Evidence for a thromboembolic pathogenesis of lung cavitations in severely ill COVID-19 patients

COVID-19 associated lung cavitary lesions: A case series

Background

Our study discusses the probable etiologies and characteristics of pulmonary cavities in post-COVID-19 patients. A pulmonary cavity is a late complication of the disease, yet it has led to multiple referrals to our tertiary hospital in Tehran, Iran.

Methods

We conducted a retrospective case-series study on 20 patients who were admitted to our center between April 2020 and September 2021. They were all diagnosed with COVID-19 and concomitantly developed pulmonary cavities. We assessed their electronic medical records in 2021 and compared their characteristics with other studies based on the available literature.

Result

Of the 20 patients with cavities, 12 (60%) had been diagnosed with prior COVID-19, and 9 (45%) had type 2 diabetes mellitus. 9 patients (45%) had bacterial superinfections while 4 (44%) had fungal infections. All patients received corticosteroids, but only 4 (20%) were additionally administered Tocilizumab.

Conclusion

COVID-19 patients can develop pulmonary cavities during recovery; however, this infrequent radiologic finding depends on specific risk factors.

[Risk factors of pulmonary cavitation in COVID-19 pneumonia]

OBJECTIVE

To identify the risk factors of pulmonary cavitation in COVID-19 pneumonia.

MATERIAL AND METHODS

A retrospective study included 8261 patients with COVID-19 between April 2020 and March 2022. Inclusion criteria: age >18 years, COVID-19 confirmed by polymerase chain reaction. Two cohorts of patients were formed: 40 patients with pulmonary cavitation and 40 patients without these lesions. Both groups were comparable in age, lung lesion volume and oxygenation. Sex, age, length of hospital-stay, CT grade of lung lesion, comorbidities, treatment, respiratory support, oxygen saturation and in-hospital outcomes were evaluated. The highest lung lesion volume during hospitalization was assessed. CT was performed upon admission and approximately every 5 days for evaluation of treatment. Statistical analysis was performed using the IBM SPSS Statistics software (IBM Corporation, USA).

RESULTS

Patients with pulmonary cavitation significantly differed in age, SpO2, lung lesion volume, more common non-invasive ventilation and prolonged hospital-stay. Cardiovascular diseases were more common in both groups. Univariate logistic regression analysis revealed age, cardiovascular diseases, CT-based severity of lung damage, absence of biological therapy and non-invasive ventilation as risk factors of pulmonary cavitation. According to multivariate logistic regression analysis, these predictors were CT-based severity of lung damage and absence of biological therapy. Univariate logistic regression analysis showed that pulmonary cavitation had no significant effect on mortality (OR=2.613, 95% CI: 0.732-9.322, p=0.139).

CONCLUSION

The risk of pulmonary cavitation in COVID-19 is directly related to advanced lung damage and untimely or absent biological therapy with IL-6 inhibitors. Pulmonary cavitation in COVID-19 is not a typical manifestation of disease and can be caused by some factors: fungal infection, secondary bacterial infection, tuberculosis and pulmonary infarction. Further study of this problem is required to develop diagnostic algorithms and treatment tactics.

[Cavitary lung lesions in COVID-19 associated pneumonia: a single-center study of 40 cases]

OBJECTIVE

To demonstrate clinical features and outcomes in patients with cavitary lung lesions and COVID-19 associated pneumonia.

MATERIAL AND METHODS

A retrospective analysis of electronic medical records of 8261 patients with COVID-19 was performed. We selected 40 patients meeting the inclusion criteria. Sex, age, hospital-stay, lung tissue lesion, comorbidities, treatment, methods of respiratory support, complications and outcomes were evaluated.

RESULTS

Cavitary lung lesions were more common in men (67.5%). Age of patients ranged from 28 to 88 (mean 64.9±13.7) years. Hospital-stay in patients with cavitary lung lesions was 9-58 (median 27.5) days. There were 18 complications in 14 (35%) patients. Pneumothorax, isolated pneumomediastinum, pleural empyema, hemoptysis and sigmoid colon perforation were considered as complications of cavitary lung lesions. Nine (22.5%) patients died (5 of them with complications). Three patients died after surgical treatment. Long-term results were analyzed in 8 (25.8%) patients. Patients were followed-up for 3 months after discharge. Shrinkage of lesions occurred after 7-60 (mean 23) days, and complete obliteration of cavities came after 32 (range 14-90) days.

