Drug-induced lung disease: a pragmatic classification incorporating HRCT appearances

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

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.

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.

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.

Alemtuzumab-associated diffuse alveolar damage - a case report

Background

Identifying causes of alemtuzumab induced respiratory symptoms in Multiple Sclerosis (MS) patients is crucial.

Case presentation

We report a case of diffuse alveolar damage (DAD) in a patient with MS after the first course of alemtuzumab treatment. A 42-year-old female developed progressive non-productive cough and exertional dyspnea 2 months after alemtuzumab treatment. DAD was diagnosed histopathologically by lung biopsy. The patient recovered completely, alemtuzumab was not continued.

Conclusions

Our case highlights another pathomechanism for non-infective lung-disorders in alemtuzumab treated MS patients. DAD is a potential, albeit rare side effect of alemtuzumab, broadening the spectrum of non-infective lung disorders that should be considered in the diagnostic work-up.

Pathological interpretation of connective tissue disease-associated lung diseases

Connective tissue diseases (CTDs) can affect all compartments of the lungs, including airways, alveoli, interstitium, vessels, and pleura. CTD-associated lung diseases (CTD-LDs) may present as diffuse lung disease or as focal lesions, and there is significant heterogeneity between the individual CTDs in their clinical and pathological manifestations. CTD-LDs may presage the clinical diagnosis a primary CTD, or it may develop in the context of an established CTD diagnosis. CTD-LDs reveal acute, chronic or mixed pattern of lung and pleural manifestations. Histopathological findings of diverse morphological changes can be present in CTD-LDs airway lesions (chronic bronchitis/bronchiolitis, follicular bronchiolitis, etc.), interstitial lung diseases (nonspecific interstitial pneumonia/fibrosis, usual interstitial pneumonia, lymphocytic interstitial pneumonia, diffuse alveolar damage, and organizing pneumonia), pleural changes (acute fibrinous or chronic fibrous pleuritis), and vascular changes (vasculitis, capillaritis, pulmonary hemorrhage, etc.). CTD patients can be exposed to various infectious diseases when taking immunosuppressive drugs. Histopathological patterns of CTD-LDs are generally nonspecific, and other diseases that can cause similar lesions in the lungs must be considered before the diagnosis of CTD-LDs. A multidisciplinary team involving pathologists, clinicians, and radiologists can adequately make a proper diagnosis of CTD-LDs.

Relapsing pneumonitis due to two distinct inhibitors of the MAPK/ERK pathway: report of a case

Background

BRAF and MEK are component of the MAPK/ERK pathway and inhibitors of these proteins have significantly improved the outcome of metastatic melanoma. We report for the first time two sequential episodes of pneumonitis presumably induced by trametinib (a MEK inhibitor) and vemurafenib (a BRAF inhibitor) in a 50 year-old man.

Case presentation

While receiving trametinib for a metastatic melanoma, the patient developed non-febrile acute respiratory failure in the context of bilateral ground-glass opacities and sub pleural reticulations on high resolution computed tomography. An excess of lymphocytes was found in the bronchoalveolar lavage fluid. Outcome was favorable after simple drug discontinuation. He subsequently developed a similar clinical-imaging picture 6 months into vemurafenib. A transthoracic lung biopsy disclosed interstitial lymphocytic infiltrate, poorly-formed granulomas with multinucleated giant cells and scattered eosinophils. Outcome was again favorable after simple drug discontinuation.

Conclusion

These two episodes in the same patient suggest that MAPK/ERK inhibitors may cause interstitial lung disease and may exert cross toxicity. This side effect is of particular interest for physicians in charge of patients with melanoma but this drug family is currently under development for several other solid tumors.

Histopathology of lung disease in the connective tissue diseases

The pathologic correlates of interstitial lung disease (ILD) secondary to connective tissue disease (CTD) comprise a diverse group of histologic patterns. Lung biopsies in patients with CTD-associated ILD tend to demonstrate simultaneous involvement of multiple anatomic compartments of the lung. Certain histologic patterns tend to predominate in each defined CTD, and it is possible in many cases to confirm connective tissue-associated lung disease and guide patient management using surgical lung biopsy. This article will cover the pulmonary pathologies seen in rheumatoid arthritis, systemic sclerosis, myositis, systemic lupus erythematosus, Sjögren syndrome, and mixed CTD.

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.

