Associations of Serum Clara Cell Protein 16 with Severity and Prognosis in Adults with Community-Acquired Pneumonia.

Background: Clara cell protein 16 (CC16) has multiple functions, including antioxidant, anti-inflammatory, and immune regulation properties. Nevertheless, the concrete function of CC16 in adult patients with community-acquired pneumonia (CAP) remained blurred. Methods: A total of 541 adult patients with CAP were recruited on admission. Peripheral blood specimens, clinical parameters, and demographic characteristics were collected. The concentration of serum CC16 was evaluated through ELISA. The relationships between serum CC16 and clinical parameters were appraised by Spearman or Pearson correlative analyses. The correlations of serum CC16 with severity and prognosis were assessed using linear or logistic regression models. Results: The level of CC16 was gradually decreased across with the elevated severity scores system of CAP. After treatment, the level of serum CC16 was upregulated. Correlative analyses found that serum CC16 was negatively related to inflammatory cytokines. Additionally, multivariate linear and logistic regression models revealed that serum CC16 was inversely associated with severity scores system. In addition, reduced serum CC16 on admission elevated the risks of vasoactive agent usage, ICU admission, and death during hospitalization. We observed an almost discriminatory ability for severity and death between serum CC16 and severity scores system, and were all obviously elevated compared to routine inflammatory and infectious markers. Conclusion: There are substantially inverse correlations between serum CC16 level on admission with severity scores and poorly prognostic outcomes, indicating that CC16 is involved in the pathophysiological process of CAP. This study is helpful for establishing the potential application of serum CC16 in risk evaluation and targeted treatment.

Exploring the Role of Biomarkers Associated with Alveolar Damage and Dysfunction in Idiopathic Pulmonary Fibrosis-A Systematic Review.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is one of the most aggressive forms of interstitial lung diseases (ILDs), marked by an ongoing, chronic fibrotic process within the lung tissue. IPF leads to an irreversible deterioration of lung function, ultimately resulting in an increased mortality rate. Therefore, the focus has shifted towards the biomarkers that might contribute to the early diagnosis, risk assessment, prognosis, and tracking of the treatment progress, including those associated with epithelial injury. METHODS: We conducted this review through a systematic search of the relevant literature using established databases such as PubMed, Scopus, and Web of Science. Selected articles were assessed, with data extracted and synthesized to provide an overview of the current understanding of the existing biomarkers for IPF. RESULTS: Signs of epithelial cell damage hold promise as relevant biomarkers for IPF, consequently offering valuable support in its clinical care. Their global and standardized utilization remains limited due to a lack of comprehensive information of their implications in IPF. CONCLUSIONS: Recognizing the aggressive nature of IPF among interstitial lung diseases and its profound impact on lung function and mortality, the exploration of biomarkers becomes pivotal for early diagnosis, risk assessment, prognostic evaluation, and therapy monitoring.

[Investigation of serum surface active protein D and clara cell protein levels in workers exposed to silica dust in ferrous metal foundry].

Objective: To investigate the levels of serum surface active protein D (SP-D) and clara cell protein (CCl6) in workers exposed to black silica dust, and analyze its influencing factors. Methods: From July to September 2021, 174 workers in 37 positions exposed to silica dust in 5 ferrous metal foundry were investigated by cross-sectional research method. The exposure concentration of silica dust workers was obtained through occupational health field investigation and detection, and the general situation of the study subjects was obtained through questionnaire survey and peripheral blood was collected. Double antigen sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of SP-D and CC16 in serum of workers. The mean values were compared by one-way ANOVA, and the influencing factors of SP-D and CC16 concentrations in serum were analyzed by ordered multiple logistic regression. Results: The time-weighted average concentration (C-TWA) of 174 workers exposed to silica dust (respirable dust) ranged from 0.09 mg/m(3)~3.58 mg/m(3), and the C-TWA overstandard rate of dust exposed workers was 32.18% (56/174) , with differences among workers in different positions (χ(2)=28.85, P<0.001) . The highest concentration of silica dust was (0.82±0.11) mg/m(3). Using C-TWA<50% OEL occupational exposure limit (OEL) as reference, serum SP-D concentration in workers with ≥50% OEL was increased (OR=4.95, 95%CI: 1.86~13.17, P=0.001) , while CC16 concentration was decreased (OR=0.15, 95%CI: 0.05~0.40, P<0.001) ; Serum CC16 concentration decreased in workers exposed to silica dust C-TWA≥OEL (OR=0.46, 95%CI: 0.28~0.98, P=0.043) . Compared with those with low occupational health literacy, the serum SP-D concentration of workers with high occupational health literacy decreased (OR=0.48, 95%CI: 0.25~0.92, P=0.027) and CC16 concentration increased (OR=2.09, 95%CI: 1.10-3.97, P=0.024) . Conclusion: When no abnormality was found in the physical examination of workers, the serum SP-D and CC16 concentration levels changed, and the change was related to the concentration of workers exposed to silica dust.

