Drug-induced lung diseases: most common reaction patterns and corresponding high-resolution CT manifestations

Identification of kynurenine and quinolinic acid as promising serum biomarkers for drug-induced interstitial lung diseases

BACKGROUND

Drug-induced interstitial lung disease (DILD) is a lung injury caused by various types of drugs and is a serious problem in both clinical practice and drug development. Clinical management of the condition would be improved if there were DILD-specific biomarkers available; this study aimed to meet that need.

METHODS

Biomarker candidates were identified by non-targeted metabolomics focusing on hydrophilic molecules, and further validated by targeted approaches using the serum of acute DILD patients, DILD recovery patients, DILD-tolerant patients, patients with other related lung diseases, and healthy controls.

RESULTS

Serum levels of kynurenine and quinolinic acid (and kynurenine/tryptophan ratio) were elevated significantly and specifically in acute DILD patients. The diagnostic potentials of these biomarkers were superior to those of conventional lung injury biomarkers, Krebs von den Lungen-6 and surfactant protein-D, in discriminating between acute DILD patients and patients with other lung diseases, including idiopathic interstitial pneumonia and lung diseases associated with connective tissue diseases. In addition to identifying and evaluating the biomarkers, our data showed that kynurenine/tryptophan ratios (an indicator of kynurenine pathway activation) were positively correlated with serum C-reactive protein concentrations in patients with DILD, suggesting the potential association between the generation of these biomarkers and inflammation. Our in vitro experiments demonstrated that macrophage differentiation and inflammatory stimulations typified by interferon gamma could activate the kynurenine pathway, resulting in enhanced kynurenine levels in the extracellular space in macrophage-like cell lines or lung endothelial cells. Extracellular quinolinic acid levels were elevated only in macrophage-like cells but not endothelial cells owing to the lower expression levels of metabolic enzymes converting kynurenine to quinolinic acid. These findings provide clues about the molecular mechanisms behind their specific elevation in the serum of acute DILD patients.

CONCLUSIONS

The serum concentrations of kynurenine and quinolinic acid as well as kynurenine/tryptophan ratios are promising and specific biomarkers for detecting and monitoring DILD and its recovery, which could facilitate accurate decisions for appropriate clinical management of patients with DILD.

Contribution of collagen XIII to lung function and development of pulmonary fibrosis

BACKGROUND

Collagen XIII is a transmembrane collagen associated with neuromuscular junction development, and in humans its deficiency results in congenital myasthenic syndrome type 19 (CMS19), which leads to breathing difficulties. CMS19 patients usually have restricted lung capacity and one patient developed chronic lung disease. In single-cell RNA sequencing studies, collagen XIII has been identified as a marker for pulmonary lipofibroblasts, which have been implicated in the resolution of pulmonary fibrosis.

METHODS

We investigated the location and function of collagen XIII in the lung to understand the origin of pulmonary symptoms in human CMS19 patients. Additionally, we performed immunostainings on idiopathic pulmonary fibrosis (IPF) samples (N=5) and both normal and fibrotic mouse lung. To study whether the lack of collagen XIII predisposes to restrictive lung disease, we exposed Col13a1-modified mice to bleomycin-induced pulmonary fibrosis.

RESULTS

Apparently normal alveolar septum sections of IPF patients' lungs stained faintly for collagen XIII, and its expression was pinpointed to the septal fibroblasts in the mouse lung. Lung capacity was increased in mice lacking collagen XIII by over 10%. In IPF samples, collagen XIII was expressed by basal epithelial cells, hyperplastic alveolar epithelial cells and stromal cells in fibrotic areas, but the development of pulmonary fibrosis was unaffected in collagen XIII-deficient mice.

CONCLUSIONS

Changes in mouse lung function appear to represent a myasthenic manifestation of collagen XIII deficiency. We suggest that respiratory muscle myasthenia is the primary cause of the breathing problems suffered by CMS19 patients in addition to skeletal deformities. Induction of collagen XIII expression in the IPF patients' lungs warrants further studies to reveal collagen XIII-dependent disease mechanisms.

Drug-Induced Interstitial Lung Diseases

Drug-induced interstitial lung disease (DI-ILD) is an increasingly common cause of morbidity and mortality as the list of culprit drugs continues to grow. Unfortunately, DI-ILD is difficult to study, diagnose, prove, and manage. This article attempts to raise awareness of the challenges in DI-ILD and discusses the current clinical landscape.

Differential diagnosis of infectious diseases, drug-induced lung injury, and pulmonary infiltration due to underlying malignancy in patients with hematological malignancy using HRCT

PURPOSE

To differentiate among infectious diseases, drug-induced lung injury (DILI) and pulmonary infiltration due to underlying malignancy (PIUM) based on high-resolution computed tomographic (HRCT) findings from patients with hematological malignancies who underwent chemotherapy or hematopoietic stem cell transplantation.

MATERIALS AND METHODS

A total of 221 immunocompromised patients with hematological malignancies who had proven chest complications (141 patients with infectious diseases, 24 with DILI and 56 with PIUM) were included. Two chest radiologists evaluated the HRCT findings, including ground-glass opacity, consolidation, nodules, and thickening of bronchovascular bundles (BVBs) and interlobular septa (ILS). After comparing these CT findings among the three groups using the χ2test, multiple logistic regression analyses (infectious vs noninfectious diseases, DILI vs non-DILI, and PIUM vs non-PIUM) were performed to detect useful indicators for differentiation.

