Surfactant Protein Research Articles

Efficacy and Safety of Ensovibep for Adults Hospitalized With COVID-19.

LettersFebruary 2023Efficacy and Safety of Ensovibep for Adults Hospitalized With COVID-19FREETeluguakula Narasaraju, PhD, Amita Krishnappa, MD, Marko Radic, PhD, Vincent T.K. Chow, MD, PhDTeluguakula Narasaraju, PhDAdichunchanagiri Institute of Medical Sciences, Karnataka, IndiaSearch for more papers by this author, Amita Krishnappa, MDAdichunchanagiri Institute of Medical Sciences, Karnataka, IndiaSearch for more papers by this author, Marko Radic, PhDUniversity of Tennessee Health Science Center, Memphis, TennesseeSearch for more papers by this author, Vincent T.K. Chow, MD, PhDNational University of Singapore, Kent Ridge, SingaporeSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L22-0455 SectionsAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR: The ACTIV-3/TICO (Accelerating COVID-19 Therapeutic Interventions and Vaccines/Therapeutics for Inpatients with COVID-19) Study Group (1) analyzed the efficacy and safety of ensovibep. This designed ankyrin repeat protein inhibits the interaction of SARS-CoV-2 spike protein with its host receptor, angiotensin-converting enzyme 2. This randomized controlled trial was a follow-up of earlier studies that showed antiviral activity of ensovibep in a hamster model of COVID-19 as well as reduced hospitalizations and improved clinical outcomes in outpatients with mild to moderate COVID-19. In contrast to those findings, the ACTIV-3/TICO Study Group showed that administration of ensovibep in severely ill patients hospitalized with COVID-19 did not exhibit any protection. This trial was prematurely discontinued because it failed early futility assessment and could not establish the power of the primary outcome in patients hospitalized with COVID-19. The study design has several shortcomings.First, this trial failed to establish the proof of concept of antiviral efficacy of ensovibep.Second, randomly assigning and blinding participants provide an unbiased approach; however, the 7 ordinal pulmonary or pulmonary-plus outcome scales used are unlikely to provide any direct correlation or clinical signatures specific for ensovibep-mediated effects, including lung viral loads or virus-inflicted alveolar–epithelial cytopathic injury.Third, combining remdesivir with ensovibep in the treatment regimen is unlikely to establish any beneficial effects.Finally, the lack of realistic data on viral replication and kinetics at the onset of treatment raises questions about the rationale for this clinical trial. Several clinical trials that evaluated combinations of monoclonal antibodies (for example, tixagevimab–cilgavimab or sotrovimab and BRII-196 plus BRII-198) in patients hospitalized with COVID-19 on the basis of ordinal outcome scales similarly yielded inconsistent findings and fell short of proving their efficacy in these patients (2, 3).When drugs targeting virus entry or replication in the lungs are evaluated, the inclusion of additional criteria to support the proof of concept is essential. Viral titers in nasopharyngeal or oropharyngeal samples unfortunately do not correlate well with viral loads in the deeper lungs, and use of invasive methods to collect lung samples may not be possible in patients hospitalized with COVID-19. Instead, measuring plasma viral RNA may be a better indicator to determine the antiviral effects of ensovibep or monoclonal antibodies in these patients (4). In addition, markers of alveolar epithelial injury such as podoplanin (a marker of alveolar type I epithelium) and surfactant protein C (a marker of alveolar type II epithelium) (5) in the plasma or sputum may represent virus-inflicted alveolitis in the lungs. As such, evaluating COVID-19 pathophysiology and clinical outcomes on ordinal outcome scales must be substantiated by more prudent methods that are relevant to drug target–specific signatures.

Contribution of surface-associated membranes to pulmonary surfactant-mediated drug delivery.

Pulmonary surfactant (PS) exhibits unique composition and biophysical properties to transport different type of therapeutic molecules. This has motivated its study as an efficient delivery vehicle for various drugs, especially molecules with hydrophobic character. PS is synthesized and secreted to the alveolar space by type II pneumocytes, where it spontaneously adsorbs into the air-liquid interface to reduce the surface tension. The adsorbed surfactant film is constituted by an interfacial monolayer with multi-layered membranes associated to it. Surfactant proteins SP-B and SP-C are responsible for maintaining the contact between these reservoirs and the interfacial layer. In order to study whether the multi-layered and multi-vesicular structures spread along the interface together with the interfacial monolayer, potentially serving as a vehicle for drugs, we have designed a novel vehiculization surface balance that connects a donor with a recipient compartment through a long interfacial pathway. Typically, the vehiculization of drugs mediated by PS has been evaluated in vitro by setups that combine different compartments through interfacial paper bridges. By incorporating a lipid fluorescent probe and the model hydrophobic drug Budesonide (BUD) into a porcine derived PS or into proteo-lipid vesicles, we determined that the amount of material transferred from a donor to a recipient compartment was substantially reduced due to the barrier imposed by the paper bridge. The bridge reduced the spreading to a simpler interfacial layer, while our novel setup reveals that a larger three-dimensional layer of liquid may facilitate the spreading of associated membranes and surfactant/drug complexes. We have determined that the three-dimensional structures associated to the interfacial layer spread along the air-liquid interface and entail an important contribution to the transport of lipids and drugs in surfactant-mediated delivery.

