The Utility and Limitations of Universal Polymerase Chain Reaction Screening for SARS-CoV-2 During Hospital Admission.

OBJECTIVE: Universal polymerase chain reaction (PCR) screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on hospital admission is an effective approach to preventing coronavirus disease 2019 (COVID-19) outbreaks in medical facilities. However, false-positive test results due to a recent infection are a concern. We investigated the usefulness and limitations of universal PCR screening for SARS-CoV-2 on hospital admission in a real-world setting. METHODS: We retrospectively analyzed 1320 attempted hospital admissions for 775 patients at the Department of Respiratory Medicine, Kyushu University Hospital, between January 1, 2022, and May 2, 2023. RESULTS: Thirty-nine out of 1201 PCR tests (3.2%) yielded a positive result, with 22 of these results being considered false positives on the basis of a recent infection. We found that 39% of cases showed a positive PCR result between 31 and 60 days after the onset of COVID-19, although the threshold cycle (Ct) for target 1 (ORF1ab gene) of the Cobas SARS-CoV-2 test (Roche Diagnostics, Basel, Switzerland) was >30 in most instances. CONCLUSION: Hospital admission based on the results of PCR screening for SARS-CoV-2 should take into account not only PCR positivity but also the Ct value and recent COVID-19 history.

Interstitial Pneumonia Associated with Nodal T-follicular Helper Cell Lymphoma: A Case Report.

Nodal T-follicular helper cell lymphoma (nTFHL), a hematologic neoplasm originating from T-follicular helper (TFH) cells, occasionally presents with pulmonary radiographic abnormalities, without neoplastic cellular infiltration. However, the precise mechanisms underlying non-neoplastic pulmonary opacities in patients with nTFHL remain unclear. Previous reports have shown that TFH cell abnormalities are associated with collagen disease and interstitial pneumonia with autoimmune features (IPAF). We herein report a patient with nTFHL accompanied by interstitial pneumonia diagnosed via lung and lymph node biopsies. These findings suggest the need to rule out nTFHL before diagnosing IPAF.

Lemborexant-induced interstitial lung disease: A case report.

We report the first case of drug-induced interstitial lung disease attributed to lemborexant. A 66-year-old man reported to our hospital with the acute onset of cough and breathlessness with ground-glass opacity on radiological examination. Symptoms were identified after taking lemborexant for 2 consecutive days. The patient had undergone lemborexant treatment 2 years prior and had exhibited no symptoms at that time. The drug-induced lymphocyte stimulation test for lemborexant was positive. He showed rapid improvement upon treatment with steroid. With the rise in prescriptions of lemborexant for insomnia, lemborexant should be considered as a possible cause of drug-induced interstitial lung disease.

Exploratory mass cytometry analysis reveals immunophenotypes of cancer treatment-related pneumonitis.

Anticancer treatments can result in various adverse effects, including infections due to immune suppression/dysregulation and drug-induced toxicity in the lung. One of the major opportunistic infections is Pneumocystis jirovecii pneumonia (PCP), which can cause severe respiratory complications and high mortality rates. Cytotoxic drugs and immune-checkpoint inhibitors (ICIs) can induce interstitial lung diseases (ILDs). Nonetheless, the differentiation of these diseases can be difficult, and the pathogenic mechanisms of such diseases are not yet fully understood. To better comprehend the immunophenotypes, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid from patients with PCP, cytotoxic drug-induced ILD (DI-ILD), and ICI-associated ILD (ICI-ILD) using two panels containing 64 markers. In PCP, we observed an expansion of the CD16+ T cell population, with the highest CD16+ T proportion in a fatal case. In ICI-ILD, we found an increase in CD57+ CD8+ T cells expressing immune checkpoints (TIGIT+ LAG3+ TIM-3+ PD-1+), FCRL5+ B cells, and CCR2+ CCR5+ CD14+ monocytes. These findings uncover the diverse immunophenotypes and possible pathomechanisms of cancer treatment-related pneumonitis.