RESULTS

Significant differences were detected in many HRCT findings by the χ2 test. The results from the multiple logistic regression analyses identified several indicators: nodules without a perilymphatic distribution [p = 0.012, odds ratio (95% confidence interval): 4.464 (1.355-11.904)], nodules with a tree-in-bud pattern [p = 0.011, 8.364 (1.637-42.741)], and the absence of ILS thickening[p = 0.003, 3.621 (1.565-8.381)] for infectious diseases, the presence of ILS thickening [p = 0.001, 7.166 (2.343-21.915)] for DILI, and nodules with a perilymphatic distribution [p = 0.011, 4.256 (1.397-12.961)] and lymph node enlargement (p = 0.008, 3.420 (1.385-8.441)] for PIUM.

CONCLUSION

ILS thickening, nodules with a perilymphatic distribution, tree-in-bud pattern, and lymph node enlargement could be useful indicators for differentiating among infectious diseases, DILI, and PIUM in patients with hematological malignancies.

Stratifin as a novel diagnostic biomarker in serum for diffuse alveolar damage

Among the various histopathological patterns of drug-induced interstitial lung disease (DILD), diffuse alveolar damage (DAD) is associated with poor prognosis. However, there is no reliable biomarker for its accurate diagnosis. Here, we show stratifin/14-3-3σ (SFN) as a biomarker candidate found in a proteomic analysis. The study includes two independent cohorts (including totally 26 patients with DAD) and controls (total 432 samples). SFN is specifically elevated in DILD patients with DAD, and is superior to the known biomarkers, KL-6 and SP-D, in discrimination of DILD patients with DAD from patients with other DILD patterns or other lung diseases. SFN is also increased in serum from patients with idiopathic DAD, and in lung tissues and bronchoalveolar lavage fluid of patients with DAD. In vitro analysis using cultured lung epithelial cells suggests that extracellular release of SFN occurs via p53-dependent apoptosis. We conclude that serum SFN is a promising biomarker for DAD diagnosis.

Moderne Tumortherapien und ihre pulmonalen Nebenwirkungen

Die Strahlentherapie und in jüngerer Zeit insbesondere die medikamentöse molekulare Therapie sind zentrale Bestandteile der modernen Onkologie. Beide Therapieformen eignen sich dazu, Tumoren bei vergleichsweise geringen systemischen Nebenwirkungen effektiv zu behandeln. Dennoch haben auch diese Behandlungsansätze Nebenwirkungen, die zum einen durch die Toxizität der Strahlung, zum anderen durch immunmodulatorische Effekte der verabreichten Medikamente ausgelöst werden. Das pneumotoxische Potenzial dieser Therapieformen spiegelt sich unter anderem in der Entstehung von interstitiellen Pneumonitiden wider, die in fibrotische Lungengerüstveränderungen übergehen können. Erschwert wird die klinische Diagnose der Erkrankung durch die unspezifischen Symptome. Die Computertomographie (CT) stellt ein ausgezeichnetes Mittel dar, um korrespondierende Verdichtungen zu diagnostizieren und im zeitlichen Verlauf zu monitoren. Damit wird dem Radiologen im interdisziplinären Kontext eine wichtige Rolle bei der Diagnostik dieses Krankheitsbildes zuteil.

CT Findings From Interstitial Lung Diseases in Patients With Metastatic Breast Cancer Treated With Fam-Trastuzumab Deruxtecan: A Single Institutional Experience

This single-institute, retrospective cohort study enrolled patients with human epidermal growth factor receptor 2-positive metastatic breast cancer treated with trastuzumab deruxtecan between August 2017 and January 2021 from four previous studies. Of 31 patients, 4 (12.9%) had interstitial lung disease (ILD). The dominant pattern observed on computed tomography was organizing pneumonia (100%), comprising subpleural consolidations in the lung periphery. However, no dominant distribution was observed in radiological lesions of the lungs. Of all the tested patients, lower lobe predominance was noted in 2 (50.0%) patients, upper lobe predominance in 1 (25.0%) patient, and diffused lobe distribution in 1 (25.0%) patient. All events were confined to the Common Terminology Criteria for Adverse Events grade 1 or 2 (100%). None of the patients died. Despite the small number of cases investigated, the incidence of trastuzumab deruxtecan-induced ILD in the Korean population was comparable to that previously reported.

Medication-induced Pulmonary Injury: A Scenario- and Pattern-based Approach to a Perplexing Problem

Medication-induced pulmonary injury (MIPI) is a complex medical condition that has become increasingly common yet remains stubbornly difficult to diagnose. Diagnosis can be aided by combining knowledge of the most common imaging patterns caused by MIPI with awareness of which medications a patient may be exposed to in specific clinical settings. The authors describe six imaging patterns commonly associated with MIPI: sarcoidosis-like, diffuse ground-glass opacities, organizing pneumonia, centrilobular ground-glass nodules, linear-septal, and fibrotic. Subsequently, the occurrence of these patterns is discussed in the context of five different clinical scenarios and the medications and medication classes typically used in those scenarios. These scenarios and medication classes include the rheumatology or gastrointestinal clinic (disease-modifying antirheumatic agents), cardiology clinic (antiarrhythmics), hematology clinic (cytotoxic agents, tyrosine kinase inhibitors, retinoids), oncology clinic (immune modulators, tyrosine kinase inhibitors, monoclonal antibodies), and inpatient service (antibiotics, blood products). Additionally, the article draws comparisons between the appearance of MIPI and the alternative causes of lung disease typically seen in those clinical scenarios (eg, connective tissue disease-related interstitial lung disease in the rheumatology clinic and hydrostatic pulmonary edema in the cardiology clinic). Familiarity with the most common imaging patterns associated with frequently administered medications can help insert MIPI into the differential diagnosis of acquired lung disease in these scenarios. However, confident diagnosis is often thwarted by absence of specific diagnostic tests for MIPI. Instead, a working diagnosis typically relies on multidisciplinary consensus. ^©RSNA, 2021.

