Clinical and radiological characteristics of patients with late-onset severe restrictive lung defect after hematopoietic stem cell transplantation

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.

Polysaccharide-Based Multifunctional Hydrogel Bio-Adhesives for Wound Healing: A Review

Wound healing is a long-term and complex biological process that involves multiple hemostasis, inflammation, proliferation, and remodeling stages. In order to realize comprehensive and systematic wound management, appropriate wound treatment bio-adhesives are urgently needed. Hydrogel bio-adhesives have excellent properties and show unique and remarkable advantages in the field of wound management. This review begins with a detailed description of the design criteria and functionalities of ideal hydrogel bio-adhesives for wound healing. Then, recent advances in polysaccharide-based multifunctional hydrogel bio-adhesives, which involve chitosan, hyaluronic acid, alginate, cellulose, dextran, konjac glucomannan, chondroitin sulfate, and other polysaccharides, are comprehensively discussed. Finally, the current challenges and future research directions of polysaccharide-based hydrogel bio-adhesives for wound healing are proposed to stimulate further exploration by researchers.

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.

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.

The ISHLT Chronic Lung Allograft Dysfunction Consensus Criteria is Applicable to Pulmonary Chronic Graft-versus-Host Disease

Pulmonary chronic graft-versus-host disease (PcGvHD) is a devastating complication of allogeneic hematopoietic stem cell transplant (HCT). The 2014 NIH chronic GvHD (cGvHD) Consensus Criteria (NIH Criteria) only captures bronchiolitis obliterans syndrome (BOS). In this study, we adapted the 2019 Criteria of chronic lung allograft dysfunction (CLAD) to define novel phenotypes of PcGvHD and compared the performance of this criteria with the NIH Criteria to identify high-risk PcGvHD patients. We reviewed consecutive patients in a cGvHD natural history protocol (NCT00092235) and adapted the 2019 CLAD Criteria (the Adapted Criteria) to define PcGvHD as post-HCT FEV1 <80% predicted value, with four phenotypes: obstructive, restrictive, mixed obstructive/restrictive and undefined. An independent adjudication committee evaluated subjects for diagnosis and phenotyping. We identified 166 (47.4%) patients who met the Adapted Criteria, including obstructive (n = 12, 3.4%), restrictive (n=67, 19.1%), mixed obstruction/restriction (n = 47, 13.4%) and undefined (n = 40, 11.4%). In these patients, less than half (n= 78) met the NIH criteria for BOS (NIH+), the rest (n=88) did not (NIH-). The NIH- subjects showed increased risk of death compared to those without PcGvHD (HR = 1.88, 95%CI = 1.20-2.95, p = 0.006) that was similar to NIH+ subjects (p = 0.678). Our study demonstrated the potential of the Adapted Criteria in identifying high risk PcGvHD patients that have been missed by the NIH Criteria. The Adapted Criteria could become a valuable tool to better phenotype and study lung disease in cGvHD.

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.

Noninfectious complications of hematopoietic cell transplantation

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.

Pulmonary surveillance in pediatric hematopoietic stem cell transplant: A multinational multidisciplinary survey

Background

Hematopoietic Stem Cell Transplant (HSCT) is an established treatment for malignant and non‐malignant conditions and pulmonary disease is a leading cause of late term morbidity and mortality. Accurate and early detection of pulmonary complications is a critical step in improving long term outcomes. Existing guidelines for surveillance of pulmonary complications post‐HSCT contain conflicting recommendations.

Aim

To determine the breadth of current practice in monitoring for pulmonary complications of pediatric HSCT.

Methods

An institutional review board approved, online, anonymous multiple‐choice survey was distributed to HSCT and pulmonary physicians from the United States of America and Australasia using the REDcap platform. The survey was developed by members of the American Thoracic Society Working Group on Complications of Childhood Cancer, and was designed to assess patient management and service design.

Results

A total of 40 (34.8%) responses were received. The majority (62.5%) were pulmonologists, and 82.5% were from the United States of America. In all, 67.5% reported having a protocol for monitoring pulmonary complications and 50.0% reported adhering “well” or “very well” to protocols. Pulmonary function tests (PFTs) most commonly involved spirometry and diffusion capacity for carbon monoxide. The frequency of PFTs varied depending on time post‐HSCT and presence of complications. In all, 55.0% reported a set threshold for a clinically significant change in PFT.

Conclusions

These results illustrate current variation in surveillance for pulmonary complications of pediatric HSCT. The results of this survey will inform development of future guidelines for monitoring of pulmonary complications after pediatric HSCT.

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.

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.

Functional capacity, pulmonary function, and quality of life in hematopoietic stem cell transplantation survivors

OBJECTIVE

Hematopoietic stem cell transplantation (HSCT) is used as a treatment for several diseases. The objective was to evaluate the functional capacity, pulmonary function, and quality of life (QoL) in HSCT survivors.

METHODS

The patients were submitted to spirometry and six-minute walk test (6MWT) and evaluation of QoL (Functional Assessment of Cancer Therapy Bone Marrow Transplantation-FACT-BMT) and the level of physical activity (Human Activity Profile-HAP) in the post-HSCT outpatient ambulatory.

