Clinical course and lung function change of idiopathic nonspecific interstitial pneumonia

U-net convolutional neural network applied to progressive fibrotic interstitial lung disease: Is progression at CT scan associated with a clinical outcome?

BACKGROUND

Computational advances in artificial intelligence have led to the recent emergence of U-Net convolutional neural networks (CNNs) applied to medical imaging. Our objectives were to assess the progression of fibrotic interstitial lung disease (ILD) using routine CT scans processed by a U-Net CNN developed by our research team, and to identify a progression threshold indicative of poor prognosis.

METHODS

CT scans and clinical history of 32 patients with idiopathic fibrotic ILDs were retrospectively reviewed. Successive CT scans were processed by the U-Net CNN and ILD quantification was obtained. Correlation between ILD and FVC changes was assessed. ROC curve was used to define a threshold of ILD progression rate (PR) to predict poor prognostic (mortality or lung transplantation). The PR threshold was used to compare the cohort survival with Kaplan Mayer curves and log-rank test.

RESULTS

The follow-up was 3.8 ± 1.5 years encompassing 105 CT scans, with 3.3 ± 1.1 CT scans per patient. A significant correlation between ILD and FVC changes was obtained (p = 0.004, ρ = -0.30 [95% CI: -0.16 to -0.45]). Sixteen patients (50%) experienced unfavorable outcome including 13 deaths and 3 lung transplantations. ROC curve analysis showed an aera under curve of 0.83 (p < 0.001), with an optimal cut-off PR value of 4%/year. Patients exhibiting a PR ≥ 4%/year during the first two years had a poorer prognosis (p = 0.001).

CONCLUSIONS

Applying a U-Net CNN to routine CT scan allowed identifying patients with a rapid progression and unfavorable outcome.

Relationship between idiopathic interstitial pneumonias (IIPs) and connective tissue disease-related interstitial lung disease (CTD-ILD): A narrative review

While idiopathic interstitial pneumonia (IIP) centering on idiopathic pulmonary fibrosis (IPF) is the most prevalent interstitial lung disease (ILD), especially in the older adult population, connective tissue disease (CTD)-related ILD is the second most prevalent ILD. The pathogenesis of IPF is primarily fibrosis, whereas that of other ILDs, particularly CTD-ILD, is mainly inflammation. Therefore, a precise diagnosis is crucial for selecting appropriate treatments, such as antifibrotic or immunosuppressive agents. In addition, some patients with IIP have CTD-related features, such as arthritis and skin eruption, but do not meet the criteria for any CTD, this is referred to as interstitial pneumonia with autoimmune features (IPAF). IPAF is closely associated with idiopathic nonspecific interstitial pneumonia (iNSIP) and cryptogenic organizing pneumonia (COP). Furthermore, patients with iNSIP or those with NSIP with OP overlap frequently develop polymyositis/dermatomyositis after the diagnosis of IIP. Acute exacerbation of ILD, the most common cause of death, occurs more frequently in patients with IPF than in those with other ILDs. Although acute exacerbation of CTD-ILD occurs at a low rate of incidence, patients with rheumatoid arthritis, microscopic polyangiitis, or systemic sclerosis experience more acute exacerbation of CTD-ILD than those with other CTD. In this review, the features of each IIP, focusing on CTD-related signatures, are summarized, and the pathogenesis and appropriate treatments to improve the prognoses of patients with various ILDs are discussed.

Walking the path of treatable traits in interstitial lung diseases

Interstitial lung diseases (ILDs) are complex and heterogeneous diseases. The use of traditional diagnostic classification in ILD can lead to suboptimal management, which is worsened by not considering the molecular pathways, biological complexity, and disease phenotypes. The identification of specific "treatable traits" in ILDs, which are clinically relevant and modifiable disease characteristics, may improve patient's outcomes. Treatable traits in ILDs may be classified into four different domains (pulmonary, aetiological, comorbidities, and lifestyle), which will facilitate identification of related assessment tools, treatment options, and expected benefits. A multidisciplinary care team model is a potential way to implement a "treatable traits" strategy into clinical practice with the aim of improving patients' outcomes. Multidisciplinary models of care, international registries, and the use of artificial intelligence may facilitate the implementation of the "treatable traits" approach into clinical practice. Prospective studies are needed to test potential therapies for a variety of treatable traits to further advance care of patients with ILD.

Prediction of progressive pulmonary fibrosis in patients with anti-synthetase syndrome-associated interstitial lung disease

OBJECTIVE

Interstitial lung disease (ILD) is a common extramuscular manifestation of the anti-synthetase syndrome (ASS). Patients with ASS-ILD are at risk in developing a progressive fibrosing phenotype despite appropriate treatments. This study investigated the risk factors and the predictive value of multiple risk factors for progressive pulmonary fibrosis (PPF) in patients with ASS-ILD.

METHODS

Ninety patients with a diagnosis of ASS and evidence of ILD on high-resolution computed tomography (HRCT) were recruited. Among them, 72 participants completed follow-up for more than 12 months. These patients were further divided into a PPF-ASS group (n = 18) and a non-PPF-ASS group (n = 54). Logistic regression analysis was performed to investigate the risk factors for PPF. The predictive value of the combined risk factors for predicting PPF were analyzed by a ROC curve.

RESULTS

The PPF-ASS group had a higher rate of positive non-Jo-1 antibodies, a significantly higher neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (LDH), and a significantly lower PaO2/FiO2 ratio and diffusing capacity for carbon monoxide (DLCO%pred) than the non-PPF-ASS group. In addition, elevated serum Krebs von den Lungen-6 (KL-6) level and reticular opacities were significantly more common, and corticosteroid monotherapy at onset was administered more frequently in the PPF-ASS group. The median duration of follow-up was 37.4 months, survival was poorer in the PPF-ASS group, and the overall survival was 88.9%. Multivariate regression analysis further revealed that positive non-Jo-1 antibodies, NLR, and KL-6 were independent risk factors for PPF. These combined indexes had good accuracy (area under the curve = 0.874) in predicting PPF in patients with ASS-ILD.

CONCLUSION

Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors for PPF in patients with ASS-ILD. Monitoring these markers can potentially predict PPF in this group of patients. Key Points • Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors associated with PPF in patients with ASS-ILD. • Monitoring non-Jo-1 antibodies, NLR, and serum KL-6 can potentially predict PPF in patients with ASS-ILD.

Primary-Sjögren's-Syndrome-Related Interstitial Lung Disease: A Clinical Review Discussing Current Controversies

Lung involvement, especially interstitial lung disease, is a potentially severe extra-glandular manifestation of Primary Sjogren's Syndrome (pSS-ILD). ILD can manifest either as a late complication of pSS or anticipate sicca symptoms, likely reflecting two different patho-physiological entities. Presence of lung involvement in pSS subjects can remain subclinical for a long time; therefore, patients should be actively screened, and lung ultrasound is currently being investigated as a potential low cost, radiation-free, easily repeatable screening tool for detection of ILD. In contrast, rheumatologic evaluation, serology testing, and minor salivary gland biopsy are crucial for the recognition of pSS in apparently idiopathic ILD patients. Whether the HRCT pattern influences prognosis and treatment response in pSS-ILD is not clear; a UIP pattern associated with a worse prognosis in some studies, but not in others. Many aspects of pSS-ILD, including its actual prevalence, association with specific clinical-serological characteristics, and prognosis, are still debated by the current literature, likely due to poor phenotypic stratification of patients in clinical studies. In the present review, we critically discuss these and other clinically relevant "hot topics" in pSS-ILD. More specifically, after a focused discussion, we compiled a list of questions regarding pSS-ILD that, in our opinion, are not easily answered by the available literature. We subsequently tried to formulate adequate answers on the basis of an extensive literature search and our clinical experience. At the same, we highlighted different issues that require further investigation.

