Protective role of stratum corneum in percutaneous Leptospira infection in a hamster model.

Leptospira enters humans and animals through injured skin or mucous membranes by direct or indirect contact with urine excreted from infected reservoirs. Individuals with cut or scratched skin are at high risk of infection and are recommended to be protected from contact with Leptospira, but the risk of infection via skin without apparent wounds is unknown. We hypothesized that the stratum corneum of the epidermis might prevent percutaneous invasion of leptospires. We established a stratum corneum deficient model of hamsters using the tape stripping method. The mortality rate of hamsters lacking stratum corneum that were exposed to Leptospira was higher than that of controls with shaved skin, and was not significantly different from an epidermal wound group. These results indicated that the stratum corneum plays a critical role in protecting the host against leptospiral entry. We also examined the migration of leptospires through the monolayer of HaCaT cells (human keratinocyte cell line) using Transwell. The number of pathogenic leptospires penetrating the HaCaT cell monolayers was higher than that of non-pathogenic leptospires. Furthermore, scanning and transmission electron microscopic observations revealed that the bacteria penetrated the cell monolayers through both intracellular and intercellular routes. This suggested that pathogenic Leptospira can migrate easily through keratinocyte layers and is associated with virulence. Our study further highlights the importance of the stratum corneum as a critical barrier against the invasion of Leptospira found in contaminated soil and water. Hence, preventative measures against contact infection should be taken, even without visible skin wounds.

High virulence in hamsters of four dominant Leptospira serovars isolated from rats in the Philippines.

Leptospirosis is caused by pathogenic species of Leptospira. The aim of this study was to determine and characterize the pathogenicity of four dominant Leptospira isolates prevailing among rats in the Philippines. The isolates were Leptospira interrogans serovar Manilae strain K64, L. interrogans serovar Losbanos strain K37, L. interrogans serovar Ratnapura strain K5 and Leptospira borgpetersenii serovar Javanica strain K6. Pathogenicities were studied using hamsters, which reproduce severe human leptospirosis. The minimum lethal doses were 10(0) ( = 1) leptospires for K64, K37 and K5, and 10(1) leptospires for K6. Weight loss amongst the Leptospira-infected hamsters was observed from 1 day before death (K64-, K37- and K5-infected hamsters) to as much as 1 week before death for K6-infected hamsters. Similar and varied gross and microscopic lesions were observed amongst infected hamsters, even for strains belonging to the same species (i.e. L. interrogans). The most significant and common histopathological findings were congestion of the glomerulus, disarrangement of hepatic cords and erythrophagocytosis. Other findings were foamy splenic macrophages for K6, severe petechial pulmonary haemorrhage for K64, and hematuria and severe pulmonary congestion for K37. Immunostaining and culture revealed the presence of leptospires in different organs of the infected hamsters. Based on these results, Leptospira isolates from rats in the Philippines were shown to be highly virulent, causing pulmonary haemorrhage, severe hepato-renal damage and death in hamsters even at lower doses. The present findings on experimental leptospirosis support clinical data showing that patients with severe manifestations of leptospirosis, such as pulmonary haemorrhage, are increasing in the Philippines. These findings may serve as a basis to strengthen the early diagnosis and treatment of human leptospirosis.

Natural defense by saliva and mucosa against oral infection by Leptospira.

Leptospirosis caused by drinking water has not been as frequently reported as percutaneous infection. Resistance to oral infection by pathogenic Leptospira was examined in an experimental hamster infection model. The results suggested some natural defenses against oral infection by Leptospira. First, we found that characteristic linear agglutination of Leptospira rapidly occurs when mixed with human saliva. That human saliva attenuated the infectivity of the treated leptospires by its agglutination activity suggested saliva to be the first line of defense against oral infection by leptospires. Second, only 10(1) Leptospira organisms caused death after submucosal injection into oral mucosa in hamsters, but oral infection with drinking water containing 10(5) organisms/mL did not cause death. This result showed that the mucosa plays the role of a physical barrier. Third, hamsters intragastrically infected by leptospires, with doses lethal to hamsters in oral infection, showed no signs of illness, which suggested that gastric acid plays an important role in preventing oral infection. Based on these results, saliva, mucosa, and gastric acid make up a natural defense, which confers high resistance to hosts against oral infection by leptospires.

