COVID-19 and risk of pulmonary fibrosis: the importance of planning ahead

A bioinformatics approach combined with experimental validation analyzes the efficacy of azithromycin in treating SARS-CoV-2 infection in patients with IPF and COPD These authors contributed equally: Yining Xie, Guangshu Chen, and Weiling Wu

The swift transmission rate and unfavorable prognosis associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have prompted the pursuit of more effective therapeutic interventions. Azithromycin (AZM) has garnered significant attention for its distinctive pharmacological mechanisms in the treatment of SARS-CoV-2. This study aims to elucidate the biological rationale for employing AZM in patients with chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) who are infected with SARS-CoV-2. Genetic data about COVID-19, COPD, and IPF were independently obtained from the GeneCards database. And 40 drug targets about AZM were retrieved from the STITCH database. The analysis revealed that 311 DEGs were common among COPD, IPF, and COVID-19, and we further found eight genes that interacted with AZM targets. We conducted an analysis of hub genes and their corresponding signaling pathways in these patient cohorts. Additionally, we explored the inhibitory effects of AZM on these hub genes. AZM demonstrated a significant inhibitory effect on eight key genes, except for AR and IL-17 A. These findings suggest that AZM may serve as a promising therapeutic agent for patients with COPD and IPF and SARS-CoV-2 infection.

Determination of both the expression and serum levels of epidermal growth factor and transforming growth factor β1 genes in COVID-19

We aimed to evaluate the effects of both the expression and serum levels of Epidermal growth factor (EGF) and Transforming growth factor-β1 (TGF-β1) genes in patients with different degrees of cellular damage as mild, moderate, severe, and critical illness that can lead to fibrosis caused by SARS-CoV-2. Totally 45 individuals (male: 21(46.67%); female: 24(53.33%)) with COVID-19 infection were included in this study. Four groups were constituted as mild (n = 16)], moderate (n = 10), severe (n = 10), and critical (n = 9) according to the severity of the disease. Blood samples were drawn from the patients, and all of the hemograms, EGF and TGFβ1 gene expression, and serum levels were evaluated. The mean age of individuals was 57.311 ± 18.383 (min: 28, max: 94). Significant differences were found among the groups for PLT (χ2 = 9.955; p = 0.019), CRP (χ2 = 7.693; p = 0.053), Ferritin (χ2 = 22.196; p < 0.001), D-dimer (χ2 = 21.982; p = 0.000), LDH (χ2 = 21.807; p < 0.001) and all these parameters (exclude PLT in severe groups) was increased depending on the severity of the disease. Additionally, significant differences were detected for EGF (χ2 = 29.528; p < 0.001), TGFB1 (χ2 = 28.981; p < 0.001) expression (that increased depending on the disease severity), and EGF (χ2 = 7.84; p = 0.049), TGFB1 (χ2 = 17.451; p = 0.001) serum concentration levels (that decreased depending on the disease severity). This study found statistically significant differences for both EGF 2-ΔΔCt. TGFβ1 2-ΔΔCt and EGF, TGFβ1 serum concentration values among all patient groups. As disease severity increased, EGF 2-ΔΔCt. TGFβ1 2-ΔΔCt levels increased, while EGF and TGFβ1 serum concentration levels decreased. Perhaps this study will be useful in managing COVID-19 infection severity and pulmonary fibrosis cases secondary to COVID-19.

Inhalable siRNA Targeting IL-11 Nanoparticles Significantly Inhibit Bleomycin-Induced Pulmonary Fibrosis

For idiopathic pulmonary fibrosis (IPF), interleukin 11 (IL-11) is a pivotal cytokine that stimulates the transformation of fibroblasts into myofibroblasts, thus accelerating the progression of pulmonary fibrosis. Here, we develop an innovative inhalable small interfering RNA (siRNA) delivery system termed PEI-GBZA, which demonstrates impressive efficiency in loading siIL-11 targeting IL-11 (siIL-11) and substantially suppresses the differentiation of fibroblasts into myofibroblasts and epithelial-mesenchymal transition (EMT), reduces neutrophil and macrophage recruitment, and ultimately relieves the established fibrotic lesions in the IPF model. PEI-GBZA is prepared by modifying low-molecular-weight polyethylenimine (PEI) with 4-guanidinobenzoic acid (GBZA). The resulting PEI-GBZA may effectively encapsulate siIL-11 through a variety of interactions such as hydrophobic, hydrogen bonding, and electrostatic interactions, creating stable carrier/siIL-11 nanoparticles (PEI-GBZA/siIL-11 NPs). Upon inhalation, PEI-GBZA/siIL-11 NPs demonstrate effective retention in fibrotic lesions, leading to a marked mitigation of disease progression in a bleomycin-induced pulmonary fibrosis model. Impressively, this inhalation therapy exhibits negligible systemic toxicity. This work provides a universal and noninvasive RNA therapeutic delivery platform that holds significant promise for respiratory diseases. The potential for clinical application of this platform is substantial, offering a frontier for the treatment of IPF and potentially other pulmonary disorders.

Tackling pulmonary fibrosis risks in post-COVID-19: cutting-edge treatments

INTRODUCTION

Pulmonary fibrosis (PF) post-COVID-19 has been identified as an important complication of Long-COVID, especially in patients with severe respiratory symptoms. High-resolution computed tomography (HRCT) is the main tool for detecting fibrotic lesions in patients with PF post-COVID-19.

AREAS COVERED

We conducted a systematic review with the following objectives: (1) to summarize the incidence and disease burden of post‑COVID‑19 pulmonary fibrosis, (2) to provide information on available therapies and drugs for its management, (3) to comprehensively evaluate the initial treatment efficacy of these drugs, and (4) to identify the limitations and challenges associated with current treatment approaches.

EXPERT OPINION

Cutting-edge treatments for PF post-COVID-19 are focused on the complex and multifactorial nature of the disease progreession during Long COVID, which involves chronic inflammation, fibroblast activation, and excessive extracellular matrix deposition leading to stiffening and fibrosis of lung tissue. While traditional antifibrotic drugs with nintedanid and pirfenidone are being used, novel therapies with anti-interleukines, mesenchymal stem cells, and Rho-kinase inhibitors promise the new treatment approaches for patients with PF post-COVID-19. Further research and clinical trials are needed to determine the most effective strategies for managing this complex condition, with the goal of improving patient outcomes and quality of life.

Post-COVID Interstitial Lung Disease: How do We Deal with This New Entity?

Background

In the postacute phase of coronavirus disease-2019 (COVID-19), survivors may have persistent symptoms, lung function abnormalities, and sequelae lesions on thoracic computed tomography (CT). This new entity has been defined as post-COVID interstitial lung disease (ILD) or residual disease.

Aims

To evaluate the characteristics, risk factors and clinical significance of post-COVID ILD.

Study Design

Multicenter cross-sectional analysis of data from a randomized clinical study.

Methods

In this study, patients with persistent respiratory symptoms 3 months after recovery from COVID-19 were evaluated by two pulmonologists and a radiologist. post-COVID ILD was defined as the presence of respiratory symptoms, hypoxemia, restrictive defect on lung function tests, and interstitial changes on follow-up high-resolution computed tomography (HRCT).

Results

At the three-month follow-up, 375 patients with post-COVID-19 syndrome were evaluated, and 262 patients were found to have post-COVID ILD. The most prevalent complaints were dyspnea (n = 238, 90.8%), exercise intolerance (n = 166, 63.4%), fatigue (n = 142, 54.2%), and cough (n = 136, 52%). The mean Medical Research Council dyspnea score was 2.1 ± 0.9, oxygen saturation was 92.2 ± 5.9%, and 6-minute walking distance was 360 ± 140 meters. The mean diffusing capacity of the lung for carbon monoxide was 58 ± 21, and the forced vital capacity was 70% ± 19%. Ground glass opacities and fibrotic bands were the most common findings on thoracic HRCT. Fibrosis-like lesions such as interlobular septal thickening and traction bronchiectasis were observed in 38.3% and 27.9% of the patients, respectively. No honeycomb cysts were observed. Active smoking [odds ratio (OR), 1.96; 95% confidence interval (CI), 1.44-2.67), intensive care unit admission during the acute phase (OR, 1.46; 95% CI, 1.1-1.95), need for high-flow nasal oxygen (OR, 1.55; 95% CI, 1.42-1.9) or non-invasive ventilation (OR, 1.31; 95% CI, 0.8-2.07), and elevated serum lactate dehydrogenase levels (OR, 1.23; 95% CI 1.18-1.28) were associated with the development of post-COVID ILD. At the 6-month follow-up, the respiratory symptoms and pulmonary functions had improved spontaneously without any specific treatment in 35 patients (13.4%). The radiological interstitial lesions had spontaneously regressed in 54 patients (20.6%).

Conclusion

The co-existence of respiratory symptoms, radiological parenchymal lesions, and pulmonary functional abnormalities which suggest a restrictive ventilatory defect should be defined as post-COVID-19 ILD. However, the term “fibrosis” should be used carefully. Active smoking, severe COVID-19, and elevated lactate dehydrogenase level are the main risk factors of this condition. These post-COVID functional and radiological changes could disappear over time in 20% of the patients.

Targeting mevalonate pathway by zoledronate ameliorated pulmonary fibrosis in a rat model: Promising therapy against post-COVID-19 pulmonary fibrosis

BACKGROUND

Rho kinase (ROCK) pathway plays a critical role in post-COVID-19 pulmonary fibrosis (PCPF) and its intervention with angiotensin-converting enzyme 2 (ACE2) and vascular endothelial growth factor (VEGF) will be a potential therapeutic target.