Bacterial Infections Associated with Immunosuppressive Agents Commonly Used in Patients with Interstitial Lung Diseases

There are about 200 different types of interstitial lung disease (ILD), and a crucial initial step in the assessment of a patient with suspected ILD is achieving an appropriate diagnosis. Some ILDs respond to immunosuppressive agents, while immunosuppression can be detrimental in others, hence treatment is based on the most confident diagnosis with consideration of a patient's risk factors. Immunosuppressive medications have the potential to result in substantial, and perhaps life-threatening, bacterial infections to a patient. However, data on the risk of bacterial infections from immunosuppressive treatment specifically in patients with interstitial lung disease is lacking. We hereby review the immunosuppressive treatments used in ILD patients excluding sarcoidosis, highlight their risk of bacterial infections, and discuss the potential mechanisms that contribute to the increased risk of infections.

Correlation of monocyte counts with clinical outcomes in idiopathic nonspecific interstitial pneumonia

Higher blood monocyte counts are related to worse survival in idiopathic pulmonary fibrosis. However, studies evaluating the association between blood monocyte counts and clinical outcomes of idiopathic nonspecific interstitial pneumonia (iNSIP) are lacking. We evaluated the impact of monocyte counts on iNSIP prognosis. iNSIP patients (n = 126; median age, 60 years; female, n = 64 [50.8%]) diagnosed by surgical lung biopsy were enrolled and categorized into low (monocyte < 600/µL) and high (monocyte ≥ 600/µL) monocyte groups. The median follow-up duration was 53.0 months. After adjusting for age, sex, and smoking history, the annual decline in forced vital capacity (FVC) showed differences between the monocyte groups (P_interaction = 0.006) (low vs. high; - 28.49 mL/year vs. - 65.76 mL/year). The high-monocyte group showed a worse survival rate (P = 0.01) compared to low monocyte group. The 5-year survival rates were 83% and 72% in the low- and high-monocyte groups, respectively. In the Cox-proportional hazard analysis, older age, male sex, low baseline FVC, and diffusing capacity of the lung for carbon monoxide were independent risk factors for mortality. However, monocyte count (Hazard ratio 1.61, P = 0.126) was not an independent prognostic factor. Although high monocyte count might be associated with faster lung function decline, it could not independently predict survival in iNSIP.

Lung Damage in Rheumatoid Arthritis-A Retrospective Study

The current study aimed to evaluate rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) in clinical practice and whether disease characteristics are associated with X-ray and high-resolution computed tomography (HR-CT) findings. Medical history of RA patients from a tertiary rheumatology clinic was retrieved from its electronic database starting from 1 January 2019 until the study date (8 August 2022) using International Classification of Disease version 10 codes for RA, ILD and exclusion criteria. The study included 78 RA patients (75.6% women, 15.4% active smokers), with average time from RA to ILD of 5.6 years. Regarding chest X-ray findings, men had a higher prevalence of nodules, combined fibrosis and nodules and combined bronchiectasis and nodules, rheumatoid factor (RF)-positive patients had a higher prevalence of fibrosis and anti-cyclic citrullinated peptide antibodies (ACPA)-positive patients had a higher prevalence of bronchiectasis. Regarding HR-CT findings, patients actively treated with methotrexate had a higher prevalence of nodules; a combination of fibrosis and nodules; combination of emphysema and nodules; and combination of fibrosis, emphysema and nodules. ILD develops within approximately 5 years from RA diagnosis, and ILD-associated imaging findings on chest X-rays and HR-CT are more prevalent among men with RA, among patients with positive RA serology (RF and/or ACPA) and RA patients on methotrexate.

Cell-Specific Response of NSIP- and IPF-Derived Fibroblasts to the Modification of the Elasticity, Biological Properties, and 3D Architecture of the Substrate

The fibrotic fibroblasts derived from idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP) are surrounded by specific environments, characterized by increased stiffness, aberrant extracellular matrix (ECM) composition, and altered lung architecture. The presented research was aimed at investigating the effect of biological, physical, and topographical modification of the substrate on the properties of IPF- and NSIP-derived fibroblasts, and searching for the parameters enabling their identification. Soft and stiff polydimethylsiloxane (PDMS) was chosen for the basic substrates, the properties of which were subsequently tuned. To obtain the biological modification of the substrates, they were covered with ECM proteins, laminin, fibronectin, and collagen. The substrates that mimicked the 3D structure of the lungs were prepared using two approaches, resulting in porous structures that resemble natural lung architecture and honeycomb patterns, typical of IPF tissue. The growth of cells on soft and stiff PDMS covered with proteins, traced using fluorescence microscopy, confirmed an altered behavior of healthy and IPF- and NSIP-derived fibroblasts in response to the modified substrate properties, enabling their identification. In turn, differences in the mechanical properties of healthy and fibrotic fibroblasts, determined using atomic force microscopy working in force spectroscopy mode, as well as their growth on 3D-patterned substrates were not sufficient to discriminate between cell lines.

Severe Nonspecific Interstitial Pneumonia (NSIP) in an Adolescent

Childhood interstitial lung disease (chILD) is remarkably rare with a reported prevalence from 0.13 per 100,000 children under 17 years to 16.2 per 100,000 children under 15 years of age (Kornum et al., 2008). Here, we present a case of a 15-year-old with subacute hypoxemic respiratory failure, admitted to the critical care unit. Her imaging on admission showed bilateral interstitial infiltrates; her laboratory workup, including autoimmune serologies, was unrevealing. A bronchoscopy revealed the diagnosis of nonspecific interstitial pneumonia. She had a partial recovery after a course of steroids.

Glucocorticoid therapy in respiratory illness: bench to bedside

Each year, hundreds of millions of individuals are affected by respiratory disease leading to approximately 4 million deaths. Most respiratory pathologies involve substantially dysregulated immune processes that either fail to resolve the underlying process or actively exacerbate the disease. Therefore, clinicians have long considered immune-modulating corticosteroids (CSs), particularly glucocorticoids (GCs), as a critical tool for management of a wide spectrum of respiratory conditions. However, the complex interplay between effectiveness, risks and side effects can lead to different results, depending on the disease in consideration. In this comprehensive review, we present a summary of the bench and the bedside evidence regarding GC treatment in a spectrum of respiratory illnesses. We first describe here the experimental evidence of GC effects in the distal airways and/or parenchyma, both in vitro and in disease-specific animal studies, then we evaluate the recent clinical evidence regarding GC treatment in over 20 respiratory pathologies. Overall, CS remain a critical tool in the management of respiratory illness, but their benefits are dependent on the underlying pathology and should be weighed against patient-specific risks.

Clinical characteristics and prognostic factors of fibrotic nonspecific interstitial pneumonia

Aim:

Several studies have reported favorable outcomes of nonspecific interstitial pneumonia (NSIP); however, its prognosis and prognostic factors remain unclear. This study aimed to determine the outcomes of fibrotic NSIP and the prognostic factors for progression, relapse, and survival.

Methods:

In this retrospective study, we reviewed the clinical data of 204 patients diagnosed with fibrotic NSIP by surgical lung biopsy at Samsung Medical Center. The factors associated with survival and disease progression or relapse were determined using Cox proportional hazard analysis.