Pulmonary surfactant structure as solved by neutron reflectometry and atomic force microscopy.

In order to sustain breathing mechanics, the alveolar surface needs to be covered by pulmonary surfactant, a lipid/protein system that provides with the required surface tension reduction to avoid alveolar collapse at the end of expiration. Any disruption of this system could impair its function leading to severe respiratory pathologies. Pulmonary surfactant is composed by 90 % lipids and 10 % hydrophilic (SP-A and SP-D) and hydrophobic (SP-B and SP-C) proteins. After secretion, surfactant lipids form a complex structure at the alveolar air-liquid interface consisting of an adsorbed monolayer connected to a membranous reservoir in the subphase maintained thanks to the action of both hydrophobic proteins. The molecular mechanism of surfactant proteins is still not fully understood, making the finding of treatments for some respiratory pathologies a challenge. Model lipid systems mimicking pulmonary surfactant composition (DPPC/POPC/POPG 50:25:15 w:w:w) in the presence of SP-B and/or SP-C, as well as a native surfactant isolated from animal lungs, have been used as models for the study of the structure and function of pulmonary surfactant films. In this work, we have characterized these models with different biophysical technics such as neutron reflectometry and atomic force microscopy. The results point to the importance of hydrophobic proteins in the formation of three-dimensional structures associated to highly compressed surfactant films. Furthermore, a recently isolated human amniotic fluid surfactant has also been studied. This material is thought to maintain the properties of a freshly synthetized and secreted surfactant that could cover the air-liquid interface in a more efficient way, with physiological importance to develop new surfactant therapies. Here we show that amniotic fluid surfactant exhibits a similar behavior than animal-derived surfactant once it coats the interface.

508 - Surfactant protein a impact on microbiome and intestinal integrity in an experimental murine model of necrotizing enterocolitis

508 - Surfactant protein a impact on microbiome and intestinal integrity in an experimental murine model of necrotizing enterocolitis

Lung injury and oxidative stress induced by inhaled chlorine in mice is associated with proinflammatory activation of macrophages and altered bioenergetics

Chlorine (Cl2) gas is a highly toxic and oxidizing irritant that causes life-threatening lung injuries. Herein, we investigated the impact of Cl2-induced injury and oxidative stress on lung macrophage phenotype and function. Spontaneously breathing male C57BL/6J mice were exposed to air or Cl2 (300 ppm, 25 min) in a whole-body exposure chamber. Bronchoalveolar lavage (BAL) fluid and cells, and lung tissue were collected 24 h later and analyzed for markers of injury, oxidative stress and macrophage activation. Exposure of mice to Cl2 resulted in increases in numbers of BAL cells and levels of IgM, total protein, and fibrinogen, indicating alveolar epithelial barrier dysfunction and inflammation. BAL levels of inflammatory proteins including surfactant protein (SP)-D, soluble receptor for glycation end product (sRAGE) and matrix metalloproteinase (MMP)-9 were also increased. Cl2 inhalation resulted in upregulation of phospho-histone H2A.X, a marker of double-strand DNA breaks in the bronchiolar epithelium and alveolar cells; oxidative stress proteins, heme oxygenase (HO)-1 and catalase were also upregulated. Flow cytometric analysis of BAL cells revealed increases in proinflammatory macrophages following Cl2 exposure, whereas numbers of resident and antiinflammatory macrophages were not altered. This was associated with increases in numbers of macrophages expressing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), markers of proinflammatory activation, with no effect on mannose receptor (MR) or Ym-1 expression, markers of antiinflammatory activation. Metabolic analysis of lung cells showed increases in glycolytic activity following Cl2 exposure in line with proinflammatory macrophage activation. Mechanistic understanding of Cl2-induced injury will be useful in the identification of efficacious countermeasures for mitigating morbidity and mortality of this highly toxic gas.

