Acute exacerbations of fibrotic interstitial lung diseases.

BACKGROUND AND OBJECTIVE: Acute exacerbation (AE) is a severe complication of idiopathic pulmonary fibrosis (AE-IPF). In 2016, an international working group revised its definition and diagnostic criteria; however, few studies have assessed the frequency and prognosis of AE in patients with other fibrotic interstitial lung diseases (FILD). METHODS: We used data from 1019 consecutive interstitial lung disease (ILD) patients initially evaluated between January 2008 and July 2015. All subject diagnoses were made by multidisciplinary discussion in December 2018. ILD was categorized as IPF (n = 462) and other FILD which included non-specific interstitial pneumonia (n = 22), chronic hypersensitivity pneumonitis (n = 29), connective tissue disease-associated ILD (n = 205) and unclassifiable ILD (n = 209). Using the 2016 definition of AE-IPF, we identified all subjects with an AE. RESULTS: During the observational period, 193 patients experienced a first AE (AE-FILD n = 69, AE-IPF n = 124). The time to first AE was significantly longer in FILD than IPF (log-rank test, P < 0.001). After adjusting for potentially influential confounders, FILD remained a significant predictor of longer time to first AE compared with IPF (hazard ratio: 0.453; 95% CI: 0.317-0.647, P = 0.006). In a multivariate Cox proportional analysis, baseline disease severity was closely associated with the incidence of AE-ILD. Even after adjustment for other clinical variables, AE had a negative impact on overall survival. AE-FILD and AE-IPF showed similar poor short-term outcomes. CONCLUSION: All forms of ILD are at risk of AE and have a similar outcome to AE-IPF.

Using Autoantibodies and Cutaneous Subset to Develop Outcome-Based Disease Classification in Systemic Sclerosis.

OBJECTIVE: To describe the associations between autoantibodies, clinical presentation, and outcomes among patients with systemic sclerosis (SSc) in order to develop a novel SSc classification scheme that would incorporate both antibodies and the cutaneous disease subset as criteria. METHODS: Demographic and clinical characteristics, including cutaneous subset, time of disease and organ complication onset, and autoantibody specificities, were determined in a cohort of SSc subjects. Survival analysis was used to assess the effect of the autoantibodies on organ disease and death. RESULTS: The study included 1,325 subjects. Among the antibody/skin disease subsets, anticentromere antibody-positive patients with limited cutaneous SSc (lcSSc) (n = 374) had the highest 20-year survival (65.3%), lowest incidence of clinically significant pulmonary fibrosis (PF) (8.5%) and scleroderma renal crisis (SRC) (0.3%), and lowest incidence of cardiac SSc (4.9%), whereas the frequency of pulmonary hypertension (PH) was similar to the mean value in the SSc cohort overall. The anti-Scl-70+ groups of patients with lcSSc (n = 138) and patients with diffuse cutaneous SSc (dcSSc) (n = 149) had the highest incidence of clinically significant PF (86.1% and 84%, respectively, at 15 years). Anti-Scl-70+ patients with dcSSc had the lowest survival (32.4%) and the second highest incidence of cardiac SSc (12.9%) at 20 years. In contrast, in anti-Scl-70+ patients with lcSSc, other complications were rare, and these patients demonstrated the lowest incidence of PH (6.9%) and second highest survival (61.8%) at 20 years. Anti-RNA polymerase antibody-positive SSc patients (n = 147) had the highest incidence of SRC (28.1%) at 20 years. The anti-U3 RNP+ SSc group (n = 56) had the highest incidence of PH (33.8%) and cardiac SSc (13.2%) at 20 years. Among lcSSc patients with other autoantibodies (n = 295), the risk of SRC and cardiac SSc was low at 20 years (2.7% and 2.4%, respectively), while the frequencies of other outcomes were similar to the mean values in the full SSc cohort. Patients with dcSSc who were positive for other autoantibodies (n = 166) had a poor prognosis, demonstrating the second lowest survival (33.6%) and frequent organ complications. CONCLUSION: These findings highlight the importance of autoantibodies, cutaneous subset, and disease duration when assessing morbidity and mortality in patients with SSc. Our novel classification scheme may improve disease monitoring and benefit future clinical trial designs in SSc.

Pulmonary hypertensive vasculopathy in parenchymal lung diseases and/or hypoxia: Number 1 in the Series "Pathology for the clinician" Edited by Peter Dorfmüller and Alberto Cavazza.