Results:

The median age of patients was 54 years and 67 (33%) patients were male. Also, 47 patients (23%) were current or ex-smokers. In all, 141 (69%) patients were diagnosed with idiopathic NSIP, while 63 (31%) patients were associated with connective tissue diseases. Progression or relapse was observed in 100 (49%) patients. The 5-year and 10-year survival rates were 94.6% and 90.4%, respectively. The factors associated with disease progression and relapse were diffusing capacity for carbon monoxide (DLco) <60% [adjusted hazard ratio (HR), 1.739; 95% confidence interval (CI), 1.036–2.921; p = 0.036], bronchoalveolar lavage (BAL) lymphocyte >15% (adjusted HR, 0.592; 95% CI, 0.352–0.994; p = 0.047), and treatment with corticosteroid and azathioprine (adjusted HR, 0.556; 95% CI, 0.311–0.955; p = 0.048). Disease progression or relapse was associated with mortality (adjusted HR, 7.135; 95% CI, 1.499–33.971; p = 0.014).

Conclusion:

Preserved lung function, BAL lymphocytosis, and treatment with corticosteroids and azathioprine were associated with lower risks of disease progression and relapse, which were risk factors for mortality.

Pulmonary Toxicities of Immunotherapy

Immune checkpoint inhibitors are a form of immunotherapy that are increasingly being used in a wide variety of cancers. Immune-related adverse events (irAEs) pose a major challenge in the treatment of cancer patients. Pneumonitis, the most common lung irAE, can cause significant disruptions in the treatment of cancer and may be life-threatening. The goal of this chapter is to instruct readers on the incidence and clinical manifestations of pneumonitis and to offer guidance in the evaluation and treatment of patients with pneumonitis.

Interstitial pneumonia with autoimmune features: challenges and controversies

The presence of clinical, serological and/or radiological features suggestive, but not confirmatory, of a defined connective tissue disease in patients with interstitial lung disease is a relatively frequent occurrence. In 2015, the European Respiratory Society and the American Thoracic Society proposed classification criteria for the interstitial pneumonia with autoimmune features (IPAF) research entity to capture such patients in a standardised manner, with the intention of nurturing clinical research. This initiative resulted in the publication of several series of IPAF patients, with significant variation between cohorts in clinical characteristics, outcome and the application of IPAF criteria in patient selection. From this increasing body of published work, it has become apparent that revision of IPAF criteria is now required in order to justify the eventual designation of IPAF as a standalone diagnostic term, as opposed to a provisional entity put forward as a basis for clinical research. This review covers the current state of IPAF, conclusions that can and cannot be drawn from the IPAF evidence base, and ongoing uncertainties that require further expert group consideration.

Computed Tomography Findings Suggestive of Connective Tissue Disease in the Setting of Usual Interstitial Pneumonia

PURPOSE

A usual interstitial pneumonia (UIP) pattern is common in idiopathic pulmonary fibrosis (IPF) and connective tissue disease-related interstitial lung disease (CTD-ILD). The purpose of the study was to validate imaging findings differentiating CTD-ILD from IPF in UIP.

METHODS

Patients with a multidisciplinary diagnosis of CTD-ILD or IPF and a UIP pattern on computed tomography and/or pathology were included in this study. Prevalence of 3 computed tomography findings shown to be associated with CTD-ILD (the straight edge sign [SES], the exuberant honeycombing sign, and the anterior upper lobe sign [AULS]) were tabulated in CTD-ILD and IPF subjects. The ability of each of these signs to discriminate between CTD-ILD and IPF was evaluated. Survival analysis was also performed using log-rank analysis.

RESULTS

The study cohort included 50 CTD-ILD and 100 IPF subjects with UIP. The SES and the AULS were more common in CTD-ILD than IPF (prevalence, 36.0% and 34.9% in CTD-ILD vs 8.3% and 17.2% in IPF, respectively [P = 0.0105 - <0.001]). The highest specificity (95.7%) of CTD-ILD diagnosis was seen with bilateral SES. Moreover, the SES was associated with improved survival (P = 0.0383), which appeared to be largely because of improvement in survival in IPF subjects. The presence of AULS was associated with pulmonary functional abnormalities.

CONCLUSIONS

A radiographic UIP pattern with evidence of SES or the AULS should raise suspicion for CTD-ILD rather than IPF. Patients with IPF and SES have an attenuated disease course and might represent a different phenotype than those without the SES.

International multidisciplinary team discussions on the diagnosis of idiopathic non-specific interstitial pneumonia and the development of connective tissue disease

BACKGROUND

Idiopathic Non-Specific Interstitial Pneumonia (iNSIP) is a rare interstitial lung disease, diagnosed, by definition, on the basis of a multidisciplinary team discussion (MDD). Association with an autoimmune background has been suggested in iNSIP.

AIMS

To test the feasibility of conducting a multinational MDD to review the diagnosis in iNSIP cases and to estimate the emergence of connective tissue disease (CTD) during follow-up.

METHODS

Investigators from three expert centers (Denmark, Estonia and Norway) met and discussed cases of biopsy-proven iNSIP at an international MDD. The cases were previously diagnosed at a national level between 2004 and 2014. Based on clinical, radiographic and pathological data, the diagnosis of iNSIP was re-evaluated and a consensus diagnosis was made. Cases incompatible with iNSIP were excluded. Relevant data were registered comprising any development of CTD.

RESULTS

In total, 31 cases were discussed and 23 patients were included with a diagnosis of iNSIP. The mean follow-up time was 57 months. None of the patients developed CTD according to the rheumatologic criteria during the follow up period. Four patients (17.4%) met the criteria for interstitial pneumonia with autoimmune features.

CONCLUSION

We found that an international MDD was a feasible and valuable tool in the retrospective diagnostic evaluation of iNSIP. Diagnosis was changed in a statistically significant number of patients by our international MDD team. None of the patients developed CTD during follow-up.

Consensus-Statement der Österreichischen Gesellschaften für Pneumologie und Rheumatologie zur Definition, Evaluation und Therapie von progredient fibrosierenden interstitiellen Lungenerkrankungen (pfILD)

Interstitielle Lungenerkrankungen (ILD) sind eine heterogene Gruppe von Pathologien, die zunehmend als relevanter Faktor pulmonaler Morbidität und Mortalität erkannt werden. Verschiedene ILD wie die idiopathische Lungenfibrose (IPF), aber auch durch Autoimmunprozesse oder durch exogene Noxen bedingte ILD können zu progredienter, meist irreversibler Lungenfibrose führen. Die antifibrotischen Substanzen Nintedanib und Pirfenidon können den Krankheitsverlauf bei IPF-Patienten günstig beeinflussen. Dagegen werden ILD, die auf entzündlichen Prozessen wie z. B. rheumatologischen Grunderkrankungen oder exogen-allergischer Alveolitis beruhen, bis dato klassischerweise immunsuppressiv therapiert. Immer wieder kommt es aber trotz einer solchen Behandlung zu progredienter Fibrosierung. Eine positive Wirkung antifibrotischer Medikation auf progredient fibrosierende (pf)ILD abseits der IPF konnte in rezenten Studien demonstriert werden, auch wenn der Stellenwert der Antifibrotika in solchen Situationen noch nicht vollständig geklärt ist. Dieses Consensus-Statement beruht auf einem virtuellen, multidisziplinären Expertenmeeting von Rheumatologen, Pneumologen und Radiologen und wurde durch die jeweiligen ILD-Arbeitskreise der Österreichischen Gesellschaften für Pneumologie sowie Rheumatologie (ÖGP und ÖGR) akkordiert. Ziel war es, den aktuellen Stand von klinischer Praxis und wissenschaftlicher Datenlage zu Definition, Evaluation und Therapie von pfILD darzustellen. Zusammenfassend sollen ILD-Patienten einer standardisierten Abklärung unterzogen, in einem multidisziplinären ILD-Board diskutiert und dementsprechend therapiert werden. Kern dieser Empfehlungen ist, auch Non-IPF-Patienten mit dokumentiert progredient fibrosierendem ILD-Verlauf antifibrotisch zu behandeln, insbesondere wenn Honigwabenzysten oder eine bereits ausgedehnte Erkrankung vorliegen. Patienten mit fibrotischer ILD, die auf Basis der ILD-Board-Empfehlung primär keiner oder ausschließlich einer immunsuppressiven Therapie unterzogen werden, sollten engmaschig hinsichtlich eines progredienten Verlaufes überwacht werden.

