Impacts of probiotics on the efficacies of immune checkpoint inhibitors with or without chemotherapy for patients with advanced non-small-cell lung cancer.

The relationships between the therapeutic effects of immune checkpoint inhibitors (ICIs) and the intestinal flora have attracted increasing attention. However, the effects of oral probiotics on the efficacies of ICIs used to treat non-small-cell lung cancer (NSCLC) remain unclear. We investigated the effects of probiotics on the efficacies of ICIs in patients treated with and without chemotherapy. We investigated patients with advanced NSCLC on ICI monotherapy or combination ICI and chemotherapy using the Okayama Lung Cancer Study Group Immunotherapy Database (OLCSG-ID) and the Okayama Lung Cancer Study Group Immunochemotherapy Database (OLCSG-ICD). In total, 927 patients (482 on ICI monotherapy, 445 on an ICI + chemotherapy) were enrolled. Most were male, of good performance status, smokers, and without epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) mutations. Probiotics were administered to 19% of patients on ICI monotherapies and 17% of those on ICIs + chemotherapy. Of the former patients, progression-free survival (PFS) and overall survival (OS) were significantly better in the probiotics group (PFS 7.9 vs. 2.9 months, hazard ratio [HR] 0.54, p < .001; OS not attained vs. 13.1 months, HR 0.45, p < .001). Among patients receiving ICI and chemotherapy, there were no significant differences in PFS between those on probiotics and not but OS was significantly better in the probiotics group (PFS 8.8 vs. 8.6 months, HR 0.89, p = .43; OS not attained vs. 22.6 months, HR 0.61, p = .03). Patients on probiotics experienced better outcomes following ICI treatment.

Predictive role of regional thigh tissue oxygen saturation monitoring during cardiopulmonary bypass in lung injury after cardiac surgery.

Acute respiratory distress syndrome (ARDS) is a serious complication following cardiac surgery mainly associated with the use of cardiopulmonary bypass (CPB), which could increase the risk of mortality and morbidity. This study investigated the association of regional oxygen saturation (rSO2) during CPB with postoperative outcomes, including respiratory function. Patients who underwent cardiac surgery with CPB from 2015 to 2019 were included. Near-infrared spectroscopy was used to monitor rSO2 at the forehead, abdomen, and thighs throughout the surgery. Postoperative markers associated with CPB were assessed for correlations with PaO2/FiO2 (P/F) ratios at intensive care unit (ICU) admission. Postoperative lung injury (LI) was defined as moderate or severe ARDS based on the Berlin criteria, and its incidence was 29.9% (20/67). On multiple regression analysis, the following were associated with P/F ratios at ICU admission: vasoactive-inotropic scores at CPB induction (P = 0.03), thigh rSO2 values during CPB (P = 0.04), and body surface area (P < 0.001). A thigh rSO2 of 71% during CPB was significantly predictive of postoperative LI with an area under the curve of 0.71 (P = 0.03), sensitivity of 0.70, and specificity of 0.68. Patients with postoperative LI had longer ventilation time and ICU stays. Thigh rSO2 values during CPB were a potential predictor of postoperative pulmonary outcomes.

Pembrolizumab in advanced NSCLC patients with poor performance status and high PD-L1 expression: OLCSG 1801.

BACKGROUND: The role of pembrolizumab in the treatment of poor performance status (PS) patients remains unclear. PATIENTS AND METHODS: We conducted a phase II trial to investigate the efficacy and safety of pembrolizumab as first-line therapy for non-small-cell lung cancer (NSCLC) patients with PSs of 2-3 and programmed cell death ligand 1 (PD-L1) expression ≥ 50%. The primary endpoint of this study was the objective response rate (ORR). RESULTS: Fourteen patients treated at eight institutions were enrolled. Most patients had PS 2 (12/14; 86%) and others had PS 3 (2/14; 14%). The ORR was 57.1% (95% confidence interval 28.9-82.3%), which met the primary endpoint. The median progression-free survival (PFS) and 1-year PFS rates were 5.8 months and 20.0%, respectively. At the time of data cut-off, one patient had received treatment for more than 1 year; another patient had received treatment for more than 2 years. Nine patients had improved PS with treatment (Wilcoxon signed-rank test, p = 0.003). Two patients had immune-related adverse events ≥ grade 3: grades 5 and 3 elevation in alanine and aspartate aminotransferases. Two PS 3-stage patients were diagnosed with clinically progressive disease prior to initial computed tomography; both died within 2 months. CONCLUSION: Pembrolizumab was effective for the treatment of NSCLC patients with a poor PS and PD-L1 level ≥ 50%. However, given the poor outcomes of the PS 3 patients, the drug is not indicated for such patients. Adverse events, including liver dysfunction, should be carefully monitored. REGISTRATION ID: UMIN000030955.

