Pleuroparenchymal fibroelastosis after allogeneic hematopoietic stem cell transplantation

Efficacy of Ruxolitinib with corticosteroids in idiopathic pneumonia syndrome post-allogeneic hematopoietic stem cell transplantation: A single-center experience and systematic review

BACKGROUND

Idiopathic Pneumonia Syndrome (IPS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a life-threatening complication with high morbidity and mortality. IPS is thought to arise from damage caused by various inflammatory mediators. This study assesses the effectiveness of Ruxolitinib, a Janus Kinase (JAK) 1 and 2 inhibitor that blocks cytokine production, in combination with corticosteroids (CS) for managing IPS after allo-HSCT, compared to the conventional use of CS alone in a case series and a systematic review of previously published literature.

METHODS

The study includes a retrospective case series of three patients treated for IPS with Ruxolitinib and CS from the University of Kansas Medical Center and a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement 2020 guidelines. The systematic review encompassed seven studies involving 346 cases including three cases from the case series. Statistical analyses were conducted using SPSS v.25.

RESULTS

The case series included three patients with IPS after allo-HSCT who received ruxolitinib and CS with favorable results. All patients showed substantial improvement with no IPS-associated mortality. Two of the three patients in the case series were discharged on a 2 L nasal cannula, which was later discontinued during follow-up visits, while the third was discharged on room air. There was marked improvement observed on the computed tomography (CT) following the use of ruxolitinib. Of the total 346 cases included in the systematic review, the median age was 46.6 years (Range 5-72), and 62 % were males. The primary disorders were acute leukemia (52 %), chronic myeloid leukemia (12 %), myelodysplastic syndrome (11 %), Lymphoma (10 %), and others (21 %). Stem cell sources were peripheral blood (45 %), bone marrow (49 %), and cord blood (6 %). Donor types involved match unrelated (55 %), match related (36 %), and mismatched related (4.5 %). Most patients received myeloablative conditioning (81 %). Acute GVHD was observed in 47 %, and chronic GVHD in 38 %. The primary treatment was CS (96 %), with limited use of ruxolitinib (1 %) and etanercept (9.5 %). The mortality rate was 63.3 %, whereas in our case series with the use of ruxolitinib, it was zero.

CONCLUSION

The combination of Ruxolitinib and CS for treating IPS post-allo-HSCT suggested promising results in the case series, with favorable response and improved survival by blocking the cytokine production contributing to IPS. The significant mortality difference in the systematic review supports the need for innovative treatment approaches, highlighting the potential role of Ruxolitinib in CS-refractory cases. Despite the positive outcomes in the case series, the absence of randomized controlled trials emphasizes the necessity for further research.

Outcomes of lung transplantation for pleuroparenchymal fibroelastosis: A French multicentric retrospective study

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) has no currently available specific treatment. Benefits of lung transplantation (LT) for PPFE are poorly documented.

METHODS

We conducted a nation-wide multicentric retrospective study in patients who underwent lung or heart-lung transplantation for chronic end-stage lung disease secondary to PPFE between 2012 and 2022 in France.

RESULTS

Thirty-one patients were included. At transplantation, median age was 48 years [IQR 35-55]. About 64.5% were women. Twenty-one (67.7%) had idiopathic PFFE. Sixteen (52%) had bilateral LT, 10 (32%) had single LT, 4 (13%) had lobar transplantation and one (3%) had heart-lung transplantation. Operative mortality was 3.2%. Early mortality (<90 days or during the first hospitalization) was 32%. Eleven patients (35.5%) underwent reoperation for hemostasis. Eight (30.8%) experienced bronchial complications. Mechanical ventilation time was 10 days [IQR 2-55]. Length of stay in intensive care unit and hospital were 34 [IQR 18-73] and 64 [IQR 36-103] days, respectively. Median survival was 21 months. Post-transplant survival rates after 1, 2, and 5 years were 57.9%, 42.6% and 38.3% respectively. Low albuminemia (p = 0.046), FVC (p = 0.021), FEV1 (p = 0.009) and high emergency lung transplantation (p = 0.04) were associated with increased early mortality. Oversized graft tended to be correlated to a higher mortality (p = 0.07).

CONCLUSION

LT for PPFE is associated with high post-operative morbi-mortality rates. Patients requiring high emergency lung transplantation with advanced disease, malnutrition, or critical clinical status experienced worse outcomes.

CLINICALTRIALS

GOV IDENTIFIER

NCT05044390.

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

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

KEY POINTS

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

Interstitial lung diseases after hematopoietic stem cell transplantation: New pattern of lung chronic graft-versus-host disease?

Bronchiolitis obliterans syndrome (BOS) after allogeneic HSCT is the only formally recognized manifestation of lung chronic graft-versus-host disease (GVHD). Other lung complications were reported, including interstitial lung diseases (ILDs). Whether ILDs belong to the spectrum of lung cGVHD remains unknown. We compared characteristics and specific risk factors for both ILD and BOS. Data collected from consecutive patients diagnosed with ILD or BOS from 1981-2019 were analyzed. The strength of the association between patient characteristics and ILD occurrence was measured via odds ratios estimated from univariable logistic models. Multivariable models allowed us to handle potential confounding variables. Overall survival (OS) was estimated using the Kaplan-Meier method. 238 patients were included: 79 with ILD and 159 with BOS. At diagnosis, FEV1 was lower in patients with BOS compared to patients with ILD, while DLCO was lower in ILD. 84% of ILD patients received systemic corticosteroids, leading to improved CT scans and pulmonary function, whereas most BOS patients were treated by inhaled corticosteroids, with lung-function stabilization. In the multivariable analysis, prior thoracic irradiation and absence of prior treatment with prednisone were associated with ILD. OS was similar, even if hematological relapse was more frequent in the ILD group. Both complications occurred mainly in patients with GVHD history.

