. After multidisciplinary discussion, a transbronchial lung biopsy in the right upper lobe revealed collapsed alveoli with parenchymal fibroelastosis, and elastic van Gieson staining demonstrated septal elastosis with intra-alveolar collagenosis, which met the histopathologic criteria of definite PPFE. After multidisciplinary discussion in an experienced interstitial lung disease center, we confirmed the diagnosis of unilateral PPFE. Furthermore, we confirmed the progression of PPFE on radiologic findings during the follow-up period.

CONCLUSION

Clinicians should consider PPFE, even in cases with unilateral, predominantly upper lung involvement in interstitial lung disease patients through multidisciplinary discussion.

Cause of pleuroparenchymal fibroelastosis following allogeneic hematopoietic stem cell transplantation

Late-onset noninfectious pulmonary complications (LONIPCs) are life-threatening complications after hematopoietic stem cell transplantation (HSCT). Pleuroparenchymal fibroelastosis (PPFE) is a LONIPC, but its etiology remains elusive. Chronic graft-versus-host disease (cGVHD) and alkylating agents used for conditioning have been considered possible causes of PPFE. Therefore, to investigate the primary cause of PPFE in allogeneic HSCT, we compared three secondary PPFE groups, namely, the post-lung-transplantation, post-autologous-HSCT or chemotherapy-alone, and post-allogeneic-HSCT groups, and focused on the coexistence of bronchiolitis obliterans (BO), a typical phenotype of cGVHD. We found a trend towards higher rates of PPFE with BO in the post-allogeneic-HSCT and post-lung-transplantation groups (71% and 90%, respectively) than in the post-autologous-HSCT or chemotherapy-alone group (25%). The incidence of BO following allogeneic HSCT is reportedly <10%. If PPFE in the post-allogeneic-HSCT group has no association with BO and is induced by alkylating agents rather than cGVHD, the incidence of BO in PPFE in this group is estimated to be <10%, which is inconsistent with our data (71%). Thus, this study suggests that PPFE following allogeneic HSCT could be mainly induced by cGVHD because the majority of cases are associated with BO, a typical phenotype of cGVHD.

Combination of pleuroparenchymal fibroelastosis with non-specific interstitial pneumonia and bronchiolitis obliterans as a complication of hematopoietic stem cell transplantation - Clues to a potential mechanism

Pleuroparenchymal fibroelastosis (PPFE) is a newly described entity of interstitial lung disease, which has been recently recognized as a rare complication of bone marrow transplantation. We report a case of 30-year-old man who developed a unique combination of pleuroparenchymal fibroelastosis with cellular and fibrotic non-specific interstitial pneumonia (NSIP) and bronchiolitis obliterans (BO) sixteen years after hematopoietic stem cell transplantation. Histological examination revealed almost exclusive infiltration of CD3-positive T lymphocytes associated with lymphoepithelial lesions and multi-focal denudation of covering epithelial cells in all components. This case suggests PPFE, NSIP, and BO might be conditions of the same spectrum, pathogenetically related to chronic graft-versus-host disease. Immunostaining for CD3 and CD20 in transbronchial lung biopsies may be helpful for identifying graft-versus-host-driven interstitial lung disease.