Pulmonary hypertension (PH) with complicating chronic lung diseases and/or hypoxia falls into group 3 of the updated classification of PH. Patients with chronic obstructive lung disease (COPD), diffuse lung disease (such as idiopathic pulmonary fibrosis (IPF)) and with sleep disordered breathing are particularly exposed to the risk of developing PH. Although PH in such a context is usually mild, a minority of patients exhibit severe haemodynamic impairment, defined by a mean pulmonary arterial pressure (mPAP) of ≥35 mmHg or mPAP values ranging between 25 mmHg and 35 mmHg with a low cardiac index (<2 L·min-1·m-2). The overlap between lung parenchymal disease and PH heavily affects life expectancy in such a patient population and complicates their therapeutic management. In this review we illustrate the pathological features and the underlying pathophysiological mechanisms of pulmonary circulation in chronic lung diseases, with an emphasis on COPD, IPF and obstructive sleep apnoea syndrome.

Validation of the Japanese disease severity classification and the GAP model in Japanese patients with idiopathic pulmonary fibrosis.

BACKGROUND: The clinical course of idiopathic pulmonary fibrosis (IPF) shows great inter-individual differences. It is important to standardize the severity classification to accurately evaluate each patient׳s prognosis. In Japan, an original severity classification (the Japanese disease severity classification, JSC) is used. In the United States, the new multidimensional index and staging system (the GAP model) has been proposed. The objective of this study was to evaluate the model performance for the prediction of mortality risk of the JSC and GAP models using a large cohort of Japanese patients with IPF. METHODS: This is a retrospective cohort study including 326 patients with IPF in the Hokkaido prefecture from 2003 to 2007. We obtained the survival curves of each stage of the GAP and JSC models to perform a comparison. In the GAP model, the prognostic value for mortality risk of Japanese patients was also evaluated. RESULTS: In the JSC, patient prognoses were roughly divided into two groups, mild cases (Stages I and II) and severe cases (Stages III and IV). In the GAP model, there was no significant difference in survival between Stages II and III, and the mortality rates in the patients classified into the GAP Stages I and II were underestimated. CONCLUSIONS: It is difficult to predict accurate prognosis of IPF using the JSC and the GAP models. A re-examination of the variables from the two models is required, as well as an evaluation of the prognostic value to revise the severity classification for Japanese patients with IPF.

Update on Pulmonary Fibrosis: Not All Fibrosis Is Created Equally.

CONTEXT: Three distinct patterns of pulmonary fibrosis, including usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis, can be identified on surgical lung biopsies. OBJECTIVES: To compare the pathologic definitions, clinical and radiographic presentations, etiologies and differential diagnoses, treatments, and prognoses of usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis patterns, and to address the challenges and controversies related to pulmonary fibrosis. DATA SOURCES: Data were derived from published literature and clinical experience. CONCLUSIONS: Although there may be overlap, identification of the dominant form of fibrosis in a particular case can provide a general category of disease and assist in identifying an etiology.

Pulmonary fibrosis in dyskeratosis congenita: report of 2 cases.

Dyskeratosis congenita (DC) is a disorder of poor telomere maintenance and is related to 1 or more mutations that involve the vertebrate telomerase RNA component. Most affected patients develop mucocutaneous manifestations and cytopenias in the peripheral blood between 5 and 15 years of age. DC patients may also develop pulmonary complications including fibrotic interstitial lung disease and pulmonary vascular abnormalities. The radiologic and pathologic features of pulmonary fibrosis associated with DC are poorly defined. Herein, we report 2 new DC cases and suggest that the radiologic and histopathologic findings may resemble usual interstitial pneumonia but may not neatly fit into the current classification of interstitial lung disease.

Fatal outcome in a case of dermatomyositis and Hamman-Rich syndrome.

We present the fatal outcome in a 31-year-old woman of Latin-American origin diagnosed with dermatomyositis. There were three months between death and the onset of symptoms. The initial presentation was normal dermatological symptoms to which were shortly added clinical signs of effects on the lungs, as was shown radiologically and through pulmonary function tests which were subsequently identified histologically as Hamman-Rich syndrome. The patient was treated with high doses of corticosteroids, intravenous (IV) immunoglobulin, cyclophosphamide and cyclosporin. We carried out a review of the literature on pulmonary compromise in dermatomyositis, clinical and anatomopathological forms and treatment alternatives.