Intravenous surfactant protein D inhibits lipopolysaccharide-induced systemic inflammation

BackgroundSurfactant protein D (SP-D) is an innate host defense protein that clears infectious pathogens from the lung and regulates pulmonary host defense cells. SP-D is also detected in lower concentrations in plasma and many other non-pulmonary tissues. Plasma levels of SP-D increase during infection and other proinflammatory states; however, the source and functions of SP-D in the systemic circulation are largely unknown. We hypothesized that systemic SP-D may clear infectious pathogens and regulate host defense cells in extrapulmonary systems. MethodsTo determine if SP-D inhibited inflammation induced by systemic lipopolysaccharide (LPS), E.coli LPS was administered to mice via tail vein injection with and without SP-D and the inflammatory response was measured. ResultsSystemic SP-D has a circulating half-life of 6 h. Systemic IL-6 levels in mice lacking the SP-D gene were similar to wild type mice at baseline but were significantly higher than wild type mice following LPS treatment (38,000 vs 29,900 ng/ml for 20 mg/kg LPS and 100,700 vs 73,700 ng/ml for 40 mg/kg LPS). In addition, treating wild type mice with purified intravenous SP-D inhibited LPS induced secretion of IL-6 and TNFα in a concentration dependent manner. Inhibition of LPS induced inflammation by SP-D correlated with SP-D LPS binding suggesting SP-D mediated inhibition of systemic LPS requires direct SP-D LPS interactions. ConclusionsTaken together, the above results suggest that circulating SP-D decreases systemic inflammation and raise the possibility that a physiological purpose of increasing systemic SP-D levels during infection is to scavenge systemic infectious pathogens and limit inflammation-induced tissue injury.

Abstract B022: pH-low insertion peptide detects lactic acidosis contributing metastatic niche formation in lungs

Abstract Background: Pre-metastatic niche refers to the environment prepared for efficient colonization of disseminated cancer cells in specific organs. Primary tumor secretome facilitates pre-metastatic niche through a series of molecular and cellular changes. This study focuses on interstitial pH in organs with pre-metastatic niche because dysregulated pH homeostasis plays a well-established role in tumor metastasis. In primary tumor, extracellular acidification directly promotes invasion/migration of cancer cells for extravasation. Meanwhile, little is known regarding interstitial pH in organs that are distant from primary tumor. Methods: BALB/c mice were subcutaneously inoculated with 4T1.2 cells or 66cl4 cells (mouse breast cancer cell lines) with resistance against 6-thioguanine. Absence of metastatic cells in their lungs was confirmed by long-termed culture of dissociated pulmonary cells in presence of 6-thioguanine; it defines Day 21 from inoculation as a pre-metastatic phase. Alternatively, 4T1.2 cell-conditioned media (4T1.2-CM) or control media was intraperitoneally administered every day for 21 consecutive days. pH-low insertion peptide (pHLIP® peptide) stably labels cells exposed to acidic conditions, which is feasible to evaluate interstitial acidity in each organ. Alexa Fluor® 750-labelled pHLIP® peptide was injected into mice, and fluorescent signals in harvested organs were detected by IVIS Lumina XRMS Series III. For a metastasis model, mice first received 4T1.2-CM or in combination with sodium oxamate (a lactate dehydrogenase inhibitor) followed by an intravenous injection of 66cl4 cells expressing luciferase. Results: At the pre-metastatic phase, 4T1.2 tumor-bearing mice showed great accumulation of pHLIP® peptide and high amounts of lactate in their lungs. By contrast, there was no significant fluorescence from pHLIP® peptide in lungs of low-metastatic 66cl4 cell-inoculated mice. Notable accumulation of pHLIP® peptide was also observed in the lungs of 4T1.2-CM-given mice. Intravenously injected 66cl4 cells colonized more aggressively in the acidic lungs than in control ones. Suppression of the lung acidification by sodium oxamate attenuated the metastatic burden, which significantly improved survival of the mice. In the acidic lungs, pHLIP® peptide was localized in alveolar type II (AT2) cells expressing surfactant protein C. Sorted AT2 cells from the acidic lungs strongly expressed glycolysis-related proteins. Conclusions: This study using pHLIP® peptide indicates a highly glycolytic activity with increased lactic acid in the lungs of 4T1.2 tumor-bearing mice at the pre-metastatic phase. Mechanistically, soluble factors derived from 4T1.2 cells could transform AT2 cells into acidic cells, which might provide metastasis-promoting function. This study will shed light on understanding the whole picture of pre-metastatic niche and give scientific insights to develop novel diagnosis and therapy for tumor metastasis. Citation Format: Toma Matsui, Yuki Toda, Anna Mosnikova, Oleg A. Andreev, Shigekuni Hosogi, Yana K. Reshetnyak, Eishi Ashihara. pH-low insertion peptide detects lactic acidosis contributing metastatic niche formation in lungs [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B022.

