Progressive Respiratory Failure Research Articles

Evaluation of CHROMagar™ B. cepacia agar for the detection of Burkholderia cepacia complex species from sputum samples of patients with cystic fibrosis.

Burkholderia cepacia complex (BCC) are non-fermenting Gram-negative bacteria that can chronically colonize the lungs of people with cystic fibrosis (pwCF), causing a severe and progressive respiratory failure, post-transplant complications and epidemic outbreaks. Therefore, rapid and accurate identification of these bacteria is relevant for pwCF, in order to facilitate early eradication and prevent chronic colonization. However, BCCs are often quite difficult to detect on culture media as they have a slow growth rate and can be hidden by other fast-growing microorganisms, including Pseudomonas aeruginosa and filamentous fungi. We evaluated the sensitivity of CHROMagar™ B. cepacia agar using 11 isolates from a well-characterized BCC collection, using BCA agar (Oxoid, UK) as a gold standard. We also studied 180 clinical sputum samples to calculate positive (PPV) and negative (NPV) predictive values. Furthermore, we used three of the well-characterized BCC isolates to determine the limit of detection (LOD). Eleven isolates grew on CHROMagar™ B. cepacia at 37ºC after 48h. The NPV and PPV of CHROMagar™ B. cepacia were 100% and 87.5%, respectively. The LOD of CHROMagar™ B. cepacia was around 1 × 103CFU/ml, requiring a ten-fold dilution lower bacterial load than BCA for BCC detection. CHROMagar™ B. cepacia agar proved to have a very good sensitivity and specificity for the detection of clinical BCCs. Moreover, the chromogenic nature of the medium allowed us to clearly differentiate BCC from other Gram-negative species, filamentous fungi and yeasts, thereby facilitating the identification of contaminants.

Bronchial Lavage in the Treatment of Severe Bronchopulmonary Pathology in Adults. Approaches to Classification

Introduction Currently, bronchial lavage (BL) is widely used in clinical practice for the treatment of severe bronchopulmonary lesion in adults. However, indications and contraindications for this procedure are not fully defined. In addition, it was not possible to find in the literature a classification of either BL in general or used for therapeutic purposes in particular, which significantly complicates the standardization of procedures for its use in various diseases.Aim of study To determine possible classification characteristics, as well as indications, contraindications for therapeutic BL in adults and possible complications that may arise, based on the analysis of literature data.Results Therapeutic BL can be carried out both as planned and for health reasons. Indications for planned BL are purulent bronchitis, pneumonia, purulentdestructive infiltration, as well as chronic lung diseases: bronchiectasis, interstitial lesions. In turn, the indication for emergency therapeutic BL is progressive acute or chronic respiratory failure, developing due to bronchial obstruction. Such conditions may include massive pulmonary hemorrhage, acute obstruction of the bronchi with mucus and pus, postoperative atelectasis and hypoventilation of the lungs, aspiration of gastric contents, severe bronchial asthma, purulent destruction of the lungs, acute respiratory distress syndrome, thermochemical lesions of the respiratory tract. Contraindications to therapeutic BL can be both absolute and relative. Absolute contraindications are intolerance to drugs used for local anesthesia; decompensated heart and (or) pulmonary failure; acute cerebrovascular accident; various types of arrhythmias; stenosis of the larynx and (or) trachea II–III degree; neuropsychiatric diseases; pain syndrome in the abdominal cavity; extremely serious condition of the patient, when clarification of the diagnosis can no longer affect treatment tactics. Relative contraindications include acute respiratory disease of the upper respiratory tract; coronary artery disease; severe diabetes mellitus; pregnancy (second half); chronic alcoholism; grade III enlargement of the thyroid gland. It should be noted that most of the absolute contraindications are conditional and are not taken into account when performing BL according to vital indications with appropriate medical and technical support. Classification of BL used for medicinal purposes can be carried out according to the following criteria: method of sanitation; access used; level of sanitation; sanitized area; volume and composition of the lavage solution. It is noteworthy that the methods of carrying out procedures for various conditions and diseases still remain unregulated. An exception is the final stage of the therapeutic BL procedure in the case of the use of surfactant preparations, which standardization is regulated by approved standard operating procedures. It should also be noted that bronchial lavage for therapeutic purposes is justified from a pathoanatomical and pathophysiological point of view, but is accompanied by serious, albeit temporary, changes in the lungs, which can be partially avoided by improving the lavage technique.Conclusion All of the above indicates that in order to solve existing problems, it is necessary to conduct systematic research in this direction with the involvement of all interested specialists.

Long-term course of a case with a novel homozygous kyphoscoliosis peptidase variant.