Surfactant protein D prevents mucin overproduction in airway goblet cells via SIRPα.

Mucin overproduction is a common feature of chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), and exacerbates their underlying respiratory condition. Surfactant protein D (SP-D) protects against airway diseases through modulation of immune reactions, but whether it also exerts direct effects on airway epithelial cells has remained unclear. Therefore, we sought to investigate the inhibitory role of SP-D on mucin production in airway epithelial cells. We prepared air-liquid interface (ALI) cultures of human primary bronchial epithelial cells (HBECs), which recapitulated a well-differentiated human airway epithelium. Benzo(a)pyrene (BaP), a key toxicant in cigarette smoke, induced mucin 5AC (MUC5AC) production in ALI-cultured HBECs, airway secretory cell lines, and airway epithelia of mice. Then, the protective effects of SP-D against the BaP-induced mucin overproduction were examined. BaP increased MUC5AC production in ALI cultures of HBECs, and this effect was attenuated by SP-D. SP-D also suppressed the BaP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and MUC5AC expression in NCI-H292 goblet-like cells, but not in NCI-H441 club-like cells. Signal regulatory protein α (SIRPα) was found to be expressed in HBECs and NCI-H292 cells but absent in NCI-H441 cells. In NCI-H292 cells, SP-D activated SH2 domain-containing tyrosine phosphatase-1 (SHP-1), downstream of SIRPα, and knockdown of SIRPα abolished the suppressive effects of SP-D on BaP-induced ERK phosphorylation and MUC5AC production. Consistent with these in vitro findings, intratracheal instillation of SP-D prevented the BaP-induced phosphorylation of ERK and Muc5ac expression in airway epithelial cells in a mouse model. SP-D acts directly on airway epithelial cells to inhibit mucin secretion through ligation of SIRPα and SHP-1-mediated dephosphorylation of ERK. Targeting of SIRPα is therefore a potential new therapeutic approach to suppression of mucin hypersecretion in chronic airway diseases such as COPD and asthma.

Therapeutic strategies to target connective tissue growth factor in fibrotic lung diseases.

The treatment of interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF), remains challenging as current available antifibrotic agents are not effective in halting disease progression. Connective tissue growth factor (CTGF), also known as cellular communication factor 2 (CCN2), is a member of the CCN family of proteins that regulates cell signaling through cell surface receptors such as integrins, the activity of cytokines/growth factors, and the turnover of extracellular matrix (ECM) proteins. Accumulating evidence indicates that CTGF plays a crucial role in promoting lung fibrosis through multiple processes, including inducing transdifferentiation of fibroblasts to myofibroblasts, epithelial-mesenchymal transition (EMT), and cooperating with other fibrotic mediators such as TGF-ß. Increased expression of CTGF has been observed in fibrotic lungs and inhibiting CTGF signaling has been shown to suppress lung fibrosis in several animal models. Thus, the CTGF signaling pathway is emerging as a potential therapeutic target in IPF and other pulmonary fibrotic conditions. This review provides a comprehensive overview of the current evidence on the pathogenic role of CTGF in pulmonary fibrosis and discusses the current therapeutic agents targeting CTGF using a systematic review approach.

Survival and acute exacerbation for patients with idiopathic pulmonary fibrosis (IPF) or non-IPF idiopathic interstitial pneumonias: 5-year follow-up analysis of a prospective multi-institutional patient registry.