Health symptoms, inflammation, and bioaerosol exposure in workers at biowaste pretreatment plants.

Biowaste pretreatment plants have been built within the last years in Denmark in order to recycle pre-sorted biowaste from houses, restaurants, and industry. We investigated the association between exposure and health at six biowaste pretreatment plants (visited twice) across Denmark. We measured the personal bioaerosol exposure, took blood samples, and administered a questionnaire. Thirty-one persons participated, 17 of them twice, resulting in 45 bioaerosol samples, 40 blood samples, and questionnaire answers from 21 persons. We measured exposure to bacteria, fungi, dust, and endotoxin, the total inflammatory potential of the exposures, and serum levels of the inflammatory markers serum amyloid A (SAA), high sensitivity C-reactive protein (hsCRP), and human club cell protein (CC16). Higher exposures to fungi and endotoxin were found for workers with tasks inside the production area compared to workers with main tasks in the office area. A positive association was found between the concentration of anaerobic bacteria and hsCRP and SAA, whereas bacteria and endotoxin were inversely associated with hsCRP and SAA. A positive association between hsCRP and the fungal species Penicillium digitatum and P. camemberti were found, whereas an inverse association between hsCRP and Aspergillus niger and P. italicum were found. Staff with tasks inside the production area reported more symptoms of the nose than those working in the office area. To conclude, our results indicate that workers with tasks inside the production area are exposed to elevated levels of bioaerosols, and that this may affect workers' health negatively.

Levels of Clara cell secretory protein and surfactant protein A in municipal solid waste management workers in Ibadan, Southwest Nigeria.

Toxic pneumonitis and related respiratory symptoms are common among waste management workers (WMWs). Products of different cellular responses following exposure to toxic components of wastes can lead to the production of a variety of biomolecules. There is a growing recognition of the importance of biomarkers in risk assessment and a strong advocacy for their determination and use as indicators of health and safety. This study assessed the prevalence of respiratory symptoms and the relevance of pulmonary surfactant protein A (SP-A) and Clara cell 16 protein (CC16) as indicators of occupational inhalation exposure to toxic substances and irritants in WMW. A total of 172 subjects consisting of 112 WMWs and 60 Non-WMWs were recruited by purposive sampling. Data on socio-economic and work-related symptoms were collected using structured questionnaire. CC16 and SP-A were determined by ELISA in serum samples. Clinical history reveals a slightly higher prevalence of respiratory symptoms in WMWs relative to control subjects. Increased permeability of the lung-blood barrier, characterized by significant elevation of serum SP-A and serum CC16, was associated with respiratory symptoms in WMWs. Steady increases in SP-A and CC16, respectively, in relation to occupational duration were observed in WMWs relative to control. Receiver operating characteristic curve and multivariate analyses revealed SP-A and CC16 as important lung biomarkers for assessing sub-clinical effects of occupational exposure. Our data suggest SP-A and CC16 may be relevant indicators for assessing occupational inhalation exposure to toxic substances and irritants among WMWs.

Lab on a chip for detecting Clara cell protein 16 (CC16) for potential screening of the workers exposed to respirable silica aerosol.