We herein report a case with a novel homozygous variant in the kyphoscoliosis peptidase (KY) gene. A 58-year-old Japanese female was referred to our hospital with a gait disturbance that gradually worsened after the age of 50. She had bilateral equinus foot deformity since early childhood. Neurological examination revealed moderate weakness of the neck, trunk, femoral, and brachial muscles, mild respiratory failure, and areflexia. Whole-exome sequencing revealed a novel homozygous frameshift variant of the KY gene, NM_178554.6:c.824del p.(Glu275Glyfs*53). Our case demonstrated that KY-associated neuromuscular disease can present with extremely slow progressive muscle weakness and respiratory failure over a long natural course.

Administration of adipose-derived stem cells extracellular vesicles in a murine model of spinal muscular atrophy: effects of a new potential therapeutic strategy

BackgroundSpinal Muscular Atrophy (SMA) is an autosomal-recessive neuromuscular disease affecting children. It is caused by the mutation or deletion of the survival motor neuron 1 (SMN1) gene resulting in lower motor neuron (MN) degeneration followed by motor impairment, progressive skeletal muscle paralysis and respiratory failure. In addition to the already existing therapies, a possible combinatorial strategy could be represented by the use of adipose-derived mesenchymal stem cells (ASCs) that can be obtained easily and in large amounts from adipose tissue. Their efficacy seems to be correlated to their paracrine activity and the production of soluble factors released through extracellular vesicles (EVs). EVs are important mediators of intercellular communication with a diameter between 30 and 100 nm. Their use in other neurodegenerative disorders showed a neuroprotective effect thanks to the release of their content, especially proteins, miRNAs and mRNAs.MethodsIn this study, we evaluated the effect of EVs isolated from ASCs (ASC-EVs) in the SMNΔ7 mice, a severe SMA model. With this purpose, we performed two administrations of ASC-EVs (0.5 µg) in SMA pups via intracerebroventricular injections at post-natal day 3 (P3) and P6. We then assessed the treatment efficacy by behavioural test from P2 to P10 and histological analyses at P10.ResultsThe results showed positive effects of ASC-EVs on the disease progression, with improved motor performance and a significant delay in spinal MN degeneration of treated animals. ASC-EVs could also reduce the apoptotic activation (cleaved Caspase-3) and modulate the neuroinflammation with an observed decreased glial activation in lumbar spinal cord, while at peripheral level ASC-EVs could only partially limit the muscular atrophy and fiber denervation.ConclusionsOur results could encourage the use of ASC-EVs as a therapeutic combinatorial treatment for SMA, bypassing the controversial use of stem cells.

Serum cytokines profile changes in amyotrophic lateral sclerosis

BackgroundAmyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder, characterized by progressive limb weakness, dysphagia, dysphonia, and respiratory failure due to degeneration of upper and lower motor neurons. The pathogenesis of ALS is still unclear. Neuroinflammation has been found to be involved in its development and progression. Cytokines play a significant role in the inflammatory process. This study aims to identify novel biomarkers that may assist in the diagnosis of ALS. MethodsIn Fujian Medical University Union Hospital and Huashan Hospital Fudan University, two independent centers, we prospectively recruited 50 ALS patients, and 41 healthy controls (25 ALS and 26 controls in the first stage and 25 ALS and 15 controls in the validation stage). An 18-plex Luminex kit was used to screen the serum cytokines levels in the first stage. Commercial ELISA kits were used to measure the levels of target cytokines in the validation stage. A single-molecule array HD-X platform was applied to assess the levels of serum neurofilament light chain (NFL). ResultsThe levels of serum IL-18 were markedly increased in patients with ALS in the first stage (p = 0.016). The ROC curve showed an area under the curve at 0.695 (95% CI 0.50–0.84) in distinguishing ALS patients from healthy controls. The IL-21 was decreased in elderly patients when grouped by 55 years old (the medium age). Furthermore, the IL-5, IL-13, IL-18, and NFL had a positive relationship with the disease progression of ALS. We also found that serum IL-18 was markedly increased in ALS patients in the validation stage (167.67 [148.25–175.59] vs 116.44 [102.43–122.19]pg/ml, p < 0.0015). ConclusionIn this study, we identified systemic cytokine profile changes in the serum of ALS patients, especially the elevated IL-18, as well as the decreased IL-21 in elder patients. These changes in serum cytokine profiles may shed new light on an in-depth understanding of the immunopathogenic characteristics of ALS.

