Drug-induced pulmonary disease. An update

Mimickers of novel coronavirus disease 2019 (COVID-19) on chest CT: spectrum of CT and clinical features

COVID-19 (coronavirus disease 2019) is a recently emerged pulmonary infection caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2). It started in Wuhan, China, in December 2019 and led to a highly contagious disease. Since then COVID-19 continues to spread, causing exponential morbidity and mortality and threatening economies worldwide. While the primary diagnostic test for COVID-19 is the reverse transcriptase-polymerase chain reaction (RT-PCR) assay, chest CT has proven to be a diagnostic tool of high sensitivity. A variety of conditions demonstrates CT features that are difficult to differentiate from COVID-19 rendering CT to be of low specificity. Radiologists and physicians should be aware of imaging patterns of these conditions to prevent an erroneous diagnosis that could adversely influence management and patients' outcome. Our purpose is to provide a practical review of the conditions that mimic COVID-19. A brief description of the forementioned clinical conditions with their CT features will be included.

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.

Small Airway Disease: A Step Closer to Etiology-Based Classification of Bronchiolitis

Three major histologic patterns of bronchiolitis: obliterative bronchiolitis, follicular bronchiolitis, and diffuse panbronchiolitis, are reviewed in detail. These distinct patterns of primary bronchiolar injury provide a useful starting point for formulating a differential diagnosis and considering possible causes. In support of the aim toward a cause-based classification system of small airway disease, a simple diagnostic algorithm is provided for further subclassification of the above 3 bronchiolitis patterns according to the major associated etiologic subgroups.

Acute Lung Injury

A wide variety of insults can produce acute lung damage, inclusive of those that injure the lungs directly. The clinical syndrome of acute onset respiratory distress, dyspnea, and bilateral infiltrates is referred to as acute respiratory distress syndrome. The histologic counterpart of acute respiratory distress syndrome is diffuse alveolar damage, classically characterized by hyaline membranes. Other histologic features of acute lung injury include intraalveolar fibrin, organization, interstitial edema, and reactive pneumocytes. Diffuse alveolar damage and other histologic features of acute lung injury are nonspecific as to etiology, and once identified require the pathologist to search the biopsy for further features that may help identify a specific etiology. This chapter reviews the temporal sequence of acute lung injury and explores the large variety of specific etiologic causes with emphasis on helpful histologic features to identify.

Pulmonary manifestations of urothelial carcinoma of the bladder

Urothelial carcinoma (Transitional cell carcinoma) of the bladder is the pre-dominant histological type of bladder cancer in the United States and Europe. Patients with bladder cancer usually present with painless hematuria. The diagnosis is often delayed, as the symptoms are similar to various other benign conditions such as urinary tract infection, prostatitis or renal calculi. In some patients, the metastatic lesions will cause the initial presenting symptoms. We conducted a MedLine/PubMED search identifying all relevant articles with "pulmonary manifestations", "urothelial bladder cancer", "manifestations of bladder cancer" or a combination of these terms in the title. The pulmonary manifestations of urothelial carcinoma of the bladder include metastatic disease including cavitary lesions, endobronchial, pleural, or lymph node metastasis pleural effusion and chylothorax. Pulmonary embolism and tumor embolism is another manifestation of this cancer. Intravesical Bacillus Calmette-Gurin therapy for bladder cancer has been associated with a range of adverse effects including the systemic spread of Bacilli Calmette-Guérin immunotherapy affecting the lungs. Other drugs used to treat bladder cancer can be associated with drug-related pneumonitis. Other rare manifestations include a sarcoid like reaction and systemic granulomatous disease to Bacilli Calmette-Guérin therapy. In this review we discuss the various pulmonary manifestations of urothelial carcinoma of the bladder. A high index of suspicion with these presentations can lead to an early diagnosis and assist in instituting an appropriate intervention.

Pain management in trauma: A review study

Background:

Pain in trauma has a role similar to the double-edged sword. On the one hand, pain is a good indicator to determine the severity and type of injury. On the other hand, pain can induce sever complications and it may lead to further deterioration of the patient. Therefore, knowing how to manage pain in trauma patients is an important part of systemic approach in trauma. The aim of this manuscript is to provide information about pain management in trauma in the Emergency Room settings.