Early detection of pulmonary responses to silica aerosol exposure, such as lung inflammation as well as early identification of silicosis initiation, is of great importance in disease prevention of workers. In this study, to early screen the health condition of the workers who are exposed to respirable silica dusts, an immunoassay lab on a chip (LOC) was designed, developed and fully characterized for analyzing Clara cell protein 16 (CC16) in serum which has been considered as one of the potential biomarkers of lung inflammation or lung damage due to the respirable silica dusts. Sandwich immunoassay of CC16 was performed on the LOC developed with a custom-designed portable analyzer using artificial serums spiked with CC16 protein first and then human serums obtained from the coal mine workers exposed to the respirable silica-containing dusts. The dynamic range of CC16 assay performed on the LOC was in a range of 0.625-20 ng/mL, and the achieved limit of detection (LOD) was around 0.35 ng/mL. The assay results of CC16 achieved from both the developed LOC and the conventional 96 well plate showed a reasonable corelation. The correlation between the conventional reader and the developed portable analyzer was found to be reasonable, resulting in R2 ~ 0.93. This study shows that the LOC developed for the early detection of CC16 can be potentially applied for the development of a field-deployable point-of-care testing (POCT) for the early monitoring of the field workers who are exposed to silica aerosol.

Role of aryl hydrocarbon receptor in down-regulation of Clara cell secretory protein expression during endotoxin-induced lung injury in rats / 中华麻醉学杂志

Objective:To evaluate the role of aryl hydrocarbon receptor (AhR) in the down-regulation of Clara cell secretory protein (CCSP) expression during endotoxin-induced lung injury in rats.Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 200-250 g, were divided into 4 groups ( n=6 each) using a random number table method: normal control group (group C), acute lung injury (ALI) group, ALI+ AhR antagonist group, and ALI+ vehicle group. Lipopolysaccharide(LPS) 1 mg/kg was intratracheally instilled to develop the model of lung injury, while the equal volume of normal saline was given instead in group C. At 2 h before LPS injection, AhR antagonist 6, 2′, 4′-trimethoxyflavone solution 5 mg/kg (diluted to 1 ml in dimethyl sulfoxide solution) was intraperitoneally injected in ALI+ AhR antagonist group, while dimethyl sulfoxide solution 1 ml was given in ALI+ vehicle group. The rats were sacrificed under anesthesia at 48 h after LPS administration. The left lung was lavaged and the broncho-alveolar lavage fluid (BALF) was collected for determination of the concentrations of CCSP by enzyme-linked immunosorbent assay, and the expression of CCSP in the bronchial epithelium in right lung tissues was determined by immunohistochemistry. Results:Compared with group C, the expression of CCSP in the bronchial epithelium was significantly down-regulated, and the concentrations of CCSP in BALF were decreased in the other three groups ( P<0.05 or 0.01). Compared with ALI group and ALI+ vehicle group, the histopathological injury was significantly reduced, the expression of CCSP in the bronchial epithelium was up-regulated, and the concentrations of CCSP in BALF were increased in ALI+ AhR antagonist group ( P<0.01). Conclusions:AhR partially mediates the down-regulation of CCSP expression during endotoxin-induced lung injury in rats.

Effect of lung protective ventilation on lung ventilation function, serum serum Clara cell protein 16 level and prognosis in patients undergoing gynecological laparoscopic surgery / 中国医师进修杂志