Significance of connective tissue diseases features in pulmonary fibrosis.

Interstitial lung disease (ILD) can occur in any of the connective tissue diseases (CTD) with varying frequency and severity, and an overall long-term prognosis that is less severe than that of idiopathic pulmonary fibrosis (IPF). Because ILD may be the presenting manifestation of CTD and/or the dominant manifestation of CTD, clinical extra-thoracic manifestations should be systematically considered in the diagnostic approach of ILD. When present, autoantibodies strongly contribute to the recognition and classification of the CTD. Patients with clinical extrathoracic manifestations of CTD and/or autoantibodies (especially with a high titer and/or the antibody is considered "highly specific" of an autoimmune condition), but who do not fit with established international CTD criteria may be called undifferentiated CTD or "lung-dominant CTD". Although it remains to be determined which combination of symptoms and serologic tests best identify the subset of patients with clinically relevant CTD features, available evidence suggests that such patients may have distinct clinical and imaging presentation and may portend a distinct clinical course. However, autoantibodies alone when present in IPF patients do not seem to impact prognosis or management. Referral to a rheumatologist and multidisciplinary discussion may contribute to management of patients with undifferentiated CTD.

Idiopathic pleuroparenchymal fibroelastosis: consideration of a clinicopathological entity in a series of Japanese patients.

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a recently reported group of disorders characterized by fibrotic thickening of the pleural and subpleural parenchyma predominantly in the upper lobes. We report five Japanese cases fulfilling the criteria of IPPFE and address whether it should be considered a separate clinicopathologic entity. And this study was an attempt to identify features in common between IPPFE and previously described idiopathic upper lobe fibrosis (IPUF), allowing IPPFE to be considered as a distinct entity in our Japanese series. METHODS: Five consecutive cases of idiopathic interstitial lung disease confirmed as IPPFE by surgical lung biopsy were studied. RESULTS: There were four males and one female, aged 70±2.76 yr. No associated disorder or presumed cause was found in any case. Lung function tests found a restrictive ventilatory defect (4/5) and/or impairment of DLco (4/5). Chest X-ray showed marked apical pleural thickening in all cases. Computed tomography of the chest in all cases mainly showed intense pleural thickening and volume loss associated with evidence of fibrosis, predominantly in the upper lobes. In all cases in this study, markedly thickened visceral pleura and prominent subpleural fibrosis characterized by both elastic tissue and dense collagen were clearly shown. All cases were alive at the last follow-up, 17.6±13.59 months after diagnosis; however, all had deteriorated both clinically and radiologically. CONCLUSIONS: IPPFE deserves to be defined as a separate, original clinicopathologic entity owing to its uniformity and IPPFE has some features in common with previously described idiopathic upper lobe fibrosis (IPUF). Our limited experience with a cohort of 5 subjects suggests that IPPFE can be rapidly progressive.

Epithelial-mesenchymal transition in chronic hypersensitivity pneumonitis.

Chronic hypersensitivity pneumonitis (HP) causes progressive and irreversible pulmonary fibrosis, a disease also observed in conjunction with idiopathic pulmonary fibrosis (IPF). Previous studies have demonstrated that the myofibroblast, a cell type whose origins involve the epithelial-mesenchymal transition (EMT), may play a role in the pathogenesis of IPF. The goal of this study was to determine whether EMT has a role in the pathogenesis of chronic HP. Lung specimens from a chronic HP model and from patients with chronic HP were analyzed. Cellular co-localization of epithelial and mesenchymal markers on the same alveolar epithelial cells (AECs) were examined using immunohistochemistry and cadherin switching by western blotting as indicators of EMT. EMT cells in the AECs were significantly more prevalent in lung specimens from Th2-prone A/J mice than in specimens from Th1-prone C57BL/6 mice. The percentage of EMT cells was correlated with the mRNA expressions of IL-13 and TGF-ß1, the fibrosis score, and the collagen content in the A/J mice. In human, EMT cells in the AECs were significantly more prevalent in lungs specimens from patients with usual interstitial pneumonia pattern than in specimens from patients with nonspecific interstitial pneumonia pattern at the moderate stage of fibrosis. In conclusion, EMT may play an important role in the fibrotic process of chronic HP under the Th2-biased environment.

