Purpose of reviewIdiopathic pulmonary fibrosis (IPF) is a progressive, invariably fatal condition with a median survival from diagnosis of only 3 years. Despite improvements in disease understanding, challenges remain in establishing a diagnosis and predicting prognosis in individual patients. Furthermore, limited understanding of the key pathogenetic mechanisms driving disease is hampering development of new therapies. This review outlines progress that has been made in applying systems biology to IPF and the insights into disease pathogenesis, diagnosis and monitoring that this research is providing. Recent findingsLarge-scale genome-wide association studies have highlighted polymorphisms in genes involved in epithelial integrity and host defense including MUC5B and TOLLIP. Whole blood transcriptomics points towards changes in immune cell regulation that influence the progression of fibrosis. Proteomic studies have identified serum proteins, including matrix metalloproteinase 7 and CC chemokine ligand (CCL)-18, which associate with disease severity and predict prognosis. SummaryUse of molecular research techniques in large populations of well-phenotyped patients is leading to major advances in understanding of IPF. As new treatments for IPF emerge, it is to be hoped that careful application of these findings will enable the targeting of therapy to individuals based on the predominant mechanisms driving progression of their disease.

Purpose of reviewThe purpose of this review is to provide an update on the diagnosis and classification of interstitial lung disease (ILD), with a specific focus on newly described ILD subtypes and phenotypes. In addition, the strengths and limitations of the current approach to ILD diagnosis and management are discussed. Recent findingsIdiopathic pleuroparenchymal fibroelastosis and acute fibrinous and organizing pneumonia are new entities that have been described in small case series. Undifferentiated connective tissue disease-associated ILD, smoking-related interstitial fibrosis, familial ILD, unclassifiable ILD, and subclinical ILD have also been better characterized in recent publications. New data regarding these conditions are summarized in this review. The multidisciplinary approach to ILD is reviewed, and complementary classification schemes are described that may help direct the management and improve prognostication of some ILDs. SummaryILDs are a large and heterogeneous group of diseases with several newly characterized subtypes and phenotypes. The current approach to ILD classification has limitations in some patients that can be minimized by considering complementary classification schemes.

Purpose of reviewThe purpose of this review is to describe the contribution of an altered, profibrotic extracellular matrix (ECM) microenvironment to pulmonary fibrosis and how it changes cell behaviour and actively drives disease progression. Recent findingsIdiopathic pulmonary fibrosis is a chronic and fatal disease of unknown cause. It is characterized by proliferation and accumulation of fibroblasts and myofibroblasts in clusters, termed fibroblastic foci, and extensive ECM deposition. Recent evidence from in-vivo and ex-vivo experimental studies has highlighted that the abnormal ECM in fibrotic lungs alters the behaviour of epithelial and mesenchymal cells. This profibrotic ECM microenvironment is characterized by altered biochemical and biomechanical properties and stores abundant amount of growth factors. By this, the ‘fibrotic ECM’ can drive progressive fibrogenesis in the lungs without any further initiating trigger. These concepts indicate a more complicated dynamic and active role of the fibrotic ECM than previously thought and offer many novel therapeutic targets. SummaryThe fibrotic ECM microenvironment is an active contributor to the development and progression of pulmonary fibrosis and a promising therapeutic target.

Purpose of reviewChronic thromboembolic pulmonary hypertension (CTEPH) can affect up to 4–5% of patients with acute pulmonary embolism. It is likely an underdiagnosed entity. Misdiagnosis is common because patients often present with nonspecific symptoms of pulmonary hypertension. Early diagnosis may help improve the outcome, as CTEPH is potentially curable with pulmonary thromboendarterectomy (PEA). Imaging is central to an accurate diagnosis, and for assessing correctly the technical feasibility of PEA. This review examines the findings of various imaging techniques in CTEPH and their contribution in the diagnostic and therapeutic evaluation of the disease. Recent findingsVentilation–perfusion scintigraphy remains a sensitive method for excluding CTEPH. Multidetector computed tomography angiography (MDCTA) depicts directly changes of CTEPH, provides a surgical ‘road map’, and should be used for the diagnostic assessment of all suitable patients with pulmonary arterial hypertension. In many centers, the role of conventional pulmonary angiography is gradually being replaced by cross-sectional methods. MRI has a role in preoperative and postoperative assessment of right ventricular function and can depict vascular abnormalities up to segmental level. SummaryMDCTA in combination with MRI represent the main techniques for the diagnosis and management of CTEPH. Newer techniques such as dual spectrum computed tomography may further improve preoperative and postoperative assessment of CTEPH patients.