Objective:To analyze the effect of lung protective ventilation on lung ventilation function and serum Clara cell protein 16 (CC16) level in patients undergoing gynecological laparoscopic surgery.Methods:The clinical data of 80 gynecological patients who underwent laparoscopic surgery in Yancheng City Jianhu County People′s Hospital from October 2018 to December 2020 were randomly divided into group A and group B by random number table, each group with 40 cases. The patients in group A were treated with intermittent positive-pressure ventilation, and the patients in group B were ventilated with whole course ventilation mode. The pulmonary ventilation function, CC16 level and postoperative pulmonary complications were observed before anesthesia, 10 min of pneumoperitoneum, 30 min of pneumoperitoneum, 5 min of pneumoperitoneum stop and 2 h after operation. The patients were divided into groups according to whether with pulmonary complications, and their pulmonary ventilation function and serum CC16 level were compared. The predictive value of the above indexes for pulmonary complications was analyzed by receiver operating characteristic (ROC) curve.Results:Repeated measurement analysis of variance showed that alveolar arterial oxygen differential pressure (PA-aDO 2) were significant differences in time point factors, time point interaction factors and group factors ( P<0.05); CC16 index were significant differences in time point factor and group factor ( P<0.05). According to the observation from postoperative to discharge, 4 patients (10.0%) in group A had pulmonary complications, 15 cases (37.5%) had pulmonary complications in group B, the levels of PA-aDO 2 and CC16 in patients with complications were significantly higher than those in patients without complications: group A:(332.9 ± 2.0) mmHg (1 mmHg = 0.133 kPa) vs. (290.4 ± 13.2) mmHg, (53.5 ± 1.5) μg/L vs. (39.5 ± 6.5) μg/L; group B: (339.1 ± 8.8) mmHg vs. (305.7 ± 17.9) mmHg, (41.5 ± 4.2) μg/L vs. (39.7 ± 5.8) μg/L, there were statistical differences ( P<0.05). ROC curve analysis showed that the area under the curve(AUC) of PA-aDO 2 and CC16 in predicting pulmonary complications in group A were 0.882 and 0.833, in group B was 0.885 and 0.731. Conclusions:Lung protective ventilation has little effect on lung ventilation function and serum CC16 in patients with gynecological laparoscopic surgery, and the probability of pulmonary complications is lower. The pulmonary ventilation function and CC16 have certain value in predicting postoperative pulmonary complications.

Health effects and known pathology associated with the use of E-cigarettes.

In recent years, new nicotine delivery methods have emerged, and many users are choosing electronic cigarettes (e-cigarettes) over traditional tobacco cigarettes. E-cigarette use is very popular among adolescents, with more than 3.5 million currently using these products in the US. Despite the increased prevalence of e-cigarette use, there is limited knowledge regarding the health impact of e-cigarettes on the general population. Based on published findings by others, E-cigarette is associated with lung injury outbreak, which increased health and safety concerns related to consuming this product. Different components of e-cigarettes, including food-safe liquid solvents and flavorings, can cause health issues related to pneumonia, pulmonary injury, and bronchiolitis. In addition, e-cigarettes contain alarmingly high levels of carcinogens and toxicants that may have long-lasting effects on other organ systems, including the development of neurological manifestations, lung cancer, cardiovascular disorders, and tooth decay. Despite the well- documented potential for harm, e-cigarettes do not appear to increase susceptibility to SARS-CoV- 2 infection. Furthermore, some studies have found that e-cigarette users experience improvements in lung health and minimal adverse effects. Therefore, more studies are needed to provide a definitive conclusion on the long-term safety of e-cigarettes. The purpose of this review is to inform the readers about the possible health-risks associated with the use of e-cigarettes, especially among the group of young and young-adults, from a molecular biology point of view.

The traditional Chinese patented medicine Qingke Pingchuan granules alleviate acute lung injury by regenerating club cells.

Qingke Pingchuan granules (QKPCG), a patented traditional Chinese medicine, clinically, are recommended for acute tracheobronchitis, cough, community-acquired pneumonia, and other respiratory diseases. However, its potential protective effect and mechanism of action in acute lung injury (ALI) have not been explored. We aimed to explore the mechanisms underlying the protective role of QKPCG in ALI. The therapeutic efficacy of QKPCG was investigated in a lipopolysaccharide (LPS)-induced ALI mouse model. Mice were divided into three groups, namely, the Control, LPS, and LPS + QKPCG groups. Mice in the LPS + QKPCG group were administered QKPCG intragastrically as a treatment once a day for a total of three days. QKPCG effectively increased survival and reduced lung injury in treated mice. It significantly reduced the LPS-induced expression of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), IL-1α, and IL-1ß. RNA-sequencing followed by real-time quantitative polymerase chain reaction validation suggested a critical role of the secretoglobin family 1A member 1 (Scgb1a1) gene in mediating the protective effect of QKPCG. Further, QKPCG reversed the LPS-induced downregulation of the Clara cell 10 kDa protein (CC10), a pulmonary surfactant protein encoded by Scgb1a1, which is mainly secreted by club cells in the lungs. Exogenous supplementation of CC10 alleviated LPS-induced ALI. Hematoxylin and eosin staining and enzyme-linked immunosorbent assay results further confirmed the anti-inflammatory properties of CC10, which were suggested as mediated via the inhibition of NFκB phosphorylation. In summary, our study provides evidence of the beneficial role of QKPCG in alleviating lung injury, mediated via the decreased disruption of club cells and higher expression of CC10, which leads to NFκB pathway inhibition.