Methods:

In this review we searched among electronic and manual documents covering a 15-yr period between 2000 and 2016. Our electronic search included Pub Med, Google scholar, Web of Science, and Cochrane databases. We looked for articles in English and in peer-reviewed journals using the following keywords: acute pain management, trauma, emergency room and injury.

Results:

More than 3200 documents were identified. After screening based on the study inclusion criteria, 560 studies that had direct linkage to the study aim were considered for evaluation based World Health Organization (WHO) pain ladder chart.

Conclusions:

To provide adequate pain management in trauma patients require: adequate assessment of age-specific pharmacologic pain management; identification of adequate analgesic to relieve moderate to severe pain; cognizance of serious adverse effects of pain medications and weighting medications against their benefits, and regularly reassessing patients and reevaluating their pain management regimen. Patient-centered trauma care will also require having knowledge of barriers to pain management and discussing them with the patient and his/her family to identify solutions.

Efficacy versus safety concerns for aerosol chemotherapy in non-small-cell lung cancer: a future dilemma for micro-oncology

Inhaled chemotherapy was first used more than 30 years ago. Since then, numerous chemotherapeutic agents have been used in either in vitro or in vivo studies. Several aspects of the methodology of the drug administration have been thoroughly demonstrated and explained. However, the safety concerns of these studies were not thoroughly investigated and different results regarding the same drug formulations have been reported. There are cases where the studies failed to demonstrate the long-term effects of the chemotherapeutic drug formulations to the lung parenchyma. Acute and latent effects observed in a small number of human trial studies are still under investigation of inhaled chemotherapy administration. This review provides data regarding all up-to-date inhaled chemotherapy studies and presents the methodological parameters of the safety measures incorporated. In addition, a commentary regarding the safety concerns for the medical staff participating in these studies will be presented.

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.

Thoracic complications of rheumatoid disease

Rheumatoid arthritis is a relatively common multisystem disease associated with significant mortality and morbidity. Thoracic disease, both pleural and pulmonary, is a frequent extra-articular manifestation of rheumatoid arthritis and responsible for approximately 20% of rheumatoid-associated mortality. Rheumatoid disease and its associated therapies can affect all compartments of the lung inciting a range of stereotyped pathological responses and it is not infrequent for multiple disease entities to co-exist. In some instances, development of pulmonary complications may precede typical rheumatological presentation of the disease and be the first indication of an underlying connective tissue disease. The spectrum of thoracic disease related to rheumatoid arthritis is reviewed.

Chronic cough as a complication of treatment with statins: a case report

Statins are widely used for primary and secondary prevention of cardiovascular disease. For this reason, knowledge of the side effects and interactions pertaining to this class of pharmaceuticals is of utmost importance to all physicians. In this text a case report is presented of an eighty year old gentleman, referred to the respiratory clinic at Mater Dei Hospital Malta after developing dry cough on being treated with simvastatin and fluvastatin. An attempt at switching over to a placebo was made with resolution of symptoms. This is the second described case in the literature of lone cough associated with statin therapy necessitating treatment discontinuation in our patient. Possible hypothesis are discussed as well as suggestions for further research to unravel the underlying mechanisms of this association.

Respiratory function assessment in safety pharmacology

The known effects of drugs from a variety of pharmacological/therapeutic classes on the respiratory system, the life-threatening consequences of respiratory dysfunction, and world-wide regulatory safety guidelines all support the need for conducting respiratory evaluations in safety pharmacology. This unit provides an overview of the functional disorders of the respiratory system and presents the techniques and strategies considered to be most appropriate for detecting and characterizing drug-induced respiratory disorders in safety pharmacology studies.

Subclinical interstitial lung abnormalities in stable renal allograft recipients in the era of modern immunosuppression

BACKGROUND

Interstitial lung abnormalities have been detected in up to 24% of kidney transplant patients receiving traditional immunosuppressive therapies (eg, cyclosporine, azathioprine); they usually occur early after transplantation and tend to resolve over time. Newer immunosuppressants such as mycophenolic acid and, particularly, mammalian target of rapamycin (mTOR) inhibitors (eg, sirolimus) may cause significant lung toxicity. However, the prevalence and severity of interstitial lung lesions in long-term, stable kidney transplant patients receiving either traditional or newer immunosuppressants is not known.

