Spectrum of fibrosing diffuse parenchymal lung disease

Interstitial pneumonia with autoimmune features

Interstitial lung disease (ILD) is an umbrella term for lung disease characterised by inflammation and fibrosis of the interstitium. ILD can be idiopathic or secondary to connective tissue disorders, drugs or environmental exposures. Before labelling it as idiopathic we have to rule out secondary causes. ILD is one of the most common extra-articular manifestations of connective tissue diseases (CTDs), causing significant morbidity and mortality. Patients with pre-existing CTD can develop ILD; some patients develop ILD against the background of either one or two clinical features of a CTD or isolated auto-antibody positivity. The current terminology for such an entity is interstitial pneumonia with autoimmune features (IPAF). The current criterion is based on three domains: clinical, serologic and morphologic. To satisfy the IPAF classification criteria, one needs to satisfy the mandatory criterion with one feature from two of the three domains. Classifying patients with this criterion helps in early initiation of immunosuppression and in monitoring them closely for development of features of a well defined CTD. There are a few limitations like the clinical domain being more skewed towards systemic sclerosis and in˜flammatory myositis, exclusion of antineutrophilic cytoplasmic antibody (ANCA) and cytoplasmic pattern in antinuclear antibody (ANA). There are no clear protocols for treatment of IPAF and most of the data has been extrapolated from the management of systemic sclerosis (SSc) ILD and idiopathic non-specific c interstitial pneumonia (NSIP). Progressive disease in spite of treatment demands stronger immunosuppressive agents. Studies on the role of antifibrotics in IPAF are underway, with few small studies showing positive outcomes. There are con˜flicting reports on the survival and outcome of the IPAF cohort. Certain studies suggest that they have better survival compared with idiopathic pulmonary fibrosis (IPF) though other studies contradict this statement.

High-Resolution Computed Tomography in the Diagnosis of Diffuse Parenchymal Lung Diseases: Is it Possible to Improve Radiologist's Performance?

OBJECTIVE

The aims of this study were to assess the concordance between high-resolution computed tomography (HRCT) diagnostic hypotheses (DH) and final diagnosis in patients with diffuse lung disease and to evaluate whether clinical data or the radiologist's degree of certainty influence concordance.

METHODS

Concordances between first and any one of radiologists' DH and final diagnosis were assessed before and after access to clinical data, with study of importance of degree of certainty in the DH formulated.

RESULTS

Concordances of HRCT DH and final diagnosis were 48% and 76%, respectively, considering first or any of the DH without access to clinical data. Accessing clinical data improved concordance especially for hypersensitivity pneumonitis. Diagnostic hypotheses formulated with high degree of confidence were correct in 69% of cases.

CONCLUSIONS

First HRCT DH was concordant with final diagnosis in approximately half of cases, increasing to approximately 75% when considering any 1 of the 3 DH. Radiologists' knowledge of clinical data or increased degree of certainty improved concordance of HRCT DH and the final diagnosis.

Interstitial Lung Disease in Childhood: Clinical and Genetic Aspects

Interstitial lung disease (ILD) in childhood is a heterogeneous group of rare pulmonary conditions presenting chronic respiratory disorders. Many clinical features of ILD still remain unclear, making the treatment strategies mainly investigative. Guidelines may provide physicians with an overview on the diagnosis and therapeutic directions. However, the criteria used in different clinical studies for the classification and diagnosis of ILDs are not always the same, making the development of guidelines difficult. Advances in genetic testing have thrown light on some etiologies of ILD, which were formerly classified as ILDs of unknown origins. The need of genetic testing for unexplained ILD is growing, and new classification criteria based on the etiology should be adopted to better understand the disease. The purpose of this review is to give an overview of the clinical and genetic aspects of ILD in children.

Changes in fatigability following intense aerobic exercise training in patients with interstitial lung disease

OBJECTIVE

To determine if, in patients with interstitial lung disease (ILD), fatigue might be lessened after vigorous aerobic exercise.

METHODS

13 physically inactive patients (5 men and 8 women; age 57.2 ± 9.1 years, BMI 28.2 ± 4.6 kgm(-2)) with ILD of heterogeneous etiology and able to walk on a motor driven treadmill without physical limitation were enrolled. Subjects underwent cardiopulmonary exercise (CPET) and 6-min walk (6MWT) tests and completed Fatigue Severity Scale and Human Activity Profile questionnaires before and after an aerobic exercise-training regimen. The training regimen required participation in at least 24 of 30 prescribed aerobic exercise training sessions at a target heart rate of 70-80% of the heart rate reserve, 30 min per session, 3 times per week for 10 weeks.