Comparative analysis of Leptospira strains isolated from environmental soil and water in the Philippines and Japan.

There have been few reports on the epidemiological analysis of environmental Leptospira isolates. This is probably because the isolation of leptospires from the environment was usually unsuccessful due to the overgrowth of contaminants and the slow growth of Leptospira. In this study, we collected a total of 88 samples of soil and water from three sites: Metro Manila and Nueva Ecija, Philippines (an area where Leptospira is now endemic), and Fukuoka, Japan (an area where Leptospira was once endemic). We succeeded in isolating Leptospira from 37 samples by using the novel combination of five antimicrobial agents reported in 2011. The frequencies of positive isolation of Leptospira in the Philippines and Japan were 40 and 46%, respectively. For Leptospira-positive samples, five colonies from each sample were isolated and analyzed by pulsed-field gel electrophoresis (PFGE). The isolates from each area showed their respective characteristics in phylogenetic trees based on the PFGE patterns. Some isolates were closely related to each other across borders. Based on 16S rRNA gene-based phylogenetic analysis, four isolates in Fukuoka were identified as a pathogenic species, L. alstonii; however, its virulence had been lost. One isolate from Nueva Ecija was identified as the intermediate pathogenic species Leptospira licerasiae. Most of the isolates from the environment belonged to nonpathogenic Leptospira species. We also investigated the strain variation among the isolates in a puddle over 5 months. We demonstrated, using PFGE analysis, that Leptospira survived in the wet soil on dry days and appeared in the surface water on rainy days. These results showed that the soil could be a reservoir of leptospires in the environment.

Idiopathic Pulmonary Fibrosis Complicated by Adenocarcinoma and Organizing Pneumonia.

We describe a case of a 77-year-old male with idiopathic pulmonary fibrosis (IPF) complicated by lung adenocarcinoma and organizing pneumonia (OP). On initial examination, physical examination revealed fine crackles in both sides of his chest. There were no physical findings suggestive of collagen disease. Blood tests showed no elevation of C-reactive protein, and lactate dehydrogenase and Krebs von den Lungen-6 (KL-6) were within normal limits. A high-resolution CT (HRCT) of the chest showed multiple ground-glass opacities (GGOs) in both lungs, with consolidation and traction bronchiectasis in the left lower lobe. Although a bronchoscopy was performed, no diagnosis could be made. Bronchoalveolar lavage showed elevated lymphocytes, and treatment with prednisolone was started for the possibility of OP. Subsequent chest X-ray and chest CT showed worsening of the shadows over time, and shortness of breath on exertion progressed. Surgical lung biopsy revealed IPF complicated by adenocarcinoma and OP. Although the patient was treated with pemetrexed and carboplatin combination therapy, respiratory failure progressed, and palliative care was decided. There is no report of IPF complicated by adenocarcinoma and OP, and early surgical lung biopsy may be important for diagnosis.

Tacrolimus Treatment for Post-COVID-19 Interstitial Lung Disease.

With expansion of the COVID-19 pandemic, reports of post-COVID-19 interstitial lung disease (ILD) have been emerging. However, there are few reports regarding treatment. Some reports indicate that corticosteroids are effective for post-COVID-19 ILD, but the use of long-term corticosteroid carries risks of side effects. We administered tacrolimus to an elderly patient with post-COVID-19 ILD who suffered a respiratory failure relapse during steroid tapering. The respiratory status improved with tacrolimus in the post-acute phase, but pulmonary fibrosis progressed in the late phase. Tacrolimus may be effective for treating post-COVID-19 ILD in the post-acute phase, but it does not halt progression of pulmonary fibrosis.

Early Recognition and Treatment of Relapsing Polychondritis.

We describe the case of a 60-year-old Japanese man with relapsing polychondritis (RP). The patient was referred to Hamanomachi Hospital due to mild elevation of C-reactive protein and mild anemia on medical checkup without any symptoms. Body CT imaging showed thickened tracheal and bronchial walls with no active lesions in the lung. Precise physical examination revealed swelling in both ears. Bronchoscopy revealed redness and swelling of the tracheal and bronchial mucosa in the membranous lesion. Histologic examination of the bronchial biopsy showed inflammatory cell infiltration in the sub-mucosa with no vasculitis. Serum anti-type 2 collagen antibodies were found to be positive (33.9 EU/mL). Corticosteroid treatment improved his tracheochondritis. It is challenging to diagnose RP in the early stage due to its rarity and nonspecific symptoms. Airway involvement in RP is irreversible and the major cause of morbidity and mortality; hence, early recognition of airway involvement and treatment is warranted.