OBJECTIVES

The present study was conducted to investigate the efficacy of zoledronate (ZA) on carbon tetrachloride (CCl4) induced pulmonary fibrosis (PF) in rats through targeting ACE2, ROCK, and VEGF signaling pathways.

METHODS

Fifty male Wistar rats were divided into five groups: control, vehicle-treated, PF, PF-ZA 50, and PF-ZA 100 groups. ZA was given in two different doses 100 and 50 μg/kg/week intraperitoneally. After anesthesia, mean arterial blood pressure (MBP) was measured. After scarification, lung coefficient was calculated. Lung levels of ACE 2, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β), VEGF, glutathione (GSH), and superoxide dismutase (SOD) were measured. Expression of ROCK, phosphorylated myosin phosphatase target subunit 1 (P-MYPT1), and matrix metalloproteinase (MMP-1), along with histopathological changes and immune-histochemical staining for lung α-smooth muscle actin (α-SMA), tumor necrosis factor-alpha (TNFα), and caspase-3, were evaluated.

RESULTS

ZA significantly prevented the decrease in MBP. ZA significantly increased ACE2, GSH, and SOD and significantly decreased IL-1β, TGF-β, and VEGF in lung in comparison to PF group. ZA prevented the histopathological changes induced by CCl4. ZA inhibited lung expression of ROCK, P-MYPT1, MMP-1, α-SMA, TNFα, and caspase-3 with significant differences favoring the high dose intervention.

CONCLUSION

ZA in a dose-dependent manner prevented the pathological effect of CCl4 in the lung by targeting mevalonate pathway. It could be promising therapy against PCPF.

Network pharmacology and experimental verification to decode the action of Qing Fei Hua Xian Decotion against pulmonary fibrosis

BACKGROUND

Pulmonary fibrosis (PF) is a common interstitial pneumonia disease, also occurred in post-COVID-19 survivors. The mechanism underlying the anti-PF effect of Qing Fei Hua Xian Decotion (QFHXD), a traditional Chinese medicine formula applied for treating PF in COVID-19 survivors, is unclear. This study aimed to uncover the mechanisms related to the anti-PF effect of QFHXD through analysis of network pharmacology and experimental verification.

METHODS

The candidate chemical compounds of QFHXD and its putative targets for treating PF were achieved from public databases, thereby we established the corresponding "herb-compound-target" network of QFHXD. The protein-protein interaction network of potential targets was also constructed to screen the core targets. Furthermore, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to predict targets, and pathways, then validated by in vivo experiments.

RESULTS

A total of 188 active compounds in QFHXD and 50 target genes were identified from databases. The key therapeutic targets of QFHXD, such as PI3K/Akt, IL-6, TNF, IL-1β, STAT3, MMP-9, and TGF-β1 were identified by KEGG and GO analysis. Anti-PF effects of QFHXD (in a dose-dependent manner) and prednisone were confirmed by HE, Masson staining, and Sirius red staining as well as in vivo Micro-CT and immunohistochemical analysis in a rat model of bleomycin-induced PF. Besides, QFXHD remarkably inhibits the activity of PI3K/Akt/NF-κB and TGF-β1/Smad2/3.

CONCLUSIONS

QFXHD significantly attenuated bleomycin-induced PF via inhibiting inflammation and epithelial-mesenchymal transition. PI3K/Akt/NF-κB and TGF-β1/Smad2/3 pathways might be the potential therapeutic effects of QFHXD for treating PF.

Specneuzhenide improves bleomycin-induced pulmonary fibrosis in mice via AMPK-dependent reduction of PD-L1

BACKGROUND

Pulmonary fibrosis (PF) is an escalating global health issue, characterized by rising rates of morbidity and mortality annually. Consequently, further investigation of potential damage mechanisms and potential preventive strategies for PF are warranted. Specnuezhenide (SPN), a prominent secoiridoid compound derived from Ligustrum lucidum Ait, exhibits anti-inflammatory and anti-oxidative capacities, indicating the potential therapeutic actions on PF. However, the underlying mechanisms of SPN on PF remain unclear.

PURPOSE

This work was aimed at investigating the protective actions of SPN on PF and the potential mechanism.

METHODS

In vivo, mice were administrated with bleomycin (BLM) to establish PF model. PF mice were treated with SPN (45/90 mg/kg) by gavage. In vitro, we employed TGF-β1 (10 ng/mL)-induced MLE-12 and PLFs cells, which then were treated with SPN (5, 10, 20 µM). DARTS assay, biofilm interference experiment and molecular docking were performed to investigate the molecular target of SPN.

RESULTS

In vivo, we found SPN treatment improved survival rate, alleviated pathological changes through reducing BLM-induced extracellular matrix (ECM) deposition, as well as BLM-induced epithelial-mesenchymal transition (EMT). In vitro, SPN inhibited EMT and lung fibroblast transdifferentiation. Mechanistically, SPN activated the AMPK protein to decrease the abnormally high level of PD-L1. Furthermore, the compound C, known as an AMPK inhibitor, exhibited a significant hindrance to the inhibition of SPN on TGF-β1-caused fibroblast transdifferentiation and proliferation. This outcome could be attributed to the fact that compound C could eliminate the inhibitory effects of SPN on PD-L1 expression. Interestingly, DARTS assay, biofilm interference experiment and molecular docking results all indicated that SPN could bind to AMPK, which suggested that SPN might be a potential agonist targeting AMPK protein.

CONCLUSION

Altogether, the results in our work illustrated that SPN promoted AMPK-dependent reduction of PD-L1 protein, contributing to the inhibition of fibrosis progression. Thus, SPN may represent a potential AMPK agonist for PF treatment.

Quantitative CT Texture Analysis of COVID-19 Hospitalized Patients during 3-24-Month Follow-Up and Correlation with Functional Parameters

BACKGROUND

To quantitatively evaluate CT lung abnormalities in COVID-19 survivors from the acute phase to 24-month follow-up. Quantitative CT features as predictors of abnormalities' persistence were investigated.

METHODS

Patients who survived COVID-19 were retrospectively enrolled and underwent a chest CT at baseline (T0) and 3 months (T3) after discharge, with pulmonary function tests (PFTs). Patients with residual CT abnormalities repeated the CT at 12 (T12) and 24 (T24) months after discharge. A machine-learning-based software, CALIPER, calculated the CT percentage of the whole lung of normal parenchyma, ground glass (GG), reticulation (Ret), and vascular-related structures (VRSs). Differences (Δ) were calculated between time points. Receiver operating characteristic (ROC) curve analyses were performed to test the baseline parameters as predictors of functional impairment at T3 and of the persistence of CT abnormalities at T12.

RESULTS

The cohort included 128 patients at T0, 133 at T3, 61 at T12, and 34 at T24. The GG medians were 8.44%, 0.14%, 0.13% and 0.12% at T0, T3, T12 and T24. The Ret medians were 2.79% at T0 and 0.14% at the following time points. All Δ significantly differed from 0, except between T12 and T24. The GG and VRSs at T0 achieved AUCs of 0.73 as predictors of functional impairment, and area under the curves (AUCs) of 0.71 and 0.72 for the persistence of CT abnormalities at T12.

CONCLUSIONS

CALIPER accurately quantified the CT changes up to the 24-month follow-up. Resolution mostly occurred at T3, and Ret persisting at T12 was almost unchanged at T24. The baseline parameters were good predictors of functional impairment at T3 and of abnormalities' persistence at T12.

Antifibrotic Drugs against Idiopathic Pulmonary Fibrosis and Pulmonary Fibrosis Induced by COVID-19: Therapeutic Approaches and Potential Diagnostic Biomarkers

The COVID-19 pandemic has had a significant impact on the health and economy of the global population. Even after recovery from the disease, post-COVID-19 symptoms, such as pulmonary fibrosis, continue to be a concern. This narrative review aims to address pulmonary fibrosis (PF) from various perspectives, including the fibrotic mechanisms involved in idiopathic and COVID-19-induced pulmonary fibrosis. On the other hand, we also discuss the current therapeutic drugs in use, as well as those undergoing clinical or preclinical evaluation. Additionally, this article will address various biomarkers with usefulness for PF prediction, diagnosis, treatment, prognosis, and severity assessment in order to provide better treatment strategies for patients with this disease.

NOX-2 Inhibitors may be Potential Drug Candidates for the Management of COVID-19 Complications

COVID-19 is an RNA virus that attacks the targeting organs, which express angiotensin- converting enzyme-2 (ACE-2), such as the lungs, heart, renal system, and gastrointestinal tract. The virus that enters the cell by endocytosis triggers ROS production within the confines of endosomes via a NOX-2 containing NADPH-oxidase. Various isoforms of NADPH oxidase are expressed in airways and alveolar epithelial cells, endothelial and vascular smooth muscle cells, and inflammatory cells, such as alveolar macrophages, monocytes, neutrophils, and Tlymphocytes. The key NOX isoform expressed in macrophages and neutrophils is the NOX-2 oxidase, whereas, in airways and alveolar epithelial cells, it appears to be NOX-1 and NOX-2. The respiratory RNA viruses induce NOX-2-mediated ROS production in the endosomes of alveolar macrophages. The mitochondrial and NADPH oxidase (NOX) generated ROS can enhance TGF-β signaling to promote fibrosis of the lungs. The endothelium-derived ROS and platelet-derived ROS, due to activation of the NADPH-oxidase enzyme, play a crucial role in platelet activation. It has been observed that NOX-2 is generally activated in COVID-19 patients. The post-COVID complications like pulmonary fibrosis and platelet aggregation may be due to the activation of NOX-2. NOX-2 inhibitors may be a useful drug candidate to prevent COVID-19 complications like pulmonary fibrosis and platelet aggregation.