A computer-aided diagnosis system for quantitative scoring of extent of lung fibrosis in scleroderma patients.

OBJECTIVES: To evaluate an improved quantitative lung fibrosis score based on a computer-aided diagnosis (CAD) system that classifies CT pixels with the visual semi-quantitative pulmonary fibrosis score in patients with scleroderma-related interstitial lung disease (SSc-ILD). METHODS: High-resolution, thin-section CT images were obtained and analysed on 129 subjects with SSc-ILD (36 men, 93 women; mean age 48.8±12.1 years) who underwent baseline CT in the prone position at full inspiration. The CAD system segmented each lung of each patient into 3 zones. A quantitative lung fibrosis (QLF) score was established via 5 steps: 1) images were denoised; 2) images were grid sampled; 3) the characteristics of grid intensities were converted into texture features; 4) texture features classified pixels as fibrotic or non-fibrotic, with fibrosis defined by a reticular pattern with architectural distortion; and 5) fibrotic pixels were reported as percentages. Quantitative scores were obtained from 709 zones with complete data and then compared with ordinal scores from two independent expert radiologists. ROC curve analyses were used to measure performance. RESULTS: When the two radiologists agreed that fibrosis affected more than 1% or 25% of a zone or zones, the areas under the ROC curves for QLF score were 0.86 and 0.96, respectively. CONCLUSIONS: Our technique exhibited good accuracy for detecting fibrosis at a threshold of both 1% (i.e. presence or absence of pulmonary fibrosis) and a clinically meaningful threshold of 25% extent of fibrosis in patients with SSc-ILD.

[Idiopathic interstitial pneumonia: classification and diagnostic work-up]. / Les pneumopathies interstitielles diffuses idiopathiques: classification et démarche diagnostique.

Idiopathic interstitial pneumonias represent a group of complex lung diseases among which the most frequent types are idiopathic pulmonary fibrosis (IPF), idiopathic non-specific interstitial pneumonia (idiopathic NSIP), and cryptogenic organizing pneumonia (COP). Clinicians may rely on a precise classification of these diseases from an America-European consensus that has been published in 2002. However it appears that diagnosis should always be confirmed by a multidisciplinary team discussion with experience in the field. There are generally tremendous prognostic and therapeutic implications for the patient.

Antioxidants as potential therapeutics for lung fibrosis.

Interstitial lung disease encompasses a large group of chronic lung disorders associated with excessive tissue remodeling, scarring, and fibrosis. The evidence of a redox imbalance in lung fibrosis is substantial, and the rationale for testing antioxidants as potential new therapeutics for lung fibrosis is appealing. Current animal models of lung fibrosis have clear involvement of ROS in their pathogenesis. New classes of antioxidant agents divided into catalytic antioxidant mimetics and antioxidant scavengers are being developed. The catalytic antioxidant class is based on endogenous antioxidant enzymes and includes the manganese-containing macrocyclics, porphyrins, salens, and the non-metal-containing nitroxides. The antioxidant scavenging class is based on endogenous antioxidant molecules and includes the vitamin E analogues, thiols, lazaroids, and polyphenolic agents. Numerous studies have shown oxidative stress to be associated with many interstitial lung diseases and that these agents are effective in attenuating fibroproliferative responses in the lung of animals and humans.

Idiopathic pulmonary fibrosis: multiple causes and multiple mechanisms?

Idiopathic pulmonary fibrosis (IPF) is a devastating condition that carries a prognosis worse than that of many cancers. A recent classification of the idiopathic interstitial pneumonias has redefined the diagnostic criteria necessary to determine a diagnosis of IPF. The present authors believe that this redefinition is incorrect, relying as it does on subtle histological differences for the definition of separate disease categories. A further issue affecting IPF research is the polarisation of views around two competing pathogenetic hypotheses. One argues for the primacy of inflammation as the trigger that initiates fibrosis, and the other proposes that fibrosis arises as a consequence of chronic epithelial injury and failure of repair due to aberrant epithelial-mesenchymal interactions. The present authors believe that this schism is hampering understanding of IPF and skewing research priorities. It is argued here, instead, that abnormalities in multiple pathways involved in wound healing and inflammation lead to the development of idiopathic pulmonary fibrosis, and it is suggested that a new rationale for clinical classification and pathogenesis may be more productive in driving the search for novel therapies in the future.