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

Organizing Pneumonia With Diffuse Alveolar Hemorrhage Induced by the Kampo Medicine Choreito

Kampo medicine, a traditional Japanese herbal medicine, is covered by the Japanese National Health Insurance and prescribed for various purposes. While relatively safe with few adverse effects, it may potentially cause severe adverse effects, such as lung injury. Herein, we describe the case of a 61-year-old Japanese woman with choreito-induced lung injury that manifested as organizing pneumonia (OP) with diffuse alveolar hemorrhage (DAH). She was referred to our department due to multiple abnormal opacities detected on annual chest radiography. Chest computed tomography (CT) revealed multiple nodules in bilateral lungs. Bloody bronchoalveolar lavage fluid was obtained from the left lingular lobe, appearing nearly normal, while a transbronchial lung biopsy from a subpleural nodule in the left lower lobe was pathologically consistent with OP. The drug lymphocyte stimulation test result was positive for choreito, which the patient had regularly consumed for 6 - 7 months to treat hematuria. Consequently, a diagnosis of choreito-induced OP and DAH was made. Owing to the discontinuation of choreito alone and without the introduction of systemic steroid therapy, the multiple nodules shrank and eventually disappeared on follow-up chest CT. Regardless of the type of crude drug used in Kampo medicine, clinicians must always be careful for potential lung injury, which may present as OP with DAH.

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.

Pathological Roles of Pulmonary Cells in Acute Lung Injury: Lessons from Clinical Practice

Interstitial lung diseases (ILD) are relatively rare and sometimes become life threatening. In particular, rapidly progressive ILD, which frequently presents as acute lung injury (ALI) on lung histopathology, shows poor prognosis if proper and immediate treatments are not initiated. These devastating conditions include acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF), clinically amyopathic dermatomyositis (CADM), epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-induced lung injury, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection named coronavirus disease 2019 (COVID-19). In this review, clinical information, physical findings, laboratory examinations, and findings on lung high-resolution computed tomography and lung histopathology are presented, focusing on majorly damaged cells in each disease. Furthermore, treatments that should be immediately initiated in clinical practice for each disease are illustrated to save patients with these diseases.

Serum Biomarkers in a Radiological Pattern of Non-Fibrotic Hypersensitivity Pneumonitis: Implications for Mechanistic Difference and Differential Diagnosis

Hypersensitivity pneumonitis (HP) is a consequence of immune-mediated reactions caused by recurrent exposure to environmental agents. Recently, clinical practice guidelines for the diagnosis of HP were published and increased interest in HP. On the other hand, novel therapies have recently emerged for various diseases, and the management of drug-related pneumonitis (DRP) has become increasingly important. Among DRP, the HP pattern (DRP-HP) shows small, poorly defined centrilobular nodules with or without widespread areas of ground-glass opacity or lobular areas of decreased attenuation and vascularity. A similar radiological pattern of non-fibrotic HP can be induced, irrespective of inhalation (non-fibrotic HP) or intravenous administration (DRP-HP). However, their difference has not been well described, although the distribution of lesions in the lungs was slightly different between these two conditions. In this review, we focus on serum biomarkers of lung epithelial cells in order to investigate the difference between DRP-HP and non-fibrotic HP (common-HP). Serum levels of Krebs von den Lungen 6 (KL-6) might be relatively lower (occasionally normal) in DRP-HP than in common-HP, implying a mechanistic difference. KL-6 could be useful in discriminating between DRP and non-fibrotic HP (common type).

Drug-related pneumonitis with radiographic hypersensitivity pneumonitis pattern: Three case series

Novel therapies have recently emerged for various diseases, and the management of drug-related pneumonitis (DRP) has become increasingly important. In particular, the hypersensitivity pneumonitis (HP) pattern of DRP has been increasingly recognized due to development of new therapeutic strategies, such as immunotherapy. However, literature describing detailed clinical cases is still lacking.

Herein, we report three cases of DRP with typical HP radiographic pattern. These patients were treated with different drugs, namely nano albumin-bound (nab)-paclitaxel, everolimus, or nivolumab, but had common clinical features, including a good prognosis.

Diagnosis and treatment of drug-induced interstitial lung disease

Drug-induced interstitial lung disease (DILD) is a group of adverse drug reactions that is rare but fatally toxic. Pulmonary toxicity causes inflammation and subsequent interstitial fibrosis. As novel drugs with a variety of purposes are introduced into the medical field, the number of culprit medications that are suspected to cause lung complications is accordingly increasing. In this review, DILD will be discussed from several aspects such as causality by numerous drugs, check points for a timely diagnosis, alongside some contemporary treatment options. The exact mechanism of DILD has not been elucidated, and a useful clinical, radiological, or pathological confirmation process is still lacking. Common drugs which casue DILD include bleomycin, amiodarone, epidermal growth factor receptor-targeted agents, and immune checkpoint inhibitors. Diagnosis is based on a suspicious drug administration history, somewhat inconsistent clinical symptoms and signs, radiological hints, and histopathological assistance, together with the exclusion of other lung-injuring etiologies. Cessation of the suspected drug, meticulous corticosteroid usage, and ancillary supportive management are the mainstay therapeutic strategy for DILD. Most cases of DILD respond to these countermeasures and reductions, but in some cases the fibrotic process worsens, leading to irreversible sequelae on the affected lung.