[Modern tumor therapy and its pulmonary side effects]

Die Strahlentherapie und in jüngerer Zeit insbesondere die medikamentöse molekulare Therapie sind zentrale Bestandteile der modernen Onkologie. Beide Therapieformen eignen sich dazu, Tumoren bei vergleichsweise geringen systemischen Nebenwirkungen effektiv zu behandeln. Dennoch haben auch diese Behandlungsansätze Nebenwirkungen, die zum einen durch die Toxizität der Strahlung, zum anderen durch immunmodulatorische Effekte der verabreichten Medikamente ausgelöst werden. Das pneumotoxische Potenzial dieser Therapieformen spiegelt sich unter anderem in der Entstehung von interstitiellen Pneumonitiden wider, die in fibrotische Lungengerüstveränderungen übergehen können. Erschwert wird die klinische Diagnose der Erkrankung durch die unspezifischen Symptome. Die Computertomographie (CT) stellt ein ausgezeichnetes Mittel dar, um korrespondierende Verdichtungen zu diagnostizieren und im zeitlichen Verlauf zu monitoren. Damit wird dem Radiologen im interdisziplinären Kontext eine wichtige Rolle bei der Diagnostik dieses Krankheitsbildes zuteil.

18F-FDG PET/CT imaging in the diagnosis of drug-induced lung disease and pulmonary infection in lymphoma

OBJECTIVE

Lymphoma is a hematological disease with high prevalence. Multi-cycle chemotherapy (CHT) or local radiotherapy is applied usually; however, adverse events have been reported, such as drug-induced lung disease (DILD). Positron emission tomography/computed tomography (PET/CT) is often used to evaluate the lesion, treatment effect, and prognosis of lymphoma. We investigated DILD and pulmonary infection (PI) after multi-cycle CHT in lymphoma patients, to identify DILD and PI, provide guidance for later treatment for them.

METHODS

In all, 677 patients diagnosed with lymphoma and who underwent CHT were included. These patients underwent 18fluorodeoxyglucose (18F-FDG) PET/CT before and after CHT at Shandong Cancer Hospital (affiliated with Shandong University) between April 2015 and November 2019. Fifty patients developed DILD, 41 patients had lung infections; lesion characteristics were analyzed based on clinical characteristics, laboratory examinations, and PET/CT imaging.

RESULTS

Among the 677 lymphoma patients, there were 50 cases of DILD, with an incidence rate of 7.4%. PET/CT showed an elevated 18fluorodeoxyglucose uptake lung background, septal thickening and reticulation, multiple ground glass-like shadows, and grid-shaped blur shadows, which were more common in the lung periphery and under the pleura. The maximum standardized uptake value in the lung was 2.45 ± 0.52. Pulmonary infections occurred in 41 patients, and the maximum standardized uptake value was 4.05 ± 1.42. Age, sex, CHT cycle, Ann-Arbor stage, and lymphocyte levels were not significantly different between DILD and PI patients. Leukocyte and neutrophils showed significant differences; the PI patients had increased laboratory indexes of leukocyte and neutrophils. The mean number of CHT cycles was 4 cycles for DILD and PI.

CONCLUSIONS

PET/CT imaging has high sensitivity and detection rates for primary and metastatic lymphoma lesions. DILD mostly occurs in the middle and late stages of CHT. Laboratory tests and PET/CT can evaluate the lesions and treatment effects, and provide guidance for subsequent treatment plans for patients.

Chest CT Diagnosis and Clinical Management of Drug-related Pneumonitis in Patients Receiving Molecular Targeting Agents and Immune Checkpoint Inhibitors: A Position Paper from the Fleischner Society

Use of molecular targeting agents and immune checkpoint inhibitors (ICIs) has increased the frequency and broadened the spectrum of lung toxicity, particularly in patients with cancer. The diagnosis of drug-related pneumonitis (DRP) is usually achieved by excluding other potential known causes. Awareness of the incidence and risk factors for DRP is becoming increasingly important. The severity of symptoms associated with DRP may range from mild or none to life-threatening with rapid progression to death. Imaging features of DRP should be assessed in consideration of the distribution of lung parenchymal abnormalities (radiologic pattern approach). The CT patterns reflect acute (diffuse alveolar damage) interstitial pneumonia and transient (simple pulmonary eosinophilia) lung abnormality, subacute interstitial disease (organizing pneumonia and hypersensitivity pneumonitis), and chronic interstitial disease (nonspecific interstitial pneumonia). A single drug can be associated with multiple radiologic patterns. Treatment of a patient suspected of having DRP generally consists of drug discontinuation, immunosuppressive therapy, or both, along with supportive measures eventually including supplemental oxygen and intensive care. In this position paper, the authors provide diagnostic criteria and management recommendations for DRP that should be of interest to radiologists, clinicians, clinical trialists, and trial sponsors, among others. This article is a simultaneous joint publication in Radiology and CHEST. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

Chest CT Diagnosis and Clinical Management of Drug-Related Pneumonitis in Patients Receiving Molecular Targeting Agents and Immune Checkpoint Inhibitors: A Position Paper From the Fleischner Society

Use of molecular targeting agents and immune checkpoint inhibitors (ICIs) has increased the frequency and broadened the spectrum of lung toxicity, particularly in patients with cancer. The diagnosis of drug-related pneumonitis (DRP) is usually achieved by excluding other potential known causes. Awareness of the incidence and risk factors for DRP is becoming increasingly important. The severity of symptoms associated with DRP may range from mild or none to life-threatening with rapid progression to death. Imaging features of DRP should be assessed in consideration of the distribution of lung parenchymal abnormalities (radiologic pattern approach). The CT patterns reflect acute (diffuse alveolar damage) interstitial pneumonia and transient (simple pulmonary eosinophilia) lung abnormality, subacute interstitial disease (organizing pneumonia and hypersensitivity pneumonitis), and chronic interstitial disease (nonspecific interstitial pneumonia). A single drug can be associated with multiple radiologic patterns. Treatment of a patient suspected of having DRP generally consists of drug discontinuation, immunosuppressive therapy, or both, along with supportive measures eventually including supplemental oxygen and intensive care. In this position paper, the authors provide diagnostic criteria and management recommendations for DRP that should be of interest to radiologists, clinicians, clinical trialists, and trial sponsors, among others.