A Case of Drug-Induced Interstitial Lung Disease Caused by Epirubicin and Cyclophosphamide Therapy Before Breast Cancer Surgery.

We report a case of drug-induced interstitial lung disease (ILD) caused by epirubicin and cyclophosphamide (EC) therapy in a patient with breast cancer. The patient suffered from a dry cough, fever, and exertional dyspnea after two courses of EC therapy. Antibiotic treatment did not improve her symptoms. Chest CT images revealed diffuse, ground-glass opacities and mild interlobular septal thickening in both lungs, a pattern suggesting a hypersensitivity pneumonitis. Bronchoalveolar lavage fluid analysis revealed lymphocytosis with no evidence of infection nor malignancy. Corticosteroid therapy was initiated, which led to a rapid resolution of ILD. To date, there has been only one case report regarding drug-induced ILD caused by EC therapy. This case report could increase awareness of chemotherapy-induced pneumonitis.

Three cases of sequential treatment with nintedanib following pulsed-dose corticosteroids for acute exacerbation of interstitial lung diseases.

We describe three cases of acute exacerbation of interstitial lung diseases (ILDs) in which patients were treated with pulsed-doses of corticosteroids followed by nintedanib and maintenance doses of corticosteroids. All cases responded well to pulsed-dose corticosteroids. However, in conventional practice, corticosteroids can complicate adverse events, including opportunistic infections, diabetes, and osteoporosis. One of the cases reported here involved dermatomyositis-associated ILD with anti-EJ antibodies. Considering possible side effects of corticosteroids and the frequent recurrence of ILDs associated with anti-EJ antibodies, we decided to use nintedanib as a sequential treatment for acute exacerbation of ILDs. Nintedanib has just been approved for treatment of progressive fibrosing ILD, but to date, few reports of acute exacerbation of ILDs treated with nintedanib have been published. This case series may contribute to a more thorough discussion regarding the use and timing of nintedanib in treating acute exacerbation of ILDs.

Pulmonary amyloidosis complicated with pulmonary hemosiderosis, diagnosed with bronchoscopy.

We describe a case of an 82-year-old Japanese woman with pulmonary amyloidosis and hemosiderosis associated with multiple myeloma. She had a background of end-stage renal failure of unknown etiology and had been on maintenance dialysis for 2 years. She complained of exertional dyspnea for four months. High-resolution CT of the chest revealed diffuse ground-glass opacities with mosaic attenuation, consolidation in the left lingular lobe, and wedge-shaped, subpleural nodules in the bilateral lower lobes. A transbronchial lung biopsy of the left lingular lobe showed deposition of amorphous, eosinophilic amyloid at the smooth muscle layer of bronchial tissue, with a positive Congo red staining signal in polarized light. Bronchoalveolar lavage fluid was brownish-yellow, and numerous hemosiderin-laden macrophages were detected with Berlin blue staining. From these findings, a diagnosis of pulmonary amyloidosis complicated with pulmonary hemosiderosis was made. Further work-up led to a diagnosis of multiple myeloma. Pulmonary amyloidosis complicated with pulmonary hemosiderosis is a rare disorder and may be underdiagnosed. Physical examination, such as the appearance of the tongue, can assist the diagnosis of systemic amyloidosis. Use of bronchoscopy allows physicians make an early diagnosis of pulmonary amyloidosis that is minimally invasive.

A Rare Case of Pembrolizumab-Induced Dermatomyositis in a Patient with Cancer of Unknown Primary Origin.