Interstitial lung disease induced by the roots of Achyranthes japonica Nakai: Three case reports

BACKGROUND

The roots of Achyranthes japonica Nakai (AJN), called “Useul-puli,” has been traditionally used to control pain and improve dysfunction in osteoarthritis patients in South Korea.

CASE SUMMARY

We described 3 patients diagnosed with herbal medicine induced interstitial lung disease after consuming boiled the roots of AJN. They were referred to our hospital because of the modified Medical Research Council grade 4 dyspnea. Chest computed tomography showed bilateral ground-glass opacities with patchy consolidation. After treatment with systemic glucocorticoid therapy and discontinuation of the roots of AJN, their symptoms improved, and almost all ground-glass opacities and patchy consolidations on chest radiography and chest computed tomography resolved.

CONCLUSION

We present three cases of interstitial lung disease induced by the roots of AJN.

[Drug-induced interstitial lung disease: approaches to diagnostics and treatment]

Drug-induced interstitial lung disease (D-ILD) can be caused by various drugs, including antibiotics, amiodarone, antitumor, rheumatological and non-steroidal anti-inflammatory drugs. D-ILD includes hypersensitivity reactions, organizing and non-specific interstitial pneumonia, eosinophilic lung diseases, diffuse alveolar damage and alveolar hypoventilation. To exclude other causes of pulmonary diseases, an assessment of the medical history, physical data and examination results, which may include chest X-ray/multispiral computed tomography (MSCT), lung function tests, and bronchoscopy with bronchoalveolar lavage, are necessary. Diagnosis of D-ILD is difficult due to the heterogeneity of clinical, radiological and histological data. The X-ray pathological phenotype of D-ILD is different; a specific MSCT pattern has not been identified. Treatment includes drug withdrawal and, in some cases, glucocorticoid therapy, although there are no prospective studies on their effect on the outcome of the disease. This article provides various drugs that cause ILD, approaches to their diagnosis and treatment.

Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis

BACKGROUND

Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association.

METHODS

Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated.

RESULTS

The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively.

CONCLUSIONS

In this study, a remarkable difference in radiological findings was observed among different BALF patterns.

Drug-Induced Interstitial Lung Disease: A Systematic Review

Background: Drug-induced interstitial lung disease (DIILD) occurs as a result of numerous agents, but the risk often only becomes apparent after the marketing authorisation of such agents. Methods: In this PRISMA-compliant systematic review, we aimed to evaluate and synthesise the current literature on DIILD. Results: Following a quality assessment, 156 full-text papers describing more than 6000 DIILD cases were included in the review. However, the majority of the papers were of low or very low quality in relation to the review question (78%). Thus, it was not possible to perform a meta-analysis, and descriptive review was undertaken instead. DIILD incidence rates varied between 4.1 and 12.4 cases/million/year. DIILD accounted for 3–5% of prevalent ILD cases. Cancer drugs, followed by rheumatology drugs, amiodarone and antibiotics, were the most common causes of DIILD. The radiopathological phenotype of DIILD varied between and within agents, and no typical radiological pattern specific to DIILD was identified. Mortality rates of over 50% were reported in some studies. Severity at presentation was the most reliable predictor of mortality. Glucocorticoids (GCs) were commonly used to treat DIILD, but no prospective studies examined their effect on outcome. Conclusions: Overall high-quality evidence in DIILD is lacking, and the current review will inform larger prospective studies to investigate the diagnosis and management of DIILD.

Japanese herbal medicine-induced pneumonitis: A review of 73 patients

BACKGROUND

The number of reports concerning Japanese herbal medicine (JHM)-induced pneumonitis has increased. However, comprehensive data are lacking in this regard, and the clinical characteristics of the disease remain unclear.

METHODS

A literature review was performed using PubMed and Ichushi-Web-the database of the Japan Medical Abstracts Society-to identify articles published between 1996 and 2015 describing patients with JHM-induced pneumonitis. The final cohort included 73 patients in 59 articles (7 in English; 52 in Japanese).