[Esophageal Perforation on Transesophageal Echocardiography in Open-heart Surgery:Report of a Case].

A 70-year-old woman, who was taking prednisolone to treat Takayasu arteritis, underwent surgery for aortic regurgitation and aneurysm of the ascending aorta. The probe of the transesophageal echocardiography (TEE) could not be inserted due to resistance during anesthesia induction and was inserted after starting cardiopulmonary bypass. The right pneumothorax was observed during surgery. After surgery, fever and a high C-reactive protein level continued, and a computed tomography (CT) examination revealed right thoracic empyema together with free air around the esophagus. The esophageal perforation diagnosis was confirmed by upper endoscopy. Esophageal leakage continued despite emergency esophageal repair and enterostomy. Although esophagectomy was performed 2 months later, the patient died 6 months after cardiac surgery due to sepsis. Thus, esophageal perforation related to TEE in open-heart surgery was considered to be associated with a poor prognosis.

Total Synthesis, Structure Revision, and Neuroprotective Effect of Hericenones C-H and Their Derivatives.

The first total syntheses of hericenones C-H and "putative 3-hydroxyhericenone F" were achieved. Highlights of the synthesis include the straightforward construction of the resorcinol core and geranyl side chain, assembly of the natural product skeleton by sequential O-geranylation and a clay/zeolite-mediated O → C rearrangement reaction, and a biomimetic cyclization to form a variety of bicyclic natural hericenones and their congeners. The structure of the "putative 3-hydroxyhericenone F" was revised as the 5-exo cyclization product (named: hericenone Z) of epoxyhericenone C through in-depth analyses of the cyclization modes in addition to NMR spectroscopic studies. To gain insights into the biological functions of geranyl-resorcinols in Hericium erinaceus, potential neuroprotective effects against endoplasmic reticulum (ER) stress-dependent cell death were evaluated systematically to clarify a fundamental structure-activity relationship. Among the compounds assayed, the linoleate-containing hericenone analogue, i.e., the regioisomer of hericene D, was found to possess the most potent neuroprotective effect against tunicamycin and thapsigargin-induced ER stress-dependent cell death.

Adenocarcinoma within anorectal fistulae: different clinicopathological characteristics between Crohn's disease-associated type and the usual type.

Adenocarcinoma within anorectal fistulae is rare and is sometimes associated with Crohn's disease. Crohn's disease-associated adenocarcinoma within anorectal fistulae has a poor prognosis; however, little is known about the clinicopathological differences between Crohn's disease-associated adenocarcinoma within anorectal fistulae and usual adenocarcinoma within anorectal fistulae. We retrospectively searched patients' charts and pathology archives at Tokyo Yamate Medical Center and Tokyo Medical and Dental University Hospital for adenocarcinoma within anorectal fistulae. Clinical and pathological data were collected and immunohistochemical examinations were conducted. Overall survival rate was estimated using the Kaplan-Meier method. Prognostic factors of overall survival were assessed using univariate and multivariate Cox regression analyses. We examined 82 cases of adenocarcinoma within anorectal fistulae. Fifty-nine of 82 cases (72%) had usual adenocarcinoma within anorectal fistulae, while the remaining 23 cases (28%) had Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae were diagnosed at a younger age and at a more advanced stage than those with usual adenocarcinoma within anorectal fistulae. Macroscopic and histological types were also different between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Crohn's disease-associated adenocarcinoma within anorectal fistulae included more ulcerative types and high-grade adenocarcinomas. The rate of lymphovascular invasion was higher in Crohn's disease-associated adenocarcinoma within anorectal fistulae. Immunohistochemically, the expression of E-cadherin, p53, and MUC5AC differed between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae exhibited worse overall survival than those with usual adenocarcinoma within anorectal fistulae, and vascular invasion was the strongest significant independent predictor of overall survival in patients with adenocarcinoma within anorectal fistulae. In conclusion, usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae have different clinicopathological characteristics and should be considered separate clinical entities.