Long-Term Radiological Pulmonary Changes in Mechanically Ventilated Patients with Respiratory Failure due to SARS-CoV-2 Infection

From the first reports of SARS-CoV-2, at the end of 2019 to the present, the global mortality associated with COVID-19 has reached 6,952,522 deaths as reported by the World Health Organization (WHO). Early intubation and mechanical ventilation can increase the survival rate of critically ill patients. This prospective study was carried out on 885 patients in the ICU of Mureș County Clinical Hospital, Romania. After applying inclusion and exclusion criteria, a total of 54 patients were included. Patients were monitored during hospitalization and at 6-month follow-up. We analyzed the relationship between invasive mechanical ventilation (IMV) and non-invasive mechanical ventilation (NIMV) and radiological changes on thoracic CT scans performed at 6-month follow-up and found no significant association. Regarding paraclinical analysis, there was a statistically significant association between patients grouped by IMV and ferritin level on day 1 of admission (p = 0.034), and between patients grouped by PaO2/FiO2 ratio with metabolic syndrome (p = 0.03) and the level of procalcitonin (p = 0.01). A significant proportion of patients with COVID-19 admitted to the ICU developed pulmonary fibrosis as observed at a 6-month evaluation. Patients with oxygen supplementation or mechanical ventilation require dynamic monitoring and radiological investigations, as there is a possibility of long-term pulmonary fibrosis that requires pharmacological interventions and finding new therapeutic alternatives.

Spatial distribution of COVID-19 patients in Sri Lanka

BACKGROUND

A new type of viral pneumonia, which has been named Coronavirus disease (COVID-19) began in Wuhan, China in late 2019 and has spread across the world since then. It has claimed more than 370 million confirmed cases and over 5.6 million deaths have been reported globally by the end of January 2022. This study aimed to analyze the trends, highly-nuanced patterns, and related key results relative to COVID-19 epidemiology in Sri Lanka.

METHODS

Data on COVID-19 from March 2020 to January 2022 were obtained from published databases maintained by the Epidemiology Unit of the Ministry of Health in Sri Lanka and information regarding populations in administrative districts was obtained from the Department of Census and Statistics, Sri Lanka. Descriptive spatiotemporal analysis and autocorrelations were analyzed using SPSS statistical software.

RESULTS

In Sri Lanka, the first case of COVID-19 was a Chinese national and the first local case was identified in the second week of March. As of 31st of January 2022, a total of 610,103 COVID-19 cases had been recorded in the country, and 15,420 patients had died. At the beginning, the disease was mainly concentrated in the Western province and with time, it spread to other provinces. However, very low numbers of patients were identified in the North, Eastern, North Central, and Uva provinces until April 2021. The peak of COVID-19 occurred in August and September 2021 in all provinces in Sri Lanka. Then a decreasing trend of COVID-19 cases showed after September 2021.

CONCLUSIONS

COVID-19 is an emerging public health problem in Western and Southern Sri Lanka where the population density is high. A decreasing trend of COVID-19 cases showed in all provinces after September 2021. Public awareness programs for the prevention and control of the disease in endemic regions are essential to reduce the incidence of this infection.

COVID-19 and interstitial lung diseases: A multifaceted look at the relationship between the two diseases

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although it has been a fatal disease for many patients, the development of treatment strategies and vaccines have progressed over the past 3 years, and our society has become able to accept COVID-19 as a manageable common disease. However, as COVID-19 sometimes causes pneumonia, post-COVID pulmonary fibrosis (PCPF), and worsening of preexisting interstitial lung diseases (ILDs), it is still a concern for pulmonary physicians. In this review, we have selected several topics regarding the relationships between ILDs and COVID-19. The pathogenesis of COVID-19-induced ILD is currently assumed based mainly on the evidence of other ILDs and has not been well elucidated specifically in the context of COVID-19. We have summarized what has been clarified to date and constructed a coherent story about the establishment and progress of the disease. We have also reviewed clinical information regarding ILDs newly induced or worsened by COVID-19 or anti-SARS-CoV-2 vaccines. Inflammatory and profibrotic responses induced by COVID-19 or vaccines have been thought to be a risk for de novo induction or worsening of ILDs, and this has been supported by the evidence obtained through clinical experience over the past 3 years. Although COVID-19 has become a mild disease in most cases, it is still worth looking back on the above-reviewed information to broaden our perspectives regarding the relationship between viral infection and ILD. As a representative etiology for severe viral pneumonia, further studies in this area are expected.

Post-COVID-19 Pulmonary Fibrosis: Facts-Challenges and Futures: A Narrative Review

Patients with coronavirus disease 2019 (COVID-19) usually suffer from post-acute sequelae of coronavirus disease 2019 (PASC). Pulmonary fibrosis (PF) has the most significant long-term impact on patients' respiratory health, called post-COVID-19 pulmonary fibrosis (PC19-PF). PC19- PF can be caused by acute respiratory distress syndrome (ARDS) or pneumonia due to COVID-19. The risk factors of PC19-PF, such as older age, chronic comorbidities, the use of mechanical ventilation during the acute phase, and female sex, should be considered. Individuals with COVID-19 pneumonia symptoms lasting at least 12 weeks following diagnosis, including cough, dyspnea, exertional dyspnea, and poor saturation, accounted for nearly all disease occurrences. PC19-PF is characterized by persistent fibrotic tomographic sequelae associated with functional impairment throughout follow-up. Thus, clinical examination, radiology, pulmonary function tests, and pathological findings should be done to diagnose PC19-PF patients. PFT indicated persistent limitations in diffusion capacity and restrictive physiology, despite the absence of previous testing and inconsistency in the timeliness of assessments following acute illness. It has been hypothesized that PC19-PF patients may benefit from idiopathic pulmonary fibrosis treatment to prevent continued infection-related disorders, enhance the healing phase, and manage fibroproliferative processes. Immunomodulatory agents might reduce inflammation and the length of mechanical ventilation during the acute phase of COVID-19 infection, and the risk of the PC19-PF stage. Pulmonary rehabilitation, incorporating exercise training, physical education, and behavioral modifications, can improve the physical and psychological conditions of patients with PC19-PF.

Vincamine as an agonist of G protein-coupled receptor 40 effectively ameliorates pulmonary fibrosis in mice

BACKGROUND

Pulmonary fibrosis (PF) is an irreversible and fatal lung disease with limited therapeutic options. G protein-coupled receptor 40 (GPR40) has been developed as a promising therapeutic target for metabolic disorders and functions potently in varied pathological and physiological processes. Vincamine (Vin) is a monoterpenoid indole alkaloid originated from Madagascar periwinkle and was reported as a GPR40 agonist in our previous work.

PURPOSE

Here, we aimed to clarify the role of GPR40 in PF pathogenesis by using the determined GPR40 agonist Vin as a probe and explore the potential of Vin in ameliorating PF in mice.

METHODS

Pulmonary GPR40 expression alterations were assessed in both PF patients and bleomycin-induced PF mice (PF mice). Vin was used to evaluate the therapeutic potential of GPR40 activation for PF and the underlying mechanism was intensively investigated by assays against GPR40 knockout (Ffar1^-/-) mice and the cells transfected with si-GPR40 in vitro.

RESULTS

Pulmonary GPR40 expression level was highly downregulated in PF patients and PF mice. Pulmonary GPR40 deletion (Ffar1^-/-) exacerbated pulmonary fibrosis as evidenced by the increases in mortality, dysfunctional lung index, activated myofibroblasts and extracellular matrix (ECM) deposition in PF mice. Vin-mediated pulmonary GPR40 activation ameliorated PF-like pathology in mice. Mechanistically, Vin suppressed ECM deposition by GPR40/β-arrestin2/SMAD3 pathway, repressed inflammatory response by GPR40/NF-κB/NLRP3 pathway and inhibited angiogenesis by decreasing GPR40-mediated vascular endothelial growth factor (VEGF) expression in the region of interface to normal parenchyma in pulmonary fibrotic tissues of mice.

CONCLUSION

Pulmonary GPR40 activation shows promise as a therapeutic strategy for PF and Vin exhibits high potential in treating this disease.

Pharmacological approaches to pulmonary fibrosis following COVID-19

Background: In the past few years, COVID-19 became the leading cause of morbidity and mortality worldwide. Although the World Health Organization has declared an end to COVID-19 as a public health emergency, it can be expected, that the emerging new cases at the top of previous ones will result in an increasing number of patients with post-COVID-19 sequelae. Despite the fact that the majority of patients recover, severe acute lung tissue injury can in susceptible individuals progress to interstitial pulmonary involvement. Our goal is to provide an overview of various aspects associated with the Post-COVID-19 pulmonary fibrosis with a focus on its potential pharmacological treatment options. Areas covered: We discuss epidemiology, underlying pathobiological mechanisms, and possible risk and predictive factors that were found to be associated with the development of fibrotic lung tissue remodelling. Several pharmacotherapeutic approaches are currently being applied and include anti-fibrotic drugs, prolonged use or pulses of systemic corticosteroids and non-steroidal anti-inflammatory and immunosuppressive drugs. In addition, several repurposed or novel compounds are being investigated. Fortunately, clinical trials focused on pharmacological treatment regimens for post-COVID-19 pulmonary fibrosis have been either designed, completed or are already in progress. However, the results are contrasting so far. High quality randomised clinical trials are urgently needed with respect to the heterogeneity of disease behaviour, patient characteristics and treatable traits. Conclusion: The Post-COVID-19 pulmonary fibrosis contributes to the burden of chronic respiratory consequences among survivors. Currently available pharmacotherapeutic approaches mostly comprise repurposed drugs with a proven efficacy and safety profile, namely, corticosteroids, immunosuppressants and antifibrotics. The role of nintedanib and pirfenidone is promising in this area. However, we still need to verify conditions under which the potential to prevent, slow or stop progression of lung damage will be fulfilled.