Distinct Epithelial Cell Profiles in Normal Versus Induced-Congenital Diaphragmatic Hernia Fetal Lungs.

Background: Recent studies identified a great diversity of cell types in precise number and position to create the architectural features of the lung that ventilation and respiration at birth depend on. With damaged respiratory function at birth, congenital diaphragmatic hernia (CDH) is one of the more severe causes of fetal lung hypoplasia with unspecified cellular dynamics. Objectives:  To characterize the epithelial cell tissue in hypoplastic lungs, a careful analysis regarding pulmonary morphology and epithelial cell profile was conducted from pseudoglandular-to-saccular phases in normal versus nitrofen-induced CDH rat lungs. Design: Our analysis comprises three experimental groups, control, nitrofen (NF) and CDH, in which the relative expression levels (western blot) by group and developmental stage were analyzed in whole lung. Spatiotemporal distribution (immunohistochemistry) was revealed by pulmonary structure during normal and hypoplastic fetal lung development. Surfactant protein-C (SP-C), calcitonin gene-related peptide (CGRP), clara cell secretory protein (CCSP), and forkhead box J1 (FOXJ1) were the used molecular markers for alveolar epithelial cell type 2 (AEC2), pulmonary neuroendocrine, clara, and ciliated cell profiles, respectively. Results: Generally, we identified an aberrant expression of SP-C, CGRP, CCSP, and FOXJ1 in nitrofen-exposed lungs. For instance, the overexpression of FOXJ1 and CGRP in primordia of bronchiole defined the pseudoglandular stage in CDH lungs, whereas the increased expression of CGRP in bronchi; FOXJ1 and CGRP in terminal bronchiole; and SP-C in BADJ classified the canalicular and saccular stages in hypoplastic lungs. We also described higher expression levels in NF than CDH or control groups for both FOXJ1 in bronchi, terminal bronchiole and BADJ at canalicular stage, and SP-C in bronchi and terminal bronchiole at canalicular and saccular stages. Finally, we report an unexpected expression of FOXJ1 in BADJ at canalicular and saccular stages, whereas the multi cilia observed in bronchi were notably absent at embryonic day 21.5 in induced-CDH lungs. Conclusion: The recognized alterations in the epithelial cell profile contribute to a better understanding of neonatal respiratory insufficiency in induced-CDH lungs and indicate a problem in the epithelial cell differentiation in hypoplastic lungs.

Progress in diagnosis and treatment of CC16 in children pulmonary disease / 国际儿科学杂志

Clara cell secretory protein 16(CC16)is one of the most important secreted proteins of Clara cells in respiratory epithelium, which mainly exists in the lining fluid of lung epithelial cells.When the bronchoalveolus-capillary membrane barrier is damaged, a large amount of CC16 will enter the blood.It′s eventually excreted in the urine.In recent years, more and more studies have found that CC16 not only has anti-inflammatory, immune-modulating, anti-oxidation and anti-fibrosis effects, but also is a sensitive indicator of the integrity of the airway epithelium, which can predict the occurrence and development of many children′s pulmonary diseases.This article mainly summarizes the biological characteristics and functions of CC16, and summarizes the research progress of CC16 in the diagnosis and treatment of pediatric pulmonary diseases.

CC16-TNF-α negative feedback loop formed between Clara cells and normal airway epithelial cells protects against diesel exhaust particles exposure-induced inflammation.