BACKGROUND Pembrolizumab is a humanized monoclonal antibody against programmed cell death-1 protein. Pembrolizumab sometimes causes immune-related adverse events (irAEs). Dermatomyositis is a rare irAE of immune checkpoint inhibitors. The presentation is usually acute, and symptoms include edema with erythema of the eyelids, erythema of the forehead, and muscle weakness in both thighs. CASE REPORT Here we report a case of pembrolizumab-induced dermatomyositis in a 71-year-old Japanese woman with cancer of unknown primary origin, who experienced a high fever and had difficulty walking after her sixth course of pembrolizumab. General physical examination revealed edema with a heliotrope rash, V-neck signs, and nonspecific erythema of the forehead. Laboratory evaluation revealed that myogenic enzymes were within normal ranges. Autoantibody tests revealed that antinuclear antibodies were negative, and autoantibodies related to myositis and anti-acetylcholine receptor antibodies were also negative. A magnetic resonance imaging scan of the thighs revealed signal abnormalities in the left lateral and distal vastus medialis muscle. The patient was treated with corticosteroids, subsequently followed by intravenous immunoglobulin therapy, which led to an improvement of the symptoms. CONCLUSIONS Pembrolizumab-induced dermatomyositis is rare. Corticosteroids have been administered in many cases, and this case also suggests the efficacy of intravenous immunoglobulin therapy in treating immune checkpoint inhibitor-related dermatomyositis. This case highlights practical management of pembrolizumab-induced dermatomyositis.

A fatal case of diffuse alveolar hemorrhage complicated by rheumatoid arthritis.

We describe a fatal case of diffuse alveolar hemorrhage (DAH) complicated by rheumatoid arthritis (RA). A female patient was diagnosed with RA two months earlier and was treated with prednisolone and tacrolimus due to abnormalities in chest images. The patient was admitted to Hamanomachi Hospital for exertional dyspnea and was treated for exacerbation of chronic heart failure. Even after treatment for heart failure, exertional dyspnea remained. Chest CT imaging revealed contractile, patchy consolidations and ground-glass opacities (GGO) with a peribronchial distribution, suggesting an organizing pneumonia (OP) pattern. She was then treated with an additional 25 mg/day of prednisolone following a clinical diagnosis of OP. When the prednisolone dose was tapered, chest imaging showed worsening infiltration. A bronchoscopy was conducted, and bronchoalveolar lavage fluid was sanguineous, indicating DAH. Given that additional workup for the other etiology of DAH was negative, DAH was thought to be related to RA. Intensive treatment, including pulse dose methylprednisolone, failed to halt progression of respiratory failure, leading to a fatal outcome. The clinical presentation proved challenging due to its rarity. DAH might be a differential diagnosis in RA patients with consolidations and GGO in chest CT images. We review past cases of RA-associated DAH and assess potential treatment choices for future cases.

A Refractory, Infected Lung Bulla and an Abscess Treated Using Percutaneous Drainage in a Patient With Human T-Lymphotropic Virus Type 1-Associated Myelopathy.

We present a case of a 54-year-old Japanese woman with established human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy who developed a refractory infected lung bulla and lung abscess caused by Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, and Aspergillusspecies. Since antibiotic treatment alone failed to resolve the infection, percutaneous drainage of the infected bulla was performed. Although a prolonged treatment period was necessary, the infected lung bulla and the lung abscess were eventually resolved. During her illness, the patient also developed arthritis, possibly related to the HTLV-1 infection. Thus, persons infected with HTLV-1 can develop refractory infections, myelopathy, and arthritis. Percutaneous drainage is an option to treat refractory infected lung bullae.

High Incidence of C797S Mutation in Patients With Long Treatment History of EGFR Tyrosine Kinase Inhibitors Including Osimertinib.

INTRODUCTION: Although treatment with osimertinib confers survival benefits in patients with lung cancer with the EGFR T790M mutation, the mechanism of acquired resistance to osimertinib remains poorly understood. We conducted a prospective observational study to identify the mechanism on the basis of repeated tissue biopsies. METHODS: Patients with EGFR-mutated advanced lung cancer with a T790M mutation detected on a tissue biopsy underwent a rebiopsy after developing acquired resistance to osimertinib. Nucleic acids extracted from the biopsy samples were subjected to targeted resequencing (Oncomine Comprehensive Assay), and circulating cell-free DNA (ccfDNA) was analyzed by CAncer Personalized Profiling by deep Sequencing (AVENIO ctDNA Surveillance Kit). RESULTS: Between November 2016 and March 2020, a total of 87 patients were screened. Among them, 44 developed acquired resistance. Of these, 19 samples from rebiopsies and 12 from preosimertinib biopsies were able to be analyzed by an Oncomine Comprehensive Assay. A ccfDNA analysis was performed in 16 patients. Regarding the mechanisms of acquired resistance, structural change in EGFR, namely, C797S, G796S, or L792V, was the most frequent alteration, being observed in 57.9% of the cases. MET gain was observed in 31.6% of the cases, and gains in cell cycle genes were observed in 26.3% of the cases. In addition, we identified GAS6 gain and an ATM mutation in a patient with small-cell transformation and a BRAF V600E mutation in a patient with oligoprogressive disease. CONCLUSIONS: A repeated tissue biopsy and a ccfDNA analysis were useful in analyzing the mechanisms underlying acquired resistance. A long treatment history of EGFR TKIs may result in a high percentage of EGFR structural change.