Allogeneic Mesenchymal Stromal Cells as a Global Pediatric Prospective Approach in the Treatment of Respiratory Failure Associated with Surfactant Protein C Dysfunction.

Mesenchymal stromal cells (MSCs) have been proposed as a new therapeutic strategy to treat congenital and acquired respiratory system diseases. We describe a case report of an 18-month-old male patient with progressive chronic respiratory failure, associated with mutations of the surfactant protein C gene (SFTPC) due to c.289G > T variant p.Gly97Ser (rs927644577) and c.176A > G variant (p.His59Arg), submitted to repeated intravenous infusions of allogeneic bone marrow (BM) MSCs. The clinical condition of the patient was monitored. Immunologic studies before and during MSC treatment were performed. No adverse events related to the MSC infusions were recorded. Throughout the MSC treatment period, the patient showed a growth recovery. Starting the second infusion, the patient experienced an improvement in his respiratory condition, with progressive adaptation to mechanical ventilation. After the third infusion, five hours/die of spontaneous breathing was shown, and after infusion IV, spontaneous ventilation for 24/24 h was recorded. A gradual decrease of lymphocytes and cell subpopulations was observed. No variations in the in vitro T cell response to PHA were determined by MSC treatment as well as for the in vitro B cell response. A decrease in IFN-γ, TNF-α, and IL-10 levels was also detected. Even though we cannot exclude an improvement of pulmonary function due to the physiological maturation, the well-known action of MSCs in the repair of lung tissue, together with the sequence of events observed in our patient, may support the therapeutic role of MSCs in this clinical condition. However, further investigations are necessary to confirm the result and long-term follow-up will be mandatory to confirm the benefits on the pulmonary condition.

Molecular Docking of Bacterial Protein Modulators and Pharmacotherapeutics of Carica papaya Leaves as a Promising Therapy for Sepsis: Synchronising In Silico and In Vitro Studies

Sepsis is a serious health concern globally, which necessitates understanding the root cause of infection for the prevention of proliferation inside the host's body. Phytochemicals present in plants exhibit antibacterial and anti-proliferative properties stipulated for sepsis treatment. The aim of the study was to determine the potential role of Carica papaya leaf extract for sepsis treatment in silico and in vitro. We selected two phytochemical compounds, carpaine and quercetin, and docked them with bacterial proteins, heat shock protein (PDB ID: 4PO2), surfactant protein D (PDB ID: 1PW9), and lactobacillus bacterial protein (PDB ID: 4MKS) against imipenem and cyclophosphamide. Quercetin showed the strongest interaction with 1PW9 and 4MKS proteins. The leaves were extracted using ethanol, methanol, and water through Soxhlet extraction. Total flavonoid content, DPPH assay, HPTLC, and FTIR were performed. In vitro cytotoxicity of ethanol extract was screened via MTT assay on the J774 cell line. Ethanol extract (EE) possessed the maximum number of phytocomponents, the highest amount of flavonoid content, and the maximum antioxidant activity compared to other extracts. FTIR analysis confirmed the presence of N-H, O-H, C-H, C=O, C=C, and C-Cl functional groups in ethanol extract. Cell viability was highest (100%) at 25 µg/mL of EE. The present study demonstrated that the papaya leaves possessed antibacterial and cytotoxic activity against sepsis infection.

Pulmonary surfactant function and molecular architecture is disrupted in the presence of vaping additives

Inhalation of harmful vaping additives has led to a series of lung illnesses. Some of the selected additives such as vitamin E acetate, and related molecules like vitamin E and cannabidiol, may interfere with the function of the lung surfactant. Proper lipid organization in lung surfactant is key to maintaining low surface tensions, which provides alveolar stability and effective gas exchange throughout respiration. Physiological surfactants, such as bovine lipid extract surfactant used to treat neonatal respiratory distress syndrome, serve as a good model for examining the potential effects of vape additives on proper function. We have found that all additives impede the surfactants’ ability to efficiently reach high surface pressures as these systems displayed numerous shoulders throughout compression with accompanying defects to lipid organization. Moreover, the formation of lipid bilayer stacks in the film are hindered by the additives, most notably with vitamin e acetate. Loss of these stacks leave the film prone to buckling and collapse under high compression that occurs at the end of expiration. The data suggest that the additives may interfere with both proper lipid organization and the surfactant protein function.