RIPK1 inhibitor ameliorates pulmonary injury by modulating the function of neutrophils and vascular endothelial cells

Acute lung injury (ALI) is an acute and progressive hypoxic respiratory failure that could progress to acute respiratory distress syndrome (ARDS) with a high mortality rate, thus immediate medical attention and supportive care are necessary. The pathophysiology of ALI is characterized by the disruption of the alveolar-capillary barrier and activation of neutrophils, leading to lung tissue damage. The receptor-interacting protein kinase 1 (RIPK1) has emerged as a promising target for the treatment of multiple inflammatory diseases, but the role of RIPK1 in the ALI remains poorly understood. In this study, we aimed to figure out the pathological role of RIPK1 in ALI, especially in the pulmonary immune microenvironment involving neutrophils and endothelial cells. In vivo experiments showed that RIPK1 inhibitor protected against lipopolysaccharide (LPS)-induced lung injury in mouse models, with reduced neutrophils and monocytes infiltration in the lungs. Further studies demonstrated that, besides the inhibitory action on necroptosis, RIPK1 inhibitor directly suppressed reactive oxygen species (ROS) generation and inflammatory cytokines secretion from neutrophils. Furthermore, RIPK1 inhibition maintains the barrier function in TNF-α-primed vascular endothelial cells and prevents their activation induced by the supernatant from LPS-stimulated neutrophils. Mechanistically, the aforementioned effects of RIPK1 inhibitor are associated with the NF-κB signaling pathway, which is partially independent of necroptosis inhibition. These results provide new evidence that RIPK1 inhibitor directly regulates the function of neutrophils and endothelial cells, as well as interferes with the interactions between these two cell types, therefore contributing to a better understanding of RIPK1 in ALI and providing a potential avenue for future therapeutic interventions.

Amyotrophic Lateral Sclerosis and Pain: A Narrative Review from Pain Assessment to Therapy.

Amyotrophic lateral sclerosis (ALS) is the most frequent neurodegenerative disease of the motor system that affects upper and lower motor neurons, leading to progressive muscle weakness, spasticity, atrophy, and respiratory failure, with a life expectancy of 2-5 years after symptom onset. In addition to motor symptoms, patients with ALS have a multitude of nonmotor symptoms; in fact, it is currently considered a multisystem disease. The purpose of our narrative review is to evaluate the different types of pain, the correlation between pain and the disease's stages, the pain assessment tools in ALS patients, and the available therapies focusing above all on the benefits of cannabis use. Pain is an underestimated and undertreated symptom that, in the last few years, has received more attention from research because it has a strong impact on the quality of life of these patients. The prevalence of pain is between 15% and 85% of ALS patients, and the studies on the type and intensity of pain are controversial. The absence of pain assessment tools validated in the ALS population and the dissimilar study designs influence the knowledge of ALS pain and consequently the pharmacological therapy. Several studies suggest that ALS is associated with changes in the endocannabinoid system, and the use of cannabis could slow the disease progression due to its neuroprotective action and act on pain, spasticity, cramps, sialorrhea, and depression. Our research has shown high patients' satisfaction with the use of cannabis for the treatment of spasticity and related pain. However, especially due to the ethical problems and the lack of interest of pharmaceutical companies, further studies are needed to ensure the most appropriate care for ALS patients.

Doggonit! A Classic Case of Severe Capnocytophaga canimorsus Sepsis

Capnocytophaga canimorsus is a commensal organism often found in the oropharyngeal tracts of dogs and cats, capable of causing significant morbidity and mortality in immunocompromised patients. Early identification of C. canimorsus is challenging due to the organism’s rare presentation, rapid clinical progression, and slow growth on microbiological media. We present a case of a 47-year-old man with exposure to snakes and dogs, and history of severe alcohol use disorder, who presented to the emergency department with acute generalized abdominal pain. His course was notable for progressive respiratory failure requiring intubation and multi-pressor septic shock with minimal response to initial broad-spectrum antibiotics, complicated by hypoglycemia and DIC with purpura fulminans. Multidisciplinary review of the peripheral smear, notable for long, thin, intra and extracellular gram-negative rods, rapidly characterized our pathogen as an atypical gram-negative rod. With additional review of medical history and zoonotic exposures, we were able to quickly identify and address our concern for C. canimorsus, broadening our antibiotics to account for resistance patterns particular to this organism.

Multiple Intramuscular Abscesses Caused by &lt;i&gt;Nocardia abscessus&lt;/i&gt; in a Patient with Chronic Obstructive Lung Disease: Clinical Microbiology Considerations