METHODS

We conducted a prospective, cross-sectional study examining high-resolution lung computed tomography (CT) scans in 63 stable kidney transplant recipients whose immunosuppressive therapy had remained unchanged for over 24 months. We compared CT findings of patients taking newer (mycophenolic acid and mTOR inhibitors) and traditional (calcineurin inhibitors and azathioprine) immunosuppressive drugs.

RESULTS

Interstitial lung alterations were observed in only 3/63 patients (4.8%); the prevalence was 11.5% (3/26) versus 0% (0/37) among the newer versus traditional immunosuppressive therapy groups, respectively (P = .065). The CT patterns were usual interstitial pneumonia and nonspecific interstitial pneumonia-like. The median time between transplant and CT was 49 months in the three patients with CT alterations and 95 months in the remaining 23 patients on newer immunosuppressants. It was 75 months for all patients on newer immunosuppressive drugs and 133 months for those on traditional therapies (P = .0015). A follow-up CT, performed in 2/3 patients with interstitial abnormalities, showed that the lesions were stable in one, while they had disappeared in the other.

CONCLUSIONS

Interstitial lung abnormalities are infrequent and mild in stable kidney transplant patients treated with newer as well as traditional immunosuppressive drugs. As such abnormalities were detected in patients screened earlier after transplantation, the time since transplantation rather than the drug type is probably the major determinant.

Prospective evaluation of drug-induced lung toxicity with high-resolution CT and transbronchial biopsy

PURPOSE

This study compared the results of high-resolution computed tomography (HRCT) and cytohistology after transbronchial biopsy in the evaluation of drug-related interstitial lung disease (DR-ILD).

MATERIALS AND METHODS

Patients with a clinical and imaging diagnosis of DR-ILD were prospectively included in a study protocol lasting 5 years. All patients were evaluated by bronchoscopy with transbronchial biopsy or bronchoalveolar lavage (BAL) following an HRCT examination that raised a suspicion of DR-ILD. Two radiologists (one senior and one junior), unaware of the diagnosis, reported the single HRCT findings, their distribution and predominant pattern. In the event of disagreement, the diagnosis was subsequently reached by consensus. Cytohistological examination was considered the gold standard in the diagnosis of DR-ILD. Patients who were unable to undergo the endoscopic procedure were excluded from the study.

RESULTS

The study included 42 patients (25 men, 17 women; age range 20-84 years). Transbronchial biopsy was performed in all but four patients (one case of alveolar haemorrhage and three cases of lipoid pneumonia) in whom the diagnosis was established with BAL. Assessment of the HRCT images revealed the following patterns: noncardiogenic pulmonary oedema (n=13); organising pneumonia (OP) (n=9); hypersensitivity pneumonitis (HP) (n=2); alveolar haemorrhage (AH) (n=2); nonspecific interstitial pneumonia (NSIP) (n=5); lipoid pneumonia (LP) (n=1); sarcoid-like pattern (n=1). Cytohistological diagnosis revealed diffuse alveolar damage (DAD) in 11 patients, OP in seven, HP in three, AH in three, chronic interstitial pneumonia (CIP) in eight, LP in three and pseudosarcoidosis in one. Subdivision of the drugs into antineoplastic and nonantineoplastic agents showed that the most common patterns were CIP (n=6), DAD (n=2) and OP (n=2) in the antineoplastic group and DAD (n=9) and OP (n=5) in the nonantineoplastic group. Sensitivity and specificity of the radiological analysis was excellent, especially for patterns such as OP and DAD (sensitivity 0.86 and specificity 0.88 for OP; sensitivity 1 and specificity 0.93 for DAD).

CONCLUSIONS

HRCT demonstrated excellent sensitivity and specificity. In cases in which its specificity was low, HRCT was nonetheless useful for biopsy planning and clinical-radiological monitoring after discontinuation of the drug treatment.

Grundlagen der systemischen Therapie

Die Einführung sog. »zielgerichteter Medikamente« hat einen Paradigmenwechsel in der Systemtherapic maligner Erkrankungen ausgelöst. Voraussetzung hierfür waren die in den letzten 25 Jahren gesammelten Erkenntnisse der molekularbiologischen, molekulargenetischen und immunologischen Grundlagenforschung, die ein besseres Verständnis der pathogenetischen Prozesse im Rahmen der malignen Transformation und Tumorprogression sowie die Identifikation strategischer Zielstrukturen (»Targets«) ermöglichen. Auf diese Weise wurde ein neuer Ansatz der Entwicklung antineoplastischer Therapeutika angestoßen, der auf die Wirkung an spezifischen Molekülaktivitäten und nicht primär auf zelluläre Endpunkte (Wachstumshemmung, Zelltod) ausgerichtet ist.