OBJECTIVE: Few prospective cohort studies with relatively large numbers of patients with non-idiopathic pulmonary fibrosis (non-IPF) of idiopathic interstitial pneumonia (IIP) have been described. We aimed to assess disease progression and cause of death for patients with non-IPF IIPs or IPF under real-life conditions. METHODS: Data were analysed for a prospective multi-institutional cohort of 528 IIP patients enrolled in Japan between September 2013 and April 2016. Diagnosis of IPF versus non-IPF IIPs was based on central multidisciplinary discussion, and follow-up surveillance was performed for up to 5 years after patient registration. Survival and acute exacerbation (AE) were assessed. RESULTS: IPF was the most common diagnosis (58.0%), followed by unclassifiable IIPs (35.8%) and others (6.2%). The 5-year survival rate for non-IPF IIP and IPF groups was 72.8% and 53.7%, respectively, with chronic respiratory failure being the primary cause of death in both groups. AE was the second most common cause of death for both non-IPF IIP (24.1%) and IPF (23.5%) patients. The cumulative incidence of AE did not differ significantly between the two groups (p=0.36), with a 1-year incidence rate of 7.4% and 9.0% in non-IPF IIP and IPF patients, respectively. We found that 30.2% and 39.4% of non-IPF IIP and IPF patients, respectively, who experienced AE died within 3 months after an AE event, whereas 55.8% and 66.7% of such patients, respectively, died within 5 years after registration. CONCLUSION: Closer monitoring of disease progression and palliative care interventions after AE are important for non-IPF IIP patients as well as for IPF patients.

Altered macrophage phenotypes in a case of autoimmune pulmonary alveolar proteinosis.

Mass cytometry of BALF cells from a pulmonary alveolar proteinosis patient, positive for anti-GM-CSF antibodies, suggests potential impairment in human alveolar macrophage differentiation https://bit.ly/45JHUrz.

Acute myeloid leukemia and myelodysplastic syndrome associated with a combination of immune checkpoint inhibitor and platinum-based chemotherapy.

Therapy related-acute myeloid leukemia (t-AML) and myelodysplastic syndrome (t-MDS) are complications of chemotherapy and/or radiation therapy for malignant diseases. In this report, we describe a patient with advanced lung adenocarcinoma who developed autoimmune hemolytic anemia and MDS associated with a combination of atezolizumab and platinum-based chemotherapy. The patient showed progression from t-MDS to t-AML 20 months after the treatment was initiated. A combination of immune checkpoint inhibitor (ICI) and chemotherapy may increase the risk of developing therapy-related myeloid neoplasms. As the prognosis of t-AML and t-MDS is poorer than that of de novo AML and MDS, proper surveillance, follow-up, and treatment are needed throughout the course of immunotherapy.

Expansion of ST2-expressing macrophages in a patient with bronchiolitis obliterans syndrome.

This case study of a patient with BOS after HSCT found increased ST2+CD64+ macrophages in BALF, a potential therapeutic target for treatment-refractory BOS, and reduced CCR2+CD14+ monocytes compared to other lung disorders https://bit.ly/406Uyy9.

Pleuroparenchymal fibroelastosis secondary to autologous peripheral blood stem cell transplantation: A case report.

Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonitis. Although most cases of PPFE are idiopathic, some cases of PPFE occur secondary to stem cell transplantation. We report a 41-year-old woman developed pneumonia after autologous peripheral blood system cell transplantation (PBSCT). Eleven years after PBSCT, she presented with dyspnea. A computed tomographic scan showed pleuroparenchymal thickening and predominantly in the upper lobes. She was diagnosed with PPFE secondary to PBSCT. She was started nintedanib and administered oxygen therapy. Most cases of PPFE secondary to stem cell transplantation have been reported. However, we experienced the case of PPFE post-autologous PBSCT.

Mass cytometry identifies characteristic immune cell subsets in bronchoalveolar lavage fluid from interstitial lung diseases.