Nocardiosis is uncommon. Immunocompromising conditions predispose individuals to pulmonary and disseminated nocardiosis of the brain, skin, and subcutaneous tissues. The most common pathogens are &lt;i&gt;Nocardia cyriacigeorgica&lt;/i&gt;, &lt;i&gt;Nocardia nova&lt;/i&gt;, and &lt;i&gt;Nocardia farcinica&lt;/i&gt;. The speciation of &lt;i&gt;Nocardia&lt;/i&gt; to determine antimicrobial susceptibility is difficult using traditional biochemical methods. Here, we report the case of a 73-year-old man with chronic obstructive lung disease who developed a rapidly progressing intramuscular abscess around the left hip and thigh. Within 3 days, the lesions progressed to an epidural abscess at the L4 to S1 level. Although he was treated with broad-spectrum antibiotics and extensive incision and drainage, he died of rapidly progressive respiratory failure. &lt;i&gt;Nocardia abscessus&lt;/i&gt; (&lt;i&gt;N. abscessus&lt;/i&gt;) was identified in pus samples using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This case shows that the diagnosis of an intramuscular abscess caused by &lt;i&gt;N. abscessus&lt;/i&gt; is challenging and that using MALDI-TOF MS may facilitate the diagnosis and ensure appropriate treatment.

Venovenous Extracorporeal Membrane Oxygenation in Severe Polytrauma

BACKGROUND. Road transport injuries (RTI) are the leading cause of death among the working-age population at present. Often, severe combined trauma is accompanied by significant damage to the chest with the development of severe respiratory disorders. Standard methods of intensive therapy for respiratory failure are often ineffective. The use of extracorporeal membrane oxygenation (ECMO) can be an effective method of reducing mortality in this category of patients, evenin conditions where it is impossible to use systemic anticoagulation. AIM OF THE STUDY. Consider the use of ECMO in patients with serious polytrauma trauma and a high risk of hemorrhagic complications. MATERIAL AND METHODS. Patient R., 43 years old, got a severe combined injury in a traffic accident; due to progressive acute respiratory failure, veno-venous ECMO (VV-ECMO) was performed for 11 days. RESULTS. This report reviews a clinical observation of the successful use of VV-ECMO in a patient with severe acute respiratory distress syndrome as a result of polytrauma in a road accident. Due to the high risk of hemorrhagic complications, the procedure was performed without the use of systemic anticoagulation, which is a rather rare case in modern intensive care. On the 11th day, the VV-ECMO procedure was stopped. On the 7th day of VV-ECMO, an intense hemorrhagic syndrome developed as a complication, which was successfully treated. On the 13th day after weaning, the patient was transferred from the intensive care unit to the rehabilitation center. CONCLUSIONS. The venovenous extracorporeal membrane oxygenation method can be considered as part of the treatment of severe acute respiratory distress syndrome as a result of severe chest trauma when standard methods of respiratory support are ineffective. With a high risk of hemorrhagic complications, which is often observed in patients in this category, it is possible to use venovenous extracorporeal membrane oxygenation without systemic anticoagulation.

Unlocking the potential of Rosa roxburghii Tratt polyphenol: a novel approach to treating acute lung injury from a perspective of the lung-gut axis.

Acute lung injury (ALI) is a serious respiratory disease characterized by progressive respiratory failure with high morbidity and mortality. It is becoming increasingly important to develop functional foods from polyphenol-rich medicinal and dietary plants in order to prevent or alleviate ALI by regulating intestinal microflora. Rosa roxburghii Tratt polyphenol (RRTP) has significant preventive and therapeutic effects on lipopolysaccharide-induced ALI mice, but its regulatory effects on gut homeostasis in ALI mice remains unclear. This study aims to systematically evaluate the ameliorative effects of RRTP from the perspective of "lung-gut axis" on ALI mice by intestine histopathological assessment, oxidative stress indicators detection and short-chain fatty acids (SCFAs) production, and then explore the modulatory mechanisms of RRTP on intestinal homeostasis by metabolomics and gut microbiomics of cecal contents. The results showed that RRTP can synergistically exert anti-ALI efficacy by significantly ameliorating intestinal tissue damage, inhibiting oxidative stress, increasing SCFAs in cecal contents, regulating the composition and structure of intestinal flora, increasing Akkermansia muciniphila and modulating disordered intestinal endogenous metabolites. This study demonstrated that RRTP has significant advantages in adjuvant therapy of ALI, and systematically clarified its comprehensive improvement mechanism from a new perspective of "lung-gut axis", which provides a breakthrough for the food and healthcare industries to develop products from botanical functional herbs and foods to prevent or alleviate ALI by regulating intestinal flora.