Methotrexate pneumonia lacking dyspnea and radiographic interstitial patterns during treatment for early rheumatoid arthritis: bronchoalveolar lavage and transbronchial lung biopsy in a differential diagnosis

Methotrexate (MTX) pneumonia is an unpredictable and sometimes life-threatening adverse effect occurring in the treatment of rheumatoid arthritis (RA). We present a case of MTX pneumonia lacking severe respiratory symptoms and typical radiographic findings. A 66-year-old man with early RA presented with intermittent fever and nonproductive cough during the MTX therapy, but neither hypoxemia nor dyspnea was a complaint. His chest X-ray films revealed multiple bilateral consolidations, but interstitial infiltrates were not observed. High-resolution computed tomography showed no ground-glass opacities. In contrast, the histological findings of transbronchial lung biopsy (TBLB) samples were characterized by the interstitial infiltration of mononuclear cells and hyperplasia of type II alveolar cells, which are the main features of drug-induced interstitial inflammation. Special stains for microorganisms were negative for the TBLB samples. Although cultures of bronchoalveolar lavage (BAL) fluids were slightly positive for Haemophilus influenzae, intensive antibiotic therapy was ineffective. A discontinuation of MTX followed by steroid therapy induced the patient's dramatic recovery. A new treatment with tacrolimus was started for RA. We would like to emphasize that the histological examinations and microbiological studies using BAL and TBLB are useful for the exclusion of other causes and the diagnosis of MTX pneumonia, especially in a case without typical respiratory symptoms and radiographic patterns.

Arzneimittelinduzierte Lungenerkrankungen

Von mehr als 350 Medikamenten ist bekannt, dass sie zu unerwünschten Wirkungen an Lunge, Bronchien und den benachbarten Strukturen des Thorax führen können. Dementsprechend ist das Spektrum der pathologischen Veränderungen. Leitsymptome sind häufig eine unter Belastung neu aufgetretene Dyspnoe und ein in der Regel trockener Husten. Die weiterführende Diagnostik beinhaltet eine erweiterte Lungenfunktionsprüfung inklusive Diffusionskapazitätsbestimmung, ein hochauflösendes Computertomogramm und eine Bronchoskopie mit bronchoalveolärer Lavage. Es gibt keine für ein definiertes Medikament spezifische pathologische Änderung. Im Zweifelsfall muss das potenziell pneumotoxische Medikament abgesetzt werden. Bei erheblicher funktioneller Beeinträchtigung wird ein Therapieversuch mit systemischen Kortikosteroiden eingeleitet.

Tc-99m HMPAO Scintigraphy in Amiodarone-Induced Acute Lung Toxicity

PURPOSE

This case demonstrates the use of Tc-99m HMPAO scintigraphy in amiodarone (AD)-induced lung toxicity. The aim of this presentation is also to discuss different scintigraphic modalities in the diagnosis and follow up in AD-induced lung toxicity.

MATERIALS AND METHODS

A 77-year-old man, with a suspicious AD-induced acute lung toxicity, underwent Tc-99m DTPA aerosol inhalation scintigraphy and Tc-99m HMPAO scintigraphy.

RESULTS

Rapid alveolar clearance of Tc-99m DTPA was found during AD therapy and increased lung uptake of Tc-99m HMPAO was also demonstrated. These findings supported the diagnosis AD lung toxicity. After cessation of therapy, Tc-99m DTPA alveolar clearance was decreased. Although there was some decrease in L/H and L/B ratios of Tc-99m HMPAO after 3 weeks of stopping therapy, Tc-99m HMPAO uptake in the lungs was still continued. This finding may be the result of ongoing pulmonary inflammation as a result of the long half-life of AD.

CONCLUSION

Compared with Tc-99m DTPA aerosol inhalation scintigraphy, Tc-99m HMPAO scintigraphy may have a role in the diagnosis of AD lung toxicity. Nevertheless, there is a need for longitudinal studies investigating patients under AD therapy using follow-up Tc-9m HMPAO scintigraphy.

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.