Computed Tomography Findings as Determinants of Local and Systemic Inflammation Biomarkers in Interstitial Lung Diseases: A Retrospective Registry-Based Descriptive Study

PURPOSE

To evaluate the association of peripheral blood (PBL) and broncho-alveolar lavage (BAL) biomarkers with inflammatory versus fibrotic high-resolution computed tomography (HRCT) findings in interstitial lung disease (ILD) patients.

METHODS

HRCT findings of 127 consecutive ILD-board patients were semi-quantitatively evaluated: reticulation/honeycombing (RET), traction bronchiectasis (TBR) and emphysema (EMP) were classified as non-inflammatory/fibrotic; consolidations (CON), ground glass opacities (GGO), parenchymal nodules (NDL) and mosaic attenuation (MOS) as active inflammatory. Each HRCT finding was assessed in six distinct lung regions, resulting scores were graded as minimal (0-1 regions involved), medium (2-4) or extensive (5-6). Associations of routinely assessed PBL/BAL biomarkers with these HRCT scores were evaluated using Spearman correlation coefficients and graphical presentation; significance was tested by applying Kruskal-Wallis tests.

RESULTS

Blood neutrophil, lymphocyte and eosinophil fraction, neutrophil to lymphocyte ratio (NLR) and BAL lymphocyte fraction consistently showed opposite correlations with inflammatory versus non-inflammatory/fibrotic HRCT finding scores. Blood lymphocyte fraction significantly differed by graded GGO (p = 0.032) and CON (p = 0.027) extent, eosinophil fraction by TBR (p = 0.006) and NLR by CON (p = 0.009). C-reactive protein was significantly related to GGO (p = 0.023) and CON (p = 0.004), BAL lymphocyte fraction to GGO (p = 0.017) extent.

CONCLUSION

Blood lymphocyte and eosinophil fraction, NLR, CRP and BAL lymphocyte fraction may aid to differentiate inflammatory from non-inflammatory/fibrotic ILD patterns.

TRIAL REGISTRATION

This evaluation was based on data from the ILD registry of Kepler University Hospital Linz, as approved by the ethics committee of the Federal State of Upper-Austria (EK Number. I-26-17).

Progression in the Management of Non-Idiopathic Pulmonary Fibrosis Interstitial Lung Diseases, Where Are We Now and Where We Would Like to Be

A significant proportion of patients with interstitial lung disease (ILD) may develop a progressive fibrosing phenotype characterized by worsening of symptoms and pulmonary function, progressive fibrosis on chest computed tomography and increased mortality. The clinical course in these patients mimics the relentless progressiveness of idiopathic pulmonary fibrosis (IPF). Common pathophysiological mechanisms such as a shared genetic susceptibility and a common downstream pathway—self-sustaining fibroproliferation—support the concept of a progressive fibrosing phenotype, which is applicable to a broad range of non-IPF ILDs. While antifibrotic drugs became the standard of care in IPF, immunosuppressive agents are still the mainstay of treatment in non-IPF fibrosing ILD (F-ILD). However, recently, randomized placebo-controlled trials have demonstrated the efficacy and safety of antifibrotic treatment in systemic sclerosis-associated F-ILD and a broad range of F-ILDs with a progressive phenotype. This review summarizes the current pharmacological management and highlights the unmet needs in patients with non-IPF ILD.

Interstitial lung abnormality (ILA) and nonspecific interstitial pneumonia (NSIP)

This review article aims to address mysteries existing between Interstitial Lung Abnormality (ILA) and Nonspecific Interstitial Pneumonia (NSIP). The concept and definition of ILA are based upon CT scans from multiple large-scale cohort studies, whereas the concept and definition of NSIP originally derived from pathology with evolution to multi-disciplinary diagnosis. NSIP is the diagnosis as Interstitial Lung Disease (ILD) with clinical significance, whereas only a part of subjects with ILA have clinically significant ILD. Eventually, both ILA and NSIP must be understood in the context of chronic fibrosing ILD and progressive ILD, which remains to be further investigated.

Clinical characteristics of Japanese patients with chronic obstructive pulmonary disease (COPD) with comorbid interstitial lung abnormalities: A cross-sectional study

Smoking-related interstitial lung abnormalities are different from specific forms of fibrosing lung disease which might be associated with poor prognoses. Chronic obstructive pulmonary disease with comorbid interstitial lung abnormalities and that with pulmonary fibrosis are considered different diseases; however, they could share a common spectrum. We aimed to evaluate the clinical characteristics of Japanese patients with chronic obstructive pulmonary disease and comorbid interstitial lung abnormalities. In this prospective observational study, we analyzed data from the Ishinomaki COPD Network Registry. We evaluated the clinical characteristics of patients with chronic obstructive pulmonary disease with and without comorbid interstitial lung abnormalities by comparing the annualized rate of chronic obstructive pulmonary disease exacerbations per patient during the observational period. Among 463 patients with chronic obstructive pulmonary disease, 30 (6.5%) developed new interstitial lung abnormalities during the observational period. After 1-to-3 propensity score matching, we found that the annualized rate of chronic obstructive pulmonary disease exacerbations per patient during the observational period was 0.06 and 0.23 per year in the interstitial lung abnormality and control groups, respectively (P = 0.043). Our findings indicate slow progression of interstitial lung abnormality lesions in patients with pre-existing chronic obstructive pulmonary disease. Further, interstitial lung abnormality development did not significantly influence on chronic obstructive pulmonary disease exacerbation. We speculate that post-chronic obstructive pulmonary disease interstitial lung abnormalities might involve smoking-related interstitial fibrosis, which is different from specific forms of fibrosing lung disease associated with poor prognoses.

Real-life experiences in a single center: efficacy of pirfenidone in idiopathic pulmonary fibrosis and fibrotic idiopathic non-specific interstitial pneumonia patients

Background:

Pirfenidone is the first antifibrotic drug approved for the treatment of idiopathic pulmonary fibrosis (IPF) and it is used in the treatment of other interstitial pneumonias, such as unclassifiable interstitial lung disease (ILD) and connective tissue-related ILD. This study examined the efficacy of pirfenidone in patients with IPF and fibrotic idiopathic non-specific interstitial pneumonia (f-iNSIP).

Methods:

In a retrospective real-life study, 67 IPF and 24 f-iNSIP patients were enrolled and classified into a pirfenidone group and a non-antifibrotic group. The level of forced vital capacity (FVC) and diffusing capacity of lung for carbon monoxide (DLco) at baseline, 6, 12 and 24 months were recorded. The level of KL-6 in serum was detected by chemiluminescence enzyme immunoassay (CLEIA). The prognosis and safety outcomes were collected from patients.