Immune cells have been implicated in interstitial lung diseases (ILDs), although their phenotypes and effector mechanisms remain poorly understood. To better understand these cells, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF), connective-tissue disease (CTD)-related ILD, and sarcoidosis, using two panels including 64 markers. Among myeloid cells, we observed the expansion of CD14+ CD36hi CD84hiCCR2- monocyte populations in IPF. These CD14+ CD36hi CD84hi CCR2- subsets were also increased in ILDs with a progressive phenotype, particularly in a case of acute exacerbation (AEx) of IPF. Analysis of B cells revealed the presence of cells at various stages of differentiation in BALF, with a higher percentage of IgG memory B cells in CTD-ILDs and a trend toward more FCRL5+ B cells. These FCRL5+ B cells were also present in the patient with AEx-IPF and sarcoidosis with advanced lung lesions. Among T cells, we found increased levels of IL-2R+ TIGIT+ LAG3+ CD4+ T cells in IPF, increased levels of CXCR3+ CD226+ CD4+ T cells in sarcoidosis, and increased levels of PD1+ TIGIT+ CD57+ CD8+ T cells in CTD-ILDs. Together, these findings underscore the diverse immunopathogenesis of ILDs.

Intrinsic BMP inhibitor Gremlin regulates alveolar epithelial type II cell proliferation and differentiation.

Type 1 alveolar epithelial cells (AT1s) and type 2 alveolar epithelial cells (AT2s) regulate the structural integrity and function of alveoli. AT1s mediate gas exchange, whereas AT2s serve multiple functions, including surfactant secretion and alveolar repair through proliferation and differentiation into AT1s as progenitors. However, mechanisms regulating AT2 proliferation and differentiation remain unclear. Here we demonstrate that Gremlin, an intrinsic inhibitor of bone morphogenetic protein (BMP), induces AT2 proliferation and differentiation. Transient overexpression of Gremlin in rat lungs by adenovirus vector delivery suppressed BMP signaling, induced proliferation of AT2s and the production of Bmp2, which in turn led to the recovery of BMP signaling and induced AT2 differentiation into AT1s. Bleomycin-induced lung injury upregulated Gremlin and showed a similar time course of biomarker expression comparable to the adenovirus model. TGF-ß and IL-1ß induced Gremlin expression in fibroblasts. Taken together, our findings implicate that Gremlin expression during lung injury leads to precisely timed inhibition of BMP signaling and activates AT2s, leading to alveolar repair.

Vascular-Parenchymal Cross-Talk Promotes Lung Fibrosis through BMPR2 Signaling.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by progressive lung scarring. IPF-related pulmonary vascular remodeling and pulmonary hypertension (PH) result in a particularly poor prognosis. Objectives: To study the pathogenesis of vascular remodeling in fibrotic lungs and its contribution to progression of fibrosis. Methods: We used an experimental model of lung fibrosis associated with PH by transient overexpression of active TGF-ß1 (transforming growth factor-ß1). Samples from patients with fibrotic lung diseases were analyzed in depth using immunostaining, gene expression, and gene mutations. Measurements and Main Results: We found a reduction in endothelial cells (ECs) and activation of vascular smooth muscle cells (VSMCs) in fibrotic lungs. Coculturing fibroblasts with VSMCs or ECs from fibrotic lungs induced fibrotic phenotypes in fibroblasts. IPF fibroblasts induced EC death and activation of VSMCs in coculture systems. Decreased concentrations of BMPR2 (bone morphogenic protein receptor 2) and its signaling were observed in ECs and VSMCs from fibrotic lungs in both rats and humans. On fibroblasts treated with media from VSMCs, BMPR2 suppression in VSMCs led to fibrogenic effects. Tacrolimus activated BMPR2 signaling and attenuated fibrosis and PH in rodent lungs. Whole-exome sequencing revealed rare mutations in PH-related genes, including BMPR2, in patients with IPF undergoing transplantation. A unique missense BMPR2 mutation (p.Q721R) was discovered to have dysfunctional effects on BMPR2 signaling. Conclusions: Endothelial dysfunction and vascular remodeling in PH secondary to pulmonary fibrosis enhance fibrogenesis through impaired BMPR2 signaling. Tacrolimus may have value as a treatment of advanced IPF and concomitant PH. Genetic abnormalities may determine the development of PH in advanced IPF.

Recurrent Massive Hemothorax of Unknown Etiology in an 85-Year-Old Man.