Stereocontrolled Total Synthesis of (+)-Isolaurenidificin and (-)-Bromlaurenidificin.

We report the first total syntheses of (+)-isolaurenidificin (1) and (-)-bromlaurenidificin (2), the latest acetogenins of the 2,6-dioxabicyclo[3.3.0]octane class. The synthesis features a completely stereoselective one-pot epimerization-ring contraction to establish the cis configuration with respect to C10-H and C12-H of the tetrahydrofuran ring. Six stereogenic centers and an olefin geometry were constructed in a highly stereoselective manner. Absolute configurations of the natural products were deduced by the comparison of NMR data and specific rotations.

CHAC1 overexpression in human gastric parietal cells with Helicobacter pylori infection in the secretory canaliculi.

BACKGROUND: Cation transport regulator 1 (CHAC1), a newly discovered enzyme that degrades glutathione, is induced in Helicobacter pylori (H. pylori)-infected gastric epithelial cells in culture. The CHAC1-induced decrease in glutathione leads to an accumulation of reactive oxygen species and somatic mutations in TP53. We evaluated the possible correlation between H. pylori infection and CHAC1 expression in human gastric mucosa. MATERIALS AND METHODS: Both fresh-frozen and formalin-fixed paraffin-embedded tissue samples of gastric mucosa with or without H. pylori infection were obtained from 41 esophageal cancer patients that underwent esophago-gastrectomy. Fresh samples were used for real-time polymerase chain reaction for H. pylori DNA and CHAC1 mRNA, and formalin-fixed samples were used for immunohistochemistry with anti-CHAC1 and anti-H. pylori monoclonal antibodies. Double-enzyme or fluorescence immunohistochemistry and immuno-electron microscopy were used for further analysis. RESULTS: Significant CHAC1 overexpression was detected in H. pylori-infected parietal cells that expressed the human proton pump/H,K-ATPase α subunit, whereas a constitutively low level of CHAC1 mRNA expression was observed in the other samples regardless of the H. pylori infection status, reflecting the weak CHAC1 expression detected by immunohistochemistry in the fundic-gland areas. Immuno-electron microscopy revealed intact H. pylori cells in the secretory canaliculi of infected parietal cells. Some parietal cells exhibited positive nuclear signals for Ki67 in the neck zone of the gastric fundic-gland mucosa with H. pylori infection. CONCLUSION: Cation transport regulator 1 overexpression in H. pylori-infected parietal cells may cause the H. pylori-induced somatic mutations that contribute to the development of gastric cancer.

Potential influence of interleukin-6 on the therapeutic effect of gefitinib in patients with advanced non-small cell lung cancer harbouring EGFR mutations.

Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are a key therapy used for patients with EGFR-mutant non-small cell lung cancer (NSCLC), some of whom do not respond well to its therapy. Cytokine including IL-6 secreted by tumour cells is postulated as a potential mechanism for the primary resistance or low sensitivity to EGFR-TKIs. Fifty-two patients with advanced EGFR-mutant NSCLC who had received gefitinib were assessed retrospectively. The protein expression of IL-6 in the tumour cells was assessed by immunostaining and judged as positive if ≥ 50 of 100 tumour cells stained positively. Of the 52 patients, 24 (46%) and 28 (54%) were defined as IL-6-postitive (group P) and IL-6-negative (group N), respectively. Group P had worse progression-free survival (PFS) than that of group N, which was retained in the multivariate analysis (hazard ratio: 2.39; 95 %CI: 1.00-5.68; p < 0.05). By contrast, the PFS after platinum-based chemotherapy did not differ between groups P and N (p = 0.47). In cell line-based model, the impact of IL-6 on the effect of EGFR-TKIs was assessed. The combination of EGFR-TKI and anti-IL-6 antibody moderately improved the sensitivity of EGFR-TKI in lung cancer cell with EGFR mutation. Interestingly, suppression of EGFR with EGFR-TKI accelerated the activation of STAT3 induced by IL-6. Taken together, tumour IL-6 levels might indicate a subpopulation of EGFR-mutant NSCLC that benefits less from gefitinib monotherapy.