Lenvatinib for poorly differentiated carcinoma of the anterior mediastinum.

We describe a Case of a 74-year-old Japanese man with poorly differentiated carcinoma of the anterior mediastinum. The patient underwent anterior mediastinal tumor resection through median sternotomy. The tumor, 7.0 × 5.0 cm, had invaded surrounding tissues (pericardium, right lung, right and left brachiocephalic veins, and superior vena cava). Complete resection of the tumor was not performed. One month after the operation, the patient developed multiple pulmonary metastases, right pleural dissemination, and carcinomatous pleurisy. He was treated with lenvatinib, a novel multi-kinase inhibitor, to which the metastasis responded favorably. This case reports for the first time the clinical usefulness of lenvatinib for poorly differentiated carcinoma of the anterior mediastinum. Management of side effects by several methods, including suspending use of medication on weekends (called a weekends-off strategy), is another strong argument to continue lenvatinib administration.

Successful treatment with mepolizumab for allergic bronchopulmonary mycosis complicated with bilateral septic arthritis of the knee joints caused by Methicillin-resistant Staphylococcus aureus.

We report the case of a 50-year-old man with allergic bronchopulmonary mycosis (ABPM) complicated with bilateral septic arthritis of the knees caused by Methicillin-resistant Staphylococcus aureus (MRSA). He had a background of bronchial asthma and end-stage renal failure on maintenance dialysis. He was treated with 30 mg/day of prednisolone for 14 days for ABPM. He developed bilateral septic arthritis of the knees, caused by MRSA during prednisolone treatment. He underwent bilateral arthroscopic washout with a 2-week course of intra-articular arbekacin, concomitantly treated with a 6-week course of intravenous teicoplanin and oral rifampicin, subsequently followed by oral linezolid treatment. However, he suffered exacerbation of ABPM during treatment of septic arthritis. Because of these serious infectious complications, he was treated with mepolizumab instead of corticosteroids for the ABPM, which resolved all symptoms and clinical features. This case highlights mepolizumab treatment as an alternative to corticosteroid therapy for treatment of ABPM in patients with comorbidities such as infection.

Nintedanib and intensive immunosuppressive therapy to treat rapidly progressive interstitial lung disease presenting anti-ARS antibodies.

We describe a case of fulminant onset, rapidly progressive-interstitial lung disease (RP-ILD) with anti-ARS antibodies (anti-PL-7). The patient was successfully treated with nintedanib in addition to intensive immunosuppressive therapies, including intravenous cyclophosphamide. Nintedanib has just been approved for treatment of progressive fibrosing ILD, but to date, no reports of RP-ILD treated with nintedanib have been published. This case report may advance discussions regarding the use and timing of nintedanib in treating RP-ILD.

Durable response to nivolumab in a lung adenocarcinoma patient with idiopathic pulmonary fibrosis.

The efficacy and safety of immune-checkpoint inhibitors in non-small cell lung cancer patients with idiopathic pulmonary fibrosis (IPF) remain unknown. Herein, we describe the case of a 62-year-old man with multiple pleural tumors and carcinomatous pleurisy. High-resolution computed tomography indicated usual interstitial pneumonia, and a respiratory function test revealed a restrictive disorder and decreased diffusion capacity. He was diagnosed with lung adenocarcinoma and IPF. After failure of initial chemotherapy, he was treated with nivolumab and achieved a complete response without any sign of exacerbation of IPF. The response to nivolumab has persisted for > 1 year. This is the first report of a non-small cell lung cancer patient with IPF who has been treated with immune-checkpoint inhibitors for such a long period and achieved a sustained response.