RESULTS

After training, a 55% (p < 0.001) increase in time to anaerobic threshold on the CPET, and an 11% (p = 0.045) reduction in performance fatigability index (PFI), calculated from the performance on the 6MWT were observed. Distance walked on the 6MWT (6MWD) increased by 49.7 ± 46.9 m (p = 0.002). Significant improvements in scores on the Fatigue Severity Scale (p = 0.046) and Human Activity Profile (AAS p = 0.024; MAS p = 0.029) were also observed. No adverse events related to the training regimen were noted.

CONCLUSION

After training, the decrease in fatigability appeared to result in increased 6MWD and was associated with physical activity. Since significant declines in 6MWD may be a marker for impending mortality in ILD, a better understanding of the etiological state of fatigue in patients with ILD and its reversal might provide fundamental insight into disease progression and even survival. [ClinicalTrials.gov identifier NCT00678821].

ABCA3 protects alveolar epithelial cells against free cholesterol induced cell death

Diffuse parenchymal lung diseases (DPLDs) are characterized by chronic inflammation and fibrotic remodeling of the interstitial tissue. A small fraction of DPLD cases can be genetically defined by mutations in certain genes, with ABCA3 being the gene most commonly affected. However, the pathomechanisms underlying ABCA3-induced DPLD are far from clear. To investigate whether ABCA3 plays a role in cellular cholesterol homeostasis, phospholipids, free cholesterol, and cholesteryl esters were quantified in cells stably expressing ABCA3 using mass spectrometry. Cellular free cholesterol and lipid droplets were visualized by filipin or oil red staining, respectively. Expression of SREBP regulated genes was measured using qPCR. Cell viability was assessed using the XTT assay. We found that wild type ABCA3 reduces cellular free cholesterol levels, induces the SREBP pathway, and renders cells more resistant to loading with exogenous cholesterol. Moreover, ABCA3 mutations found in patients with DPLD interfere with this protective effect of ABCA3, resulting in free cholesterol induced cell death. We conclude that ABCA3 plays a previously unrecognized role in the regulation of cellular cholesterol levels. Accumulation of free cholesterol as a result of a loss of ABCA3 export function represents a novel pathomechanism in ABCA3-induced DPLD.

Emphysema mimicking interstitial lung disease: Two case reports

Honeycombing in general is a sign of severe end-stage fibrosis. Here we present two cases, where the combination of emphysema, acute inflammation and pulmonary embolism gave an appearance of honeycombing seen in pulmonary fibrosis. HRCT interpretation in the evaluation of acutely ill patients with pulmonary infection is a challenge. Our case reports emphasize the importance of a multidisciplinary approach, when it comes to patients with suspected complicated pulmonary diseases. At the same time they give very realistic examples of the challenges found in diagnosing patients with simultaneous acute and chronic pulmonary diseases.

Predictors of mortality in patients with interstitial lung disease treated with corticosteroids: results from a cohort study

Interstitial lung disease (ILD) has a heterogeneous clinical presentation and establishing prognosis for these patients is challenging. We investigated the clinical characteristics and outcome of patients with idiopathic interstitial pneumonias (IIPs) and patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). We conducted a multicenter prospective study on 104 patients diagnosed with IIPs and 29 patients diagnosed with CTD-ILD, which were newly diagnosed and treated with corticosteroids initially. We compared the clinical characteristics, high-resolution computed tomography (HRCT) imaging date, and outcomes. Cox proportional hazard regression analysis was used to identify variables with increased risk of death. Survival was analyzed according to the Kaplan-Meier method and was assessed with the log-rank test. Of 133 patients with IIPs (n = 104) or CTD-ILD (n = 29), 44 patients died during the follow-up period (mean: 1.6 ± 0.78 years). Patients with IIPs seemed to be associated with worse survival compared with those with CTD-ILD; however, this difference was not significant (log-rank test, P = 0.084). Significant predictors for mortality in patients with IIPs at baseline were lower for performance status and definite usual interstitial pattern (UIP) on HRCT. Patients with UIP experienced worse survival than those with non-UIP. A definite UIP on HRCT and lower baseline performance status have important prognostic implications in patients with IIPs.