Idiopathic pleuroparenchymal fibroelastosis

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

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.

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.

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. The 2020 Highly morbid forms report

Chronic graft-versus-host disease (GVHD) can be associated with significant morbidity, in part because of nonreversible fibrosis, which impacts physical functioning (eye, skin, lung manifestations) and mortality (lung, gastrointestinal manifestations). Progress in preventing severe morbidity and mortality associated with chronic GVHD is limited by a complex and incompletely understood disease biology and a lack of prognostic biomarkers. Likewise, treatment advances for highly morbid manifestations remain hindered by the absence of effective organ-specific approaches targeting "irreversible" fibrotic sequelae and difficulties in conducting clinical trials in a heterogeneous disease with small patient numbers. The purpose of this document is to identify current gaps, to outline a roadmap of research goals for highly morbid forms of chronic GVHD including advanced skin sclerosis, fasciitis, lung, ocular and gastrointestinal involvement, and to propose strategies for effective trial design. The working group made the following recommendations: (1) Phenotype chronic GVHD clinically and biologically in future cohorts, to describe the incidence, prognostic factors, mechanisms of organ damage, and clinical evolution of highly morbid conditions including long-term effects in children; (2) Conduct longitudinal multicenter studies with common definitions and research sample collections; (3) Develop new approaches for early identification and treatment of highly morbid forms of chronic GVHD, especially biologically targeted treatments, with a special focus on fibrotic changes; and (4) Establish primary endpoints for clinical trials addressing each highly morbid manifestation in relationship to the time point of intervention (early versus late). Alternative endpoints, such as lack of progression and improvement in physical functioning or quality of life, may be suitable for clinical trials in patients with highly morbid manifestations. Finally, new approaches for objective response assessment and exploration of novel trial designs for small populations are required.

Major pulmonary complications following Hematopoietic stem cell transplantation: What the pulmonologist needs to know

Hematopoietic stem cell transplantation (HSCT) is used for treatment of a myriad of both malignant and non-malignant disorders. However, despite many advances over the years which have resulted in improved patient mortality, this subset of patients remains at risk for a variety of post-transplant complications. Pulmonary complications of HSCT are categorized into infectious and non-infectious and occur in up to one-third of patients undergoing HSCT. Infectious etiologies include bacterial, viral and fungal infections, each of which can have significant mortality if not identified and treated early in the course of infection. Advances in the diagnosis and management of infectious complications highlight the importance of non-infectious pulmonary complications related to chemoradiation toxicities, immunosuppressive drugs toxicities, and graft-versus-host disease. This report aims to serve as a guide and clinical update of pulmonary complications following HSCT for the general pulmonologist who may be involved in the care of these patients.

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.

Quantitative inspiratory-expiratory chest CT to evaluate pulmonary involvement in pediatric hematopoietic stem-cell transplantation patients

Pulmonary complications following allogeneic hematopoietic stem-cell transplantation (HSCT) are a significant source of morbidity and complications may arise from a myriad of infectious and noninfectious sources. These complications may occur soon or many months post-transplantation and can have a broad range of outcomes. Surveillance for pulmonary involvement in the pediatric HSCT population can be challenging due to poor compliance with clinical pulmonary function testing, primarily spirometry, and there may be a role for clinical imaging to provide an additional means of monitoring, particularly in the era of clinical low-dose computed tomography (CT) protocols. In this single-site, retrospective study, a review of our institution's radiological and HSCT databases was conducted to assess the utility of a quantitative CT algorithm to describe ventilation abnormalities on high-resolution chest CT scans of pediatric HSCT patients. Thirteen non-contrast enhanced chest CT examinations acquired both in inspiration and expiration, from 12 deceased HSCT patients (median age at HSCT 10.4 years, median days of CT 162) were selected for the analysis. Also, seven age-matched healthy controls (median age 15.5) with non-contrast-enhanced inspiration-expiration chest CT were selected for comparison. We report that, compared to healthy age-matched controls, HSCT patients had larger percentages of poorly ventilated (median, 13.5% vs. 2.3%, p < .001) and air trapped (median 12.3% vs. 0%, p < .001) regions of lung tissue, suggesting its utility as a potential screening tool. Furthermore, there was wide variation within individual HSCT patients, supporting the use of multivolume CT and quantitative analysis to describe and phenotype post-transplantation lung involvement.

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.

Noninfectious pulmonary complications of haematopoietic stem cell transplantation

Haematopoietic stem cell transplantation (HSCT) is an established treatment for a variety of malignant and nonmalignant conditions. Pulmonary complications, both infectious and noninfectious, are a major cause of morbidity and mortality in patients who undergo HSCT. Recent advances in prophylaxis and treatment of infectious complications has increased the significance of noninfectious pulmonary conditions. Acute lung injury associated with idiopathic pneumonia syndrome remains a major acute complication with high morbidity and mortality. On the other hand, bronchiolitis obliterans syndrome is the most challenging chronic pulmonary complication facing clinicians who are taking care of allogeneic HSCT recipients. Other noninfectious pulmonary complications following HSCT are less frequent. This review provides a clinical update of the incidence, risk factors, pathogenesis, clinical characteristics and management of the main noninfectious pulmonary complications following HSCT.