miR-146a regulates emphysema formation and abnormal inflammation in the lungs of two mouse models.

miR-146a, a microRNA (miRNA) that regulates inflammatory responses, plays an important role in many inflammatory diseases. Although an in vitro study had suggested that miR-146a is involved in abnormal inflammatory response, being a critical factor in the pathogenesis of chronic obstructive pulmonary disease (COPD), in vivo evidence of its pathogenic role in COPD remains limited. Eight-week-old male B6(FVB)-Mir146tm1.1Bal/J [miR-146a knockout (KO)] and C57BL/6J mice were intratracheally administered elastase and evaluated after 28 days or exposed to cigarette smoke (CS) and evaluated after 5 mo. miR-146a expression was significantly increased in C57BL/6J mouse lungs due to elastase administration (P = 0.027) or CS exposure (P = 0.019) compared with that in the control group. Compared with C57BL/6J mice, elastase-administered miR-146a-KO mice had lower average computed tomography (CT) values (P = 0.017) and increased lung volume-to-weight ratio (P = 0.016), mean linear intercept (P < 0.001), and destructive index (P < 0.001). Moreover, total cell (P = 0.006), macrophage (P = 0.001), neutrophil (P = 0.026), chemokine (C-X-C motif) ligand 2/macrophage inflammatory protein-2 [P = 0.045; in bronchoalveolar lavage fluid (BALF)], cyclooxygenase-2, and matrix metalloproteinase-2 levels were all increased (in the lungs). Following long-term CS exposure, miR-146a-KO mice showed a greater degree of emphysema formation in their lungs and inflammatory response in the BALF and lungs than C57BL/6J mice. Collectively, miR-146a protected against emphysema formation and the associated abnormal inflammatory response in two murine models.NEW & NOTEWORTHY This study demonstrates that miR-146a expression is upregulated in mouse lungs because of elastase- and CS-induced emphysema and that the inflammatory response by elastase or CS is enhanced in the lungs of miR-146a-KO mice than in those of control mice, resulting in the promotion of emphysema. This is the first study to evaluate the protective role of miR-146a in emphysema formation and the associated abnormal inflammatory response in different in vivo models.

Exposure to the heated tobacco product IQOS generates apoptosis-mediated pulmonary emphysema in murine lungs.

Pulmonary emphysema is predominantly caused by chronic exposure to cigarette smoke (CS). Novel tobacco substitutes, such as heated tobacco products (HTPs), have emerged as healthier alternatives to cigarettes. IQOS, the most popular HTP in Japan, is advertised as harmless compared with conventional cigarettes. Although some studies have reported its toxicity, few in vivo studies have been conducted. Here, 12-wk-old C57BL6/J male mice were divided into three groups and exposed to air (as control), IQOS aerosol, or CS for 6 mo. After exposure, the weight gain was significantly suppressed in the IQOS and CS groups compared with the control (-4.93 g; IQOS vs. air and -5.504 g; CS vs. air). The serum cotinine level was significantly higher in the IQOS group than in the control group. The neutrophils and lymphocyte count increased in the bronchoalveolar lavage fluid of the IQOS and CS groups compared with those in the control group. Chronic IQOS exposure induced pulmonary emphysema similar to that observed in the CS group. Furthermore, expression levels of the genes involved in the apoptosis-related pathways were significantly upregulated in the lungs of the IQOS-exposed mice. Cytochrome c, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase-1 were overexpressed in the IQOS group compared with the control. Single-stranded DNA and TdT-mediated dUTP nick-end labeling-positive alveolar septal cell count significantly increased in the IQOS group compared with the control. In conclusion, chronic exposure to IQOS aerosol induces pulmonary emphysema predominantly via apoptosis-related pathways. This suggests that HTPs are not completely safe tobacco products.

Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways.