Leiden mutation (rs6025) in a severe COVID-19 pneumonia patient with Down syndrome: a clinical case

COVID-19 was first reported in December 2019 in Wuhan (Hubei Province, China). Later, the pandemic of this disease took the world by storm, challenging the medical community. Its clinical manifestations vary from asymptomatic to a severe course that requires hospitalization and intensive therapy with oxygen support. The mortality rate in patients with a severe course of COVID-19 can exceed 50% The majority of fatal cases of COVID-19 were associated with thrombotic events, despite the prophylactic use of anticoagulant therapy. Numerous theoretical overviews and research articles indicate the need for genetic testing in patients with COVID-19 to determine the genetic profile of proteins involved in thrombophilia. According to the researchers, the Leiden mutation (G1691A, rs6025) of the FV gene is one of the promising candidates for testing. The aim of the work was to demonstrate the clinical features of the severe course of COVID-19 in the presence of the Leiden mutation. 58 patients with COVID-19 of the intensive care unit were genotyped. The Leiden mutation in the heterozygous state was found only in one patient, who had Down syndrome. The Leiden mutation was detected with a frequency of 1.72% in the investigated group. The described clinical case clearly showed that individuals with Down syndrome, associated with hereditary thrombophilia are at risk of undesirable clinical consequences in the treatment of COVID-19. The condition of the patient with the Leiden mutation was severe when admitted to the hospital. The score according to the sequential organ failure assessment scale was 2 points. Bilateral multisegmental pneumonia was detected on the X-ray. On the second day after admission, due to the development of acute respiratory distress syndrome and multiple organ failure, the patient was transferred to the intensive care unit, where he received oxygen therapy through a facial mask. Medical treatment was carried out according to the protocol: non-steroidal anti-inflammatory drugs, antibacterial therapy, anticoagulants, sympatho¬mimetics, and glucocorticosteroids. Despite the medical measures taken, progression of respiratory failure, renal failure, and portal hypertension was noted. On the 11th day, the patient developed asystole. Resuscitation measures were unsuccessful. Thus, the described case of a severe course of COVID-19 in a carrier of a heterozygous variant of the Leiden mutation with Down syndrome confirms the recommendations regarding the need for genetic testing for thrombophilia in high-risk groups and the appointment of personalized measures to prevent complications.

The content of matrix metalloproteinase-1, -9 and tissue inhibitor of matrix metalloproteinase-1 in patients with bronchial asthma and obesity

Airway remodeling is a significant factor in the progression of respiratory failure in bronchial asthma (BA). Obesity can contribute to inflammation, and consequently – airway remodeling, by increased production of matrix proteinase (MMP). However, the mechanisms of remodeling in different phenotypes of BA, especially in comorbid patients, remain poorly understood. The aim of the research was to examine the levels of remodeling markers MMP-1, MMP-9 and tissue inhibitor of matrix proteinases (TIMP-1) in obese asthmatic patients, taking into account their age at the onset of BA, the severity of symptoms and the level of control. Material and methods. 195 patients with BA associated with obesity were examined. The control group consisted of 95 practically healthy people. Patients were divided into two groups: Group I included 100 patients with early onset, and Group II included 95 patients with late onset of BA. The study was approved by the Bioethics Commission of the Medical Institute of Sumy State University. Statistical analysis of the obtained results was carried out using the SPSS-17 program. Results. The content of MMP-1, -9 and TIMP-1 was higher in patients with early (129.40 ± 7.86; 177.30 ± 9.19; 142.40 ± 12.22 ng/ml, respectively) and late (196.60 ± 9.62; 289.80 ± 16.23; 187.50 ± 11.34 ng/ml, respectively) BA with obesity compared to practically healthy individuals (р &lt; 0.005). Patients with late-onset BA associated with obesity likely had higher indicators than those with early BA. In patients with early BA, the levels of MMP-1, -9, and TIMP-1 were not significantly different depending on the severity of the disease (р &gt; 0.05). However, in patients with severe late BA, the levels of these markers were higher compared to those with mild BA (р &lt; 0.05). Levels of MMP-1 and MMP-9 in patients with early-onset and late-onset BA with obesity were higher in the absence of disease control compared to those in complete and partial control, but in late-onset exceeded those in early-onset. Conclusions. Considering the obtained results, it can be assumed that the level of MMP-1, MMP-9 and TIMP-1 in obese patients with BA can serve as biomarkers of airway remodeling, namely, the severity and the level of BA control.