Results:

In IPF patients, pirfenidone decreased the mean change of FVC and DLco, and decreased the proportion of patients with a ⩾10% decline in FVC or a ⩾15% decline in DLco compared with the non-antifibrotic group. There was no difference in the mean change of FVC and DLco between smokers and non-smokers who received pirfenidone treatment. There was an improvement in progression-free survival, defined as the time to the first occurrence of acute exacerbation or death related to pulmonary fibrosis. Moreover, the ratio of patients who experienced acute exacerbation and death related to pulmonary fibrosis was lower in the pirfenidone group. There was no change in lung function and prognosis between the pirfenidone and non-antifibrotic groups in f-iNSIP patients. The KL-6 level slightly decreased after 1 year of pirfenidone treatment but not significantly. Gastrointestinal and skin-related adverse events were most common, and four patients ceased treatment due to the side effects.

Conclusions:

Pirfenidone safely reduced disease progression by improving the lung function and progression-free survival in IPF patients, with acceptable side effects. The efficacy of pirfenidone on f-iNSIP was not significant, suggesting the need for further studies.

The reviews of this paper are available via the supplemental material section.

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.

Effectiveness of Lung Transplantation in Patients With Interstitial Lung Diseases

BACKGROUND

Interstitial lung diseases (ILDs) are a heterogeneous group of more than 200 diseases manifested by progressive exercise dyspnea, radiological lung changes, and ventilation restrictive disorders. ILDs are the second most common indication for lung transplantation (LTx). Our study group consisted of 139 patients who qualified for LTx at the Silesian Center for Heart Diseases between 2004 and 2018. Of the 139, 92 patients died while on the waiting list, and 47 patients underwent LTx. Medical records including laboratory test results, spirometry, and the 6-minute walk test (6MWT) were analyzed to determine eligibility for LTx. We also assessed quality of life post-LTx.

RESULTS

Patients who qualified for LTx showed decreased values of parameters measured by spirometry (43.69 ± 19.05% of forced expiratory volume in the first second [FEV1] and 43.07 ± 20.55% of forced vital capacity [FVC] and severe desaturation during the 6MWT (SpO₂ = 88.78% before 6-minute walk test and 73.23% after the test). After LTx, longer distances were achieved in the 6MWT (235.47 ± 159.57 m during qualification vs 533.2 ± 34.15 m 12 months after LTx) and increased values of spirometry. On average, patients had stopped working 6 years prior to LTx.

CONCLUSION

There is no effective medical treatment for patients with end-stage ILDs. Therefore, lung transplantation is a lifesaving procedure for patients that also extends patients' lives and improves their quality of life.

Prognosis and causes of death of patients with acute exacerbation of fibrosing interstitial lung diseases

BACKGROUND

The aim of this study was to compare the clinical characteristics, causes of death and factors impacting on the prognosis of patients with idiopathic pulmonary fibrosis (IPF) and other fibrosing interstitial lung disease (FILD) with a history of acute exacerbation (AE) of IPF or FILD.

METHODS

Retrospective data of hospital treatment periods caused by AE-IPF and AE-FILD were collected from medical records. Clinical features and survival data of IPF and non-IPF cases were evaluated and compared. The underlying and immediate causes of death were gathered from death certificates.

RESULTS

A total of 128 patients fulfilled the criteria for inclusion. IPF (n=79/62%), rheumatoid arthritis-associated interstitial lung disease (RA-ILD; n=17/14%) and asbestosis (n=11/8.6%) were the most common FILD subgroups in the study. The median survival after hospitalisation in AE-IPF was 2.6 months compared with 21 months in other AE-FILDs (p<0.001). The survival difference was not explained by age, gender or pulmonary function test results at the time of hospitalisation. Patients with non-specific interstitial pneumonia and RA-ILD had the most favourable prognosis. ILD was the most common underlying cause of death in both patients with IPF and with other FILD accounting for 87% and 78% of deaths, respectively.

CONCLUSIONS

We detected a significantly longer survival in AE of patients with non-IPF compared with that of AE-IPFs. The prognosis of patients was affected by the underlying lung disease since pulmonary fibrosis was the underlying cause of death in the majority of all patients with FILD having experienced an AE.

Immune-Related Adverse Events: Pneumonitis

Checkpoint inhibitors are part of the family of immunotherapies and are increasingly being used in a wide variety of cancers. Immune-related adverse events pose a major challenge in the treatment of cancer patients. Pneumonitis is a rare immune-related adverse event that presents in distinct patterns. The goal of this chapter is to instruct readers on the incidence and clinical manifestations of pneumonitis and to offer guidance in the evaluation and treatment of patients with pneumonitis.

Pathology of Idiopathic Interstitial Pneumonias

This review discusses diagnostic pathology in idiopathic interstitial pneumonias (IIPs). Accurate understanding of basic structure of lung lobules is critical because the location of abnormalities inside the lobule is an important effector of pathology diagnosis. Depending on the method of obtaining tissue, recognition of the location may be difficult or impossible. Cryobiopsy is a new technology and its coverage of lung lobules is limited. This article discusses fundamental anatomy and approach to interstitial pneumonia. In addition, most histologic types of IIPs are covered, but the focus is on diagnosis of usual interstitial pneumonia because of its clinical importance.

Evaluation of changes in the serum levels of Krebs von den Lungen-6 and surfactant protein-D over time as important biomarkers in idiopathic fibrotic nonspecific interstitial pneumonia

BACKGROUND

Some cases of idiopathic fibrotic nonspecific interstitial pneumonia (f-NSIP) show a progressive course that is similar to that of idiopathic pulmonary fibrosis. However, it is difficult to predict poor patient outcomes. This study aimed to evaluate whether serial changes in serum levels of Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) can predict disease progression.

METHODS

We retrospectively analyzed the medical records of 75 patients with idiopathic f-NSIP. Disease behavior was categorized into two groups depending on long-term change of pulmonary function: progressive type (≥5%/year relative decline in the slope of forced vital capacity [FVC] and/or ≥7.5%/year relative decline in the slope of %diffusing capacity of the lung for carbon monoxide [%D_LCO]) and stable type. Levels of KL-6 and SP-D and results of pulmonary function tests, which were performed parallelly, were reviewed and analyzed using a linear mixed-effects model.

RESULTS

The study subjects comprised 62 patients with stable type and 13 patients with progressive type disease behavior. Among these subjects, 50 patients fulfilled the diagnostic criteria of interstitial pneumonia with autoimmune features (IPAF). Serum levels of both KL-6 and SP-D at baseline showed a negative correlation with %D_LCO, but not with FVC, and these biomarkers were not related to disease progression. Persistently high levels of KL-6 and SP-D correlated with progressive type disease behavior in idiopathic (non-IPAF) f-NSIP.

CONCLUSIONS

Changes in serum KL-6 and SP-D levels over time may provide useful predictive information on disease behavior during treatment in patients with idiopathic f-NSIP and especially in those with non-IPAF f-NSIP.

The acoustic characteristics of fine crackles predict honeycombing on high-resolution computed tomography

Background

Honeycombing on high-resolution computed tomography (HRCT) is a distinguishing feature of usual interstitial pneumonia and predictive of poor outcome in interstitial lung diseases (ILDs). Although fine crackles are common in ILD patients, the relationship between their acoustic features and honeycombing on HRCT has not been well characterized.

Methods

Lung sounds were digitally recorded from 71 patients with fine crackles and ILD findings on chest HRCT. Lung sounds were analyzed by fast Fourier analysis using a sound spectrometer (Easy-LSA; Fukuoka, Japan). The relationships between the acoustic features of fine crackles in inspiration phases (onset timing, number, frequency parameters, and time-expanded waveform parameters) and honeycombing in HRCT were investigated using multivariate logistic regression analysis.