BACKGROUND: Electronic cigarettes (e-cigarettes) are used worldwide as a substitute for conventional cigarettes. Although they are primarily intended to support smoking cessation, e-cigarettes have been identified as a gateway to smoking habits for young people. Multiple recent reports have described the health effects of inhaling e-cigarettes. E-cigarette liquid (e-liquid) is mainly composed of propylene glycol (PG) and glycerol (Gly), and the aerosol generated by these devices primarily contains these two components. Thus, this study aimed to evaluate the effects of PG and Gly on human small airway epithelial cells (SAECs). METHODS: SAECs were exposed to PG or Gly, and cell proliferation, cell viability, lactate dehydrogenase (LDH) release, DNA damage, cell cycle, and apoptosis were evaluated. Additionally, SAECs derived from chronic obstructive pulmonary disease (COPD) patients (COPD-SAECs) were investigated. RESULTS: Exposure of SAECs to PG significantly inhibited proliferation (1%, PG, p = 0.021; 2-4% PG, p < 0.0001) and decreased cell viability (1-4% PG, p < 0.0001) in a concentration-dependent manner. Gly elicited similar effects but to a reduced degree as compared to the same concentration of PG. PG also increased LDH release in a concentration-dependent manner (3% PG, p = 0.0055; 4% PG, p < 0.0001), whereas Gly did not show a significant effect on LDH release. SAECs exposed to 4% PG contained more cells that were positive for phosphorylated histone H2AX (p < 0.0001), a marker of DNA damage, and an increased proportion of cells in the G1 phase (p < 0.0001) and increased p21 expression (p = 0.0005). Moreover, caspase 3/7-activated cells and cleaved poly (ADP-ribose) polymerase 1 expression were increased in SAECs exposed to 4% PG (p = 0.0054). Furthermore, comparing COPD-SAECs to SAECs without COPD in PG exposure, cell proliferation, cell viability, DNA damage and apoptosis were significantly greater in COPD-SAECs. CONCLUSION: PG damaged SAECs more than Gly. In addition, COPD-SAECs were more susceptible to PG than SAECs without COPD. Usage of e-cigarettes may be harmful to the respiratory system, especially in patients with COPD.

Disseminated nontuberculous mycobacteriosis and fungemia after second delivery in a patient with MonoMAC syndrome/GATA2 mutation: a case report.

BACKGROUND: Heterozygous mutations in the transcription factor GATA2 result in a wide spectrum of clinical phenotypes, including monocytopenia and Mycobacterium avium complex (MAC) infection (MonoMAC) syndrome. Patients with MonoMAC syndrome typically are infected by disseminated nontuberculous mycobacteria, fungi, and human papillomavirus, exhibit pulmonary alveolar proteinosis during late adolescence or early adulthood, and manifest with decreased content of dendritic cells (DCs), monocytes, and B and natural killer (NK) cells. CASE PRESENTATION: A 39-year-old woman was diagnosed with MonoMAC syndrome postmortem. Although she was followed up based on the symptoms associated with leukocytopenia that was disguised as sarcoidosis with bone marrow involvement, she developed disseminated nontuberculous mycobacterial infection, fungemia, and MonoMAC syndrome after childbirth. Genetic testing revealed a heterozygous missense mutation in GATA2 (c.1114G > A, p.A372T). Immunohistochemistry and flow cytometry showed the disappearance of DCs and decreased frequency of NK cells in the bone marrow, respectively, after childbirth. CONCLUSIONS: To the best of our knowledge, this is the first study reporting that MonoMAC syndrome can be exacerbated after childbirth, and that immunohistochemistry of bone marrow sections to detect decreased DC content is useful to suspect MonoMAC syndrome.

Artificial intelligence-based point-of-care lung ultrasound for screening COVID-19 pneumoniae: Comparison with CT scans.

BACKGROUND: Although lung ultrasound has been reported to be a portable, cost-effective, and accurate method to detect pneumonia, it has not been widely used because of the difficulty in its interpretation. Here, we aimed to investigate the effectiveness of a novel artificial intelligence-based automated pneumonia detection method using point-of-care lung ultrasound (AI-POCUS) for the coronavirus disease 2019 (COVID-19). METHODS: We enrolled consecutive patients admitted with COVID-19 who underwent computed tomography (CT) in August and September 2021. A 12-zone AI-POCUS was performed by a novice observer using a pocket-size device within 24 h of the CT scan. Fifteen control subjects were also scanned. Additionally, the accuracy of the simplified 8-zone scan excluding the dorsal chest, was assessed. More than three B-lines detected in one lung zone were considered zone-level positive, and the presence of positive AI-POCUS in any lung zone was considered patient-level positive. The sample size calculation was not performed given the retrospective all-comer nature of the study. RESULTS: A total of 577 lung zones from 56 subjects (59.4 ± 14.8 years, 23% female) were evaluated using AI-POCUS. The mean number of days from disease onset was 9, and 14% of patients were under mechanical ventilation. The CT-validated pneumonia was seen in 71.4% of patients at total 577 lung zones (53.3%). The 12-zone AI-POCUS for detecting CT-validated pneumonia in the patient-level showed the accuracy of 94.5% (85.1%- 98.1%), sensitivity of 92.3% (79.7%- 97.3%), specificity of 100% (80.6%- 100%), positive predictive value of 95.0% (89.6% - 97.7%), and Kappa of 0.33 (0.27-0.40). When simplified with 8-zone scan, the accuracy, sensitivity, and sensitivity were 83.9% (72.2%- 91.3%), 77.5% (62.5%- 87.7%), and 100% (80.6%- 100%), respectively. The zone-level accuracy, sensitivity, and specificity of AI-POCUS were 65.3% (61.4%- 69.1%), 37.2% (32.0%- 42.7%), and 97.8% (95.2%- 99.0%), respectively. INTERPRETATION: AI-POCUS using the novel pocket-size ultrasound system showed excellent agreement with CT-validated COVID-19 pneumonia, even when used by a novice observer.