Combining Oxidative Stress Markers and Expression of Surfactant Protein A in Lungs in the Diagnosis of Seawater Drowning.

The diagnosis of seawater drowning (SWD) remains one of the most complex and contentious. It is one of the leading causes of unintentional death around the world. In most cases, the forensic pathologist must reach an accurate diagnosis from the autopsy findings and a series of complementary tests such as histopathological, biological, and chemical studies. Despite the lung being the most affected organ in death by submersion, there are few studies on this type of death's impact on this organ. The aim was to investigate human lung cadavers of forensic cases due to different causes of death, the concentration of the oxidative stress markers malondialdehyde (MDA) and γ-glutamyl-l-cysteinyl glycine (GSH), and the relationship with the expression of surfactant protein A (SP-A) to try to discriminate SWD from other types of causes of death. A total of 93 forensic autopsy cases were analyzed. Deaths were classified into three major groups based on the scene, cause of death, and autopsy findings (external foam, frothy fluid in airways, overlapping medial edges of the lungs): (a) drowning in seawater (n = 35), (b) other asphyxia (n = 33), such as hangings (n = 23), suffocations (n = 6), and strangulation (n = 4), and (c) other causes (n = 25), such as multiple suffocations. Oxidative stress markers (MDA and GSH) and the immunohistochemical expression of SP-A were determined in both lungs. MDA levels were statistically higher in both lungs in cases of SWD than in other causes of death (p = 0.023). Similarly, significantly higher levels of GSH were observed in SWD compared to the rest of the deaths (p = 0.002), which was more significant in the right lung. Higher immunohistochemical expression of SP-A was obtained in the cases of SWD than in the other causes of death, with higher levels in both lungs. The correlation analysis between the levels of oxidative stress (MDA and GSH) in the lung tissue and the expression level of SP-A showed positive and significant results in SWD, both in the alveolar membrane and the alveolar space. Determining the levels of MDA and GSH in lung tissue and the expression level of SP-A can be of great importance in diagnosing SWD and the circumstances of death. A better understanding of the physiology of submersion is essential for its possible repercussions in adopting measures in the approach to patients who have survived a submersion process. It is also necessary for forensic pathology to correctly interpret the events that lead to submersion.

Surfactant Protein B Plasma Levels: Reliability as a Biomarker in COPD Patients.

The diagnosis of COPD is based on both clinical signs and functional tests. Although there are different functional tests used to assess COPD, no reliable biomarkers able to provide information on pathogenesis and severity are available. The aim of the present study is to explore the relationship between surfactant protein B (Sp-B) serum levels and clinical, radiological, and functional pulmonary parameters in COPD patients. Forty COPD patients and twenty smokers without airflow limitations or respiratory symptoms were enrolled. Each patient was given questionnaires (CAT and mMRC) and 6MWT, spirometry, DLCO, and computer tomography (CT) were performed. All participants underwent a venous blood sample drawing, and quantitative detection of their Sp-B plasma levels was performed by an enzyme-linked immunosorbent assay. The spirometry and Sp-B plasma levels were assessed after 12 months. A statistically significant difference was found in the plasma Sp-B levels between COPD patients compared to the other group (4.72 + 3.2 ng/mL vs. 1.78 + 1.5 ng/mL; p < 0.001). The change in FEV1 after 12 months (Delta FEV1) showed a significantly negative correlation with respect to the change in Sp-B levels (Delta SpB) (r = -0.4; p < 0.05). This correlation indicates that increasing the plasma dosage of SpB is a foretoken of functional decline. SpB may be considered as a useful marker in COPD assessment and provides prognostic information on lung functional decline. Despite its usefulness, further studies are needed to define its reliability as a biomarker.

Association of surfactant protein A2 with acute respiratory failure in children.

