The Diagnosis and Treatment of Pulmonary Fibrosis

[Pulmonary involvement in idiopathic inflammatory myopathies]

Idiopathic inflammatory myopathies are rare systemic diseases with different types of pulmonary manifestations depending on the underlying aetiology; here, interstitial lung diseases (ILD) are the most frequently found patterns depending on the underlying disorder. There is a lack of sufficient prospective studies on this heterogeneous group of patients, particularly in case of ILD being involved. The diagnosis is based upon guideline recommendations for ILD and requires a multidisciplinary discussion within a team with specific expertise in this field. Myositis specific antibodies and myositis associated antibodies form an essential part of the diagnostic tools and may also be associated with a certain phenotype or disease progression. Anti-t-RNA-synthetase antibodies (Anti-ARS) and anti-melanoma differentiation-associated gene 5 antibodies (MDA5) play an important clinical role for treatment the estimation of response and prognosis. The most common ILD patterns are nonspecific interstitial pneumonia (NSIP) and organising pneumonia (OP) or a mixed pattern of both. Treatment is based on systemic steroids and early initiation of other immunosuppressant drugs. Evidence for this is, however, sparse, since most of the studies having investigated treatment modalities are of retrospective nature, even though some new prospective data may be useful for the establishment of treatment pathways in the future.

Ferroptosis in organ fibrosis: From mechanisms to therapeutic medicines

Fibrosis occurs in many organs, and its sustained progress can lead to organ destruction and malfunction. Although numerous studies on organ fibrosis have been carried out, its underlying mechanism is largely unknown, and no ideal treatment is currently available. Ferroptosis is an iron-dependent process of programmed cell death that is characterized by lipid peroxidation. In the past decade, a growing body of evidence demonstrated the association between ferroptosis and fibrotic diseases, while targeting ferroptosis may serve as a potential therapeutic strategy. This review highlights recent advances in the crosstalk between ferroptosis and organ fibrosis, and discusses ferroptosis-targeted therapeutic approaches against fibrosis that are currently being explored.

Human tendon-on-a-chip for modeling vascular inflammatory fibrosis

Understanding vascular inflammation and myofibroblast crosstalk is critical to developing therapies for fibrotic diseases. Here we report the development of a novel human Tendon-on-a-Chip (hToC) to model this crosstalk in peritendinous adhesions, a debilitating fibrotic condition affecting flexor tendon, which currently lacks biological therapies. The hToC enables cellular and paracrine interactions between a vascular compartment harboring endothelial cells and monocytes with a tissue hydrogel compartment containing tendon fibroblasts and macrophages. We find that the hToC replicates in vivo inflammatory and fibrotic phenotypes in preclinical and clinical samples, including myofibroblast differentiation and tissue contraction, excessive ECM deposition, and inflammatory cytokines secretion. We further show that the fibrotic phenotypes are driven by the transmigration of monocytes from the vascular to the tissue compartments of the chip. We demonstrate significant overlap in fibrotic transcriptional signatures in the hToC with human tenolysis samples, including mTOR signaling, a regulatory nexus of fibrosis across various organs. Treatment with rapamycin suppressed the fibrotic phenotype on the hToC, which validates the hToC as a preclinical alternative for investigating fibrosis and testing therapeutics.

Imperatorin ameliorates pulmonary fibrosis via GDF15 expression

Background: Pulmonary fibrosis features in damaged pulmonary structure or over-produced extracellular matrix and impaired lung function, leading to respiratory failure and eventually death. Fibrotic lungs are characterized by the secretion of pro-fibrotic factors, transformation of fibroblasts to myofibroblasts, and accumulation of matrix proteins. Hypothesis/purpose: Imperatorin shows anti-inflammatory effects on alveolar macrophages against acute lung injury. We attempt to evaluate the properties of imperatorin on the basis of fibroblasts. Methods: In in vitro, zymosan was introduced to provoke pro-fibrotic responses in NIH/3T3 or MRC-5 pulmonary fibroblasts. Imperatorin was given for examining its effects against fibrosis. The mice were stimulated by bleomycin, and imperatorin was administered to evaluate the prophylactic potential in vivo. Results: The upregulated expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and collagen protein due to zymosan introduction was decreased by imperatorin in fibroblasts. Zymosan induced the activity of transglutaminase 2 (TGase2) and lysyl oxidase (LOX), which was also inhibited by the administration of imperatorin. Imperatorin alone enhanced sirtuin 1 (SIRT1) activity and growth differentiation factor 15 (GDF15) secretion in fibroblasts via LKB1/AMPK/CREB pathways. In addition, GDF15 exerted a beneficial effect by reducing the protein expression of CTGF, α-SMA, and collagen and the activities of TGase and LOX. Moreover, orally administered imperatorin showed prophylactic effects on bleomycin-induced pulmonary fibrosis in mice. Conclusion: Imperatorin reduces fibrotic marker expression in fibroblasts and also increases GDF15 secretion via the LKB1/AMPK/CREB pathway, attenuating pro-fibrotic responses in vitro. Imperatorin also alleviates pulmonary fibrosis induced by bleomycin in vivo.