Blood Eosinophil Count as a Predictive Biomarker of Chronic Obstructive Pulmonary Disease Exacerbation in a Real-World Setting.

Introduction: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death, and COPD exacerbation worsens the prognosis. Eosinophilic airway inflammation is a COPD phenotype that causes COPD exacerbation and is correlated with peripheral blood eosinophil count. We analyzed real-world data of COPD patients to assess the risk factors of COPD exacerbation focusing on blood eosinophils. Materials and Methods: Patients with COPD who visited our hospital between January 1, 2018, and December 31, 2018, were recruited, and their background information, spirometry data, laboratory test results, and moderate-to-severe exacerbation events during the one-year follow-up period were collected from the electronic medical records and analyzed. The COPD exacerbation risk factors were assessed using univariate and multivariate logistic regression analyses. Results: Twenty-two of 271 (8.1%) patients experienced moderate-to-severe exacerbation. Patients with exacerbation showed worse pulmonary function, and we found that a high blood eosinophil count (≥350 cells/µL; p=0.014), low % FEV1 (<50%; p=0.002), increase in white blood cell (≥9000 cells/µL; p=0.039), and use of home oxygen therapy (p=0.005) were risk factors for future exacerbations. We also found a strong correlation between eosinophil count cut-offs and exacerbation risk (r = 0.89, p < 0.001). On the other hand, there was no relation between exacerbation risk and inhalation therapy for COPD. Conclusion: In a real-world setting, peripheral blood eosinophil count could be a predictor of future COPD exacerbation.

Evaluation of the aggregation states of monoclonal antibodies by diverse and complementary methods.

Therapeutic monoclonal antibodies (MAbs) with high specificity and fewer adverse effects are becoming widely used for the treatment of various diseases. MAbs need to be stored and administered at high concentrations in solution, the conditions under which MAbs may aggregate. As aggregated MAbs compromise their safety and efficacy, aggregation should be prevented; thus, it is important to analyze the aggregation states of MAbs in detail. We obtained 2 MAbs against dinitrophenol (DNP) that exhibited different aggregation properties: anti-DNP1 exhibited a much higher aggregate content (dimer or trimer) than anti-DNP2 when analyzed by size-exclusion chromatography (SEC). As anti-DNP1 had a longer complementarity-determining region 3 (CDR3) light chain than anti-DNP2 by 2 amino acid residues, we hypothesized that the increased aggregation of DNP1 was due to these extra residues; therefore, we prepared mutant antibodies with shorter CDR3s to compare their aggregation properties. Anti-DNP1-ΔEI, with the same CDR3 length as anti-DNP2, exhibited no aggregates as expected. Anti-DNP1-ΔI, with 1 additional residue, exhibited a smaller peak than wild-type (WT) in SEC, whereas this mutant exhibited stronger thioflavin T fluorescence than WT, which is indicative of amyloid formation. In addition, the anti-DNP1-ΔI solution (but not others) became opalescent at 4°C and exhibited large visible particles, which are undetectable by SEC. The fragment antigen-binding region of this mutant was found to have lower thermal stability than the others by differential scanning calorimetry. These data suggest that diverse analytical methods should be applied to evaluate MAb aggregation, in addition to the commonly used SEC.