Interactions among single nucleotide polymorphisms (SNPs) of surfactant protein (SP) are associated with acute respiratory failure (ARF) and its short-term outcome, pulmonary dysfunction at discharge (PDAD) in children. However, genetic association studies using individual SNPs have not been conducted before. We hypothesize that SP genetic variants are associated with pediatric ARF and its short-term complications by themselves. We used available genotype and clinical data in the Floros biobank consisting of 248 children aged ≤24 months with ARF; 86 developed PDAD. A logistic regression analysis was performed for each of the 14 selected SNPs, SP-A1 and SP-A2 genotypes. A p-value less than the Bonferroni correction threshold was considered significant. A likelihood ratio test was done to compare two models (one with demographic data and another with genetic variants). Before Bonferroni correction, female sex is associated with a decreased risk of ARF. Black race and the rs721917 of the SFTPD are associated with increased risk of ARF. After Bonferroni correction, the 1A0 1A1 genotype of SFTPA2 was associated with decreased risk of ARF. The likelihood ratio test showed that the model of the genotype information with demographic data was a better fit to predict ARF risk. None of the SP SNPs and SP-A1, SP-A2 genotypes were associated with PDAD. Our results indicate that SNPs and genotypes of SPs involved in innate immunity and host defense play an important role in ARF and, in the future, may be used as biomarkers.

Synchrotron radiation circular dichroism spectroscopy reveals that gold and silver nanoparticles modify the secondary structure of a lung surfactant protein B analogue.

Inhaled nanoparticles (NPs) depositing in the alveolar region of the lung interact initially with a surfactant layer and in vitro studies have demonstrated that NPs can adversely affect the biophysical function of model pulmonary surfactants (PS), of which surfactant protein B (SP-B) is a key component. Other studies have demonstrated the potential for NPs to modify the structure and function of proteins. It was therefore hypothesised that NPs may affect the biophysical function of PS by modifying the structure of SP-B. Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to explore the effect of various concentrations of gold nanoparticles (AuNPs) (5, 10, 20 nm), silver nanoparticles (AgNPs) (10 nm) and silver citrate on the secondary structure of surfactant protein B analogue, SP-B1-25, in a TFE/PB dispersion. For Au and Ag NPs the SRCD spectra indicated a concentration dependent reduction in the α-helical structure of SP-B1-25 (5 nm AuNP ≈ 10 nm AgNP ≫ 10 nm AuNP > 20 nm AuNP). For AuNPs the effect was greater for the 5 nm size, which was not fully explained by consideration of surface area. The impact of the 10 nm AgNPs was greater than that of the 10 nm AuNPs and the effect of AgNPs was greater than that of silver citrate at equivalent Ag mass concentrations. For 10 nm AuNPs, SRCD spectra for dispersions in, the more physiologically relevant, DPPC showed a similar concentration dependent pattern. The results demonstrate the potential for inhaled NPs to modify SP-B1-25 structure and thus potentially adversely impact the physiological function of the lung, however, further studies are necessary to confirm this.

The Soluble Lectin Families as Novel Biomarkers for COVID-19 Pneumonia.

The lung-specific soluble lectins, SP-A and SP-D have been clinically used to diagnose interstitial lung disease, but their clinical significance in COVID-19 remains controversial. This study was undertaken to determine their association with other lectins (MBL and FCN1), disease severity, and radiographs in COVID-19 patients. A total of 131 patients with COVID-19 admitted in the Sapporo Medical University Hospital between May 22 and September 19, 2021, were enrolled in the study. Data including demographics, medical history, symptoms, signs, laboratory findings, and radiological images were collected from the patients' medical records. Chest computed tomography (CT) scanning was performed at admission. Serum levels of surfactant protein A and D (SP-A and SP-D), mannose-binding lectin (MBL) and ficolin1 (FCN1) were measured using enzyme-linked immunosorbent assay (ELISA) kits. Compared to the control group, the COVID-19 group had significantly higher serum SP-A and FCN1 levels on admission (SP-A: 59.60±38.89 vs. 35.61±11.22 ng/ml; p<0.01, FCN1: 542.45±506.04 vs. 250.6±161.1 ng/ml; p<0.01). The severe group in COVID-19 had significantly higher serum SP-D and lower MBL levels than the non-severe group (SP-D: 141.7±155.7 vs. 61.41±54.54 ng/ml; p<0.01, MBL: 1,670±1,240 vs. 2,170±1,140 ng/ml; p<0.05). SP-D strongly reflected the degree of imaging findings, whereas SP-A showed a significant correlation, albeit slightly weaker than SP-D. Conversely, MBL and FNC1 were not significantly correlated with imaging findings. Among soluble serum lectins, SP-A and SP-D may be more sensitive to CT findings than reported disease biomarkers such as IL-6, LDH, and CRP due to their lung-specific characteristics.

Risk factors for clinically significant diffuse parenchymal lung abnormalities persisting after severe COVID-19 pneumonia.