A case of pulmonary fibrosis associated with rheumatoid arthritis, scleroderma sine scleroderma and ANCA associated vasculitis

Introduction

Diffuse parenchymal lung disease (DPLD) may be idiopathic or may be due to known associations such as autoimmune diseases. The prognosis in cases associated with autoimmune diseases depends on many factors such as histopathology, baseline lung function, auto-antibody level, et cetera. DPLD and its prognosis is worse in patients with overlap syndromes.

Case description

We present a rare case of a 71 year old Caucasian lady with gradually worsening pulmonary fibrosis secondary to an overlap syndrome with rheumatoid arthritis (RA), scleroderma sine scleroderma (SSS) and anti neutrophil cytoplasmic antibody (ANCA) associated vasculitis.

Discussion and Evaluation

In this paper, we share information from review of literature regarding DPLD associated with RA, systemic sclerosis (SSc) and ANCA associated vasculitis. Details of our discussion include prognostic factors, histology and radiographic features of these individual disease entities.

Conclusion

Since pulmonary fibrosis in overlap syndromes has a poor prognosis, extensive work up should be performed even when clinical evidence of only one autoimmune disease is present.

Lung involvement in connective tissue diseases: a comprehensive review and a focus on rheumatoid arthritis

The lungs are frequently involved in Connective Tissue Diseases (CTDs). Interstitial lung disease (ILD) is one of the most common pleuropulmonary manifestations that affects prognosis significantly. In practice, rheumatologists and other physicians tend to underestimate the impact of CTD-ILDs and diagnose respiratory impairment when it has reached an irreversible fibrotic stage. Early investigation, through clinical evidence, imaging and - in certain cases - lung biopsy, is therefore warranted in order to detect a possible ILD at a reversible initial inflammatory stage. In this review, we focus on lung injury during CTDs, with particular attention to ILDs, and examine their prevalence, clinical manifestations and histological patterns, as well as therapeutic approaches and known complications till date. Although several therapeutic agents have been approved, the best treatment is still not certain and additional trials are required, which demand more knowledge of pulmonary involvement in CTDs. Our central aim is therefore to document the impact that lung damage has on CTDs. We will mainly focus on Rheumatoid Arthritis (RA), which - unlike other rheumatic disorders - resembles Idiopathic Pulmonary Fibrosis (IPF) in numerous aspects.

Antisynthetase antibody syndrome: case report and review of the literature

Antisynthetase antibody syndrome is a rare autoimmune disease that may present with variable systemic manifestations, mainly polymyositis, interstitial lung disease, skin lesions, and Raynaud's phenomenon. This diagnosis should always come to mind in patients that present with signs of myositis, dermatomyositis, or polymyositis associated with interstitial lung disease. On the following paper, we report the case of a 52-year-old man who presented with a 2-month history of asymmetric polyarthralgia, myalgia, weight loss of 8 kg, and progressive muscle weakness associated with dyspnea, orthopnea, and dysphonia. Further tests revealed myositis, interstitial pneumonia, and elevation of anti-Jo-1 antibodies. A diagnosis of antisynthetase antibody syndrome was made and the patient showed good response to treatment with corticoids and methotrexate. Finally, we present a short review of the literature.

Surgical lung biopsy for diffuse lung disease. Our experience in the last 15 years

INTRODUCTION

Surgical lung biopsy is a technique that presents a morbi-mortality rate of considerable importance. We analyze our experience with surgical lung biopsies for the diagnosis of diffuse lung disease and the effect produced on the indications for surgical biopsy in these pathologies after the publication of the consensus of the ATS (American Thoracic Society) and ERS (European Respiratory Society) for Idiopathic Pulmonary Fibrosis (IPF).

PATIENTS AND METHODS

We performed a retrospective review of 171 patients operated between January 1997 and December 2011. We divided the series into 2 groups: group 1 (operated between 1997 and 2002) and group 2 (operated between 2003 and 2011). Suspected preoperative diagnosis, respiratory status, pathological postoperative diagnoses, percentage of thoracotomies, mean postoperative stay and perioperative morbidity and mortality were analyzed.

RESULTS

Group 1 consisted of 99 patients and group two 72. The most frequent postoperative diagnoses were: usual interstitial pneumonia and extrinsic allergic alveolitis. There were ten (5.84%) deaths. Death was caused by progressive respiratory failure that was related to interstitial lung disease in 7 (70%) of 10 cases, alveolar haemorrhage in 2 (20%) and heart failure in 1 (10%).

CONCLUSIONS

Since the publication of the ATS and ERS consensus on the IPF, we have observed a noticeable decrease in the number of indications for surgical lung biopsy. This technique, though simple, has a considerable morbidity and mortality.