Results

On analysis, the presence of honeycombing on HRCT was independently associated with onset timing (early vs. not early period; odds ratios [OR] 10.407, 95% confidence interval [95% CI] 1.366–79.298, P = 0.024), F99 value (the percentile frequency below which 99% of the total signal power is accumulated) (unit Hz = 100; OR 5.953, 95% CI 1.221–28.317, P = 0.029), and number of fine crackles in the inspiratory phase (unit number = 5; OR 4.256, 95% CI 1.098–16.507, P = 0.036). In the receiver-operating characteristic curves for number of crackles and F99 value, the cutoff levels for predicting the presence of honeycombing on HRCT were calculated as 13.2 (area under the curve [AUC], 0.913; sensitivity, 95.8%; specificity, 75.6%) and 752 Hz (AUC, 0.911; sensitivity, 91.7%; specificity, 85.2%), respectively. The multivariate logistic regression analysis additionally using these cutoff values revealed an independent association of number of fine crackles in the inspiratory phase, F99 value, and onset timing with the presence of honeycombing (OR 33.907, 95% CI 2.576–446.337, P = 0.007; OR 19.397, 95% CI 2.311–162.813, P = 0.006; and OR 12.383, 95% CI 1.443–106.293, P = 0.022; respectively).

Conclusions

The acoustic properties of fine crackles distinguish the honeycombing from the non-honeycombing group. Furthermore, onset timing, number of crackles in the inspiratory phase, and F99 value of fine crackles were independently associated with the presence of honeycombing on HRCT. Thus, auscultation routinely performed in clinical settings combined with a respiratory sound analysis may be predictive of the presence of honeycombing on HRCT.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 3. Idiopathic Nonspecific Interstitial Pneumonia

Idiopathic nonspecific interstitial pneumonia (NSIP) is one of the varieties of idiopathic interstitial pneumonias. Diagnosis of idiopathic NSIP can be done via multidisciplinary approach in which the clinical, radiologic, and pathologic findings were discussed together and exclude other causes. Clinical manifestations include subacute or chronic dyspnea and cough that last an average of 6 months, most of which occur in non-smoking, middle-aged women. The common findings in thoracic high-resolution computed tomography in NSIP are bilateral reticular opacities, traction bronchiectasis, reduced volume of the lobes, and ground-glass opacity in the lower lungs. These lesions can involve diffuse bilateral lungs or subpleural area. Unlike usual interstitial pneumonia, honeycombing is sparse or absent. Pathology shows diffuse interstitial inflammation and fibrosis which are temporally homogeneous, namely NSIP pattern. Idiopathic NSIP is usually treated with steroid only or combination with immunosuppressive agents such as azathioprine, cyclophosphamide, cyclosporine, and mycophenolate mofetil. Prognosis of idiopathic NSIP is better than idiopathic pulmonary fibrosis. Many studies have reported a 5-year survival rate of more than 70%.

The natural history of progressive fibrosing interstitial lung diseases

A proportion of patients with certain types of interstitial lung disease (ILD), including chronic hypersensitivity pneumonitis and ILDs associated with autoimmune diseases, develop a progressive fibrosing phenotype that shows similarities in clinical course to idiopathic pulmonary fibrosis. Irrespective of the clinical diagnosis, these progressive fibrosing ILDs show commonalities in the underlying pathogenetic mechanisms that drive a self-sustaining process of pulmonary fibrosis. The natural history of progressive fibrosing ILDs is characterized by decline in lung function, worsening of symptoms and health-related quality of life, and early mortality. Greater impairment in forced vital capacity or diffusion capacity of the lungs for carbon monoxide, and a greater extent of fibrotic changes on a computed tomography scan, are predictors of mortality in patients with fibrosing ILDs. However, the course of these diseases is heterogenous and cannot accurately be predicted for an individual patient. Data from ongoing clinical trials and patient registries will provide a better understanding of the clinical course and impact of progressive fibrosing ILDs.

Cyclosporin A in idiopathic chronic fibrosing interstitial pneumonia without idiopathic pulmonary fibrosis

Background

We have sometimes observed interstitial pneumonia which had chronic course and unknown causes but not diagnosed as idiopathic pulmonary fibrosis (IPF). However, the treatment strategy was not established definitely. To clarify the usefulness of cyclosporin A (CsA) in idiopathic chronic fibrosing interstitial pneumonia (iCFIP) without IPF, we examined longitudinal changes in pulmonary physiology.

Methods

Japanese patients with iCFIP without IPF treated with CsA were identified retrospectively. Linear mixed-effects models were used to evaluate changes in pulmonary physiology after adjusting for age, sex, and smoking history. Primary outcomes were longitudinal trajectories of the percent predicted forced vital capacity (%FVC), percent predicted diffusing capacity for carbon monoxide (%DLco), and composite physiologic index (CPI) before and after CsA.

Results

Thirty-three patients were included. Before CsA initiation, %FVC, %DLco, and CPI declined at rates of 9.1%, 8.6% and -7.1 per 1 year, respectively. After CsA initiation, the gradient of %FVC showed significant improvements in 0-1 years (6.2%±3.0%; P<0.01) and in 1-2 years (10.0%±3.6%; P<0.01); %DLco improved in 0-1 year (4.0%±4.6%; P=0.09) and in 1-2 years (7.0%±5.6%; P=0.02); and CPI improved in 0-1 year (3.2%±3.3%; P=0.06) and in 1-2 years (4.6%±4.1%; P=0.03).

Conclusions

CsA for iCFIP without IPF may be associated with improvements in pulmonary physiology in 2 years. Further studies are needed to determine the role of CsA in iCFIP without IPF.

A case of panitumumab containing chemotherapy causing interstitial lung disease: early recognition and treatment resulting in a good outcome

Panitumumab is a recombinant human IgG₂ monoclonal antibody which is used for the treatment of patients with metastatic colorectal cancer (mCRC) with disease progression on or following FOLFIRI (fluoropyrimidine, oxaliplatin and irinotecan) containing chemotherapy regimen. We report a case of an 83-year-old Hispanic man, non-smoker, with KRAS/NRAS wild-type mCRC of the liver who was treated with 9 cycles of FOLFOX4 (fluorouracil, leucovorin and oxaliplatin) and cetuximab. Follow-up abdominal imaging showed progression of CRC, requiring initiation of panitumumab in addition to FOLFIRI. After 2 cycles of this combination chemotherapy, he presented with acute hypoxaemic respiratory failure. Pulmonary imaging showed new onset of interstitial lung disease (ILD). He was treated with systemic corticosteroids with marked improvement of ILD. We aim to highlight the risk of severe life-threatening ILD associated with panitumumab. Early recognition of this serious adverse event helps avoid unnecessary administration of systemic antibiotics and prevent mortality.

Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases

Although these conditions are rare, a proportion of patients with interstitial lung diseases (ILDs) may develop a progressive-fibrosing phenotype. Progressive fibrosis is associated with worsening respiratory symptoms, lung function decline, limited response to immunomodulatory therapies, decreased quality of life and, potentially, early death. Idiopathic pulmonary fibrosis may be regarded as a model for other progressive-fibrosing ILDs. Here we focus on other ILDs that may present a progressive-fibrosing phenotype, namely idiopathic nonspecific interstitial pneumonia, unclassifiable idiopathic interstitial pneumonia, connective tissue disease-associated ILDs (e.g. rheumatoid arthritis-related ILD), fibrotic chronic hypersensitivity pneumonitis, fibrotic chronic sarcoidosis and ILDs related to other occupational exposures. Differential diagnosis of these ILDs can be challenging, and requires detailed consideration of clinical, radiological and histopathological features. Accurate and early diagnosis is crucial to ensure that patients are treated optimally.