The risk factors for clinically significant diffuse parenchymal lung abnormalities (CS-DPLA) persisting after severe coronavirus disease 2019 (COVID-19) pneumonia remain unclear. The present study was conducted to assess whether COVID-19 severity and other parameters are associated with CS-DPLA. The study participants included patients who recovered after acute severe COVID-19 and presented with CS-DPLA at two or six month follow up and control group (without CS-DPLA). Adults volunteers without any acute illness, chronic respiratory illness and without a history of severe COVID-19 were included as healthy controls for the biomarker study. The CS-DPLA was identified as a multidimensional entity involving clinical, radiological and physiological pulmonary abnormalities. The primary exposure was the neutrophil-lymphocyte ratio (NLR). Recorded confounders included age, sex, peak lactate dehydrogenase (LDH), advanced respiratory support (ARS), length of hospital stay (LOS) and others; associations were analyzed using logistic regression. The baseline serum levels of surfactant protein D, cancer antigen 15-3 and transforming growth factor-β (TGF-β) were also compared among cases, controls and healthy volunteers. We identified 91/160 (56.9%) and 42/144 (29.2%) participants with CS-DPLA at two and six months, respectively. Univariate analyses revealed associations of NLR, peak LDH, ARS and LOS with CS-DPLA at two months and of NLR and LOS at six months. The NLR was not independently associated with CS-DPLA at either visit. Only LOS independently predicted CS-DPLA at two months [adjusted odds ratios (aOR) (95% confidence interval [CI]), 1.16 (1.07-1.25); P<0.001] and six months [aOR (95% CI) and 1.07 (1.01-1.12); P=0.01]. Participants with CS-DPLA at six months had higher baseline serum TGF-β levels than healthy volunteers. Longer hospital stay was observed to be the only independent predictor of CS-DPLA six months after severe COVID-19. Serum TGF-β should be evaluated further as a biomarker.

Генетические дисфункции системы сурфактанта у детей: результаты многоцентрового исследования

Aim: Genetic, clinical, laboratory-instrumental and morphological characteristics of genetic dysfunctions of the surfactant system in children, therapy and outcomes of the disease. Design: Multicentre, ambispective, open-label, descriptive pilot longitudinal study. Materials and methods. We observed 17 children from 16 families with identified mutations in the SFTPC, ABCA3, NKX2-1 genes. Methods used: genealogical, Sanger sequencing, clinical exome sequencing, computed tomography and histological examination of the lungs. Results. The study included 8 children with congenital deficiency of surfactant protein C, 8 children with brain-lung-thyroid syndrome and 1 patient with congenital deficiency of protein ABSA3. Based on the results of a genetic examination of patients, nucleotide variants c.218T&gt;C were identified in 2 out of 8 patients with a mutation in the SFTPC gene, which is the most common according to the literature. In 5 children, the mutations were hereditary. Congenital deficiency of surfactant protein C, ABCA3 protein and brain-lung-thyroid syndrome were characterized by clinical, computed tomography, and morphological signs of interstitial lung disease. Despite complex respiratory, anti-inflammatory therapy, the frequency of deaths in congenital deficiency of surfactant protein C was 37.5%. Conclusion. Children with severe respiratory distress syndrome of newborns, interstitial lung disease with the development of severe chronic respiratory failure, burdened with a family history should undergo genetic testing to detect mutations in the genes SFTPB, SFTPC, ABCA3. The patient's combination of respiratory symptoms with congenital hypothyroidism and neurological pathology is the basis for genetic examination for NKX2-1 gene mutations to exclude the brain-lung-thyroid syndrome. Keywords: genetic dysfunctions of the surfactant system, congenital deficiency of surfactant protein C, congenital deficiency of ABCA3 protein, brain-lung-thyroid syndrome, NKX2-1 gene, children.

Abstract P013: Impact of blood-based biomarkers for predicting lung cancer mortality in the PLCO cohort