CC16 is almost exclusively expressed in non-ciliated epithelial Clara cells, and widely used as a Clara cell marker. Diesel exhaust particles (DEPs), the fine particulate matters produced by diesel engines, cause or exacerbate airway-related diseases. Our previous study documented that DEP inhibits the CC16 expression in the immortalized mouse Clara cell line through methylation of C/EBPα promoter. However, the molecular mechanism by which DEP regulates CC16 secretion is unclear. Here, we isolated CC16 containing Clara cells (CC16+) from human distal lung, and found that DEP inhibited CC16 secretion from CC16+ cells via methylation of C/EBPα and inhibition of Munc18b transcription. CC16+ cell conditioned media containing different concentrations of CC16 was prepared and used for culture of airway epithelial cells BEAS-2B with no expression of CC16. A positive correlation was observed between CC16 level and DEP-induced autophagy activity, and a negative correlation between CC16 level and DEP-induced pro-inflammatory cytokine TNF-α, IL-6, and IL-8 level, suggesting that CC16 might mitigate DEP-induced inflammation via promoting autophagy in BEAS-2B cells. This result was further confirmed by adding recombinant CC16 to BEAS-2B cells exposed to DEP. Moreover, CC16 level was significantly increased when CC16+ cells were cultured in BEAS-2B cell conditioned medium containing TNF-α or the normal medium supplemented with recombinant TNF-α, suggesting that TNF-α induced CC16 production and secretion from CC16+ cells. Collectively, these data point that CC16 and TNF-α form a negative feedback loop, and this negative feedback loop between Clara cells and normal airway epithelial cells protects against DEP exposure-induced inflammation.

Club Cell Loss as a Feature of Bronchiolization in ILD.

Background: Distal airway metaplasia may precede honeycombing in progressive fibrosing interstitial lung disease (ILD). The SCGB1A1+ bronchiolar-specific club cell may play a role in this aberrant regenerative process. Objective: To assess the presence of club cells in the small airways of patients suffering from ILD. Methods: Small airways (internal diameter <2 mm) in lung samples [surgical lung biopsy (SLB) and/or transbronchial lung cryobiopsy (TBLC)] from 14 patients suffering from ILD and 10 controls were morphologically assessed and stained for SCGB1A1. SCGB1A1 was weighted by epithelial height as a marker of airway generation (SCGB1A1/EH). Correlations between clinical, functional, and high-resolution CT (HRCT) prognostic factors and histomorphometry were assessed. Results: Small airways from samples with ILD patterns were significantly less dense in terms of SCGB1A1+ cells [0.064 (0.020-0.172)] as compared to controls' sample's small airways [0.393 (0.082-0.698), p < 0.0001]. Usual interstitial pneumonia (UIP) patterns most frequently contained small airways with limited or absent SCGB1A1 expression (SCGB1A1/EH <0.025): UIP (18/33; 55%) as compared with non-UIP patterns (4/31; 13%) or controls (0/29; 0%): p < 0.0001. In addition, correlations with HRCT indicated a significant negative relationship between SCGB1A1 and bronchiectasis as a feature of bronchiolization (Rho -0.63, p < 0.001) and a positive relationship with both forced vital capacity (FVC) and Hounsfield unit (HU)-distribution pattern in kurtosis (Rho 0.38 and 0.50, respectively, both p < 0.001) as markers of fibrotic changes. Conclusion: Compared with controls, the small airways of patients with ILD more often lack SCGB1A1, especially so in UIP. Low densities of SCGB1A1-marked cells correlate with bronchiectasis and fibrotic changes. Further research investigating SCGB1A1 staining as a pathological feature of the bronchiolization process is merited.

Measurement of Tryptase and CC16/Albumin in Nasal Lavage Fluid as a Screening Tool of Allergic Rhinitis.

BACKGROUND: There is no trial to make a diagnostic tool of allergic rhinitis (AR) utilizing biomarkers from nasal fluid. Base on previous studies, we selected following five biomarkers in nasal fluids that represent the characteristics of allergic reactions: tryptase, eosinophil cationic protein (ECP), interleukin 5 (IL-5), Clara cell protein 16 (CC16) and CC16-to-albumin ratio. OBJECTIVE: This study aimed to identify biomarkers in nasal discharge that may be used in biosensors to diagnose AR as an additional diagnostic tool. METHODS: Patients showed rhinorrhea and tested positive on allergic skin and specific immunoglobulin E (IgE) tests were included in the AR group. The non-AR group included individuals no dominant nasal symptoms and tested negative on allergy tests. Nasal lavage fluid samples were collected from all participants. Biomarkers in the samples were quantified using enzyme-linked immunosorbent assay. RESULTS: Forty-five patients with AR and 28 non-AR subjects were enrolled in this study. Comparing the concentrations of biomarkers, the concentrations of tryptase and IL-5 were significantly higher in the AR group than in the NAR group. And CC16 level and CC16-to-albumin ratio were significantly lower in the AR group. In the combination of tryptase or CC16-to-albumin ratio, the sensitivity was 90.7% and the specificity was 64.3% (p = 0.013). CONCLUSION: The combination of "tryptase or CC16-to-albumin" could be used as a screening tool for AR. Although this diagnostic method could not replace conventional diagnostic tools, we could consider the method we proposed as an additional screening tool for patients who could not undergo allergy tests.