A Diversity-Oriented Library of Fluorophore-Modified Receptors Constructed from a Chemical Library of Synthetic Fluorophores.

The practical application of biosensors can be determined by evaluating the sensing ability of fluorophore-modified derivatives of a receptor with appropriate recognition characteristics for target molecules. One of the key determinants for successfully obtaining a useful biosensor is wide variation in the fluorophores attached to a given receptor. Thus, using a larger fluorophore-modified receptor library provides a higher probability of obtaining a practically useful biosensor. However, no effective method has yet been developed for constructing such a diverse library of fluorophore-modified receptors. Herein, we report a method for constructing fluorophore-modified receptors by using a chemical library of synthetic fluorophores with a thiol-reactive group. This library was converted into a library of fluorophore-modified adenosine-binding ribonucleopeptide (RNP) receptors by introducing the fluorophores to the Rev peptide of the RNP complex by alkylation of the thiol group. This method enabled the construction of 263 fluorophore-modified ATP-binding RNP receptors and allowed the selection of suitable receptor-based fluorescent sensors that target ATP.

Cortical Actin Alteration at the Matrix-Side Cytoplasm in Lung Adenocarcinoma Cells and Its Significance in Invasion.

OBJECTIVES: Cortical actin is a thin layer of filamentous (F-)actin that lies beneath the plasma membrane, and its role in pathophysiology remains unclear. We investigated the subcellular localization of cortical actin by the histopathological and experimental studies of lung adenocarcinomas. MATERIALS AND METHODS: The subcellular localization of cortical actin was studied in surgically resected lung adenocarcinomas tissues and in 3-dimensionally cultured lung adenocarcinoma A549 cells. RESULTS: In normal type II alveolar cells and the bronchiolar epithelium, cortical actin was localized to the apical-side cytoplasm. In invasive adenocarcinoma cells, cortical actin was frequently localized to the matrix side. The degree of cortical actin localized to the matrix side was associated with the loss of basement membrane and a poor prognosis. In A549 cell spheroids cultured in a type I collagen and basement membrane extract Matrigel™ mixed gel, cortical F-actin was localized to the matrix side with phosphorylated myosin light chain. Super-resolution and electron microscopy results suggest that compact wrinkling of the plasma membrane by myosin-mediated F-actin contraction is an explanation for cortical actin accumulation at the matrix side. The myosin II inhibitor blebbistatin suppressed the 3-dimensional collective migration of A549 cells induced by constitutively active Cdc42 and MT1-MMP. CONCLUSION: Cortical actin accumulation at the matrix-side cytoplasm of cancer cells occurs in invasive lung adenocarcinomas and it possibly participates in the migration of cancer cells through myosin-mediated contraction.

Construction of a library of structurally diverse ribonucleopeptides with catalytic groups.

Functional screening of structurally diverse libraries consisting of proteins or nucleic acids is an effective method to obtain receptors or aptamers with unique molecular recognition characteristics. However, further modification of these selected receptors to exert a newly desired function is still a challenging task. We have constructed a library of structurally diverse ribonucleopeptides (RNPs) that are modified with a catalytic group, in which the catalytic group aligns with various orientations against the ATP binding pocket of RNA subunit. As a proof-of-principle, the screening of the constructed RNP library for the catalytic reaction of ester hydrolysis was successfully carried out. The size of both the substrate-binding RNA library and the catalytic group modified peptide library are independently expandable, and thus, the size of RNPs library could be enlarged by a combination of these two subunits. We anticipate that the library of functionalized and structurally diverse RNPs would be expanded for various other catalytic reactions.

Short-term low-volume hydration in cisplatin-based chemotherapy for patients with lung cancer: the second prospective feasibility study in the Okayama Lung Cancer Study Group Trial 1201.