Multimodality Radiological Pictorial Review of Testicular Carcinoma: From Initial Staging to Restaging

With an overall 5-year survival rate >95%, patients with testicular cancer have a great prognosis. Although initial diagnosis is based on clinical examination, imaging does play a significant role in the diagnosis and prognosis of testicular cancer, which are dependent on tumor burden and staging. Successful treatment requires appropriate disease assessment throughout a patient’s treatment: evaluating treatment response, restaging, and monitoring for disease recurrence after treatment completion. Ultrasound is usually the initial screening modality for painless testicular masses, and computedtomography (CT) the most commonly used for staging and restaging. However, with regard to seminomas, positron-emission tomography (PET) combined with CT is slowly taking priority. With regard to nonseminomatous germ-cell tumors, PET-CT has not proven to be completely effective, due to a high number of false-negative results. The purpose of this paper is to provide radiologists with a pictorial review of testicular carcinoma from initial staging through posttreatment follow-up.

Lung clearance index: A new measure of late lung complications of cancer therapy in children

INTRODUCTION

Childhood cancer survivors (CSs) might face an increased lifelong risk of lung function impairment. The lung clearance index (LCI) has been described as being more sensitive than spirometry in the early stages of some lung diseases. The aim of this study was to evaluate this index in a cohort of patients with a history of childhood cancer for the first time.

MATERIALS AND METHODS

We evaluated 57 off-treatment CSs aged 0-18 years old and 50 healthy controls (HCs). We used the multiple-breath washout method to study LCI and spirometry.

RESULTS

CSs did not show any differences from the controls in ventilation homogeneity (LCI 6.78 ± 1.35 vs. 6.32 ± 0.44; p: not significant [ns]) or lung function (FEV1 99.9 ± 11.3% vs. 103.0 ± 5.9% of predicted; p: ns; FVC 98.2 ± 10.3% vs. 101.1 ± 3.3% of predicted). LCI significantly correlated with the number of years since the last chemotherapy (r = .35, p < .05).

CONCLUSIONS

Our study describes the trend of LCI in a cohort of CSs and compares it with the results obtained from HCs. The results show that patients maintain both good values of respiratory function and good homogeneity of ventilation during childhood. Moreover, as LCI increases and worsens as the years pass after the end of the treatment could identify the tendency toward pulmonary fibrosis, which is typical of adult CSs, at an earlier time than spirometry.

Influenza H1N1 virus-associated pneumonia often resembles rapidly progressive interstitial lung disease seen in collagen vascular diseases and COVID-19 pneumonia; CT-pathologic correlation in 24 patients

Purpose

To describe computed tomography (CT) findings of influenza H1N1 virus-associated pneumonia (IH1N1VAP), and to correlate CT findings to pathological ones.

Methods

The study included 24 patients with IH1N1VAP. Two observers independently evaluated the presence, distribution, and extent of CT findings. CT features were divided into either classical form (C-form) or non-classical form (NC-form). C-form included: A.) broncho-bronchiolitis and bronchopneumonia type, whereas NC-forms included: B.) diffuse peribronchovascular type, simulating subacute rheumatoid arthritis-associated (RA) interstitial lung disease (ILD) and C.) lower peripheral and/or peribronchovascular type, resembling dermatomyositis-associated ILD and COVID-19 pneumonia. In 10 cases with IH1N1VAP where lung biopsy was performed, CT and pathology findings were correlated.

Results

The most common CT findings were ground-glass opacities (24/24, 100 %) and airspace consolidation (23/24, 96 %). C-form was found in 11 (46 %) patients while NC-form in 13 (54 %). Types A, B, and C were seen in 11(46 %), 4 (17 %), and 9 (38 %) patients, respectively. The lung biopsy revealed organizing pneumonia in all patients and 6 patients (60 %) showed incorporated type organizing pneumonia that was common histological findings of rapidly progressive ILD.

Conclusion

In almost half of patients of IH1N1VAP, CT images show NC-form pneumonia pattern resembling either acute or subacute RA or dermatomyositis-associated ILD and COVID-19 pneumonia.