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.

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.

Diagnosis of interstitial lung diseases

Interstitial lung diseases (ILDs), a broad heterogeneous group of parenchymal lung disorders, can be classified into those with known and unknown causes. The definitions and diagnostic criteria for several major forms of ILDs have been revised in recent years. Although well over 100 distinct entities of ILDs are recognized, a limited number of disorders, including idiopathic pulmonary fibrosis, sarcoidosis, and connective tissue disease-related ILDs, account for most ILDs encountered clinically. In evaluating patients with suspected ILD, the clinician should confirm the presence of the disease and then try to determine its underlying cause or recognized clinicopathologic syndrome. Clues from the medical history along with the clinical context and radiologic findings provide the initial basis for prioritizing diagnostic possibilities for a patient with ILD. High-resolution computed tomography of the chest has become an invaluable tool in the diagnostic process. A confident diagnosis can sometimes be made on the basis of high-resolution computed tomography and clinical context. Serologic testing can be helpful in selected cases. Histopathologic findings procured through bronchoscopic or surgical lung biopsy are often needed in deriving a specific diagnosis. An accurate prognosis and optimal treatment strategy for patients with ILDs depend on an accurate diagnosis, one guided by recent advances in our understanding of the causes and pathogenetic mechanisms of ILDs.

Causes and prognosis of diffuse alveolar damage diagnosed on surgical lung biopsy

BACKGROUND

Diffuse alveolar damage (DAD) is a relatively common histopathologic finding at autopsy, particularly in patients dying with ARDS, and can result from a variety of causes. The spectrum of causes and associated prognostic implications for DAD diagnosed by surgical lung biopsy are unclear.

METHODS

We identified 58 consecutive patients with DAD diagnosed by surgical lung biopsy over a 7-year period, January 1996 through December 2002. The presenting clinicoradiologic features, causes, and clinical course of these patients were studied.

RESULTS

The median age was 61 years, 48% were women, and 60% were immunocompromised. Ninety percent of patients fulfilled the criteria for ARDS at the time of surgical lung biopsy. Chest radiography demonstrated bilateral parenchymal infiltrates, while CT revealed predominantly ground-glass and consolidative opacities. Infections were the most common cause of DAD (22%). Other causes were noninfectious pulmonary complications of hematopoietic stem-cell or solid-organ transplantation (17%), connective tissue diseases (16%), acute exacerbation of idiopathic pulmonary fibrosis (12%), drugs (10%), and radiation therapy (2%). Twelve patients (21%) had acute interstitial pneumonia (ie, no identifiable cause or predisposing condition for DAD). Overall hospital mortality was 53%, with the highest mortality (86%) occurring among patients for whom DAD represented acute exacerbation of idiopathic pulmonary fibrosis.

CONCLUSION

Our study showed that infections and acute interstitial pneumonia are the most common causes of DAD diagnosed by surgical lung biopsy. Hospital mortality rate associated with DAD may vary depending on the underlying cause.

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

Drug-induced lung disease is an increasingly common cause of morbidity and mortality. The diagnosis is based on clinical history and consistent radiologic findings. Lung biopsy is performed in a small percentage of cases. High-resolution CT may demonstrate parenchymal abnormalities in patients with normal radiographs and provides a better depiction of the pattern and distribution of findings. Knowledge of the most common high-resolution CT manifestations and the corresponding histologic patterns is important for early recognition and proper management of drug-induced lung disease.

Diagnosis and management of drug-associated interstitial lung disease

Symptoms of drug-associated interstitial lung disease (ILD) are nonspecific and can be difficult to distinguish from a number of illnesses that commonly occur in patients with non-small-cell lung cancer (NSCLC) on therapy. Identification of drug involvement and differentiation from other illnesses is problematic, although radiological manifestations and clinical tests enable many of the alternative causes of symptoms in advanced NSCLC to be excluded. In lung cancer patients, high-resolution computed tomography (HRCT) is more sensitive than a chest radiograph in evaluating the severity and progression of parenchymal lung disease. Indeed, the use of HRCT imaging has led to the recognition of many distinct patterns of lung involvement and, along with clinical signs and symptoms, helps to predict both outcome and response to treatment. This manuscript outlines the radiology of drug-associated ILD and its differential diagnosis in NSCLC. An algorithm that uses clinical tests to exclude alternative diagnoses is also described.