A Precise Method to Detect Post-COVID-19 Pulmonary Fibrosis Through Extreme Gradient Boosting

The association of pulmonary fibrosis with COVID-19 patients has now been adequately acknowledged and caused a significant number of mortalities around the world. As automatic disease detection has now become a crucial assistant to clinicians to obtain fast and precise results, this study proposes an architecture based on an ensemble machine learning approach to detect COVID-19-associated pulmonary fibrosis. The paper discusses Extreme Gradient Boosting (XGBoost) and its tuned hyper-parameters to optimize the performance for the prediction of severe COVID-19 patients who developed pulmonary fibrosis after 90 days of hospital discharge. A dataset comprising Electronic Health Record (EHR) and corresponding High-resolution computed tomography (HRCT) images of chest of 1175 COVID-19 patients has been considered, which involves 725 pulmonary fibrosis cases and 450 normal lung cases. The experimental results achieved an accuracy of 98%, precision of 99% and sensitivity of 99%. The proposed model is the first in literature to help clinicians in keeping a record of severe COVID-19 cases for analyzing the risk of pulmonary fibrosis through EHRs and HRCT scans, leading to less chance of life-threatening conditions.

Molecular Pathogenesis of Fibrosis, Thrombosis and Surfactant Dysfunction in the Lungs of Severe COVID-19 Patients

The global scope and scale of the SARS-CoV-2 pandemic led to huge amounts of important data from clinical observations and experimental analyses being collected, in particular, regarding the long-term impact of COVID-19 on lung tissue. Visible changes in lung tissue mainly relate to the destruction of the alveolar architecture, dense cellularity, and pulmonary fibrosis with myofibroblast proliferation and collagen deposition. These changes are the result of infection, mainly with virus variants from the first pandemic waves (Alpha to Delta). In addition, proper regulation of immune responses to pathogenic viral stimuli is critical for the control of and recovery from tissue/organ damage, including in the lungs. We can distinguish three main processes in the lungs during SARS-CoV-2 infection: damage or deficiency of the pulmonary surfactant, coagulation processes, and fibrosis. Understanding the molecular basis of these processes is extremely important in the context of elucidating all pathologies occurring after virus entry. In the present review, data on the abovementioned three biochemical processes that lead to pathological changes are gathered together and discussed. Systematization of the knowledge is necessary to explore the three key pathways in lung tissue after SARS-CoV-2 virus infection as a result of a prolonged and intense inflammatory process in the context of pulmonary fibrosis, hemostatic disorders, and disturbances in the structure and/or metabolism of the surfactant. Despite the fact that the new Omicron variant does not affect the lungs as much as the previous variants, we cannot ignore the fact that other new mutations and emerging variants will not cause serious damage to the lung tissue. In the future, this review will be helpful to stratify the risk of serious complications in patients, to improve COVID-19 treatment outcomes, and to select those who may develop complications before clinical manifestation.

Acute toxicological study: EZY-1 with potent therapeutic effects of idiopathic pulmonary fibrosis and its mechanisms

EZY-1 is an antifibrosis peptide purified from Eucheuma. In this study, we explored the acute toxicology of EZY-1 and the signaling pathways involved in its antifibrotic role. The mouse model of pulmonary fibrosis was induced by bleomycin. Pathological changes in lung tissue could be effectively inhibited by EZY-1. Acute toxicity and cell proliferation tests indicated that EZY-1 had no apparent toxicity to mice and cells. We identified proteins that could bind directly to EZY-1 in vitro on the basis of liquid chromatography-tandem mass spectrometry and bioinformatics analysis. EZY-1 inhibited pulmonary fibrosis via Wnt/β-catenin, transforming growth factor (TGF)-β/Smad, phosphoinositide 3-kinase/protein kinase B/ mammalian target of rapamycin, and activator of transcription 3 and Janus kinase 2/signal transducer pathways. A transwell micropore experiment showed that EZY-1 could inhibit cell migration and invasion. Western blotting analysis on transforming growth factor-β1 (TGF-β1)-induced A549 pulmonary fibrosis cell model suggested that EZY-1 could downregulate p-Smad3 (Ser423/Ser425), Smad4, β-catenin, vimentin, and N-cadherin expression. ELISA showed that EZY-1 could inhibit collagen-I secretion. EZY-1 alleviated idiopathic pulmonary fibrosis (IPF) through regulating TGF-β/Smad pathways, epithelial-mesenchymal transition processes, and collagen secretion, which provides a potential foundation for theoretical development of EZY-1 as a potential drug against IPF. PRACTICAL APPLICATIONS: We isolated a new 16-amino-acid peptide derived from the polypeptide extract of Eucheuma, named EZY-1. In vitro and in vivo assays show peptide EZY-1 is safe. The EZY-1 peptide alleviates IPF at lower doses than pirfenidone. EZY-1 alleviated idiopathic pulmonary fibrosis (IPF) through regulating TGF-β/Smad pathways, epithelial-mesenchymal transition (EMT) processes, and collagen secretion, which provides a theoretical basis for the development of EZY-1 as a potential drug against IPF.

Histopathological pulmonary findings of survivors and autopsy COVID-19 cases: A bi-center study

The coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), evolved into a global pandemic. As ACE2 on the surface of alveolar cells of the lung epithelium is one of the potential target receptors for SARS-CoV-2, the respiratory symptoms are the most common presentation of COVID-19. The aim of our study was to investigate the morphological findings in lung tissue after being infected by SARS-CoV-2 and compare histopathologic changes in patients with COVID-19 infection history who died to those who survived. We analyzed lung tissue samples from 9 patients who died from COVID-19 and from 35 patients with COVID-19 infection history who survived and had undergone lung surgery for different reasons. Most of histopathological changes in autopsy and survivors' cases overlapped; however, they occurred with different frequency. The predominant histologic finding both in the case of the deceased and the survivors was patchy distribution of foamy macrophages in the alveolar spaces. In comparison with autopsy cases viral cytopathic-like changes in hyperplastic pneumocytes were rarely observed in the survivors' lung tissue. Pulmonary edema, fibrin deposition within alveoli, bronchopneumonia, small vessel thrombosis and type II pneumocyte hyperplasia were also more often observed within autopsy cases. Life-threatening complications such as hyaline membrane formations and diffuse alveolar damage were present only within the deceased, whereas changes requiring enough time to progress to the fibrotic phase, such as organizing pneumonia, bronchiolization of the alveoli, and interstitial fibrosis were observed in the lung parenchyma only in survivors. Additionally, 14 cases of pulmonary pneumo-hematocele in patients with COVID-19 infection history who survived were observed. It is a newly observed entity in the form of a cystic lesion formed by large accumulation of blood and fibrin between the collapsed and rejected lung parenchyma and/or present with air-fluid levels. The thin wall of pneumo-hematocele is formed by the inter lobar interstitial fibroconnective tissue and has no epithelial lining or bronchial wall elements. As the COVID-19 pandemic continues, new complications following SARS-CoV-2 infection are identified. Newly observed entity in patients with COVID-19 infection history who survived is pulmonary pneumo-hematocele. The appearance of these lesion has become increasingly frequent.

The effect of Pirfenidone on pulmonary function parameters in post recovery COVID-19 patients with pulmonary fibrosis compared to placebo in a Government Medical College, West Bengal

Introduction and Aim: The recent COVID 19 pandemic has created an unprecedented challenge to the entire global healthcare system by affecting many people worldwide. Post COVID complications are multi-systemic, but pulmonary post COVID complications are most common. Involvement of the lung parenchyma ultimately leads to pulmonary fibrosis in many of the patients. Pirfenidone is a widely used antifibrotic medication in the field of idiopathic pulmonary fibrosis (IPF) management. Our study has assessed the effect of Pirfenidone on spirometry parameters in post recovery COVID 19 patients with diagnosed pulmonary fibrosis as compared to those that received placebo.   Materials and Methods: After obtaining approval from Institutional Ethics Committee, 70 adult patients of COVID-19 with established pulmonary fibrosis in the post recovery phase were chosen and allocated into two groups by randomization in 1:1 ratio. All other factors remaining same, one group was administered the recommended dose of Pirfenidone and the other group received a placebo. Spirometry parameters such as FEV1, FEV1 /FVC ratio, FVC, PEFR of both the groups were recorded on Day 0 and Day 90 and compared using standard statistical tests.   Results: It was found that on Day 0, PFT parameters of the two groups was comparable (P value>0.05). PFT parameters of the group receiving Pirfenidone showed significant improvement on day 90 (P value<0.05). In addition, on day 90, the PFT parameters of the group receiving Pirfenidone showed significantly better values than the group receiving placebo, P value <0.05.   Conclusion: As there is a significant improvement in the PFT parameters of post recovery COVID-19 patients suffering from pulmonary fibrosis, we conclude that Pirfenidone is helpful to improve the pulmonary function parameters in post recovery COVID -19 patients with established lung fibrosis as compared to placebo.

Yiqi Huayu decoction alleviates bleomycin-induced pulmonary fibrosis in rats by inhibiting senescence

Overview: In treating pulmonary fibrosis (PF), traditional Chinese medicine (TCM) has received much attention, but its mechanism is unclear. The pharmacological mechanisms of TCM can be explored through network pharmacology. However, due to its virtual screening properties, it still needs to be verified by in vitro or in vivo experiments. Therefore, we investigated the anti-PF mechanism of Yiqi Huayu Decoction (YHD) by combining network pharmacology with in vivo experiments.