Serum Soluble Interleukin-2 Receptor Is a Biomarker for Pneumocystis jirovecii Pneumonia among Patients with Rheumatoid Arthritis under Methotrexate Therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic joint inflammation and may manifest as interstitial pneumonia (IP). Methotrexate (MTX) is one of the main therapeutic drugs used for RA, but MTX could cause severe side effects, including Pneumocystis jirovecii pneumonia (PCP) and IP. Owing to similar symptoms, it is sometimes difficult to discriminate MTX therapy-associated PCP (MTX-PCP) and MTX therapy-associated IP (MTX-IP). Soluble interleukin-2 receptor (sIL-2R) is considered a marker of T-cell activation, and serum sIL-2R levels are elevated in RA and PCP. This led us to hypothesize that serum sIL-2R is a potential biomarker for discriminating MTX-PCP and MTX-IP. Accordingly, we carried out a retrospective analysis of 20 MITX-PCP cases, 30 MTX-IP cases, and as controls, 16 patients with RA-associated IP (RA-IP) and 13 patients with PCP without MTX treatment (PCP group). C-reactive protein and alveolar-arterial oxygen differences were higher in the MTX-PCP group than those in the RA-IP and MTX-IP groups. Importantly, serum levels of sIL-2R in MTX-PCP were significantly higher than those in other three groups. Based on the receiver operating characteristic curve, the cut-off level of sIL-2R resulting in the highest diagnostic accuracy for MTX-PCP was 1,311.5 U/mL, discriminating between MTX-PCP and other groups with 91.7% sensitivity and 78.6% specificity. Thus, patients with MTX-PCP show a higher degree of systemic inflammation, severe hypoxemia, and increased sIL-2R levels compared with those in MTX-IP cases. In conclusion, serum sIL-2R could be a biomarker for PCP diagnosis among patients with RA under MTX therapy.

Imaging of Metastatic Germ Cell Tumors in Male Patients From Initial Diagnosis to Treatment-Related Toxicities: A Primer for Radiologists

OBJECTIVE. This review describes the influence of histology and metastatic sites on prognosis in male patients with metastatic germ cell tumors (GCTs) and explains the role imaging in assessing therapeutic response, residual disease, recurrence, sand treatment-related toxicities. CONCLUSION. Seminomatous and nonseminomatous GCTs differ in imaging appearance, pattern of spread, and prognosis, and an organ-based approach is helpful in prognostication. Multimodality imaging aids in accurate staging, prognostication, characterization of treatment response, and identification of therapy-related toxicity.

Radiologic evaluation of pulmonary injury following carmustine- and cyclophosphamide-based preparative regimen for autologous peripheral blood stem cell transplantation in children

BACKGROUND

Toxicity of carmustine and cyclophosphamide can cause pulmonary injury after hematopoietic stem cell transplantation.

OBJECTIVE

To evaluate the radiologic findings of pulmonary injuries following carmustine- and cyclophosphamide-based preparative regimens in children.

MATERIALS AND METHODS

From 2010 to 2014, 35 children received carmustine- and cyclophosphamide-based preparative regimens. Fourteen of 35 children presented with symptoms and radiologic abnormalities. Eight of 14 children had no evidence of infection, cardiogenic edema, or other explainable causes. We retrospectively analyzed their chest radiographs and CT scans for ground-glass opacity, consolidation, septal thickening and pleural effusion.

RESULTS

Major chest radiographic findings were bilateral diffuse ground-glass opacity (n=8) and septal thickening (n=7). CT findings were multifocal patchy (n=4) or inhomogeneously diffuse (n=4) ground-glass opacity, multifocal consolidations (n=7) and septal thickening (n=7). All of these lesions at CT were bilateral, but showed lower lobe predominance in 88, 100, and 63%, respectively. There was no central/peripheral or anterior/posterior predilection. Six children had small pleural effusions, which were bilateral in five children.

CONCLUSION

Bilateral ground-glass opacity with or without consolidation, septal thickening and pleural effusion were common radiologic findings in pulmonary injury following carmustine- and cyclophosphamide-based preparative regimens.

Connective tissue disease-related interstitial lung disease

Interstitial lung disease (ILD) is commonly present in patients with an underlying connective tissue disease (CTD), particularly those with systemic sclerosis, rheumatoid arthritis, and inflammatory myositis. The clinical spectrum can range from asymptomatic findings on imaging to respiratory failure and death. Distinguishing features in the clinical, radiographic, and histopathologic characteristics of CTD-ILD subsets can predict prognosis and treatment response. Treatment often consists of combinations of immunosuppressive medications, but there is a paucity of guidance in the literature to help clinicians determine appropriate screening and management of CTD-ILD. As such, there is a critical need for studies that can elucidate the natural history of the CTD-ILD, as well as clarify optimal therapies for CTD patients with ILD.

Acute fibrinous and organising pneumonia: a rare histopathological variant of chemotherapy-induced lung injury

Bleomycin-induced lung injury is the most common chemotherapy-associated lung disease, and is linked with several histopathological patterns. Acute fibrinous and organising pneumonia (AFOP) is a relatively new and rare histological pattern of diffuse lung injury. We report the first known case of bleomycin-induced AFOP. A 36-year-old man with metastatic testicular cancer received three cycles of bleomycin, etoposide and cisplatin, before being transitioned to paclitaxel, ifosfamide and cisplatin. He subsequently presented with exertional dyspnoea, cough and pleuritic chest pain. CT of the chest demonstrated bilateral ground glass opacities with peribronchovascular distribution and pulmonary function tests demonstrated a restrictive pattern of lung disease with impaired diffusion. Transbronchial biopsy revealed intra-alveolar fibrin deposits with organising pneumonia, consisting of intraluminal loose connective tissue consistent with AFOP. The patient received high-dose corticosteroids with symptomatic and radiographic improvement. AFOP should be recognised as a histopathological variant of bleomycin-induced lung injury.

Drug-induced lung injury associated with combination therapy of daclatasvir and asunaprevir: The first case report

Combination therapy with direct acting antiviral agents (DAAs) without interferon (IFN) has emerged as a treatment for chronic hepatitis C because of its high overall sustained virologic response rates and favorable side effect profile as compared to that with interferon. We report the first case of drug-induced lung injury (DLI) associated with IFN-free therapy with the DAAs, daclatasvir (NS5A inhibitor) and asunaprevir (NS3/4A protease inhibitor). Although this combination therapy of DAAs has been considered to have fewer side effects than IFN, more attention should be paid to DLI as an important side effect.