Age is an independent predictor in pathological diagnosis of sarcoidosis: a retrospective analysis of diagnosis by endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the current major modality for the diagnosis of sarcoidosis with hilar and mediastinal lymphadenopathy because of its higher diagnostic yield and safety; however, predictors for the pathological diagnosis of sarcoidosis by EBUS-TBNA remain uncertain. The objective of this study was to determine a novel predictor for the pathological diagnosis of sarcoidosis by EBUS-TBNA. METHODS: Patients with pathological and/or clinical diagnosis of sarcoidosis were identified from patients who underwent EBUS-TBNA between February 2010 and December 2017, retrospectively. We extracted data on age, sex, stage of disease, number of punctured lymph nodes, number of punctures per procedure and target lymph node, and size of punctured lymph node. Next, we divided patients into groups of pathological positive and negative by EBUS-TBNA, and multivariate logistic regression analysis was performed following univariate analyses to evaluate the efficacy of these parameters as a predictive factor of the pathological diagnosis of sarcoidosis by EBUS-TBNA. RESULTS: We selected 89 patients involving 115 mediastinal and hilar lymph nodes. The diagnostic yield of sarcoidosis by EBUS-TBNA was 74/89 (83.1%). There were no significant differences in the size of lymph node and number of punctures between the groups, there was a significant difference in age by univariate analyses. In addition, multivariate logistic regression revealed that age was significantly associated with pathological diagnosis of sarcoidosis by EBUS-TBNA [5 years = 1 unit, odds ratio (OR), 0.79; 95% CI, 0.64-0.97; P=0.03]. CONCLUSIONS: The diagnostic yield of sarcoidosis by EBUS-TBNA was higher in younger than older patients. Therefore, age may be a novel independent predictor for the pathological diagnosis of sarcoidosis by EBUS-TBNA.

Autofluorescence imaging bronchoscopy as a novel approach to the management of tracheobronchopathia osteochondroplastica: a case report.

Tracheobronchopathia osteochondroplastica (TO) is not only rare but also presents highly varied and unpredictable clinical manifestations. Consequently, the management and treatment strategies remain unclear. An accurate evaluation tool is important for the management of individual patients in the absence of standard guidelines. Although bronchoscopy is the gold standard for diagnosis, it cannot satisfactorily detect the treatment response and disease progression because subtle mucosal changes can go undetected. Therefore, improved techniques that can detect subtle mucosal changes associated with TO are desirable. Autofluorescence imaging bronchoscopy (AFI) is a recently introduced advanced endoscopic technology that can detect subtle mucosal changes with the aid of different colors. Here we report the first case, to the best of our knowledge, involving a 42-year-old man with TO in whom tracheal involvement was evaluated by AFI and detected as the appearance of a magenta color.

Acquired factor v inhibitor developing after treatment with dabigatran etexilate methanesulfonate: a case report and review of the literature.

A 90-year-old man presented with subcutaneous ecchymoses. He had been under treatment with dabigatran etexilate methanesulfonate (DEM). Prolonged APTT and decreased PT was developed 2 months after the start of DEM, more prolonged 6 months later. DEM was discontinued, the coagulopathy did not improve. Factor V activity was decreased, along with appearance of coagulation factor V inhibitor (FVI). He did not have antiphospholipid syndrome or malignancy. He was diagnosed as having acquired FVI caused by DEM. Steroid pulse therapy was effective. There have been 74 reported cases of AFVI induced by drug treatment, but none after treatment with DEM.

Primary hepatic circumscribed Burkitt's lymphoma that developed after acute hepatitis B: report of a case with a review of the literature.

A Japanese man aged 30 years old contracted acute hepatitis B in October 2011, and was cured following conservative treatment. Mild hepatosplenomegaly was the only positive finding on computed tomography (CT) and ultrasonography at that time. In May 2012, slight impairment of the liver function was detected again in the patient; an abdominal CT at this time revealed a tumor mass in the right hepatic lobe, so subsegmentectomy of the right hepatic lobe was performed. On the basis of the findings of the resected specimen, primary hepatic circumscribed Burkitt's lymphoma (sporadic form), stage IA, was diagnosed. Multiple cycles of hyper-CVAD/MTX-Ara-C therapy with concomitant rituximab were administered, under which the patient was successfully maintained in complete remission. To date, at least 15 cases of primary hepatic Burkitt's lymphoma have been reported in the literature; all of the 11 patients without concurrent human immunodeficiency virus (HIV) infection had the sporadic form of the disease. Asians were relatively common (7 patients) among these patients, and patients in their childhood or adolescence accounted for a considerable proportion. Therefore, the present case may be regarded as rather typical. The presence of hepatitis virus infection as a background disorder other than HIV is considered to be of profound interest etiologically.