Long-term pulmonary function after lobectomy for primary lung cancer

The aim of this study was to investigate the factors affecting long-term postoperative pulmonary function with a view to increasing the application of combined resection, bronchoplasty, and induction therapy. Results in 80 patients who underwent lobectomy for primary lung cancer were analyzed. Predicted postoperative pulmonary function was calculated using the formula: postoperative predicted function=preoperative function x[1-(b-n)/(42-n)], where n and b are the numbers of obstructed segments and total segments, respectively, in the resected lobe. Spirometry was performed serially on the preoperative day, and at 3, 6, 12, 18, and 24 months postoperatively. The difference between the predicted postoperative pulmonary function and the function measured at 12 months postoperatively was calculated, and clinical and therapeutic variables were analyzed. Univariate analysis revealed that the difference in vital capacity was significantly related to surgical approach, bronchoplasty, and induction therapy, while the difference in forced expiratory volume in one second (FEV1) correlated with surgical approach and induction therapy. Multiple regression analysis showed induction therapy to be the sole factor related to the differences in both vital capacity and FEV1. Lung resection after induction therapy may cause an additional loss of pulmonary function in the late phase.

Drug-Induced Eosinophilic Pneumonia: High-Resolution CT Findings in 14 Patients

OBJECTIVE

The purpose of this study was to evaluate the high-resolution CT findings of drug-induced eosinophilic pneumonias.

CONCLUSION

Drug-induced eosinophilic pneumonias usually manifest as areas of consolidation and ground-glass opacity most commonly involving the outer third of the lungs.

[Drug-induced pulmonary damage]

The frequency of drug-induced damage to the lung in inpatients is estimated to be about 10%. Pathoanatomically, varying damage patterns result, ranging from acute pulmonary edema via inflammatory reactions to pulmonary fibrosis. The ATS/ERS 2001 classification, which is based on the suggestions made by Liebow 1969, is an accepted system for classifying findings according to recurring patterns. Generally, there are no specific morphological findings which allow safe conclusions on possible administered drugs. Clinical information is mandatory. Differentiation from pulmonary alterations due to the underlying disease is often difficult. In daily routine diagnostics, it is important to consider iatrogenic causal factors in cases of "undetermined pulmonary disease".

Bronchiolitis obliterans organizing pneumonia as an initial manifestation in systemic lupus erythematosus

Bronchiolitis obliterans organizing pneumonia (BOOP) is a rare complication of adult systemic lupus erythematosus (SLE). This is the first report of a pediatric patient with BOOP as an initial presentation of SLE. She had dyspnea, cough, arthralgia, and erythema on her face. Laboratory examinations revealed pancytopenia, low serum levels of complements, and positivity for anti-nuclear antibody, anti-double stranded DNA antibody, and anti-SM antibody. Her respiratory symptoms, pulmonary function tests, and radiologic findings showed significant improvement after treatment with oral prednisolone. Although it is a rare complication among the pleuro-pulmonary manifestations in SLE, BOOP can be the first presentation, even in pediatric patients.

Methotrexate pulmonary toxicity

Methotrexate is a commonly prescribed antineoplastic and immune modulating compound that has gained wide acceptance in the management of rheumatoid arthritis, psoriasis, sarcoidosis and a number of neoplastic disorders. Although generally considered safe and easy to use, methotrexate has been associated with a number of adverse reactions. Pulmonary toxicity has been well-described and may take a variety of forms. Pulmonary infiltrates are the most commonly encountered form of methotrexate pulmonary toxicity and these infiltrates resemble hypersensitivity lung disease. This discussion focuses primarily on low-dose methotrexate pulmonary toxicity and will discuss the diagnosis using clinical, pulmonary function, radiographical and pathological manifestations. Suggestions for clinical monitoring to detect adverse effects are given. In addition, management of pulmonary toxicity through discontinuation of the methotrexate, support and possibly the administration of corticosteroids is discussed.

[Drug-associated interstitial lung disease: a diagnostic challenge]

Drugs are frequently incriminated as the cause of interstitial pneumonia. There are two major mechanisms of drug-associated interstitial lung disease: direct toxicity and immunoallergic reaction. When a drug is suspected, the difficulty lies in obtaining proof. The chronology of the disease and its manifestations together with earlier evidence reported in the literature can lead to a tentative diagnosis of drug-associated interstitial pneumonia. Proof is obtained through surveillance during the disease course. In nearly all patients, therapeutic decisions must be taken on the basis of suspected drug involvement.