Procainamide-induced pulmonary fibrosis after orthotopic heart transplantation: a case report and literature review

A 33-year-old African-American woman was bridged to heart transplantation with a left ventricular assist device. She had a 14-month history of heart failure secondary to viral cardiomyopathy. The patient's refractory ventricular tachycardia was treated with intravenous procainamide owing to the patient's history of amiodarone-induced thyroiditis. After orthotopic cardiac transplant, she experienced prolonged respiratory failure. Serial computed tomography evaluation of the lung revealed diffuse bilateral ground-glass opacities and septal thickening. Bronchoscopies with tissue biopsies were performed with no conclusive results. Specimen samples displayed septal fibrosis with loose fibromyxoid tissue and some hobnail nodularities with no indication of granulomas, neutrophilic infiltration, malignancy, or fungal, viral, or bacterial growth. Histopathological evaluation of the lung wedge biopsy supported a diagnosis of pulmonary fibrosis and noted interstitial fibrosis with areas of focal alveolar hemorrhage and increased macrophage infiltration. Antinuclear body was found to be negative. After in-depth evaluation of the patient's medication history, procainamide was identified as the cause of the toxicity. As procainamide-induced lung fibrosis is relatively uncommon, we present this case to highlight procainamide's potential harm and the need for careful monitoring in postsurgical patients.

Consolidation with a twisted appearance along the airways: a report of five cases of interstitial pneumonia

High-resolution CT showed areas of airspace consolidation with a twisted appearance of the airways, along with areas of peribronchial ground-glass attenuation and traction bronchiectasis, in five patients with interstitial pneumonia. These areas of airspace consolidation were termed "twisted consolidation" (TwC). The five patients included two patients receiving treatment for rheumatoid arthritis (RA), one patient with newly diagnosed RA, and one patient who subsequently showed RA. Three patients showed improvement after steroid administration. An association of TwC with RA is suspected, but further studies are necessary.

Ayurvedic medicine and the lung

A middle-aged Indian woman with knee pain had consumed ayurvedic medicine (Ostolief and Arthrella tablets) daily for 6 months. She presented to the respiratory clinic with worsening dyspnea, cough and weight loss of 2 months' duration. She was a homemaker, never-smoker and did not keep birds. Physical examination detected fine end-inspiratory crackles. There was no clubbing of the fingers, joint deformity or swelling, skin lesion or enlarged cervical lymphadenopathy. High-resolution computed tomography showed diffuse centrilobular nodules with ground-glass attenuation. Restrictive ventilatory defect (FVC 44% predicted, FEV1/FVC ratio 93%) was observed on spirometry, and the autoimmune screen was negative. Bronchoalveolar lavage fluid revealed lymphocytosis with an increased CD4/CD8 (T helper:T suppressor) ratio. Cultures for bacteria, mycobacteria, fungi, viruses and Pneumocystis carinii were negative. Alveolitis with infiltration of interstitium by lymphocytes and peribronchiolar noncaseating granulomas were observed on bronchoscopic lung biopsy. A diagnosis of hypersensitivity pneumonitis as a result of ayurvedic medicine was made. She was advised to stop the offending medicine; high-dose steroids and bactrim prophylaxis were commenced and tapered over 3 months with good response and radiological resolution. She was followed for 1 year without relapse.

Connective Tissue Disease-Associated Interstitial Lung Disease

The connective tissue diseases (CTDs) are a group of systemic disorders characterized by autoimmunity and autoimmune-mediated organ damage. The lung is a frequent target and all components of the respiratory system are at risk. Interstitial lung disease (ILD) represents a broad group of diffuse parenchymal lung injury patterns characterized by varying degrees of inflammation and fibrosis, is a common manifestation of CTD particularly common in systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis, and is a leading cause of significant morbidity and mortality. The lung injury patterns of CTD-associated ILD (CTD-ILD) mirror those of idiopathic interstitial pneumonia and may arise at any time during the course of the CTD or may be the first manifestation of CTD. Patients with CTD that present with respiratory failure often present significant diagnostic dilemmas. Thorough and comprehensive assessments to exclude respiratory *infection, acute interstitial pneumonia, medication toxicity, pulmonary embolism, cardiac dysfunction, and diffuse alveolar hemorrhage are the fundamental components for the evaluation of such patients. Furthermore, patients with CTD are also at risk of acute exacerbations of underlying ILD. Acute exacerbations are manifested by subacute respiratory deterioration with worsening hypoxemia in the setting of new radiographic abnormalities. The prognosis of patients with CTD having respiratory failure is often quite poor, highlighting the need for prompt and thorough clinical assessments to determine the underlying etiology and implementation of appropriate therapeutic strategies.

Serum heat shock protein 47 levels in patients with drug-induced lung disease

Background

Heat shock protein (HSP) 47 is a collagen-specific molecular chaperone that is required for molecular maturation of various types of collagens. We recently reported that HSP47 serum levels were markedly higher in patients with acute exacerbations of idiopathic pulmonary fibrosis (IPF) when compared with patients with stable IPF, suggesting that serum HSP47 levels correlate with interstitial pneumonia activity. The aim of this study was to evaluate serum HSP47 levels in patients with drug-induced lung disease (DILD).

Methods

Findings from high-resolution computed tomographic chest scans of 47 patients with DILD were classified into one of four predominant patterns: organizing pneumonia (OP) (n = 4), nonspecific interstitial pneumonia (NSIP) (n = 24), hypersensitivity pneumonitis (HP) (n = 11), and diffuse alveolar damage (DAD) (n = 8). Serum levels of HSP47, Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-A, and SP-D were measured in these patients.