Methods: Firstly, we used classical bleomycin (BLM)-induced rat model of PF and administrated fibrotic rats with YHD (low-, medium-, and high-dose). We comprehensively assessed the treatment effect of YHD according to body weight, lung coefficient, lung function, and histopathologic examination. Second, we predict the potential targets by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) combined with network pharmacology. In brief, we obtained the chemical ingredients of YHD based on the UHPLC-MS/MS and TCMSP database. We collected drug targets from TCMSP, HERB, and Swiss target prediction databases based on active ingredients. Disease targets were acquired from drug libraries, Genecards, HERB, and TTD databases. The intersecting targets of drugs and disease were screened out. The STRING database can obtain protein-protein interaction (PPI) networks and hub target proteins. Molecular Complex Detection (MCODE) clustering analysis combined with enrichment analysis can explore the possible biological mechanisms of YHD. Enrichment analyses were conducted through the R package and the David database, including the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Reactome. Then, we further validated the target genes and target proteins predicted by network pharmacology. Protein and gene expression detection by immunohistochemistry, Western blot (WB), and real-time quantitative PCR (rt-qPCR).

Results: The results showed that high-dose YHD effectively attenuated BLM-induced lung injury and fibrosis in rats, as evidenced by improved lung function, relief of inflammatory response, and reduced collagen deposition. We screened nine core targets and cellular senescence pathways by UHPLC-MS/MS analysis and network pharmacology. We subsequently validated key targets of cellular senescence signaling pathways. WB and rt-qPCR indicated that high-dose YHD decreased protein and gene expression of senescence-related markers, including p53 (TP53), p21 (CDKN1A), and p16 (CDKN2A). Increased reactive oxygen species (ROS) are upstream triggers of the senescence program. The senescence-associated secretory phenotypes (SASPs), containing interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-β1 (TGF-β1), can further exacerbate the progression of senescence. High-dose YHD inhibited ROS production in lung tissue and consistently reduced the SASPs expression in serum.

Conclusion: Our study suggests that YHD improves lung pathological injury and lung function in PF rats. This protective effect may be related to the ability of YHD to inhibit cellular senescence.

Prognostic Factors for Pulmonary Fibrosis Following Pneumonia in Patients with COVID-19: A Prospective Study

The frequency and clinical manifestation of lung fibrosis accompanied by coronavirus disease (COVID-19) are not well-established. We aimed to identify the factors attributed to post-COVID-19 fibrosis. This single-center prospective study included patients diagnosed with COVID-19 pneumonia from 12 April to 22 October 2021 in the Republic of Korea. The primary outcome was the presence of pulmonary fibrosis on a CT scan 3 months after discharge; the fibrosis risk was estimated by a multiple logistic regression. The mean patient age was 55.03 ± 12.32 (range 27–85) years; 65 (66.3%) were men and 33 (33.7%) were women. The age, Charlson Comorbidity Index, lactate dehydrogenase level, aspartate aminotransferase level, and Krebs von den Lungen-6 level were significantly higher and the albumin level and the saturation of the peripheral oxygen/fraction of inspired oxygen (SpO2/FiO2) ratio were significantly lower in the fibrosis group than in the non-fibrosis group; the need for initial oxygen support was also greater in the fibrosis group. An older age (adjusted odds ratio (AOR) 1.12; 95% confidence interval (CI) 1.03–1.21) and a lower initial SpO2/FiO2 ratio (AOR 7.17; 95% CI 1.72–29.91) were significant independent risk factors for pulmonary fibrosis after COVID-19 pneumonia. An older age and a low initial SpO2/FiO2 ratio were crucial in predicting pulmonary fibrosis after COVID-19 pneumonia.

Renalase Challenges the Oxidative Stress and Fibroproliferative Response in COVID-19

The hallmark of the coronavirus disease 2019 (COVID-19) pathophysiology was reported to be an inappropriate and uncontrolled immune response, evidenced by activated macrophages, and a robust surge of proinflammatory cytokines, followed by the release of reactive oxygen species, that synergistically result in acute respiratory distress syndrome, fibroproliferative lung response, and possibly even death. For these reasons, all identified risk factors and pathophysiological processes of COVID-19, which are feasible for the prevention and treatment, should be addressed in a timely manner. Accordingly, the evolving anti-inflammatory and antifibrotic therapy for severe COVID-19 and hindering post-COVID-19 fibrosis development should be comprehensively investigated. Experimental evidence indicates that renalase, a novel amino-oxidase, derived from the kidneys, exhibits remarkable organ protection, robustly addressing the most powerful pathways of cell trauma: inflammation and oxidative stress, necrosis, and apoptosis. As demonstrated, systemic renalase administration also significantly alleviates experimentally induced organ fibrosis and prevents adverse remodeling. The recognition that renalase exerts cytoprotection via sirtuins activation, by raising their NAD⁺ levels, provides a “proof of principle” for renalase being a biologically impressive molecule that favors cell protection and survival and maybe involved in the pathogenesis of COVID-19. This premise supports the rationale that renalase's timely supplementation may prove valuable for pathologic conditions, such as cytokine storm and related acute respiratory distress syndrome. Therefore, the aim for this review is to acknowledge the scientific rationale for renalase employment in the experimental model of COVID-19, targeting the acute phase mechanisms and halting fibrosis progression, based on its proposed molecular pathways. Novel therapies for COVID-19 seek to exploit renalase's multiple and distinctive cytoprotective mechanisms; therefore, this review should be acknowledged as the thorough groundwork for subsequent research of renalase's employment in the experimental models of COVID-19.

Pathophysiology of Pulmonary Fibrosis in the Context of COVID-19 and Implications for Treatment: A Narrative Review

Pulmonary fibrosis (PF) is a feared outcome of many pulmonary diseases which results in a reduction in lung compliance and capacity. The development of PF is relatively rare, but it can occur secondary to viral pneumonia, especially COVID-19 infection. While COVID-19 infection and its complications are still under investigation, we can look at a similar outbreak in the past to gain better insight as to the expected long-term outcomes of COVID-19 patient lung function. In the current article, we review the literature relative to PF via PubMed. We also performed a literature search for COVID-related pathological changes in the lungs. Finally, the paper was reviewed and summarized based on the studies’ integrity, relative, or power calculations. This article provides a narrative review that endeavors to elucidate the current understanding of the pathophysiological mechanisms underlying PF and therapeutic strategies. We also discussed the potential for preventing progression to the fibrotic state within the context of the COVID-19 pandemic. With the massive scale of the COVID-19 pandemic, we expect there should more instances of PF due to COVID-19 infection. Patients who survive severe COVID-19 infection may suffer from a high incidence of PF.

Targeting autophagy regulation in NLRP3 inflammasome-mediated lung inflammation in COVID-19

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Emerging evidence indicates that the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is activated, which results in a cytokine storm at the late stage of COVID-19. Autophagy regulation is involved in the infection and replication of SARS-CoV-2 at the early stage and the inhibition of NLRP3 inflammasome-mediated lung inflammation at the late stage of COVID-19. Here, we discuss the autophagy regulation at different stages of COVID-19. Specifically, we highlight the therapeutic potential of autophagy activators in COVID-19 by inhibiting the NLRP3 inflammasome, thereby avoiding the cytokine storm. We hope this review provides enlightenment for the use of autophagy activators targeting the inhibition of the NLRP3 inflammasome, specifically the combinational therapy of autophagy modulators with the inhibitors of the NLRP3 inflammasome, antiviral drugs, or anti-inflammatory drugs in the fight against COVID-19.

Cellular and Molecular Mechanism of Pulmonary Fibrosis Post-COVID-19: Focus on Galectin-1, -3, -8, -9

Pulmonary fibrosis is a consequence of the pathological accumulation of extracellular matrix (ECM), which finally leads to lung scarring. Although the pulmonary fibrogenesis is almost known, the last two years of the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its post effects added new particularities which need to be explored. Many questions remain about how pulmonary fibrotic changes occur within the lungs of COVID-19 patients, and whether the changes will persist long term or are capable of resolving. This review brings together existing knowledge on both COVID-19 and pulmonary fibrosis, starting with the main key players in promoting pulmonary fibrosis, such as alveolar and endothelial cells, fibroblasts, lipofibroblasts, and macrophages. Further, we provide an overview of the main molecular mechanisms driving the fibrotic process in connection with Galactin-1, -3, -8, and -9, together with the currently approved and newly proposed clinical therapeutic solutions given for the treatment of fibrosis, based on their inhibition. The work underlines the particular pathways and processes that may be implicated in pulmonary fibrosis pathogenesis post-SARS-CoV-2 viral infection. The recent data suggest that galectin-1, -3, -8, and -9 could become valuable biomarkers for the diagnosis and prognosis of lung fibrosis post-COVID-19 and promising molecular targets for the development of new and original therapeutic tools to treat the disease.

Evaluation of pulmonary function and exercise capacity after COVID-19 pneumonia

BACKGROUND

Individuals who suffer from coronavirus disease 2019 (COVID-19) pneumonia may experience pulmonary dysfunction during the chronic period due to pulmonary parenchymal damage after acute disease.

OBJECTIVES

The aim of the present study was to evaluate the pulmonary function and exercise capacity of patients treated for COVID 19 pneumonia after discharge.

METHODS

In this cross-sectional study, 79 people who were hospitalized with COVID-19 between March and October 2020 were evaluated at least two months after discharge. A pulmonary function test and a six-minute walk test were administered to the individuals included in the study.

RESULTS

Restrictive-type disorder was detected in 21.5% of the individuals who were evaluated at least two months after discharge. The forced expiratory volume in the first second (FEV1) and the forced vital capacity (FVC) values of the pulmonary function tests were significantly lower in the individuals with severe/critical clinical disease compared to those with moderate disease (p = 0.004 and p = 0.001, respectively). Although the six-minute walk test (6MWT) distances were lower in the severe/critical group than in the moderate group, the difference was not statistically significant (p > 0.05).