RESULTS

The sample was composed of 103 individuals with a mean age of 42.1 ± 12 and a median HSCT time of 5 (2-11) years. The average distance walked in the 6MWT was 524.7 ± 73.5 m; the FACT-BMT score, 82 ± 8.7 points; FEV₁, 76.8 ± 22.6%; and HAP, 71.9 ± 11.2 points. There was a significant difference between debilitated and physically active individuals for the variables: forced expiratory volume in the first second (FEV₁) in liters (p = 0.008) and % of predicted (p = 0.017), FEV₁/FVC (p = 0.032), distance on the 6MWT (p < 0.001), fatigue after the 6MWT (p < 0.001), and physical well-being (p = 0.005).

CONCLUSIONS

HSCT survivors have long-term changes in functional capacity, pulmonary function, and QoL. Subjects more active had better results in pulmonary function and functional capacity.

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.

Pulmonary acute graft-versus-host disease and infections after allogeneic hematopoietic stem cell transplantation in pediatric recipients: A comparative study on CT

OBJECTIVE

To compare the chest CT patterns of acute graft-versus-host disease (aGVHD) and infections within 100 days after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in pediatric recipients to help hematologist make definitive diagnosis as early as possible.

METHODS

A total of 143 pediatric recipients from January 2015 to June 2019 who were diagnosed pulmonary aGVHD or infections within 100 days after allo-HSCT were enrolled in this study. Two observers evaluated the extent and distribution (unilateral, bilateral) of the CT patterns. The patterns were then classified as ground-glass opacity (GGO) (localized, patchy, diffuse), consolidation (localized, patchy, diffuse), reticulation (localized, patchy, diffuse), nodules (localized, multiple), bronchiectasis, pleural effusion, air trapping, tree-in-bud sign, and pneumomediastinum. The onset time and radiological patterns of the two cohorts were statistically compared.

RESULTS

The mean onset time of aGVHD (n = 85) and infections group (viral n = 29, bacterial n = 22, fungal n = 7, total n = 58) was 36.89 ± 24.34 (range, 10-99 days) and 23.48 ± 20.65 days (range, 4-94 days) with a significant difference (P = .001). The top three underlying diseases were acute lymphoblastic leukemia (ALL) (n = 49, 57.6%); acute myeloid leukemia (AML) (n = 24, 28.2%); and aplastic anemia (AA) (7.1%) in aGVHD group and hemophagocytic syndrome (HPS) (n = 33, 56.9%); AA (n = 9, 15.5%); and ALL (n = 6, 10.3) in infection group. GGO (41.2%) in aGVHD prevailed on CT, whereas GGO (53.4%) and consolidations (43.1%) were more prevalent in infections. The distribution of GGO showed more diffuse in aGVHD (P = .031) and symmetric while patchier GGO prefers infections (P < .001). No differences were found in the reticulation. Nodules were more common in infections (P = .004) while pleural effusion was more common in aGVHD group (P < .035).

CONCLUSION

Imaging patterns of aGVHD on CT differ substantially from that of infections. Physicians and radiologists should be aware of such radiological differences in order to give accurate treatment. Notably, definite diagnosis should be made in combination with clinical manifestations, signs, and laboratory tests.

IASLC Multidisciplinary Recommendations for Pathologic Assessment of Lung Cancer Resection Specimens After Neoadjuvant Therapy

Currently, there is no established guidance on how to process and evaluate resected lung cancer specimens after neoadjuvant therapy in the setting of clinical trials and clinical practice. There is also a lack of precise definitions on the degree of pathologic response, including major pathologic response or complete pathologic response. For other cancers such as osteosarcoma and colorectal, breast, and esophageal carcinomas, there have been multiple studies investigating pathologic assessment of the effects of neoadjuvant therapy, including some detailed recommendations on how to handle these specimens. A comprehensive mapping approach to gross and histologic processing of osteosarcomas after induction therapy has been used for over 40 years. The purpose of this article is to outline detailed recommendations on how to process lung cancer resection specimens and to define pathologic response, including major pathologic response or complete pathologic response after neoadjuvant therapy. A standardized approach is recommended to assess the percentages of (1) viable tumor, (2) necrosis, and (3) stroma (including inflammation and fibrosis) with a total adding up to 100%. This is recommended for all systemic therapies, including chemotherapy, chemoradiation, molecular-targeted therapy, immunotherapy, or any future novel therapies yet to be discovered, whether administered alone or in combination. Specific issues may differ for certain therapies such as immunotherapy, but the grossing process should be similar, and the histologic evaluation should contain these basic elements. Standard pathologic response assessment should allow for comparisons between different therapies and correlations with disease-free survival and overall survival in ongoing and future trials. The International Association for the Study of Lung Cancer has an effort to collect such data from existing and future clinical trials. These recommendations are intended as guidance for clinical trials, although it is hoped they can be viewed as suggestion for good clinical practice outside of clinical trials, to improve consistency of pathologic assessment of treatment response.