CASE PRESENTATION: An 85-year-old Japanese man, who was taking aspirin and edoxaban for previous myocardial infarction and atrial fibrillation, came to our hospital with a chief complaint of dyspnea for 3 weeks. Chest radiography showed a massive left pleural effusion (Fig 1A). Analysis of pleural fluid showed an elevated hematocrit level at 32.8% (blood hematocrit level, 32.0%), and he was diagnosed with hemothorax. However, he had neither coagulation disorder nor thrombocytopenia, and the pleural effusion was negative for atypical cells. These findings suggested that the antithrombotic and anticoagulant medications might have induced the hemothorax.

Connective-Tissue Growth Factor Contributes to TGF-ß1-induced Lung Fibrosis.

Idiopathic pulmonary fibrosis is a fatal lung disease characterized by progressive and excessive accumulation of myofibroblasts and in the lung. Connective-tissue growth factor (CTGF) exacerbates pulmonary fibrosis in radiation-induced lung fibrosis, and in this study, we demonstrate upregulation of CTGF in a rat lung fibrosis model induced by an adenovirus vector encoding active TGF-ß1 (AdTGF-ß1). We show that CTGF is also upregulated in patients with idiopathic pulmonary fibrosis. Expression of CTGF was upregulated in vascular smooth muscle cells cultured from fibrotic lungs on Days 7 and 14 as well as endothelial cells sorted from fibrotic lungs on Days 14 and 28. These findings suggest contributions of different cells in maintaining the fibrotic phenotype during fibrogenesis. Treatment of fibroblasts with recombinant CTGF along with TGF-ß increases profibrotic markers in fibroblasts, confirming the synergistic effect of recombinant CTGF with TGF-ß in inducing pulmonary fibrosis. Also, the fibrotic extracellular matrix upregulated CTGF expression, compared with the normal extracellular matrix, suggesting that not only profibrotic mediators but also a profibrotic environment contributes to fibrogenesis. We also showed that pamrevlumab, a CTGF inhibitory antibody, partially attenuates fibrosis in the model. These results suggest that pamrevlumab could be an option for treatment of pulmonary fibrosis.

A Rare Case of Pulmonary Tumor Thrombotic Microangiopathy Associated with Micropapillary Urothelial Carcinoma of the Urinary Bladder: An Autopsy Case.

A 70-year-old woman was hospitalized with dyspnea. A transthoracic echocardiogram indicated an elevated systolic pulmonary artery pressure, and the cytology specimens obtained using a pulmonary artery catheter confirmed adenocarcinoma metastasis. Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) detected high-signal-intensity lesions in the urinary bladder. The patient died of respiratory failure and a postmortem examination was performed. Tumor cells in the bladder were immunohistochemically positive for GATA3, indicating micropapillary urothelial carcinoma, which is a rare variant of urothelial carcinoma and considered an adenocarcinoma subtype. This case is the first autopsy case of pulmonary tumor thrombotic microangiopathy (PTTM) associated with micropapillary urothelial carcinoma of the urinary bladder.

Tumor Embolism as a Cause of Renal Artery Occlusion and Acute Kidney Injury Diagnosed and Treated with Endovascular Intervention in a Patient with Mediastinal Undifferentiated Sarcoma.

A 72-year-old man presented with back pain due to a mass in the left posterior mediastinum that had surrounded and partly infiltrated the descending aorta. Mediastinal undifferentiated sarcoma was diagnosed. After the diagnosis, sudden anuria was observed. Contrast-enhanced computed tomography revealed an enhancement defect at the origins of the bilateral renal arteries. He received catheter-directed thrombolysis and was weaned off dialysis. The aspirated artery thrombus contained tumor cells, proving our diagnosis of acute kidney injury secondary to bilateral renal artery tumor embolism. In cancer patients, endovascular intervention may be a useful diagnostic and therapeutic option in cases of acute kidney injury secondary caused by peripheral thromboembolic complications.