Single Cell Transcriptomics of Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a manifestation of pulmonary chronic graft versus host disease (cGVHD), a serious complication of allogeneic stem cell transplantation (ASCT). BOS also occurs following bi-orthotopic lung transplant (BOLT), where it is termed chronic lung allograft dysfunction (CLAD)-BOS and is the leading cause of long-term allograft failure. In both contexts, fibrotic obliteration of the small airways leads to progressive respiratory failure. Since the molecular mechanisms leading to fibrotic airway remodeling in humans are poorly understood, we used single cell RNA-sequencing to map intercellular interactions between immune (CD45+ve) and non-immune (CD45-ve) cells of lung explants from patients undergoing first lung transplantation for cGVHD-BOS (n=1) or second lung transplantation for CLAD-BOS (n=2) compared to normal controls (NC) (n=3). BOS patients ranged in age from 44 to 61 years old; NC were similar in age and died of cerebrovascular accidents. Lungs were surgically removed at the time of BOLT (BOS samples) or at autopsy (NC). CD45+ve and CD45-ve cells were magnetically sorted and freshly processed. Single cell libraries were prepared using the 10X Genomics Chromium Controller and sequenced on an Illumina Novaseq 6000 instrument. Quality control filtering, transcript count normalization, integration, PCA, UMAP projection, and cell clustering were performed with Seurat in R v4.2.1. CD45+ve and CD45-ve cells were annotated in Azimuth using the Human Lung Cell Atlas and LungMAP Cell Cards reference data sets, respectively. Differences in gene expression between conditions were evaluated with the Seurat FindMarkers function. Inter-cellular communications were characterized with CellChat. Interaction strength was calculated as a function of ligand/receptor pair expression, and incoming and outgoing signaling was classified using network centrality analysis. We identified 45,932 CD45+ve cells (28,241 in BOS and 17,691 in NC) and 33,428 CD45-ve cells (23,390 in BOS and 10,038 in NC) including 17 distinct cell types in the CD45+ve fractionand 24 in the CD45-ve fraction. As samples came from patients with end-stage disease, we hypothesized that CD45+ve cells would be highly activated while CD45-ve cells would exhibit strongly fibrogenic programs. To test this hypothesis, we analyzed the incoming and outgoing signal strength for each cell type. Stromal cells such as type 1 (AF1) and type 2 alveolar fibroblasts (AF2), secondary crest myofibroblasts (SCMF), and pericytes had the strongest outgoing signals in BOS ( Figure 1). Except for AF2, incoming and outgoing signaling from stromal cells was stronger in BOS than in NC. These observations support stromal cells as important drivers of BOS pathogenesis. Next, we characterized signaling directionality between stromal cells and CD45+ve cells. In general, incoming signals to stromal cells from CD45+ve cells were weaker in BOS than in NC, while outgoing signals from stromal cells to CD45+ve cells were stronger. For example, signaling from stromal cells expressing THY1, which may attenuate fibrosis in fibrotic lung disease, to integrins on monocytes and macrophages was stronger in BOS. Likewise, BOS was enriched for signaling from collagens and fibronectin on stromal cells to CD44 on CD45+ve cells. As expected, genes implicated in fibrosis and wound healing were upregulated in stromal cells in BOS patients. In AF1 ( Figure 2), these included genes encoding collagens (COL6A3, COL14A1), actins (ACTA2), matricellular proteins (POSTN, TNC, SPARC), protease inhibitors (SERPINE1, TIMP1), hyaluronic acid synthetases (HAS2), proteoglycans (LUM, VCAN), and proteases (MMP19, ADAMTS9). Interestingly, we found evidence for active anti-fibrotic programs such as MMP19, PTGS2, and THY1. To our knowledge, this is the first study employing single cell transcriptomics of lung explants from patients with cGVHD-associated BOS. Robust signaling from stromal cells to CD45+ve cells may support their role in modifying the inflammatory infiltrate in BOS. We identified outgoing, stromal derived signaling associated with fibrotic (collagen and fibronectin) and anti-fibrotic programs (THY1). Our findings illustrate an interplay between pro- and anti-fibrotic programs even in end-stage BOS lungs, raising the tantalizing possibility to intervene therapeutically in this dyshomeostatic balance.

501. Risk Factors for Persistent Active COVID-19 Among Patients Receiving B-Cell Depleting Therapy versus Non-B-Cell Immunosuppression

