Background: The 2013 American Thoracic Society/European Respiratory Society Statement on the classification of the idiopathic interstitial pneumonias described 6 major and 2 rare subtypes of idiopathic interstitial pneumonia, as well as recognising unclassifiable disease. Objective: The objective of this statement is to update the 2013 classification of interstitial pneumonia. Methods: Five co-chairs identified a committee of 32 experts in the field as well as two individuals with lived experience. Creation of the document was supported by a series of video meetings, first including the full committee and then subgroups assigned to draft specific sections of the document. The classification scheme was developed by consensus. Results: The multidisciplinary committee of experts identified four major advances to the classification of interstitial pneumonia: (1) expansion beyond idiopathic interstitial pneumonias to also include secondary causes; (2) identification of new subcategories and updated terms, including addition of bronchiolocentric interstitial pneumonia as a major pattern as well as changing from acute interstitial pneumonia to idiopathic diffuse alveolar damage and desquamative interstitial pneumonia to alveolar macrophage pneumonia; (3) subclassification of interstitial and alveolar filling disorders, with interstitial disorders further subclassified as fibrotic versus non-fibrotic; and (4) consideration of diagnostic confidence in patient evaluation and management. The committee also provided a comprehensive update on the status of potential molecular tools and identified future research priorities. Conclusions: This update builds upon the previous classification approach by describing major advances in the classification of interstitial pneumonia over the last decade.

Obesity is one of the leading preventable causes of cancer; however, little is known about the effects of obesity on anti-tumor immunity. Here, we investigated the effects of obesity on CD8 T cells in mouse models and patients with endometrial cancer. Our findings revealed that CD8 T cell infiltration is suppressed in obesity, which was associated with a decrease in chemokine production. Tumor-resident CD8 T cells were also functionally suppressed in obese mice, which was associated with a suppression of amino acid metabolism. Similarly, we found that a high BMI negatively correlated with CD8 infiltration in human endometrial cancer and that weight loss was associated with a complete pathological response in six of nine patients. Moreover, immunotherapy using anti–PD-1 led to tumor rejection in lean and obese mice and partially restored CD8 metabolism and anti-tumor immunity. These findings highlight the suppressive effects of obesity on CD8 T cell anti-tumor immunity, which can partially be reversed by weight loss and/or immunotherapy.

Background: Interstitial lung disease (ILD) is a frequent manifestation of connective tissue diseases (CTDs) and is associated with high morbidity and mortality. Clinical practice guidelines to standardise screening, diagnosis, treatment and follow-up for CTD-ILD are of high importance for optimised patient care. Methods: A European Respiratory Society and European Alliance of Associations for Rheumatology task force committee, composed of pulmonologists, rheumatologists, pathologists, radiologists, methodologists and patient representatives, developed recommendations based on PICO (Patients, Intervention, Comparison, Outcomes) questions with grading of the evidence according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) methodology and complementary narrative questions agreed on by both societies. For both PICO and narrative questions, the Evidence to Decision framework was used to formulate the recommendations. Results: The task force committee concluded with recommendations for 25 PICO and 28 narrative questions, regarding ILD in the context of systemic sclerosis, rheumatoid arthritis (RA), idiopathic inflammatory myopathies, Sjögren disease (SjD), systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). In four narrative questions, regarding screening and assessment of risk for ILD progression in MCTD, SjD and SLE and one PICO question regarding pirfenidone in CTD-ILD other than RA-ILD, the task force had insufficient evidence to support recommendations. Screening, diagnostic, monitoring and treatment algorithms were developed based on the recommendations and usual clinical practice. Conclusions: We provide practical guidance by evidence-based recommendations to clinicians for each of the CTDs. In many cases there is low certainty or absence of evidence and we encourage further research to fill these gaps.