Chest imaging in iatrogenic respiratory disease

Iatrogenic respiratory disease is an important cause of patient morbidity and mortality. Clinical and radiologic findings are nonspecific and diagnosis can be difficult. Therefore, it is important for physicians to be familiar with the iatrogenic diseases for which their patients are at risk, as well as their common radiologic appearances. Causes of iatrogenic respiratory disease include drugs, transplantation, radiation, transfusion, or other miscellaneous therapies.

Pathologic characteristics of drug-induced lung disease

The surgical pathologist's role in the diagnosis of adverse pulmonary and pleural drug effect requires an appreciation of the clinico-radiologic scenario and particular knowledge of morphologic patterns of lung injury. Bronchoscopic biopsies may be helpful in some cases of DAD, eosinophilic pneumonia, or OP. Extrapolating patterns of lung involvement from small biopsies and cytologic preparations often is difficult and surgical lung biopsy is required. Although lung biopsies are not pathognomonic for drug toxicity and correlation with clinical, laboratory, and radiologic data is required, they can be a powerful tool in the evaluation of suspected drug-induced pulmonary disease by helping to exclude underlying disease or infection and documenting the pattern of lung injury. The latter information is helpful in making the diagnosis of drug toxicity as well as guiding the optimal management of the patient.

Association between acute and chronic graft-versus-host disease and bronchiolitis obliterans organizing pneumonia in recipients of hematopoietic stem cell transplants

Bronchiolitis obliterans organizing pneumonia (BOOP) has been reported following hematopoietic stem cell (HSC) transplantation, but the clinical features and risk factors for this disorder have not been well characterized. This case-control study of 49 patients with histologic BOOP and 161 control subjects matched by age and year of transplantation describes the clinical features and analyzes the risk factors for BOOP following HSC transplantation. Data on clinical features and outcome were collected by chart review. Odds ratios, estimating the relative risk of BOOP in allogeneic HSC recipients, were calculated by conditional logistic regression with adjustment for potential confounding factors. Clinical features of BOOP in this population were similar to idiopathic BOOP and BOOP occurring in other disease settings. There was an association between acute and chronic graft-versus-host disease (GVHD) and the subsequent development of BOOP (odds ratios, 3.8 [95% CI, 1.2 to 12.3] and 3.1 [95% CI, 1.1 to 9.2], respectively). Patients with BOOP were more likely to have acute GVHD involving the skin (odds ratio, 4.6; P =.005) and chronic GVHD involving the gut (odds ratio, 6.6; P =.018) and oral cavity (odds ratio, 5.9; P =.026). This study shows that histologic BOOP following HSC transplantation has clinical features that resemble idiopathic BOOP and is strongly associated with prior acute and chronic GVHD. These results have important implications for the care of patients who develop respiratory symptoms after HSC transplantation and may help elucidate the pathogenesis of idiopathic BOOP.

Circulating KL-6 levels in patients with drug induced pneumonitis

BACKGROUND

The circulating level of KL-6/MUC1 is a sensitive marker for various interstitial lung diseases. Previous case reports have suggested that KL-6 may also be increased in some patients with drug induced pneumonitis. A study was undertaken to determine whether serum KL-6 could be a marker for particular types of drug induced pneumonitis.

METHODS

The findings of high resolution computed tomographic (HRCT) chest scans of 30 patients with drug induced pneumonitis were reviewed separately by two independent observers. The pneumonitis was classified into four predominant patterns: widespread bilateral consolidation (diffuse alveolar damage, DAD; n=7), fibrosis with or without consolidation (chronic interstitial pneumonia, CIP; n=11), consolidation without fibrosis (bronchiolitis obliterans organising pneumonia or eosinophilic pneumonia, BOOP/EP; n=8), and diffuse ground glass opacities without fibrosis (hypersensitivity pneumonitis, HP; n=4). Serum KL-6 levels were measured by a sandwich enzyme linked immunosorbent assay.

RESULTS

The overall sensitivity of serum KL-6 in detecting drug induced lung disease was 53.3%, which was lower than its sensitivity in detecting other interstitial lung diseases. However, the KL-6 level was increased in most patients with a DAD or CIP pattern (16/18; 88.9%) and was closely correlated with their clinical course. In contrast, serum KL-6 levels were within the normal range in all patients with a BOOP/EP or HP pattern.