Abstract Background Cases of COVID-19 characterized by prolonged replication of SARS-CoV-2 (persistent active COVID [PAC]) have been reported among immunocompromised patients, particularly those receiving B-cell depleting therapy (BCDT); however, the risk has not been quantified. We aimed to identify risk factors associated with PAC, including quantifying the risk associated with receipt of BCDT vs. other types of immunosuppression. Methods We retrospectively identified four groups of immunocompromised patients who tested positive for SARS-CoV-2 between 4/01/2020 and 4/30/2021. These groups included one group of patients who received an anti-CD20 BCDT within 1 year before a positive SARS-CoV-2 PCR and three groups who received non-BCDT which included hematopoietic cell transplant (HCT) recipients, solid organ transplant (SOT) recipients, and patients receiving chemotherapy for hematologic malignancies (HM). Chart review was performed to characterize the clinical course and development of PAC, which was defined as any of the following: (1) initial clinical improvement followed by progression of illness extending beyond 14 days, characterized by persistent fevers or progressive respiratory failure; or (2) persistent symptoms with demonstration of absent seroconversion ≥ 14 days into illness. This distinction may be supported by low crossing thresholds that occurred ≥ 14 days into illness. Logistic models were performed to identify factors associated with development of PAC and other COVID outcomes. Results We identified 67 COVID-positive patients who had received BCDT as well as 30 HM, 118 SOT, and 29 HCT patients. PAC occurred in 15/67 (22%) of patients receiving BCDT vs. 3/177 (1.7%) patients (all SOT recipients) in the non-BCTD group (SOT, HCT, HM) (Odds Ratio, 16.7; 95% confidence interval [CI] 4.7 to 60.0; p=0.00005). 30-day hospitalization and 90-day mortality were similar in BCDT and non-BCDT groups (Table 1, Figure 1) (p &amp;gt; 0.05). Table 1. Risk factors for specific outcomes of COVID-19 Figure 1. Proportion of patients from each cohort of immunocompromised patients who developed persistent active COVID (1A), required hospitalization within 30 days (1B), required mechanical ventilation (1C), required ICU admission (1D), or died within 90 days after diagnosis of COVID-19 (1E) Conclusion Receipt of BCDTs was significantly associated with the development of PAC in comparison to other forms of severe immunosuppression. However, rates of severe outcomes associated with COVID-19 were similar across all groups. More research is necessary to determine effective prevention or treatment strategies for PAC. Disclosures All Authors: No reported disclosures

A Successfully Managed Case of Progressive Respiratory Failure Due to Ruptured Pulmonary Hydatid Cyst

A Successfully Managed Case of Progressive Respiratory Failure Due to Ruptured Pulmonary Hydatid Cyst

The Role of Small Airway Disease in Pulmonary Fibrotic Diseases.

Small airway disease (SAD) is a pathological condition that affects the bronchioles and non-cartilaginous airways 2 mm or less in diameter. These airways play a crucial role in respiratory function and are often implicated in various pulmonary disorders. Pulmonary fibrotic diseases are characterized by the thickening and scarring of lung tissue, leading to progressive respiratory failure. We aimed to present the link between SAD and fibrotic lung conditions. The evidence suggests that SAD may act as a precursor or exacerbating factor in the progression of fibrotic diseases. Patients with fibrotic conditions often exhibit signs of small airway dysfunction, which can contribute to worsening respiratory symptoms and decreased lung function. Moreover, individuals with advanced SAD are at a heightened risk of developing fibrotic changes in the lung. The interplay between inflammation, environmental factors, and genetic predisposition further complicates this association. The early detection and management of SAD can potentially mitigate the progression of fibrotic diseases, highlighting the need for comprehensive clinical evaluation and research. This review emphasizes the need to understand the evolving connection between SAD and pulmonary fibrosis, urging further detailed research to clarify the causes and potential treatment between the two entities.

Management of severe acute pulmonary oedema, from expert guidelines to bedside strategies: multidisciplinary survey involving 1048 physicians

Abstract Introduction Current recommendations regarding the management of severe acute pulmonary oedema (APE) have low levels of recommendation and/or evidence (LOR/E) that may lead to high heterogeneity in clinical practice 1–3. We hypothesized that practice may diverge from guidelines and differ according to medical specialty and level of expertise. The objective of this survey was to evaluate the clinical management of 4 phenotypes of APE by physicians of 3 specialties and their divergence from guidelines. Methods Four vignettes were designed by a scientific committee representing the French scientific societies of cardiology, emergency medicine, and intensive care (Table 1). In addition, 20 experts in the field of APE care were enrolled. Target participants and designated experts were French physicians of the 3 specialties. From 06/2022 to 09/2022, the vignettes were submitted to the physicians and experts using an open online survey. Results Among the 1048 respondents, 781 completed the 4 cases whereas all 20 experts completed the whole survey (Table 1). Accordance with international guidelines was heterogenous (Table 2). Compliance with SpO2&amp;lt;90% threshold for O2 administration (LOE/R: I-C 1): 22% of physicians and 53% of experts were in accordance with the guidelines. Initiation of non-invasive ventilation (NIV) for respiratory distress (LOE/R: IIa-B 1): concordance was 54% and 93%, respectively. Intubation for progressive respiratory failure despite O2 or NIV (LOE/R: I-C 1): in case of pre-hospital NSTEMI worsening despite NIV and medications, compliance was 55% among physicians and 85% among experts. In case of STEMI with worsening respiratory failure, compliance was respectively 44% and 70%. Intravenous (iv) loop diuretics indications and choice of a loop diuretic (LOE/R: I-C 1): 91% of physicians and 95% of experts were in accordance. For the systolic blood pressure&amp;gt;110 mmHg threshold for iv vasodilators (LOE/R: IIb-C 1) and iv nitrates during NSTEMI with signs of APE (LOE/R: I-C 2): concordance was respectively 8% and 96% among physicians, 32% and 100% among experts. For reperfusion strategies, 20% of physicians and experts acted according to the guidelines. For early PCI within 24h of NSTEMI (LOE/R: I-A 2) and immediate strategy (&amp;lt; 2 hours) for very high-risk NSTEMI (LOE/R: I-C 2): concordance was respectively 62% and 12% among physicians, 80% and 10% among experts. Except for indications of mechanical ventilation and NSTEMI early invasive strategy, results were homogenous among medical specialties (Table 2). Conclusion Our data show that therapeutic strategies regarding classical clinical cases of severe APE often diverge from guidelines with expected differences between specialties. The low level of evidence fuelling the Guidelines may explain these heterogeneities 4. There is a need for more clinical investigation to fill the current gap in evidence and strengthen future guidelines that may reduce heterogeneity in care.Table 1Table 2