The place of high-resolution computed tomography imaging in the investigation of interstitial lung disease

INTRODUCTION

High-resolution computed tomography (HRCT) has revolutionized the diagnosis, prognosis and in some cases the prediction of therapeutic response in interstitial lung disease (ILD). HRCT represents an essential second step to a patient's clinical history, before considering any other investigation, including lung biopsy. Areas covered: This review describes the current place of HRCT in the diagnosis, prognosis and monitoring of ILD. It also lists some perspectives for the near future. Expert commentary: Since the 1980s, HRCT and its interpretation have improved, the diagnosis value of patterns, and the integration of bio-clinical elements to HRCT have been better standardized. The interobserver agreement has been investigated, allowing a better use of some limits in the interpretation of various signs. It not only takes into account one particular predominant sign, but the combination of patterns and the distribution of findings. Thanks to HRCT, the range of diagnoses and their probability are more accurately identified. The contribution of HRCT has been optimized during the multidisciplinary discussion that a difficult diagnosis calls for. HRCT quantification of the extent of diffuse lung disease becomes possible and is linked to prognosis. In the future, artificial intelligence may significantly modify the practice of radiology.

Diagnosis of Idiopathic Pulmonary Fibrosis: Differential Diagnosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fibrotic interstitial lung disease of unknown origin with a characteristic imaging and histologic pattern called usual interstitial pneumonia (UIP). The diagnosis of IPF is a complex procedure that requires the support of various specialists, who must integrate clinical, radiological, and histological data. The multidisciplinary team (MDT) has become the new gold standard to diagnose and manage the disease, increasing the accuracy and agreement of the diagnosis between different centers. It is mandatory to exclude nonspecific interstitial pneumonia or other diseases that can cause the UIP pattern, particularly drugs or exposure diseases, including chronic hypersensitivity pneumonitis or systemic autoimmune disease. The role of the MDT is also to decide who could need a biopsy or to review patient diagnoses at regular intervals in those with additional information or unexpected evolution. This review provides updated information to achieve a proper IPF diagnosis.

Immune-Related Adverse Events: Pneumonitis

Checkpoint inhibitors are part of the family of immunotherapies and are increasingly being used in a wide variety of cancers. Immune-related adverse events pose a major challenge in the treatment of cancer patients. Pneumonitis is a rare immune-related adverse event that presents in distinct patterns. The goal of this chapter is to instruct readers on the incidence and clinical manifestations of pneumonitis and to offer guidance in the evaluation and treatment of patients with pneumonitis.

Factors affecting treatment outcome in patients with idiopathic nonspecific interstitial pneumonia: a nationwide cohort study

Background

The effects of corticosteroid-based therapy in patients with idiopathic nonspecific interstitial pneumonia (iNSIP), and factors affecting treatment outcome, are not fully understood. We aimed to investigate the long-term treatment response and factors affecting the treatment outcome in iNSIP patients from a multi-center study in Korea.

Methods

The Korean interstitial lung disease (ILD) Study Group surveyed ILD patients from 2003 to 2007. Patients were divided into two groups to compare the treatment response: response group (forced vital capacity (FVC) improves ≥10% after 1 year) and non-response group (FVC <10%). Factors affecting treatment response were evaluated by multivariate logistic regression analysis.

Results

A total of 261 patients with iNSIP were enrolled, and 95 patients were followed-up for more than 1 year. Corticosteroid treatment was performed in 86 patients. The treatment group showed a significant improvement in lung function after 1-year: FVC, 10.0%; forced expiratory volume (FEV₁), 9.8%; diffusing capacity of the lung for carbon monoxide (DLco), 8.4% (p < 0.001). Sero-negative anti-nuclear antibody (ANA) was significantly related with lung function improvement. Sero-positivity ANA was significantly lower in the response group (p = 0.013), compared to that in the non-response group. A shorter duration of respiratory symptoms at diagnosis was significantly associated with a good response to treatment (p = 0.018).

Conclusion

Treatment with corticosteroids and/or immunosuppressants improved lung function in iNSIP patients, which was more pronounced in sero-negative ANA and shorter symptom duration patients. These findings suggest that early treatment should be considered in iNSIP patients, even in an early disease stage.

Electronic supplementary material

The online version of this article (10.1186/s12931-017-0686-7) contains supplementary material, which is available to authorized users.

CT Features of the Usual Interstitial Pneumonia Pattern: Differentiating Connective Tissue Disease-Associated Interstitial Lung Disease From Idiopathic Pulmonary Fibrosis

OBJECTIVE

A substantial proportion of cases of usual interstitial pneumonia (UIP) are due to connective tissue disease (CTD)-associated interstitial lung disease (ILD). The purpose of this study was to determine whether specific CT findings can help differentiate a UIP pattern of CTD-ILD from a UIP pattern of idiopathic pulmonary fibrosis (IPF) and whether these signs are associated with survival.

MATERIALS AND METHODS

Adults visiting an ILD clinic from 2006 to 2015 enrolled in a research registry with a multidisciplinary diagnosis of CTD-ILD or IPF and a UIP pattern at high-resolution CT were included in the study. In these subjects with CT findings of UIP due to either IPF or CTD-ILD, three CT findings anecdotally associated with CTD-ILD were assessed for diagnostic accuracy: the "straight-edge" sign, the "exuberant honeycombing" sign, and the "anterior upper lobe" sign. Survival assessments were performed with univariate and multivariable techniques.

RESULTS

The subjects included 63 patients who had CTD-ILD and 133 patients who had IPF with a UIP pattern at CT. All three CT signs were significantly more common in subjects with CTD-ILD than those with IPF (prevalence, 22.2-25.4% for CTD-ILD, 6.0-12.8% for IPF; p = 0.028 to < 0.001). The highest specificity (94.0%) and sensitivity (25.4%) were seen for the straight-edge sign. No CT sign was associated with survival in multivariable analysis.

CONCLUSION

Although UIP is usually associated with IPF, the index of suspicion for CTD-ILD should be raised in the care of patients with any of the three CT signs. A thorough workup for CTD-ILD should be pursued, including referral to the rheumatology department.

[Pulmonary manifestations in collagen vascular diseases]

CLINICAL/METHODICAL ISSUE

Pulmonary complications are frequent in patients with collagen vascular diseases (CVD). Frequent causes are a direct manifestation of the underlying disease, side effects of specific medications and lung infections.

STANDARD RADIOLOGICAL METHODS

The standard radiological procedure for the work-up of pulmonary pathologies in patients with CVD is multidetector computed tomography (MDCT) with thin-slice high-resolution reconstruction.

PERFORMANCE

The accuracy of thin-slice CT for the identification of particular disease patterns is very high. The pattern of usual interstitial pneumonia (UIP) representing the direct pulmonary manifestation of rheumatoid arthritis (RA) can be identified with a sensitivity of 45 % and a specificity of 96 %.

ACHIEVEMENTS

Both direct pulmonary manifestations, drug-induced toxicity and certain infections can have a similar appearance in thin-slice MDCT in various forms of CVD. Knowledge of the patterns and causes contributes to the diagnostic certainty.

PRACTICAL RECOMMENDATIONS

At first diagnosis of a CVD and associated pulmonary symptoms thin-slice MDCT is recommended. Clinical, lung function and imaging follow-up examinations should be performed every 6-12 months depending on the results of the MDCT. In every case the individual CT morphological patterns of pulmonary involvement must be identified. The combination of information on the anamnesis, clinical and imaging results is a prerequisite for an appropriate disease management.