Association between anti-TNF-α therapy and interstitial lung disease

BACKGROUND

Anti-tumor necrosis factor-α (TNF-α) agents have been hypothesized to increase the risk of interstitial lung disease (ILD), including its most severe manifestation, pulmonary fibrosis.

METHODS

We conducted a cohort study among autoimmune disease patients who were members of Kaiser Permanente Northern California, 1998-2007. We obtained therapies from pharmacy data and diagnoses of ILD from review of X-ray and computed tomography reports. We compared new users of anti-TNF-α agents to new users of non-biologic therapies using Cox proportional hazards analysis to adjust for baseline propensity scores and time-varying use of glucocorticoids. We also made head-to-head comparisons between anti-TNF-α agents.

RESULTS

Among the 8417 persons included in the analysis, 38 (0.4%) received a diagnostic code for ILD by the end of follow-up, including 23 of 4200 (0.5%) who used anti-TNF-α during study follow-up, and 15 of 5423 (0.3%) who used only non-biologic therapies. The age-standardized and gender-standardized incidence rate of ILD, per 100 person-years, was 0.21 [95% confidence interval (CI) 0-0.43] for rheumatoid arthritis and appreciably lower for other autoimmune diseases. Compared with the use of non-biologic therapies, use of anti-TNF-α therapy was not associated with a diagnosis of ILD among patients with rheumatoid arthritis (adjusted hazard ratio, 1.03; 95%CI 0.51-2.07), nor did head-to-head comparisons across anti-TNF-α agents suggest important differences in risk, although the number of cases available for analysis was limited.

CONCLUSION

The study provides evidence that compared with non-biologic therapies, anti-TNF-α therapy does not increase the occurrence of ILD among patients with autoimmune diseases and informs research design of future safety studies of ILD.

Antisynthetase syndrome

Autoantibodies to eight of the aminoacyl-transfer RNA synthetases-the most well-recognized of which is anti-histidyl (Jo-1)-have all been implicated in the pathogenesis of antisynthetase syndrome (AS). AS is characterized by varying degrees of interstitial lung disease, myositis, arthropathy, fever, Raynaud's phenomenon, and mechanic's hands, and the morbidity and mortality of the disease are usually linked to the pulmonary findings. The value of a lung biopsy in AS cannot be overemphasized, as it serves to describe the underlying etiology of the interstitial lung disease, guide therapy, and estimate prognosis. Muscle disease shares many clinical features of polymyositis, yet histologically, the inflammatory involvement resembles that of dermatomyositis. Because inflammatory arthritis mimics rheumatoid arthritis, AS should be considered in atypical cases. Corticosteroids are the mainstay of acute therapy, although treatment often requires immunosuppressant medications such as cyclophosphamide, azathioprine, mycophenolate mofetil, cyclosporine, tacrolimus, or rituximab.

A rare case of cor pulmonale secondary to idiopathic pulmonary fibrosis in Nigeria

Idiopathic pulmonary fibrosis (IPF) is a rarely reported disease in Nigeria. Cor pulmonale, one of the complications of this type of diffuse parenchymal lung disease is even rarer. The authors present a Nigerian patient with IPF with a classical high-resolution CT features, managed in our centre together with associated problems.

Interstitial lung diseases in children

Interstitial lung disease (ILD) in infants and children comprises a large spectrum of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. These disorders are characterized by inflammatory and fibrotic changes that affect alveolar walls. Typical features of ILD include dyspnea, diffuse infiltrates on chest radiographs, and abnormal pulmonary function tests with restrictive ventilatory defect and/or impaired gas exchange. Many pathological situations can impair gas exchange and, therefore, may contribute to progressive lung damage and ILD. Consequently, diagnosis approach needs to be structured with a clinical evaluation requiring a careful history paying attention to exposures and systemic diseases. Several classifications for ILD have been proposed but none is entirely satisfactory especially in children. The present article reviews current concepts of pathophysiological mechanisms, etiology and diagnostic approaches, as well as therapeutic strategies. The following diagnostic grouping is used to discuss the various causes of pediatric ILD: 1) exposure-related ILD; 2) systemic disease-associated ILD; 3) alveolar structure disorder-associated ILD; and 4) ILD specific to infancy. Therapeutic options include mainly anti-inflammatory, immunosuppressive, and/or anti-fibrotic drugs. The outcome is highly variable with a mortality rate around 15%. An overall favorable response to corticosteroid therapy is observed in around 50% of cases, often associated with sequelae such as limited exercise tolerance or the need for long-term oxygen therapy.