CONCLUSIONS

Particular patterns detected by HRCT scanning, such as DAD and CIP but not the BOOP/EP or HP patterns, are associated with increased circulating KL-6 levels in drug induced pneumonitis. Serum KL-6 levels may reflect the clinical activity of the particular disorders.

Technetium-99m-DTPA aerosol scintigraphy in amiodarone induced pulmonary toxicity in comparison with Ga-67 scintigraphy

Amiodarone hydrochloride, which is used in life-threatening cardiac tachyarrhythmia, has been known to cause amiodarone induced pulmonary toxicity (AIPT) as a complication. In this study we aimed to investigate the clinical value of technetium-99m diethylene triamine penta-acetic acid (DTPA) aerosol lung scintigraphy in patients with AIPT in comparison with gallium-67 (Ga-67) scan. The study group included 26 cases, 7 patients with diagnosis of AIPT (Group A), 8 patients receiving amiodarone therapy but without AIPT (Group B) and 11 healthy subjects as a control group (Group C). All patients underwent Ga-67 and Tc-99m-DTPA aerosol scintigraphy in addition to various laboratory tests, Ga-67 scintigraphy was positive in 4 of 7 AIPT patients but quite normal in Group B. A positive correlation was found (r = 0.52, p < 0.05) between kep values determined by Tc-99m-DTPA aerosol scintigraphy and the cumulative dose of amiodarone. The mean kep values were 2.04% +/- 0.85%/min, 1.30% +/- 0.42%/min and 0.86% +/- 0.19%/min for groups A, B and C, respectively. The mean clearance rate of group A was significantly faster than that of normals (p < 0.0005) and group B (p = 0.028). In addition, there was a significant difference between groups B and C (p = 0.015). In conclusion, Ga-67 lung scintigraphy is a useful method for the detection of AIPT but Tc-99m-DTPA aerosol scintigraphy offers better results than Ga-67 scintigraphy. Early changes in Tc-99m-DTPA clearance may be observed in patients receiving amiodarone. The kep value in patients with AIPT is noticeably increased with respect to the control group. With its favorable physical properties, low cost, lower radiation burden and its ability to be used as an objective measure for the pulmonary clearance rate, Tc-99m-DTPA aerosol scintigraphy appears to be promising in patients receiving amiodarone therapy.

Drug-induced lung disease: high-resolution CT and histological findings

AIM

To compare the parenchymal high-resolution computed tomography (HRCT) appearances with histological findings in patients with drug-induced lung disease and to determine the prognostic value of HRCT.

MATERIALS AND METHODS

Drug history, HRCT features, histological findings and outcome at 3 months in 20 patients with drug induced-lung disease were reviewed retrospectively. The HRCT images were assessed for the pattern and distribution of abnormalities and classified as most suggestive of interstitial pneumonitis/fibrosis, diffuse alveolar damage (DAD), organizing pneumonia (OP) reaction, or a hypersensitivity reaction.

RESULTS

On histopathological examination there were eight cases of interstitial pneumonitis/fibrosis, five of DAD, five of OP reactions, one of hypersensitivity reaction and one of pulmonary eosinophilia. The most common abnormalities on HRCT were ground-glass opacities (n = 17), consolidation (n = 14), interlobular septal thickening (n = 15) and centrilobular nodules (n = 8). HRCT interpretation and histological diagnosis were concordant in only nine (45%) of 20 patients. The pattern, distribution, and extent of HRCT abnormalities were of limited prognostic value: all eight patients with histological findings of OP, hypersensitivity reaction, or eosinophilic infiltrate improved on follow-up compared to only five of 13 patients with interstitial pneumonitis/fibrosis or DAD.

CONCLUSION

In many cases of drug-induced lung injury HRCT is of limited value in determining the histological pattern and prognosis.

High-resolution CT of drug-induced lung disease

Drug-induced pulmonary toxicity is increasing and early diagnosis is important because of the associated morbidity and mortality. Diagnosis is often difficult and is usually based on a history of drug therapy and exclusion of infection, radiation pneumonitis, and recurrence of the underlying disease. Although HRCT findings are frequently nonspecific, diagnosis can be facilitated by an understanding of the most common histopathologic and radiologic manifestations of drug-induced lung injury and knowledge of the drugs usually involved.