[The lungs: starting point for many diseases]

The lungs are a frequent site for the manifestation of systemic, neoplastic and immunological multiorgan diseases. In the clinical routine, patients frequently present with symptoms from the respiratory spectrum of disorders, such as dyspnea. After a clinical examination, lung function testing and imaging an initial pulmonary manifestation can often be detected; however, the ultimate assignment to a systemic disease is usually only successful in the synopsis of the clinical results, pulmonary involvement, extrapulmonary manifestation and further diagnostics. This review article presents three systemic diseases that become clinically relevant due to the primary pulmonary manifestations.

Efficacy of exercise in patients with pulmonary fibrosis: A systematic review and meta-analysis

BACKGROUND

Pulmonary fibrosis (PF) is easily caused by a variety of factors, resulting in dyspnea, exertion and movement intolerance. This systematic review aims to synthesize evidence on exercise training during rehabilitation for PF in order to improve patients' exercise capacity, quality of life, and lung function.

METHODS

Retrieved from the Cochrane Library, Web of Science, PubMed, Scopus and Embase from inception until April 2022. Participants: patients with PF; Intervention measures: exercise training; Results: exercise ability, quality of life, lung function and cardiopulmonary endurance. Two reviewers independently screen the title, abstract and full text. Finally, quality evaluation and meta-analysis were conducted.

RESULTS

In this study, 13 randomized controlled studies from 1468 articles were selected. A total of 456 patients with PF were enrolled. Compared with usual care in the control group, the 6-minute walking distance, predicted forced vital capacity, predicted forced expiratory volume at 1 second and maximal rate of oxygen consumption were increased significantly after exercise training, while there was no significant change in quality of life and predicted diffusing capacity of the lung for carbon monoxide.

CONCLUSION

Exercise training can significantly improve the exercise capacity, lung function and cardiopulmonary endurance of patients with PF, but has no effect on the quality of life. Exercise training is an effective rehabilitation strategy for PF.

Guidelines of the Polish Respiratory Society on the Diagnosis and Treatment of Progressive Fibrosing Interstitial Lung Diseases Other than Idiopathic Pulmonary Fibrosis

The recommendations were developed as answers to previously formulated questions concerning everyday diagnostic and therapeutic challenges. They were developed based on a review of the current literature using the GRADE methodology. The experts suggest that PF-ILD be diagnosed based on a combination of different criteria, such as the aggravation of symptoms, progression of radiological lesions, and worsening of lung function test parameters. The experts recommend a precise diagnosis of an underlying disease, with serological testing for an autoimmune disease always being included. The final diagnosis should be worked out by a multidisciplinary team (MDT). Patients with an interstitial lung disease other than IPF who do not meet the criteria for the progressive fibrosis phenotype should be monitored for progression, and those with systemic autoimmune diseases should be regularly monitored for signs of interstitial lung disease. In managing patients with interstitial lung disease associated with autoimmune diseases, an opinion of an MDT should be considered. Nintedanib rather than pirfenidon should be introduced in the event of the ineffectiveness of the therapy recommended for the treatment of the underlying disease, but in some instances, it is possible to start antifibrotic treatment without earlier immunomodulatory therapy. It is also admissible to use immunomodulatory and antifibrotic drugs simultaneously. No recommendations were made for or against termination of anti-fibrotic therapy in the case of noted progression during treatment of a PF-ILD other than IPF. The experts recommend that the same principles of non-pharmacological and palliative treatment and eligibility for lung transplantation should be applied to patients with an interstitial lung disease other than IPF with progressive fibrosis as in patients with IPF.

[Treatment of lung fibrosis in systemic rheumatic diseases (new treatment)]

An interstitial lung disease represents a relevant organ manifestation in many systemic rheumatic diseases (connective tissue disease-interstitial lung disease, CTD-ILD). In 10% of the cases pulmonary fibrosis even results in an underlying systemic disease. The CTD-ILDs are frequently associated with a poor prognosis. Therefore, it is important to test patients with systemic rheumatic diseases timely and regularly for the presence of an ILD. Treatment decisions should be made together with pneumologists and rheumatologists, particularly with respect to the initiation of a specific treatment. Treatment is based on randomized studies only in a few cases and can mostly be derived from case control studies. For systemic sclerosis-associated ILD (SSc-ILD) antifibrotic treatment with nintedanib has also now been approved in addition to an immunosuppressive treatment. For other CTD-ILDs an antifibrotic treatment should be discussed in an interdisciplinary approach depending on the underlying disease corresponding to a progressively fibrosing ILD.