CONCLUSIONS

Individuals who are discharged after hospitalization for COVID-19 pneumonia may develop a restrictive type of pulmonary dysfunction. Therefore, survivors of COVID-19 pneumonia should be evaluated for pulmonary function and rehabilitation needs and should be provided with treatment as required.

Upcoming and urgent challenges in critical care research based on COVID-19 pandemic experience

While the coronavirus disease 2019 (COVID-19) pandemic placed a heavy burden on healthcare systems worldwide, it also induced urgent mobilisation of research teams to develop treatments preventing or curing the disease and its consequences. It has, therefore, challenged critical care research to rapidly focus on specific fields while forcing critical care physicians to make difficult ethical decisions. This narrative review aims to summarise critical care research -from organisation to research fields- in this pandemic setting and to highlight opportunities to improve research efficiency in the future, based on what is learned from COVID-19. This pressure on research revealed, i.e., i/ the need to harmonise regulatory processes between countries, allowing simplified organisation of international research networks to improve their efficiency in answering large-scale questions; ii/ the importance of developing translational research from which therapeutic innovations can emerge; iii/ the need for improved triage and predictive scores to rationalise admission to the intensive care unit. In this context, key areas for future critical care research and better pandemic preparedness are artificial intelligence applied to healthcare, characterisation of long-term symptoms, and ethical considerations. Such collaborative research efforts should involve groups from both high and low-to-middle income countries to propose worldwide solutions. As a conclusion, stress tests on healthcare organisations should be viewed as opportunities to design new research frameworks and strategies. Worldwide availability of research networks ready to operate is essential to be prepared for next pandemics. Importantly, researchers and physicians should prioritise realistic and ethical goals for both clinical care and research.

Residual lesions on chest-Xray after SARS-CoV-2 pneumonia: Identification of risk factors

Introduction

COVID-19 pneumonia is the most frequent clinical manifestation of this disease, and its long-term sequelae and possible progression to pulmonary fibrosis are still unknown. The aim of this study is a mid-term review of the sequelae on plain chest radiography (CXR) in patients with a previous diagnosis of COVID-19 pneumonia.

Patients and methods

Retrospective review of patients with a diagnosis of COVID-19 pneumonia, assessing the persistence of residual lesions in the control CXR and analysing their possible relationship with epidemiological factors, risk factors, treatments received and initial radiological patterns.

Results

A total of 143 patients (52 women and 91 men) were analysed. Mean age was 64 years. Radiological complete resolution (CR) was observed in 104 (73%) and partial resolution (PR) in 39 (27%). Of the risk factors only age was significantly related to persistence of residual lesions (OR 1.06 CI95% (1.02,1.10). In relation to treatments, significant differences were found with tocilizumab and glucocorticoids, where treated patients had a higher risk of residual lesions (OR 2.44 (1.03,5.80) and 3.05(1.43,6.51) respectively. In the analysis of radiological patterns, significant differences were observed in patients with peripheral condensations in the acute course and a pattern of early radiological worsening. A clinical-radiological dissociation was evident: 83% of patients with residual lesions had no respiratory symptoms.

Discussion

COVID19 pneumonias may have a slower radiological resolution in older patients with certain initial radiological patterns, but the development of pulmonary fibrosis in these patients is still questionable.

Bioavailability Enhancement of Cepharanthine via Pulmonary Administration in Rats and Its Therapeutic Potential for Pulmonary Fibrosis Associated with COVID-19 Infection

Cepharanthine (CEP) has excellent anti-SARS-CoV-2 properties, indicating its favorable potential for COVID-19 treatment. However, its application is challenged by its poor dissolubility and oral bioavailability. The present study aimed to improve the bioavailability of CEP by optimizing its solubility and through a pulmonary delivery method, which improved its bioavailability by five times when compared to that through the oral delivery method (68.07% vs. 13.15%). An ultra-performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) method for quantification of CEP in rat plasma was developed and validated to support the bioavailability and pharmacokinetic studies. In addition, pulmonary fibrosis was recognized as a sequela of COVID-19 infection, warranting further evaluation of the therapeutic potential of CEP on a rat lung fibrosis model. The antifibrotic effect was assessed by analysis of lung index and histopathological examination, detection of transforming growth factor (TGF)-β1, interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and hydroxyproline level in serum or lung tissues. Our data demonstrated that CEP could significantly alleviate bleomycin (BLM)-induced collagen accumulation and inflammation, thereby exerting protective effects against pulmonary fibrosis. Our results provide evidence supporting the hypothesis that pulmonary delivery CEP may be a promising therapy for pulmonary fibrosis associated with COVID-19 infection.

COVID-19 and Lung Cancer: A Comprehensive Overview from Outbreak to Recovery

Lung cancer patients have been associated with an increased risk of COVID-19 infection, pulmonary complications, and worse survival outcomes compared to the general population. The world's leading professional organizations provided new recommendations for the diagnosis, treatment, and follow-up of lung cancer patients during the pandemic as a guide for prioritizing cancer care issues. Telemedicine was preferred for non-urgent consultations, and screening programs were temporarily suspended, leading to possible diagnostic delays along with an estimated increase in cause-specific mortality. A vaccine campaign has recently emerged as the main weapon to fight the COVID-19 pandemic, inverting this negative trend. This work aims to provide a comprehensive overview of the epidemiology and immune-pathophysiology of SARS-CoV-2 infection in cancer patients, highlighting the most relevant changes in the clinical management of lung cancer patients during the pandemic.

Post-COVID-19 Pulmonary Fibrosis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions worldwide with a high mortality rate due to a lack of definitive treatment. Despite having a wide range of clinical features, acute respiratory distress syndrome (ARDS) has emerged as the primary cause of mortality in these patients. Risk factors and comorbidities like advanced age with limited lung function, pre-existing diabetes, hypertension, cardiovascular diseases, and obesity have increased the risk for severe COVID-19 infection. Rise in inflammatory markers like transforming growth factor β (TGF-β), interleukin-6 (IL-6), and expression of matrix metalloproteinase 1 and 7 (MMP-1, MMP-7), along with collagen deposition at the site of lung injury, results in extensive lung scarring and fibrosis. Anti-fibrotic drugs, such as Pirfenidone and Nintedanib, have emerged as potential treatment options for post-COVID-19 pulmonary fibrosis. A lung transplant might be the only life-saving treatment. Despite the current advances in the management of COVID-19, there is still a considerable knowledge gap in the management of long-term sequelae in such patients, especially concerning pulmonary fibrosis. Follow up on the current clinical trials and research to test the efficacy of various anti-inflammatory drugs is needed to prevent long-term sequelae early mortality in these patients.

Anti-inflammatory effects of GLP-1 in patients with COVID-19

INTRODUCTION

Understanding the pathogenesis and risk factors to control the coronavirus disease 2019 (COVID-19) is necessary. Due to the importance of the inflammatory pathways in the pathogenesis of COVID-19 patients, evaluating the effects of anti-inflammatory medications is important. Glucagon-like peptide 1 receptor agonist (GLP-1 RA) is awell-known glucose-lowering agent with anti-inflammatory effects.

AREAS COVERED

Resources were extracted from the PubMed database, using keywords such as glucagon-like peptide-1, GLP-1 RA, SARS-CoV-2, COVID-19, inflammation, in April2021. In this review, the effects of GLP-1RA in reducing inflammation and modifying risk factors of COVID-19 severe complications are discussed. However, GLP-1 is degraded by DPP-4 with aplasma half-life of about 2-5 minutes, which makes it difficult to measure GLP-1 plasma level in clinical settings.

EXPERT OPINION

Since no definitive treatment is available for COVID-19 so far, determining promising targets to design and/or repurpose effective medications is necessary.

Evolution of COVID-19 Pulmonary Fibrosis-Like Residual Changes Over Time - Longitudinal Chest CT up to 9 Months After Disease Onset: a Single-Center Case Series

The aim of the study was to evaluate the temporal evolution of fibrotic-like pulmonary interstitial abnormalities secondary to Sars-CoV-2 virus (COVID-19) pneumonia detected on chest-CTs of patients hospitalized for COVID-19 infection. We retrospectively reviewed chest-CTs obtained up to 9 months after disease onset in a group of patients with COVID-19 pneumonia and CT features suggestive of lung fibrosis at the first follow-up after hospital discharge. We observed a complete and unexpected resolution of all interstitial abnormalities, including reticulations and bronchial dilatation, in a period of about 6-9 months after discharge. Interstitial fibrotic-like changes detectable in the first months after COVID-19 pneumonia could be slowly or very slowly resolving but still completely reversible and probably secondary to an organizing pneumonia reaction.

Post COVID-19 pneumo-hematocele: clinical presentation and treatment pathway

Objectives

The appearance of characteristic pulmonary lesions has been noted after COVID-19, being described as post-COVID-19 pneumo-hematocele. The aim of this study is to describe the clinical, histopathologic, and imaging features of pneumo-hematocele and to suggest a treatment algorithm for these patients.

Methods

A retrospective study was performed in patients admitted with a diagnosis of SARS-CoV2 infection from March 2020 to September 2021 who presented a pneumo-hematocele on imaging studies. Clinical and demographic variables were recorded, and CT scans were analyzed. A secondary analysis was performed to estimate the risk provided by the pneumo-hematocele diameter of developing pneumothorax.