Abstract 18700: Immune Checkpoint Inhibitor-Related Myocarditis and Overlapping Syndromes

Background: Immune checkpoint inhibitor (ICI)-related myocarditis is a rare adverse effect of ICI's. When accompanied by overlapping myasthenia gravis, prognosis is worsened. While established guidelines aid in the treatment of ICI-associated adverse events, management of overlapping syndromes is complex and challenging. Case description: A 66-year-old man with metastatic renal cell carcinoma recently started on ipilimumab and nivolumab presented with dizziness and diplopia. He had high-grade atrioventricular (AV) block with junctional escape. He had elevated troponin, transaminases, and creatinine kinase. Coronary angiogram showed no evidence of obstructive coronary artery disease. A permanent pacemaker was placed. Cardiac MRI showed no specific features of myocarditis, though quality was limited by pacemaker artifact; left ventricular ejection fraction was 29%. MRI of the orbits showed no signs of extraocular myositis. Acetylcholine receptor (AChR) antibody and muscle-specific kinase (MuSK) antibody was negative. Given ongoing suspicion for ICI-associated adverse events, the patient underwent endomyocardial biopsy. This revealed lymphocytic myocarditis, confirming the diagnosis of ICI-related myocarditis. Despite improvement of troponin, transminases, and creatinine kinase, he developed progressive weakness, dysphagia, and respiratory failure, and died one month after initial presentation. Discussion: We highlight a case of ICI-related myocarditis presenting as high-grade AV block with concurrent hepatitis, myositis, and probable serologic-negative myasthenia gravis (MG). Overlapping syndromes are common in patients with exposure to ICI's, and are associated with significantly higher mortality. Although steroids are first-line for treating ICI-associated adverse events including myocarditis, they can initially lead to acute worsening of MG symptoms. While our patient had laboratory and biomarker improvement of his myocarditis, hepatitis, and myositis, he developed progressive weakness and respiratory failure. Our case highlights the complexity and challenges of managing ICI-related myocarditis and overlapping syndromes, including MG, and its poor prognosis despite prompt treatment.

Enhanced fatty acid oxidation through metformin and baicalin as therapy for COVID-19 and associated inflammatory states in lung and kidney

Progressive respiratory failure is the primary cause of death in the coronavirus disease 2019 (COVID-19) pandemic. It is the final outcome of the acute respiratory distress syndrome (ARDS), characterized by an initial exacerbated inflammatory response, metabolic derangement and ultimate tissue scarring. A positive balance of cellular energy may result crucial for the recovery of clinical COVID-19. Hence, we asked if two key pathways involved in cellular energy generation, AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) signaling and fatty acid oxidation (FAO) could be beneficial. We tested the drugs metformin (AMPK activator) and baicalin (CPT1A activator) in different experimental models mimicking COVID-19 associated inflammation in lung and kidney. We also studied two different cohorts of COVID-19 patients that had been previously treated with metformin. These drugs ameliorated lung damage in an ARDS animal model, while activation of AMPK/ACC signaling increased mitochondrial function and decreased TGF-β-induced fibrosis, apoptosis and inflammation markers in lung epithelial cells. Similar results were observed with two indole derivatives, IND6 and IND8 with AMPK activating capacity. Consistently, a reduced time of hospitalization and need of intensive care was observed in COVID-19 patients previously exposed to metformin. Baicalin also mitigated the activation of pro-inflammatory bone marrow-derived macrophages (BMDMs) and reduced kidney fibrosis in two animal models of kidney injury, another key target of COVID-19. In human epithelial lung and kidney cells, both drugs improved mitochondrial function and prevented TGF-β-induced renal epithelial cell dedifferentiation. Our results support that favoring cellular energy production through enhanced FAO may prove useful in the prevention of COVID-19-induced lung and renal damage.