OBJECTIVE: We previously reported the feasibility of short-term low-volume hydration in patients with advanced lung cancer who received cisplatin-based chemotherapy (Jpn J Clin Oncol 2013). We sought to determine the clinical usefulness of a more convenient hydration method, evaluating the safety and efficacy of shorter-term and lower-volume hydration. METHOD: Chemonaïve patients with advanced lung cancer who were ≤ 75 years and reserved an adequate renal function for cisplatin use (≥ 60 mg/m(2)) were eligible. An intravenously administered hydration of 1700 ml in ~3.5 h with 1500 ml of orally administered hydration was investigated. The primary endpoint was the proportion of patients without grade 2 or worse renal toxicity in the first cycle. RESULTS: A total of 45 patients were registered, all of whom were evaluable for renal toxicity. The median baseline creatinine score was 0.70 mg/dl, and the median cisplatin dose on day 1 was 75 mg/m(2). In the first cycle, one patient (2 %) developed grade 2 creatinine toxicity, and thus, the proportion of patients with less than grade 2 was 98 % (the lower limit of 95 % confidence interval; 93 %), which met the primary endpoint. Five patients (11 %) had grade 1 or greater nephrotoxicity, three of whom successfully recovered. The objective response rate was 24 % and median progression-free survival 5.8 months. CONCLUSION: This prospective study demonstrated the safety and efficacy of shorter-term lower-volume hydration.

A Phase I Trial of 100 mg/m2 Docetaxel in Patients with Advanced or Recurrent Breast Cancer.

Docetaxel is a standard treatment for patients with advanced or recurrent breast cancer. The recommended dose is 60 to 100 mg/m2. Previous study have shown that the tumor response rates of patients who received docetaxel monotherapy at doses of 60, 75, and 100 mg/m2 were 22.1% , 23.3% , and 36.0% , respectively, and there was a significant relationship between the dose and response. In Europe and the United States, docetaxel is approved at a dose of 100 mg/m2, and Japanese guidelines also recommend a dose of 100 mg/m2. However, the approved dose in Japan is up to 75 mg/m2. We have launched a phase I trial evaluating 100 mg/m2 docetaxel in patients with advanced or relapsed breast cancer. The major eligibility criteria are as follows: age 20 years, pathologically diagnosed breast cancer, recurrent or advanced breast cancer, a good performance status, and HER2 [human epidermal growth factor receptor 2] negative. The primary endpoint is demonstrated safety of 100 mg/m2 docetaxel. This study will clarify whether 100mg/m2 docetaxel can be administrated safely in Japanese patients with advanced or recurrent breast cancer.

Norwood Procedure Performed on a Patient With Trisomy 13.

Trisomy 13 is associated with a variety of congenital anomalies, some of which are life-threatening and related to poor prognosis. Therefore, cardiac surgery is rarely offered to these patients, especially to those with complex cardiac anomalies. We report the case of a neonate weighing 2324 g who was born with severe congenital heart defects. Transthoracic echocardiography revealed the diagnoses of asplenia, single ventricle, aortic stenosis, coarctation of the aorta, hypoplastic aortic arch, and total anomalous pulmonary venous return. She was hemodynamically unstable. Palliative Norwood procedure with right ventricle-pulmonary artery conduit (RV-PA conduit) was performed at the age of 1 day to save her life. On postoperative day 7, chromosome analysis revealed trisomy 13. Echocardiography revealed good heart function; stable hemodynamic status was achieved with minimal amounts of inotropic agents. However, she developed anuria, which did not improve despite situational possible interventions, including peritoneal dialysis and continuous hemodiafiltration. On postoperative day 37, she succumbed to sudden cardiorespiratory failure. Nevertheless, this case indicates that a neonate with trisomy 13 can have a better chance at survival with cardiac surgery such as the Norwood procedure with an RV-PA conduit.

Seventeen-month-long paracorporeal biventricular mechanical support as a bridge to transplantation for severe dilated cardiomyopathy.

The long-term management of paracorporeal biventricular assist devices (BiVAD) is difficult because of significant risks of bleeding, thrombosis, and infection. Here we report the case of a 41-year-old woman with severe dilated cardiomyopathy who developed serious cerebral bleeding after receiving a paracorporeal BiVAD but recovered well after treatment. She eventually underwent cardiac transplantation 17 months after implantation of the paracorporeal BiVAD.

[HER2-Positive Advanced Gastric Cancer with Disseminated Intravascular Coagulation and Diffuse Bone Marrow Carcinomatosis Successfully Treated with S-1/Trastuzumab Chemotherapy--A Case Report].