Results

37 patients were diagnosed with pneumo-hematoceles, 97.3% were males with a median age of 41 ± 13 years and 51% were smokers. The mean diameter of the pneumatocele was 6.3 ± 2.8 cm; they were more common on the subpleural surface and in the inferior lobe. Thirty patients had ruptured pneumo-hematoceles and developed pneumothorax (81.1%); a total of 26 patients required surgery (70.3%). Lesions measuring 5 cm had a high risk of rupture (OR 6.8, CI 95% 1.1–42); those measuring 3 cm were prone to this complication. For each centimeter that the pneumo-hematocele diameter increases, the OR for rupture increases 1.5.

Conclusions

It appears that post-COVID-19 pneumo-hematocele occurs secondary to encapsulation of blood accumulation inside the lung, as a result of micro-capillary bleeding, with partial reabsorption of blood and subsequent air filling. We recommend surgery for patients with pneumo-hematoceles of 5 cm and those with persistent lesions of 3 cm.

Trial registration

Clinical Trial Registration: NCT05067881.

The Interaction Between Pulmonary Fibrosis and COVID-19 and the Application of Related Anti-Fibrotic Drugs

COVID-19 is a highly contagious respiratory disease, which mainly affects the lungs. Critically ill patients are easily complicated by cytokine storms, acute respiratory distress syndrome (ARDS), and respiratory failure, which seriously threaten their lives. Pulmonary fibrosis (PF) is a common interstitial lung disease, and its pathogenesis may involve the participation of a variety of immune cells and inflammatory factors. Current studies have shown that patients with COVID-19 may be complicated by pulmonary fibrosis, and patients with pulmonary fibrosis may also be at higher risk of contracting COVID-19 than healthy people. Pulmonary fibrosis is an important risk factor leading to the aggravation of COVID-19 disease. COVID-19 complicated by cytokine storm and ARDS mechanism pathways are similar to the pathogenesis of pulmonary fibrosis. The potential interaction between pulmonary fibrosis and COVID-19 can cause acute exacerbation of the patient's condition, but the potential mechanism between the two has not been fully elucidated. Most of the drug treatment programs for COVID-19-related pulmonary fibrosis are currently formulated about the relevant guidelines for idiopathic pulmonary fibrosis (IPF), and there is no clear drug treatment program recommendation. This article aims to summarize the relevant mechanism pathways of COVID-19 and pulmonary fibrosis, explore the interrelationships and possible mechanisms, and discuss the value and risks of existing and potential COVID-19-related pulmonary fibrosis treatment drugs, to provide reference for anti-fibrosis treatment for patients.

Six-month follow-up of functional status in discharged patients with coronavirus disease 2019

Background

The long-term functional outcome of discharged patients with coronavirus disease 2019 (COVID-19) remains unresolved. We aimed to describe a 6-month follow-up of functional status of COVID-19 survivors.

Methods

We reviewed the data of COVID-19 patients who had been consecutively admitted to the Tumor Center of Union Hospital (Wuhan, China) between 15 February and 14 March 2020. We quantified a 6-month functional outcome reflecting symptoms and disability in COVID-19 survivors using a post-COVID-19 functional status scale ranging from 0 to 4 (PCFS). We examined the risk factors for the incomplete functional status defined as a PCFS > 0 at a 6-month follow-up after discharge.

Results

We included a total of 95 COVID-19 survivors with a median age of 62 (IQR 53–69) who had a complete functional status (PCFS grade 0) at baseline in this retrospective observational study. At 6-month follow-up, 67 (70.5%) patients had a complete functional outcome (grade 0), 9 (9.5%) had a negligible limited function (grade 1), 12 (12.6%) had a mild limited function (grade 2), 7 (7.4%) had moderate limited function (grade 3). Univariable logistic regression analysis showed a significant association between the onset symptoms of muscle or joint pain and an increased risk of incomplete function (unadjusted OR 4.06, 95% CI 1.33–12.37). This association remained after adjustment for age and admission delay (adjusted OR 3.39, 95% CI 1.06–10.81, p = 0.039).

Conclusions

A small proportion of discharged COVID-19 patients may have an incomplete functional outcome at a 6-month follow-up; intervention strategies are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06970-3.

Recovery solutions for ecotourism centers during the Covid-19 pandemic: Utilizing Fuzzy DEMATEL and Fuzzy VIKOR methods

Obviously, the Covid-19 pandemic has huge impact on most businesses and has caused serious and countless problems for them. Therefore, providing solutions for affected businesses to recover and improve their activities during pandemic times is inevitable. In this regard, ecotourism centers are one of the businesses that went through this problem and have faced significant dilemmas in their activities. Also, reportedly, there is no related research focusing on the recovery approaches to address these obstacles relating to these kinds of businesses during the pandemic. Therefore, all of these exhorted us to do the current research. In this paper, some practical and useful action plans for ecotourism centers are firstly developed to help these businesses. To obtain the action plans, some brainstorming sessions were held consisting of tourism experts, university professors, managers, owners, and some personnel of eco-tourism centers. In order to prioritize the defined action plans, four criteria are considered. Firstly, we compute the weights of the considered criteria by the Fuzzy DEMATEL and then they are prioritized using the Fuzzy VIKOR. The findings of the current study divulge that the AP2 "Standardization of the centers" and AP3 "Estimating demand number and increasing the capacity" and AP7 "Identifying other natural tourist attractions of the region" have the highest and lowest priority to be implemented.

Emerging spectrum of post-COVID-19 syndrome

'Post-COVID-19 syndrome' refers to symptoms in the convalescent phase following initial COVID-19 infection. This term encompasses a wide array of presentation involving lungs, heart and the neuromuscular system. Pulmonary manifestations include post-COVID-19 fibrosis, which is akin to post acute respiratory distress syndrome fibrosis and may reflect the permanent damage to the lungs following an initial bout of infection. Cardiovascular system is often involved, and the presentation can be in terms of acute coronary syndrome, myocarditis and heart failure. Clinical manifestations are often varied and non-specific, which entails a detailed workup and a multidisciplinary approach. Post-COVID-19 syndrome adds to the overall disease morbidity and leads to a prolonged hospital stay, greater healthcare utilisation and loss of productivity marring the country's dwindling economy. Thus, it is imperative that post-COVID-19 syndrome be prevented and identified early followed by a prompt treatment.

Involvement of the ACE2/Ang-(1-7)/MasR Axis in Pulmonary Fibrosis: Implications for COVID-19

Pulmonary fibrosis is a chronic, fibrotic lung disease affecting 3 million people worldwide. The ACE2/Ang-(1–7)/MasR axis is of interest in pulmonary fibrosis due to evidence of its anti-fibrotic action. Current scientific evidence supports that inhibition of ACE2 causes enhanced fibrosis. ACE2 is also the primary receptor that facilitates the entry of SARS-CoV-2, the virus responsible for the current COVID-19 pandemic. COVID-19 is associated with a myriad of symptoms ranging from asymptomatic to severe pneumonia and acute respiratory distress syndrome (ARDS) leading to respiratory failure, mechanical ventilation, and often death. One of the potential complications in people who recover from COVID-19 is pulmonary fibrosis. Cigarette smoking is a risk factor for fibrotic lung diseases, including the idiopathic form of this disease (idiopathic pulmonary fibrosis), which has a prevalence of 41% to 83%. Cigarette smoke increases the expression of pulmonary ACE2 and is thought to alter susceptibility to COVID-19. Cannabis is another popular combustible product that shares some similarities with cigarette smoke, however, cannabis contains cannabinoids that may reduce inflammation and/or ACE2 levels. The role of cannabis smoke in the pathogenesis of pulmonary fibrosis remains unknown. This review aimed to characterize the ACE2-Ang-(1–7)-MasR Axis in the context of pulmonary fibrosis with an emphasis on risk factors, including the SARS-CoV-2 virus and exposure to environmental toxicants. In the context of the pandemic, there is a dire need for an understanding of pulmonary fibrotic events. More research is needed to understand the interplay between ACE2, pulmonary fibrosis, and susceptibility to coronavirus infection.

Alveolar Regeneration in COVID-19 Patients: A Network Perspective

A viral infection involves entry and replication of viral nucleic acid in a host organism, subsequently leading to biochemical and structural alterations in the host cell. In the case of SARS-CoV-2 viral infection, over-activation of the host immune system may lead to lung damage. Albeit the regeneration and fibrotic repair processes being the two protective host responses, prolonged injury may lead to excessive fibrosis, a pathological state that can result in lung collapse. In this review, we discuss regeneration and fibrosis processes in response to SARS-CoV-2 and provide our viewpoint on the triggering of alveolar regeneration in coronavirus disease 2019 (COVID-19) patients.

Interstitial Lung Disease at High Resolution CT after SARS-CoV-2-Related Acute Respiratory Distress Syndrome According to Pulmonary Segmental Anatomy

Background: The purpose of this study was to evaluate High-Resolution CT (HRCT) findings in SARS-CoV-2-related ARDS survivors treated with prolonged low-dose methylprednisolone after hospital discharge. Methods: A total of 44 consecutive patients (M: 32, F: 12, average age: 64), hospitalised in our department from April to September 2020 for SARS-CoV-2-related ARDS, who had a postdischarge CT scan, were enrolled into this retrospective study. We reviewed the electronic medical charts to collect laboratory, clinical, and demographic data. The CT findings were evaluated and classified according to lung segmental distribution. The imaging findings were correlated with spirometry results and included ground glass opacities (GGOs), consolidations, reticulations, bronchiectasis/bronchiolectasis, linear bands, and loss of pulmonary volume. Results: Alterations in the pulmonary parenchyma were observed in 97.7% of patients at HRCT (median time lapse between ARDS diagnosis and HRCT: 2.8 months, range 0.9 to 6.7). The most common findings were linear bands (84%), followed by GGOs (75%), reticulations (34%), bronchiolectasis (32%), consolidations (30%), bronchiectasis (30%) and volume loss (25%). They had a symmetric distribution, and both lower lobes were the most affected areas. Conclusions: A reticular pattern with a posterior distribution was observed 3 months after discharge from severe COVID-19 pneumonia, and this differs from previously described postCOVID-19 fibrotic-like changes. We hypothesized that the systematic use of prolonged low-dose of corticosteroid could be the main reason of this different CT scan appearance.