RESULTS

Among the various JHMs reported, sho-saiko-to was the most frequently used drug (26%), followed by sairei-to (16%), seishin-renshi-in (8%), and bofu-tsusyo-san (8%). These drugs commonly contain ougon (skullcap) and kanzo (liquorice). The mean age at pneumonitis diagnosis was 63.2 ± 15.5 years (range: 7-89 years). The male/female ratio was 44/29. Sixty-five patients (89%) developed pneumonitis within 3 months of beginning JHM treatment. Bilateral ground-glass attenuations on chest computed tomography, as well as lymphocytosis with a low CD4/CD8 T-cell ratio in bronchoalveolar lavage fluid, were common findings. Twenty-six patients (36%) recovered from the pneumonitis after simply discontinuing the causative JHM. However, the remainder required immunosuppressive therapy, and 13 patients (18%) received mechanical ventilation. Importantly, three patients (4%) did not survive, with two showing pathological diffuse alveolar damage upon autopsy.

CONCLUSIONS

Clinicians should be cautious regarding JHM-induced pneumonitis, particularly when using drugs/ingredients known to cause this complication, and during the early treatment period. Although most events are non-severe, critical cases should be recognized.

Soluble thrombomodulin in bronchoalveolar lavage fluid is an independent predictor of severe drug-induced lung injury

BACKGROUND AND OBJECTIVE

Drug-induced lung injury (DLI) can result from a vast number of agents, and sometimes presents findings similar to those of acute respiratory distress syndrome (ARDS). Previous studies have reported that circulating levels of soluble thrombomodulin (TM) reflect endothelial injuries, which play key roles in the development of ARDS. We hypothesized that endothelial injuries are an important aspect of pathogenesis in severe DLI. The primary aim of this study was to examine the associations between soluble TM and disease severity in DLI patients.

METHODS

Of the 2580 patients who underwent a bronchoalveolar lavage (BAL) procedure at Tosei General Hospital between May 2007 and February 2015, we retrospectively analysed the data of 68 DLI patients. Soluble TM in plasma and BAL fluid (BALF), and other biomarkers were included in our analysis.

RESULTS

At the time of diagnosis, 39 patients (57%) had respiratory failure (partial pressure of oxygen/inspiratory oxygen fraction ratio, PaO₂ /FiO₂ ratio < 300). There was a significant negative linear correlation between the PaO₂ /FiO₂ ratio and soluble TM in BALF (r = -0.448, P < 0.001). In a stepwise multiple regression analysis, soluble TM in BALF and surfactant protein D (SP-D) were the only independent determinants of the PaO₂ /FiO₂ ratio. Additionally, in a multivariate logistic regression model, soluble TM in BALF (adjusted OR (aOR): 7.48, 95% CI: 1.60-34.98) and SP-D (aOR: 5.31, 95% CI: 1.40-20.15) was an independent predictor of respiratory failure (PaO₂ /FiO₂ ratio < 300).

CONCLUSION

Soluble TM in BALF is an independent predictor of severe DLI. These findings underscore the importance of pulmonary endothelial injuries in the pathogenesis of severe DLI.

Pulmonary drug toxicity: presentation of a case of recurrent diffuse alveolar damage caused by paroxetine

Pulmonary drug toxicity is being diagnosed more often as a cause of acute and chronic lung disease. Numerous agents including cytotoxic and noncytotoxic drugs have the potential to cause pulmonary toxicity. Recurrent diffuse alveolar damage is a rare manifestation of drug toxicity. We described an extremely rare case of recurrent diffuse alveolar damage caused by the antidepressant drug (paroxetine) resolved by a definitive suspension of the drug, after a recurrent respiratory failure because of inadvertently administering the drug.

Clarification of clinical features of interstitial lung disease induced by irinotecan based on postmarketing surveillance data and spontaneous reports

Irinotecan-induced interstitial lung disease (ILD) requires accurate diagnosis, followed by prompt and appropriate treatment. This study was conducted to compile information and imaging data to define the characteristics of irinotecan-induced ILD. Searches were performed on information collected for a drug reexamination application and on data from spontaneous safety reports submitted to Daiichi Sankyo Company, Limited. These database searches revealed 153 cases of serious ILD that occurred in association with irinotecan therapy, and which were reported as adverse drug reactions. Computed tomographic findings obtained after the onset of ILD were categorized based on four typical patterns. A total of 66 patients (including 15 for whom a relationship between death and serious ILD could not be excluded; incidence of serious ILD: 0.74%; death rate of ILD: 0.17%) were detected during the postmarketing surveillance along with 87 patients (22 deaths) that were identified from spontaneous reports. Within 16 weeks of starting treatment, 80.7% of the patients developed ILD. A total of 61.3% of the cases treated using steroids responded to the steroid therapy. These results indicate that there is no specific clinical or imaging feature associated with ILD related to irinotecan and that the prognosis of ILD related to irinotecan was poor in patients with preexisting ILD. The relative risk calculated for the association between preexisting ILD and death was 2.25 (P=0.29). During irinotecan treatments, patients need to be carefully observed for symptoms, especially at 16 weeks after starting treatment. In addition, when patients are receiving this type of therapy, they also need to undergo chest imaging studies.