Drug-induced lung injury

Lung injury is an increasing cause of morbidity and mortality in patients treated with cytotoxic and noncytotoxic drugs. Prompt diagnosis is important because early drug-induced lung injury will often regress with the cessation of therapy. Diagnosis requires a high index of suspicion because infection, radiation pneumonitis, and recurrence of the underlying disease can manifest clinically and radiologically in a similar manner. Because the lungs have only a limited number of histopathologic responses to injury, including pulmonary edema/diffuse alveolar damage, NSIP, BOOP, EP, and pulmonary hemorrhage, knowledge of these manifestations and the corresponding radiologic manifestations can often be useful in suggesting a diagnosis of drug-induced lung injury. An understanding of the drugs most commonly associated with lung injury can also facilitate diagnosis.

Noncardiogenic pulmonary edema: an unusual and serious complication of anticancer therapy

Noncardiogenic pulmonary edema (NCPE) is a rare and less well-recognizable pulmonotoxic syndrome of anticancer therapy than pneumonitis/fibrosis. NCPE is a clinical syndrome characterized by simultaneous presence of severe hypoxemia, bilateral alveolar infiltrates on chest radiograph, and no evidence of left atrial hypertension/congestive heart failure. The diagnosis of drug-related NCPE relies upon documented exclusion of any infectious, metabolic, or cancer-related causes. The time proximity to therapy with drugs that are known to precipitate NCPE, any preceding episodes of flu-like symptoms during previous chemotherapy courses and possible response to corticosteroids may further support such a diagnosis. Cancer therapeutic agents clearly associated with NCPE are cytarabine, gemcitabine, and interleukin-2, as well as all-trans retinoic acid in acute promyelocytic leukemia patients, while a few other compounds have rarely or occasionally been implicated. The pathophysiology of lung injury in drug-induced NCPE remains unclear. There are indications suggesting that both a direct cytotoxic insult to the lung epithelial cells and induction of a cytokine-triggered inflammatory response may be involved in its pathogenesis. By distinction to drug-induced pulmonary pneumonitis that may lead to permanent pulmonary fibrosis, NCPE if not fatal, can be reversed upon prompt recognition, following immediate discontinuation of the offensive drug and start of intensive supportive treatment and intravenous corticosteroids.

Evaluation of pulmonary infiltrates in critically ill patients with cancer and marrow transplant

Pulmonary infiltrates in critically ill patients with cancer or marrow transplant can be evaluated by the differential diagnosis presented at the beginning of this article. The patient's quantitative immune system dysfunction, epidemiologic history and chest radiographic findings (pattern, rapidity, and time of onset) will help focus the differential diagnosis. In this patient population, however, common diagnoses can have atypical presentations, unusual diagnoses do occur, and more than one process may be responsible for a patient's infiltrates. Early bronchoscopy to rule out infection is the focus of diagnostic testing. Surgical lung biopsy in this patient population has a low yield.

Melphalan-associated pulmonary toxicity following high-dose therapy with autologous hematopoietic stem cell transplantation

Melphalan can rarely cause interstitial pneumonitis and fibrosis. Although it has been reported previously in patients after conventional doses, we report four cases developing diffuse interstitial pneumonitis (DIP) after high-dose melphalan-based therapy. In a 3-year period, four of 57 (7%) consecutive patients undergoing high-dose melphalan (200 mg/m2; MEL 200) were identified with DIP. Two patients who were heavily pre-treated with alkylators developed progressive respiratory failure despite high-dose steroids and eventually died. The other two patients previously treated with vincristine, adriamycin, and dexamethasone (VAD) improved dramatically on high-dose steroids with complete resolution of their pneumonitis. Melphalan should be added to the growing list of alkylators causing pulmonary toxicity.

Recent advances in the aetiology of cryptogenic fibrosing alveolitis

Crytogenic fibrosing alveolitis is the commonest intersititial lung disease but, until recently, very little has been known about its aetiology. The histopathologist usually sees this disease at transbronchial biopsy or at autopsy. This article reviews the current knowledge of the aetiology of cryptogenic fibrosing alveolitis looking at possible infective, occupational, drug-related, smoking-associated, genetic and dietary factors. Knowledge of the possible roles of these factors in the disease process informs histopathologists when they are reporting these biopsies and enables them to make a larger contribution to defining the pathogenetic mechanisms.