[Refractory ceramic fibers induced changes in serum Clara cell protein 16 and surfactant protein D levels in rats].

Objective: To explore the effect of refractory ceramic fibers (RCFs) on the serum Clara cell protein 16 (CC16) and surfactant protein D (SP-D) levels in Wistar rats. Methods: In October 2020, 96 healthy adult male Wistar rats were randomly divided into control group (equal volume of normal saline) , low-dose group (5 mg/ml RCFs) , medium-dose group (10 mg/ml RCFs) and high-dose group (20 mg/ml RCFs) , and subjected to non-exposure tracheal instillation. After intraperitoneal anesthesia, the rats were instilled with 200 µl of RCFs suspension or normal saline, once every 3 days for a total of 4 times. At 7, 14, 28, and 90 days after exposure, 6 rats were sacrificed by blood sampling through the abdominal aorta. The organs were separated, histopathological changes of lungs were observed and lung injury scores were performed. The contents of serum CC16 and SP-D were determined by enzyme-linked immunosorbent assay (ELISA) . Results: RCFs could cause inflammatory cells in rat lung tissues, widening of the lung septum and destruction of alveolar structure. 7 days after exposure, the lung injury scores of rats in each dose group were higher than control group, and the lung injury score of the high-dose group was higher than low-dose group (P<0.05) . 14 and 90 days after exposure, the lung injury scores of the medium-dose and high-dose groups were higher than control group (P<0.05) . 28 days after exposure, the lung injury score of the high-dose group was higher than control group (P<0.05) . 7 days after exposure, the serum CC16 and SP-D concentrations of rats in the medium-dose and high-dose groups were significantly higher than control and low-dose groups (P<0.05) . 28 days after exposure, the serum CC16 concentrations of rats in the low-dose and medium-dose groups were significantly lower than those of the control and high-dose groups (P<0.05) . After 90 days of exposure, the serum CC16 concentrations of rats decreased with the increase of the exposure dose (F=28.853, P<0.01) , and the concentrations of SP-D increased with the increase of the exposure dose (F=25.636, P<0.01) . Conclusion: RCFs exposure may cause certain damage to rat Clara cells and alveolar-capillary barrier. The severity of lung injury can be indirectly understood through the dynamic changes of serum CC16 and SP-D.

The relationship between the expression of serum IL-18 mRNA, CC16, and sTREM-1 and the severity and prognosis of ventilator-associated pneumonia in elderly patients.

BACKGROUND: This study aimed to explore the relationship between the severity and prognosis of elderly patients with ventilator-associated pneumonia (VAP) and the expression of serum interleukin-18 mRNA (IL-18 mRNA), Clara cell secretory protein 16 (CC16) and the soluble triggering receptor expressed on myeloid cells 1 (sTREM-1). METHODS: The patients were divided into a VAP group (n=75) and a non-VAP group (n=110). According to the Acute Physiology and Chronic Health Evaluation II (APACHEII) score, the patients with VAP were divided into a low-risk group, an intermediate-risk group and a high-risk group. According to the 28-day outcome, the patients were divided into a survival group and a death group. Serum levels of IL-18, CC16 and sTREM-1 were detected, and their value in the prediction and prognosis of VAP was analyzed using a receiver operating characteristic (ROC) curve. RESULTS: Serum levels of IL-18 and sTREM-1 in the VAP group were higher than those in the non-VAP group, while CC16 levels were lower in the VAP group than those in the non-VAP group (P<0.05). Serum levels of IL-18 and sTREM-1 decreased in order from the high-risk group to the intermediate-risk group to the low-risk group, while CC16 levels increased in order (P<0.05). ROC curve analysis showed that the Youden index and AUC of combined diagnosis of VAP with serum IL-18 mRNA, CC16 and sTREM-1 were 0.710 and 0.930, which were higher than those of single diagnosis (P<0.05). Serum levels of IL-18 mRNA and sTREM-1 in the survival group were lower than those in the death group, and the CC16 level was higher than that in the death group (P<0.05). ROC curve analysis showed that the Youden index and AUC of combined diagnosis with serum IL-18 mRNA, CC16 and sTREM-1 were 0.506 and 0.731, which were higher than those of single diagnosis (P<0.05). CONCLUSIONS: The combination of these 3 factors is of high value in predicting the severity and prognosis of VAP and can provide reference for clinical treatment.