Clinical profile of unclassifiable interstitial lung disease: Comparison with chronic fibrosing idiopathic interstitial pneumonias

Objective

Unclassifiable interstitial lung disease (ILD) is a common problem in clinical practice. These patients pose a distinct challenge with regard to appropriate evaluation and management. We investigated the clinical features and prognosis of unclassifiable ILD and compared its clinical profile with that of idiopathic pulmonary fibrosis (IPF) and idiopathic nonspecific interstitial pneumonia (NSIP).

Methods

Patients with IPF (n = 40), NSIP (n = 14), and unclassifiable ILD (n = 27) were selected from an ongoing database. Baseline clinical features, pulmonary function, and the extent of fibrosis on high-resolution computed tomography (HRCT) were evaluated. Mortality was estimated based on the ILD–Gender, Age, Physiology (ILD-GAP) index and composite physiologic index (CPI).

Results

IPF was associated with the worst survival (hazard ratio [HR] = 4.361 compared with NSIP), followed by unclassifiable cases (HR = 1.251 compared with NSIP). Increasing mortality was significantly impacted by age (HR = 1.04 per 1-year increase), lower carbon monoxide diffusing capacity of the lung (HR = 0.97), HRCT interstitial score (HR = 1.119 per 1-point increase), ILD-GAP score (HR = 1.570 per 1-point increase), and CPI (HR = 1.039 per 1-point increase).

Conclusions

Patients with unclassifiable ILD had an intermediate prognosis between that of IPF and NSIP. Patients at high risk of mortality can be identified using baseline clinical, physiological, and radiological features.

Nonspecific interstitial pneumonia preceding diagnosis of collagen vascular disease

BACKGROUND

The aim of this study was to evaluate the incidence and clinical features of patients who developed collagen vascular disease (CVD) after an initial diagnosis of idiopathic nonspecific interstitial pneumonia (NSIP).

METHODS

We conducted a retrospective review of 72 consecutive patients with NSIP who were diagnosed by surgical lung biopsy in our institution (idiopathic NSIP, n = 35; CVD-NSIP, n = 37 at initial diagnosis). No patients fulfilled the American College of Rheumatology criteria for a diagnosis with CVD within six months after the diagnosis of idiopathic NSIP.

RESULTS

Of 35 patients initially diagnosed with idiopathic NSIP, six patients (17.1%) developed CVD during the follow-up period (5.5 ± 5.0 years); three patients were diagnosed with dermatomyositis (DM), two patients with overlap syndrome (DM and Sjogren's syndrome), and one patient with rheumatoid arthritis. The mean time until CVD diagnosis was 2.0 years (six months - 3.5 years), and the one-, two- and three-year incidences of CVD development were 3.6%, 15.2% and 20.0%, respectively. There was no significant difference in clinical characteristics and survival among patients with NSIP preceding CVD diagnosis, those with idiopathic NSIP, or those with CVD-NSIP. In addition, at the time of initial diagnosis, there was no significant difference for the fulfillment of previous criteria such as interstitial pneumonia with autoimmune feature (IPAF) between patients with NSIP preceding CVD diagnosis and those with idiopathic NSIP.

CONCLUSIONS

It is difficult to predict CVD occurrence and careful attention is needed to detect the development of CVD in patients with idiopathic NSIP.

Effect of Muc5b promoter polymorphism on disease predisposition and survival in idiopathic interstitial pneumonias

BACKGROUND AND OBJECTIVE

A common polymorphism in the MUC5B gene (rs35705950) is associated with susceptibility to idiopathic pulmonary fibrosis (IPF) and familial interstitial pneumonia (FIP). We investigated predisposition of the MUC5B polymorphism to fibrotic interstitial pneumonias in Dutch Caucasian patient cohorts. Furthermore, we investigated the correlation between MUC5B genotype and survival in these cohorts.

METHODS

Sporadic IPF (spIPF, n = 115), FIP (n = 55), idiopathic non-specific interstitial pneumonia (iNSIP, n = 43), connective tissue disease associated interstitial pneumonia (CTD_IP, n = 35) and a control cohort (n = 249) were genotyped for rs35705950.

RESULTS

Rs35705950 minor allele frequency (MAF) in controls was 0.09. Case-control analysis showed significant allelic association with spIPF (MAF = 0.27; P = 5.0 × 10(-10)), FIP (MAF = 0.30; P = 2.7 × 10(-9)) and iNSIP (MAF = 0.22; P = 3.4 × 10(-4)). No association was observed in CTD_IP (MAF = 0.07). FIP subgroup analysis revealed an association between MUC5B and telomerase mutated FIP (P = 0.003), and between MUC5B and FIP with unknown genetic cause (P = 1.2 × 10(-8)). In spIPF carriership of MUC5B minor allele did not influence survival. In FIP MUC5B minor allele carriers had better survival (non-carriers 37 vs carriers 53 months, P = 0.01). In iNSIP survival analysis showed an opposite effect. Worse survival was found in iNSIP patients that carried the MUC5B minor allele (non-carriers 118 vs carriers 46 months, P = 0.027) CONCLUSION: This study showed that MUC5B minor allele predisposes to spIPF, FIP and iNSIP. In spIPF, survival is not influenced by MUC5B alleles. In FIP, MUC5B minor allele predicts better survival, pointing towards a subgroup of FIP patients with a milder, MUC5B-driven form of pulmonary fibrosis.

Case-based discussion: Lymphocytic interstitial pneumonia a rare presentation in an immunocompetent adult male

Lymphocytic interstitial pneumonia (LIP) is a rare form of interstitial lung disease usually associated with other systemic diseases; however, idiopathic cases are being reported. As per recent ATS/ERS 2013 guidelines, diagnostic criteria of clinical, radiological and histopathological for LIP is same as 2002 except some cystic changes on HRCT chest. Many cases diagnosed in the past as LIP now turn out to be NSIP; therefore as per new ATS/ERS classification whenever anybody report a case of LIP, NSIP should always be kept in mind as differential diagnosis. Here we present a case of LIP in an immunocompetent adult male presented with history of persistent dry cough and breathlessness on exertion, confirmed on HRCT chest and histopathologically, treated successfully with steroids.

Idiopathic non-specific interstitial pneumonia

Non-specific interstitial pneumonia (NSIP) is an interstitial lung disease that may be idiopathic or secondary to connective tissue disease, toxins or numerous other causes. Idiopathic NSIP is a rare diagnosis and requires exclusion of these other possible causes. Patients typically present in mid-adulthood with dyspnoea, cough and often constitutional symptoms including fever and fatigue. The disease has a female predominance, and more than 50% of patients have never smoked. Physical exam features mild hypoxaemia and inspiratory rales. Pulmonary function tests demonstrate restriction and a low diffusing capacity for carbon monoxide. High-resolution computed tomography abnormalities include predominantly lower lobe subpleural reticular changes, traction bronchiectasis and ground-glass opacities; honeycombing is rarely seen. An evaluation of the underlying pathology is necessary for a firm diagnosis. Histologically, alveolar and interstitial mononuclear cell inflammation and fibrosis are seen in a temporally uniform pattern with preserved underlying alveolar architecture. NSIP must be differentiated from other parenchymal lung diseases including idiopathic pulmonary fibrosis and hypersensitivity pneumonitis. A thorough exposure history and assessment for underlying connective tissue diseases are highly important, as positive findings in these categories would likely denote a case of secondary NSIP. A multi-disciplinary discussion that includes pulmonologist(s), radiologist(s) and pathologist(s) assists in reaching a consensus diagnosis and improves diagnostic accuracy. Treatment of idiopathic NSIP, although not well proven, is generally instituted in the form of immunosuppression. Prognosis is favourable compared with idiopathic pulmonary fibrosis, although the diagnosis still carries an attributable mortality. Herein we will summarize the clinical characteristics and management of idiopathic NSIP.