Abstract Purpose: To investigate the utility of integrating a panel of circulating protein biomarkers in combination with a risk model based on subject characteristics for identifying individuals at high risk of harboring a lethal lung cancer. Methods: Data for a 4-marker protein panel (4MP) (consisting of the precursor form of surfactant protein B, cancer antigen 125, carcinoembryonic antigen, and cytokeratin-19 fragment) previously assayed in pre-diagnostic sera from 552 lung cancer cases and 2,193 non-cases from the Prostate Lung Colorectal and Ovarian (PLCO) cohort as well as a scores from a logistic regression model that combined the 4MP with the PLCOm2012 risk model were used for this study. Of the 552 lung cancer cases, 387 (70%) died from lung cancer. Cumulative incidence of lung cancer death as well as sub-distributional and cause-specific hazard ratios were calculated based on 4MP+PLCOm2012 risk scores at a pre-defined 1.0%/6-year risk threshold, which corresponds to current US Preventive Services Task Force screening criteria. For hazard modeling, stage at the time of clinical diagnosis and treatment modality were considered as co-variables. Results: When considering cases diagnosed within 1 year of blood draw and all non-cases, the performance estimate of the 4MP+PLCOm2012 model for risk prediction of lung cancer death was 0.88 (95% CI: 0.86-0.90). Among cases only, at the 1.0%/6-year risk threshold the cumulative incidence of lung cancer death was statistically significantly higher in ‘test positive’ cases compared to ‘test negative’ cases (Chi-square test: 5.42, P: 0.02). The adjusted sub distributional hazard ratio for ‘test positive’ cases was 1.67 (95% CI: 1.02-2.74). The adjusted lung-cancer death-specific hazard ratio for ‘test positive’ cases was 2.02 (95% CI: 1.28-3.17). Conclusions and Relevance: The blood-based biomarker panel in combination with PLCOm2012 identifies individuals at high risk of a lethal lung cancer. Citation Format: Ehsan Irajizad, Johannes F. Fahrmann, Jody V. Vykoukal, Jennifer B. Dennison, James P. Long, Kim-Anh Do, Edwin J. Ostrin, Sam Hanash. Impact of blood-based biomarkers for predicting lung cancer mortality in the PLCO cohort. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P013.

Canine amniotic fluid at birth: From a discarded sample to a potential diagnostic of neonatal maturity

The definition of new reliable markers for neonatal maturity evaluation is crucial in canine clinical practice. Concerns about the safety of amniotic sampling in pregnant dogs have prevented its collection for diagnostic purposes. Moreover, amniotic fluid had been considered waste material until the latest studies reported amniocentesis as a reliable and safe procedure, even in the canine species. In our study, amniotic fluid (n = 63) collected at birth from ten dogs undergoing elective Caesarean sections at term was analysed to discover new potential indices of canine neonatal maturity. Based on gestational age, mothers and puppies were divided into two groups: the early group (≤65 days from luteinizing hormone (LH) surge, n = 5) and the late group (>65 days from LH surge, n = 5). Amniotic parameters of the lightest and heaviest puppy in individual/each litter, with a birth weight difference of at least 20% among littermates, were also compared. In particular, the content of lecithin, sphingomyelin, surfactant protein A (SP-A), cortisol, and pentraxin 3 (PTX3) in amniotic fluid, which is considered predictive of foetal development in humans, were investigated. Maternal serum SP-A and cortisol were also measured simultaneously.All amniotic parameters were detectable in canine amniotic fluid. Interestingly, the concentrations of different amniotic parameters correlated with each other. Lecithin was positively correlated with sphingomyelin (p < 0.0001), maternal SP-A (p < 0.0005), and the ratio of amniotic and maternal cortisol (p < 0.004). Amniotic SP-A was inversely correlated to maternal SP-A (p < 0.05), lecithin (p < 0.005), and lecithin-sphingomyelin ratio (p < 0.05). A positive correlation was also recorded between amniotic and maternal cortisol (p < 0.008). Considering that all puppies were born alive and mature, these data could provide a potential range of expected amniotic values in full-term new-born dogs. Furthermore, since gestational age was positively correlated with both maternal and amniotic cortisol (p < 0.0001) and amniotic PTX3 (p < 0.05), amniotic fluid seems to be an attractive, innovative, and minimally invasive matrix with potential diagnostic and prognostic utility for the investigation of canine maturity.

Bebeklerde akut bronşiolit ve surfaktan protein B gen lokusu arasındaki ilişki

Purpose: The aim of this study was to investigate whether there is a relationship between surfactant protein B (SFTPB) C1580T polymorphism and acute bronchiolitis.&#x0D; Materials and Methods: The study analyzed the allele frequency and genotype distribution for the SFTPB C1580T polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique in 103 acute bronchiolitis infants and 102 healthy infants.&#x0D; Results: The results showed no association between SFTPB C1580T polymorphism and clinical characteristics of acute bronchiolitis. The distribution of the CT genotype was higher in acute bronchiolitis infants (43%) than in healthy subjects (39%) and distribution of the TT genotype was found lower in acute bronchiolitis infants (38%) than in healthy subjects (41%). No significant differences in genotype distribution and allele frequency for the SFTPB C1580T polymorphism were found between case group and control group&#x0D; Conclusion: SFTPB C1580T gene polymorphism plays no important role in susceptibility to acute bronchiolitis. Further work on the relevance of SFTPB C1580T polymorphism in larger cohorts will require validating our results.