Results

The PaO₂/fraction of inspired oxygen (FiO₂) (P/F) ratios were significantly lower and the alveolar-arterial difference of oxygen (A-a DO₂) was significantly higher in the DAD group than in the other groups. Patients with DAD had the worst outcomes among the different subgroups. Patients in the DAD group had significantly higher serum HSP47 levels than those in other groups. Receiver operating characteristic curves revealed that HSP47 was superior to KL-6, SP-A, and SP-D for discriminating between the DAD group and the other groups. The cut-off level for HSP47 that resulted in the highest diagnostic accuracy was 1711.5 pg/mL. The sensitivity, specificity, and diagnostic accuracy were 87.5%, 97.4%, and 95.7%, respectively. Serum levels of HSP47 in the group of patients requiring glucocorticoids were significantly higher than those in patients who experienced clinical improvement without glucocorticoid administration. Serum HSP47 levels also significantly correlated with various respiratory parameters.

Conclusion

This study demonstrated that serum HSP47 levels were elevated in patients with DILD with a DAD pattern who had the worst outcomes among the different subgroups, and that this was correlated with P/F ratio and A-a DO₂.

Bleomycin-Induced Lung Injury

Bleomycin is a chemotherapeutic agent commonly used to treat curable diseases such as germinative tumors and Hodgkin’s lymphoma. The major limitation of bleomycin therapy is pulmonary toxicity, which can be life threatening in up to 10% of patients receiving the drug. The mechanism of bleomycin-induced pneumonitis (BIP) involves oxidative damage, relative deficiency of the deactivating enzyme bleomycin hydrolase, genetic susceptibility, and the elaboration of inflammatory cytokines. Ultimately, BIP can progress to lung fibrosis. The diagnosis of BIP is established by the combination of systemic symptoms, radiological and histological findings, and respiratory function tests abnormalities, while other disorders should be excluded. Although the diagnosis and pathophysiology of this disease have been better characterized over the past few years, there is no effective therapy for the disease. In general, the clinical picture is extremely complex. A greater understanding of the BIP pathogenesis may lead to the development of new agents capable of preventing or even treating the injury already present. Physicians who prescribe bleomycin must be aware of the potential pulmonary toxicity, especially in the presence of risk factors. This review will focus on BIP, mainly regarding recent advances and perspectives in diagnosis and treatment.

Drug-associated acute lung injury: a population-based cohort study

BACKGROUND

A number of drugs have been reported as risk factors for acute lung injury (ALI) and ARDS. However, evidence is largely limited to case reports, and there is a paucity of data on the incidence and outcome of drug-associated ALI (DALI).

METHODS

Using a population-based retrospective cohort study design, critically ill patients with a diagnosis of ALI were studied. These patients were classified as having DALI or non-DALI, based on whether they were exposed to prespecified drugs prior to development of ALI. Outcomes were compared between the two groups and frequencies and incidences reported.

RESULTS

Among 514 patients with ALI, 49 (9.5%) had DALI with an estimated population-based incidence of 6.6 (95% CI, 4.8-8.5) per 100,000 person-years. Of the 49 patients with DALI,36 received chemotherapeutic/antiinflammatory agents, and 14 received amiodarone. Twelve patients had no additional risk factors for ALI (probable DALI), whereas 37 had alternative risk factors (possible DALI). Patients with and without DALI had similar baseline characteristics. However, the APACHE (Acute Physiology and Chronic Health Evaluation) III scores (median, 83 vs 70, P 5 .03), ICU mortality (35% vs 20%, P 5 .03), and hospital mortality (63% vs 32%, P , .001)were significantly higher in the DALI group compared with those of the non-DALI group. Hospital mortality remained significantly higher after adjusting for APACHE III score on admission and the presence of malignancy in logistic regression analysis (OR, 2.8; 95% CI, 1.3-6.4; P 5 .009).

CONCLUSIONS

Drugs are important risk factors for ALI, and recognizing them as such may have important implications for early identification of patients at risk, discontinuation of the offending agent, and prognosis.

Drug-induced interstitial lung disease: mechanisms and best diagnostic approaches

Drug-induced interstitial lung disease (DILD) is not uncommon and has many clinical patterns, ranging from benign infiltrates to life-threatening acute respiratory distress syndrome. There are two mechanisms involved in DILD, which are probably interdependent: one is direct, dose-dependent toxicity and the other is immune-mediated. Cytotoxic lung injury may result from direct injury to pneumocytes or the alveolar capillary endothelium. Drugs can induce all types of immunological reactions described by Gell and Coombs; however, most reactions in immune-mediated DILD may be T cell-mediated.

DILD can be difficult to diagnose; diagnosis is often possible by exclusion alone. Identifying the causative drug that induces an allergy or cytotoxicity is essential for preventing secondary reactions.

One method to confirm the diagnosis of a drug-induced disease is re-exposure or re-test of the drug. However, clinicians are reluctant to place patients at further risk of illness, particularly in cases with severe drug-induced diseases. Assessment of cell-mediated immunity has recently increased, because verifying the presence or absence of drug-sensitized lymphocytes can aid in confirmation of drug-induced disease. Using peripheral blood samples from drug-allergic patients, the drug-induced lymphocyte stimulation test (DLST) and the leukocyte migration test (LMT) can detect the presence of drug-sensitized T cells. However, these tests do not have a definite role in the diagnosis of DILD. This study explores the potential of these new tests and other similar tests in the diagnosis of DILD and provides a review of the relevant literature on this topic.