Background: Pulmonary alveolar proteinosis (PAP) is a rare syndrome caused by several distinct diseases leading to progressive dyspnoea, hypoxaemia, risk of respiratory failure and early death due to accumulation of proteinaceous material in the lungs. Diagnostic strategies may include computed tomography (CT) of the lungs, bronchoalveolar lavage (BAL), evaluation of antibodies against granulocyte–macrophage colony-stimulating factor (GM-CSF), genetic testing and, eventually, lung biopsy. The management options are focused on removing the proteinaceous material by whole lung lavage (WLL), augmentation therapy with GM-CSF, rituximab, plasmapheresis and lung transplantation. The presented diagnostic and management guidelines aim to provide guidance to physicians managing patients with PAP.Methods: A European Respiratory Society Task Force composed of clinicians, methodologists and patients with experience in PAP developed recommendations in accordance with the ERS Handbook for Clinical Practice Guidelines and the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach. This included a systematic review of the literature and application of the GRADE approach to assess the certainty of evidence and strength of recommendations. The Task Force formulated five PICO (Patients, Intervention, Comparison, Outcomes) questions and two narrative questions to develop specific evidence-based recommendations.Results: The Task Force developed recommendations for the five PICO questions. These included management of PAP with WLL, GM-CSF augmentation therapy, rituximab, plasmapheresis and lung transplantation. Also, the Task Force made recommendations regarding the use of GM-CSF antibody testing, diagnostic BAL and biopsy based on the narrative questions. In addition to the recommendations, the Task Force provided information on the hierarchy of diagnostic interventions and therapy.Conclusions: The diagnosis of PAP is based on CT and BAL cytology or lung histology, whereas the diagnosis of specific PAP-causing diseases requires GM-CSF antibody testing or genetic analysis. There are several therapies including WLL and augmentation therapy with GM-CSF available to treat PAP, but supporting evidence is still limited.

It has become more and more evident that the BCL-2 family proteins mediate a wide range of non-apoptotic functions. The pro-apoptotic BAX protein has been reported in interphasic nuclei. Whether the nuclear form of BAX could be involved in non-apoptotic function is still unknown. Our study showed for the first time that BAX was associated with chromatin in vitro. Next, we used gain and loss of function approaches to decipher the potential role of nuclear BAX in non-apoptotic cells. In vitro, nuclear BAX promoted cell proliferation in lung epithelial cells and primary human lung fibroblasts by modulating CDKN1A expression. Interestingly, BAX occupancy of CDKN1A promoter was specifically enriched close to the transcription-starting site. Nuclear BAX also modulated the basal myofibroblastic differentiation and migration of primary human lung fibroblasts. Finally, BAX nuclear localization was associated in vivo with the remodelling of lung parenchyma during development, tumorigenesis as well as fibrosis compared to control adult human lungs. Hence, our study established for the first time, a strong link between the nuclear localization of the pro-apoptotic BAX protein and key basic cellular functions in the non-apoptotic setting.

Idiopathic pulmonary fibrosis is a chronic, progressive fibrotic disease with a poor prognosis. The balance between transforming growth factor β1 and bone morphogenetic protein (BMP) signaling plays an important role in tissue homeostasis, and alterations can result in pulmonary fibrosis. We hypothesized that multiple BMP accessory proteins may be responsible for maintaining this balance in the lung. Using the bleomycin mouse model for fibrosis, we examined an array of BMP accessory proteins for changes in mRNA expression. We report significant increases in mRNA expression of gremlin 1, noggin, follistatin, and follistatin-like 1 (Fstl1), and significant decreases in mRNA expression of chordin, kielin/chordin-like protein, nephroblastoma overexpressed gene, and BMP and activin membrane-bound inhibitor (BAMBI). Protein expression studies demonstrated increased levels of noggin, BAMBI, and FSTL1 in the lungs of bleomycin-treated mice and in the lungs of idiopathic pulmonary fibrosis patients. Furthermore, we demonstrated that transforming growth factor β stimulation resulted in increased expression of noggin, BAMBI, and FSTL1 in human small airway epithelial cells. These results provide the first evidence that multiple BMP accessory proteins are altered in fibrosis and may play a role in promoting fibrotic injury.