Respiratory effects induced by occupational exposure to refractory ceramic fibers.

Refractory ceramic fibers (RCFs) are increasingly used as heating-insulated materials in various industries. However, toxicological and epidemiological studies focusing on the adverse effects of RCFs were still insufficient, particularly in China. We conducted a cross-sectional study to evaluate comprehensively the associations between occupational exposure to RCFs and respiratory health effects among Chinese workers. We measured and calculated cumulative RCFexposure levels of RCFs workers from the biggest RCFs factory in China. In total, 430 RCF-exposed workers and 121 controls were enrolled in this study. Physical examinations of the respiratory system were performed and serum levels of biomarkers including Clara cell protein 16 (CC16), surfactant protein D (SP-D), transforming growth factor ß1 (TGF-ß1), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were determined among all subjects. RCF exposure workers showed a higher prevalence rate of respiratory symptoms (cough: 11.9%) and lower levels of small airways function indices (V50 %: 82.71 ± 20.01, maximal mid expiratory flow (MMEF)%: 81.08 ± 19.56) compared with the control group (cough: 5.0%, V50 %: 90.64 ± 24.36, MMEF%: 88.83 ± 24.22). RCFs workers showed higher levels of TGF-ß1 (31.04 ng/mL) and 8-OHdG (130.72 ng/mL) and lower levels of CC16 (3.68 ng/mL) compared with the controls (TGF-ß1: 26.63 ng/mL, 8-OHdG: 106.86 ng/mL, CC16: 5.65 ng/mL). After adjusting for covariates, cumulative RCF exposure levels showed significant positive associations with the levels of TGF-ß1 and 8-OHdG and negative association with the level of CC16. Occupational RCF exposure could induce adverse respiratory health effects, including cough and small airways damage, which may correlate to the altered levels of lung damage markers (CC16 and TGF-ß1) and oxidative markers (8-OHdG).

Clinical significance of Clara cell secreted protein 16 and pulmonary surfactant protein-A in early diagnosis of neonatal acute respiratory distress syndrome / 中国小儿急救医学

Objective:To investigate the clinical significance of changes of serum Clara cell secretory protein(CC16) and pulmonary surfactant protein A(SP-A) in neonates with acute respiratory distress syndrome(ARDS).Methods:The data of 30 neonates with ARDS who needed mechanical ventilation in neonatal intensive care unit of Xi′an Children′s Hospital from January 2016 to November 2018 were collected as observation group, including 12 cases in mild group, 10 cases in moderate group and 8 cases in severe group.The data of healthy newborns during the same period were taken as control group.The serum levels of CC16 and SP-A were detected by ELISA.The serum levels of CC16 and SP-A among different groups were compared.Results:The levels of serum CC16 and SP-A in ARDS group were (59.35±3.67)mg/L and(75.38±6.27)mg/L respectively, (11.26±1.32)mg/L and(18.15±2.69)mg/L in healthy group.The difference was significant( P<0.05). And the differences of serum CC16 and SP-A levels among different degree ARDS groups were significant( P<0.05). The levels of serum CC16 in mild, moderate and severe subgroup were(38.27±16.01)mg/L, (51.25±15.63)mg/L, (84.76±13.12)mg/L and SP-A were(47.02±7.18)mg/L, (73.12±7.98)mg/L, (96.45±12.50)mg/L, which increased with disease severity. Conclusion:Serum CC16 and SP-A are increased and correlated with the severity of neonatal ARDS, which may be used as the index for evaluating the severity of neonatal ARDS in the future.