Trastuzumab, a humanized monoclonal antibody against human epidermal growth factor receptor 2 (HER2), has been proven to result in a survival benefit for the treatment of patients with HER2-positive advanced gastric cancer (AGC). However, data are lacking for the treatment of those with disseminated intravascular coagulation (DIC) and diffuse bone marrow carcinomatosis. A 77-year-old woman presented with back pain and fatigue since 2 months. Esophagogastroduodenoscopy showed a scirrhous lesion in the gastric corpus, which was biopsied and identified as signet-ring cell carcinoma with HER2 overexpression on immunohistochemistry. Laboratory testing, bone scintigraphy, and bone marrow biopsy were conducted, and she was diagnosed with HER2-positive AGC with DIC and diffuse bone marrow carcinomatosis. She underwent chemotherapy with the following regimen: oral administration of 80 mg/m2 S-1 for 2 weeks and 6 mg/kg trastuzumab infusion on day 6 every 3 weeks, which significantly improved the DIC. She was discharged from the hospital 73 days after admission and survived for 438 days after diagnosis. To the best of our knowledge, this is the first case report in which HER2-positive AGC complicated by DIC with diffuse bone marrow carcinomatosis was successfully treated with combined chemotherapy consisting of S-1 plus trastuzumab.

[Graft replacement under percutaneous cardiopulmonary system for traumatic aortic rupture with multiple injuries].

We report a case of traumatic aortic rupture with multiple injuries. A 20-year-old man was transferred to our hospital. He was suffering from traumatic thoracic aortic rupture with multiple injuries (femoral fracture, pelvis fracture and so 4th) due to a traffic accident. Enhanced computed tomography revealed leakage from the aortic isthmus and hematoma in the surrounding area. Emergency operation was performed. The left 4th intercostal thoracotomy was performed and a lacerated foramen was observed across the lesser curvature of the aortic isthmus. The affected site was replaced by a prosthetic graft under percutaneous cardiopulmonary system. He was treated with open fixation of the right femur 11 days after the 1st operation. The postoperative recovery was generally uneventful and he was discharged on the 51st hospital day.

Preoperative respiratory assessment predicts post-operative survival in stage IA non-small cell lung cancer.

Background: Respiratory impairment can lead to pulmonary complications after surgery; therefore, it should be considered when determining the choice of surgical procedure. Several studies have examined the relationship between preoperative respiratory function and postoperative mortality and morbidity after lung resection; however, there are no indicators for limited surgical procedure selection. The aim of this study was to examine the association between preoperative respiratory function and postoperative early and late complications, recurrence-free survival (RFS), and overall survival (OS) in patients undergoing pulmonary resection for stage I lung cancer. Methods: We performed a retrospective analysis of data from 192 patients undergoing pulmonary resection for primary pathological stage IA non-small cell lung cancer (NSCLC) at the Iwakuni Clinical Center in Japan between 2012 and 2015. We reviewed clinicopathological characteristics including preoperative pulmonary function and elucidated the relationship between them and postoperative survival. Results: Obstructive ventilatory impairment was present in 55 patients (28.6%), and restrictive ventilatory impairment was present in 31 patients (16.1%). Seven patients (3.6%) had both ventilatory impairment. Obstructive ventilatory impairment did not affect the 5-year RFS (P=0.08) or OS (P=0.21). However, restrictive ventilatory impairment reduced the 5-year RFS (P=0.002) and OS (P=0.009). The rates of early and late complications were not significantly different based on the preoperative respiratory function. Conclusions: In patients with preoperative restrictive ventilatory impairment in whom lobectomy or segmentectomy cannot be performed, careful consideration is needed for surgical indications.

A Case of Dupilumab-Induced Diffuse Alveolar Hemorrhage.

Eosinophilic pneumonia is a known side effect of dupilumab; however, diffuse alveolar hemorrhage has not yet been reported in association with dupilumab. We herein report a case of diffuse alveolar hemorrhage caused by dupilumab. A 57-year-old man with severe asthma was unable to discontinue oral steroids and thus was prescribed dupilumab. The patient was admitted to the hospital four weeks after treatment because of suspected eosinophilic pneumonia. Bronchoscopy revealed diffuse alveolar hemorrhage characterized by hemosiderin-phagocytic macrophages in the bronchoalveolar lavage fluid without eosinophils. The steroid dosage improved the respiratory status and resolved the infiltrate shadow. Dupilumab may thus cause diffuse alveolar hemorrhage, which can be differentiated using bronchoscopy.