Pulmonary fibrosis and its related factors in discharged patients with new corona virus pneumonia: a cohort study

BACKGROUND

Thousands of Coronavirus Disease 2019 (COVID-19) patients have been discharged from hospitals Persistent follow-up studies are required to evaluate the prevalence of post-COVID-19 fibrosis.

METHODS

This study involves 462 laboratory-confirmed patients with COVID-19 who were admitted to Shenzhen Third People's Hospital from January 11, 2020 to April 26, 2020. A total of 457 patients underwent thin-section chest CT scans during the hospitalization or after discharge to identify the pulmonary lesion. A total of 287 patients were followed up from 90 to 150 days after the onset of the disease, and lung function tests were conducted about three months after the onset. The risk factors affecting the persistence of pulmonary fibrosis were identified through regression analysis and the prediction model of the persistence of pulmonary fibrosis was established.

RESULTS

Parenchymal bands, irregular interfaces, reticulation and traction bronchiectasis were the most common CT features in all COVID-19 patients. During the 0-30, 31-60, 61-90, 91-120 and > 120 days after onset, 86.87%, 74.40%, 79.56%, 68.12% and 62.03% patients developed with pulmonary fibrosis and 4.53%, 19.61%, 18.02%, 38.30% and 48.98% patients reversed pulmonary fibrosis, respectively. It was observed that Age, BMI, Fever, and Highest PCT were predictive factors for sustaining fibrosis even after 90 days from onset. A predictive model of the persistence with pulmonary fibrosis was developed based-on the Logistic Regression method with an accuracy, PPV, NPV, Sensitivity and Specificity of the model of 76%, 71%, 79%, 67%, and 82%, respectively. More than half of the COVID-19 patients revealed abnormal conditions in lung function after 90 days from onset, and the ratio of abnormal lung function did not differ on a statistically significant level between the fibrotic and non-fibrotic groups.

CONCLUSIONS

Persistent pulmonary fibrosis was more likely to develop in patients with older age, higher BMI, severe/critical condition, fever, a longer viral clearance time, pre-existing disease and delayed hospitalization. Fibrosis developed in COVID-19 patients could be reversed in about a third of the patients after 120 days from onset. The pulmonary function of less than half of COVID-19 patients could turn to normal condition after three months from onset. An effective prediction model with an average area under the curve (AUC) of 0.84 was established to predict the persistence of pulmonary fibrosis in COVID-19 patients for early diagnosis.

What's going on following acute covid-19? Clinical characteristics of patients in an out-patient rehabilitation program

BACKGROUND

Coronavirus disease 2019 (COVID-19) patients present long-lasting physical and neuropsychological impairment, which may require rehabilitation.

OBJECTIVES

The current cross-sectional study characterizes post COVID-19 sequelae and persistent symptoms in patients in an outpatient rehabilitation program.

METHODS

Thirty patients [16 post-ICU and 14 non-ICU; median age = 54(43.8-62) years; 19 men] presenting sequelae and/or persistent symptoms (>3 months after acute COVID-19) were selected of 41 patients referred for neurorehabilitation. Patients underwent physical, neuropsychological and respiratory evaluation and assessment of impact of fatigue and quality of life.

RESULTS

The main reasons for referral to rehabilitation were: fatigue (86.6%), dyspnea (66.7%), subjective cognitive impairment (46.7%) and neurological sequelae (33.3%). Post-ICU patient presented sequelae of critical illness myopathy and polyneuropathy, stroke and encephalopathy and lower forced vital capacity compared to non-ICU patients. Cognitive impairment was found in 63.3% of patients, with a similar profile in both sub-groups. Increased physical fatigue, anxiety and depression and low quality of life were prevalent irrespective of acute COVID-19 severity.

CONCLUSIONS

The variability of post COVID-19 physical and neuropsychological impairment requires a complex screening process both in ICU and non-ICU patients. The high impact of persistent symptoms on daily life activities and quality of life, regardless of acute infection severity, indicate need for rehabilitation.

Broad auto-reactive IgM responses are common in critically ill patients, including those with COVID-19

The pathogenesis of severe coronavirus disease 2019 (COVID-19) remains poorly understood. While several studies suggest that immune dysregulation plays a central role, the key mediators of this process are yet to be defined. Here, we demonstrate that plasma from a high proportion (93%) of critically ill COVID-19 patients, but not healthy controls, contains broadly auto-reactive immunoglobulin M (IgM) and less frequently auto-reactive IgG or IgA. Importantly, these auto-IgMs preferentially recognize primary human lung cells in vitro, including pulmonary endothelial and epithelial cells. By using a combination of flow cytometry, analytical proteome microarray technology, and lactose dehydrogenase (LDH)-release cytotoxicity assays, we identify high-affinity, complement-fixing, auto-reactive IgM directed against 260 candidate autoantigens, including numerous molecules preferentially expressed on the cellular membranes of pulmonary, vascular, gastrointestinal, and renal tissues. These findings suggest that broad IgM-mediated autoimmune reactivity may be involved in the pathogenesis of severe COVID-19, thereby identifying a potential target for therapeutic interventions.

Residual lesions on chest-Xray after SARS-CoV-2 pneumonia: Identification of risk factors

Introducción

La neumonía por la enfermedad por el coronavirus 19 (COVID-19) es la manifestación clínica más frecuente de esta afección, siendo aún desconocidas sus secuelas a largo plazo y la posible evolución a fibrosis pulmonar. El objetivo de este trabajo es una revisión a medio plazo de las secuelas en la radiografía simple de tórax (RxTx) de pacientes con diagnóstico previo de neumonía por la COVID-19.

Pacientes y métodos

Revisión retrospectiva de pacientes con diagnóstico de neumonía por la COVID-19 en la que hemos valorado la persistencia de lesiones residuales en la RxTx de control y hemos analizado su posible relación con factores epidemiológicos, factores de riesgo, tratamientos recibidos y patrones radiológicos iniciales.

Resultados

Se analizan 143 pacientes (52 mujeres y 91 hombres), con una edad media de 64 años. Se objetivó una resolución completa radiológica en 104 (73%) y resolución parcial en 39 (27%). De los factores de riesgo solo la edad se relacionó significativamente con la persistencia de lesiones residuales (OR: 1,06; IC 95%: 1,02-1,10). En relación con los tratamientos se encontraron diferencias significativas con el tocilizumab y los glucocorticoides, donde los pacientes tratados tenían más riesgo de lesiones residuales (OR 2,44 [1,03; 5,80] y 3,05 [1;43; 6,51]) respectivamente. En el análisis de los patrones radiológicos se observaron diferencias significativas en los pacientes que presentaban en la evolución aguda condensaciones periféricas y un patrón de empeoramiento radiológico precoz. Se evidenció una disociación clínico-radiológica: de los pacientes con lesiones residuales un 83% no tenía síntomas respiratorios.

Discusión

Las neumonías por la COVID-19 pueden tener una resolución radiológica más lenta en pacientes de mayor edad y con ciertos patrones radiológicos iniciales, pero el desarrollo de fibrosis pulmonar en estos pacientes es un hecho aún cuestionable.

Discrepancies in the clinical and radiological profiles of COVID-19: A case-based discussion and review of literature

The current gold standard for the diagnosis of coronavirus disease-19 (COVID-19) is a positive reverse transcriptase polymerase chain reaction (RT-PCR) test, on the background of clinical suspicion. However, RT-PCR has its limitations; this includes issues of low sensitivity, sampling errors and appropriate timing of specimen collection. As pulmonary involvement is the most common manifestation of severe COVID-19, early and appropriate lung imaging is important to aid diagnosis. However, gross discrepancies can occur between the clinical and imaging findings in patients with COVID-19, which can mislead clinicians in their decision making. Although chest X-ray (CXR) has a low sensitivity for the diagnosis of COVID-19 associated lung disease, especially in the earlier stages, a positive CXR increases the pre-test probability of COVID-19. CXR scoring systems have shown to be useful, such as the COVID-19 opacification rating score which helps to predict the need of tracheal intubation. Furthermore, artificial intelligence-based algorithms have also shown promise in differentiating COVID-19 pneumonia on CXR from other lung diseases. Although costlier than CXR, unenhanced computed tomographic (CT) chest scans have a higher sensitivity, but lesser specificity compared to RT-PCR for the diagnosis of COVID-19 pneumonia. A semi-quantitative CT scoring system has been shown to predict short-term mortality. The routine use of CT pulmonary angiography as a first-line imaging modality in patients with suspected COVID-19 is not justifiable due to the risk of contrast nephropathy. Scoring systems similar to those pioneered in CXR and CT can be used to effectively plan and manage hospital resources such as ventilators. Lung ultrasound is useful in the assessment of critically ill COVID-19 patients in the hands of an experienced operator. Moreover, it is a convenient tool to monitor disease progression, as it is cheap, non-invasive, easily accessible and easy to sterilise. Newer lung imaging modalities such as magnetic resonance imaging (MRI) for safe imaging among children, adolescents and pregnant women are rapidly evolving. Imaging modalities are also essential for evaluating the extra-pulmonary manifestations of COVID-19: these include cranial imaging with CT or MRI; cardiac imaging with ultrasonography (US), CT and MRI; and abdominal imaging with US or CT. This review critically analyses the utility of each imaging modality to empower clinicians to use them appropriately in the management of patients with COVID-19 infection.