Pulmonary complications in the non-HIV immunocompromised patient

The incidence of non-HIV immunocompromised patients is increasing. This is primarily due to improved immunosuppressive regimes for autoimmune diseases and also increases in stem cell transplantation. Pulmonary complications are a major cause of morbidity and mortality in these patients. Imaging is frequently used to assess these complications and to streamline therapies, as microbiological and/or pathological diagnosis can often be difficult, invasive, or protracted. This review provides the reader with a structured approach to interpret the imaging findings and differentiate between different infective and non-infective complications in these patients.

Drug-induced interstitial lung disease in tyrosine kinase inhibitor therapy for non-small cell lung cancer: a review on current insight

PURPOSE

With recent advances in targeted therapy such as tyrosine kinase inhibitor (TKI) therapy for non-small cell lung cancer (NSCLC), pulmonary toxicity has emerged as a problem. The recognition of common CT findings and patterns of TKI-induced interstitial lung disease (ILD) is mandatory for achieving a timely diagnosis and for the appropriate management of this condition. Therefore, familiarity with this complicating ILD is crucial.

METHODS

We reviewed all published literature in the English language regarding the ILD among NSCLC patients receiving TKIs.

RESULTS

The previous reports focused on the incidence, mortality rate, and risk factors of TKI-induced ILDs. This review elaborates on the diverse CT findings and predominant patterns of ILDs associated with TKI therapy. Emphases will be given on the role of CT, in particular, for the diagnosis of the subacute or chronic appearance of ILDs. This review also offers information about the pathogenesis and risk factor for the development of TKI-induced ILD. Representative cases will be presented as a pictorial review.

CONCLUSIONS

It is important to recognize the various patterns of TKI-induced ILDs, which increase in incidence with the introduction of diverse types of molecularly targeted agents. Poor prognoses are expected when there is a short interval from the initiation of target therapy to the onset of ILD, acute interstitial pneumonia pattern of ILD, and preexisting pulmonary fibrosis.

Pathology of small airways disease

CONTEXT

The term small airways disease encompasses a generally poorly understood group of lung diseases that may arise primarily within the small airways or secondarily from diseases primarily affecting the bronchi or lung parenchyma. Their histology may be confusing; however, because treatments and prognoses vary, correct pathologic diagnosis is important.

OBJECTIVE

To present a nonexhaustive review of the pathology of primary and secondary small airways diseases, including small airways disease related to tobacco; to various other exposures, including mineral dusts; to diseases involving other areas of the lung with secondary bronchiolar involvement; and to recently described bronchiolitic disorders.

DATA SOURCES

Current literature is reviewed.

CONCLUSIONS

Small airways diseases include a wide variety of diseases of which the pathologist must consider. Uncommon conditions such as diffuse idiopathic neuroendocrine cell hyperplasia and diffuse panbronchiolitis may show relatively specific diagnostic features histologically; however, most small airways diseases exhibit nonspecific histologic features. Conditions not considered primary pulmonary diseases, such as collagen vascular diseases, bone marrow transplantation, and inflammatory bowel disease, must also be considered in patients with small airways changes histologically. Clinical and radiologic correlation is important for obtaining the best possible diagnosis.

Padrões tomográficos das doenças intersticiais pulmonares difusas com correlação clínica e patológica

A tomografia de alta resolução (TCAR) é a técnica de imagem radiológica que reflete mais de perto as alterações da estrutura pulmonar. Os vários achados tomográficos podem ser combinados para formar padrões típicos. Estes, conjuntamente com a distribuição anatômica dos achados, e com os dados clínicos, podem estreitar o diagnóstico das doenças intersticiais pulmonares difusas, e em vários casos sugerir o diagnóstico correto com alto grau de acurácia. Os padrões mais comuns das doenças intersticiais pulmonares difusas na TCAR são o nodular, linear e reticular, lesões císticas, opacidades em vidro fosco e consolidações. Este artigo revisa as correlações entre os padrões tomográficos na TCAR e os achados patológicos e resume as causas mais comuns e os métodos de investigação para se atingir um diagnóstico nas doenças pulmonares crônicas difusas mais comuns.

High-resolution computed tomography patterns and immunopathogenetic findings in drug-induced pneumonitis

We tried to determine whether high-resolution computed tomography (HRCT) patterns correlate with the immunopathogenetic findings and whether they could provide helpful information for predicting the outcomes in non-neoplastic drug-induced pneumonitis. The HRCT images were classified as most suggestive of pneumonitis, diffuse alveolar damage (DAD), non-specific interstitial pneumonia, organizing pneumonia (OP), hypersensitivity pneumonitis, and acute eosinophilic pneumonia (AEP) in 34 patients with non-neoplastic drug-induced pneumonitis. The patients were analyzed for the bronchoalveolar lavage (BAL) cell findings and for the circulating levels of interferon-inducible protein 10 (IP-10) and macrophage-derived chemokine (MDC), which were measured by an enzyme-linked immunosorbent assay. The cumulative dose of corticosteroids received by the patients and the day when they required supplemental oxygen were calculated as outcome markers. There were no differences in the circulating chemokine levels and the BAL cell profiles except for the eosinophil percentages among the HRCT patterns. Most of the cases with pulmonary eosinophilia belonged to the OP and AEP groups, and the circulating MDC levels correlated with BAL eosinophil percentages. We could not find any relationship between the BAL cell profiles or the chemokine levels and the outcome markers. In contrast, the HRCT patterns rather predicted the outcomes because larger cumulative dose of steroids and longer oxygen supply were required for the patients in the DAD and OP groups. In contrast, all patients with AEP recovered without steroid administration. The present study suggests that HRCT does not predict cellular pathophysiology but it may predict the corticosteroid use in non-neoplastic drug-induced pneumonitis.