CONCLUSION

Cavitary lung lesions are a rare complication of COVID-19 pneumonia. There was no significant correlation of complications with age, sex, therapy, volume of lung lesions and non-invasive ventilation (NIV). Despite more common fatal outcomes in older patients undergoing NIV, the last one was prescribed exclusively due to disease progression and respiratory failure. Further research on this problem is necessary to identify possible risk factors of cavitary lung lesions.

Thromboinflammation: Dynamik physiologischer und pathologischer Wechselwirkungen von Entzündung und Koagulation

Das konzertante Zusammenspiel zwischen endothelialer Dysfuntion, aktivierten Thrombozyten und anderen Immunzellen sowie simultaner Komplementaktivierung führt zur Aktivierung und gegenseitigen Verstärkung sowohl der Immunantwort als auch der Gerinnungskaskade. Durch die unkontrollierte Fortdauer dieser physiologischen Mechanismen kann der pathologische Prozess der Thromboinflammation induziert werden. In dieser Übersichtsarbeit fassen wir grundlegende Mechanismen zusammen, die zur Thromboinflammation als ein Auslöser von venösen Thromboembolien führen.

Co-Infections and Superinfections in COVID-19 Critically Ill Patients Are Associated with CT Imaging Abnormalities and the Worst Outcomes

Background: Bacterial and fungal co-infections and superinfections have a critical role in the outcome of the COVID-19 patients admitted to the Intensive Care Unit (ICU). Methods: The present study is a retrospective analysis of 95 patients admitted to the ICU for COVID-19-related ARDS during the first (February−May 2020) and second waves of the pandemic (October 2020−January 2021). Demographic and clinical data, CT imaging features, and pulmonary and extra-pulmonary complications were recorded, as well as the temporal evolution of CT findings when more than one scan was available. The presence of co-infections and superinfections was registered, reporting the culprit pathogens and the specimen type for culture. A comparison between patients with and without bacterial and/or co-infections/superinfections was performed. Results: Sixty-three patients (66.3%) developed at least one confirmed co-infection/superinfection, with 52 (82.5%) developing pneumonia and 43 (68.3%) bloodstream infection. Gram-negative bacteria were the most common co-pathogens identified and Aspergillus spp. was the most frequent pulmonary microorganism. Consolidations, cavitations, and bronchiectasis were significantly associated with the presence of co-infections/superinfections (p = 0.009, p = 0.010 and p = 0.009, respectively); when considering only patients with pulmonary co-pathogens, only consolidations remained statistically significative (p = 0.004). Invasive pulmonary aspergillosis was significantly associated with the presence of cavitations and bronchiectasis (p < 0.001). Patients with co-infections/superinfections presented a significantly higher mortality rate compared to patients with COVID-19 only (52.4% vs. 25%, p = 0.016). Conclusions: Bacterial and fungal co-infections and superinfections are frequent in COVID-19 patients admitted to ICU and are associated with worse outcomes. Imaging plays an important role in monitoring critically ill COVID-19 patients and may help detect these complications, suggesting further laboratory investigations.

Acinetobacter: A Rare Cause of Rapid Development of Cavitary Lung Lesion Following COVID-19 Infection

Cavitary lesions of the lungs are a very frequent picture found in clinical practices resulting from a wide range of pathological processes with variable duration of formation depending on infectious pathogens. Common organisms causing cavitary lesions are Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae, typical and atypical Mycobacterium, and Aspergillus. Herein, we are presenting a case that developed cavitary lesions in both lungs colonizing Acinetobacter, a rare causative agent, within less than two months of a positive coronavirus disease 2019 (COVID-19) infection.

Study to assess aetiology, clinical and imaging characteristics of post Covid-19 pulmonary cavitation

Objective

The aim of this study is to determine the aetiology and characteristics of pulmonary cavities that developed in patients recovering from COVID-19 infection.

Materials and Methods

Between 1st May 2021 and 30st June 2021, we found 9 post COVID-19 patients who developed lung cavities on chest radiograph or CT during the follow-up period. These patients underwent routine blood examination, sputum examination and bronchoscopy to identify the aetiologies for the lung cavities.

Results

The duration from the onset of COVID-19 symptoms to the detection of lung cavities ranged from 18 to 82 days. Out of 7 patients, 4 had recovered from severe COVID-19 disease, 2 from moderate and 1 from mild disease. After the diagnostic workup, 5 patients were found to have COVID-19 associated pulmonary aspergillosis (CAPA), 1 patient with mucormycosis and 1 patient with mycobacterium infection. Two patients with CAPA also had bacterial infection; sputum culture from both these patients grew Klebsiella pneumonia.

Conclusion

Lung cavities can develop in patients recovering from COVID-19 pneumonia and fungal infection is the most common cause for such cavities.

Automated Quantitative Lung CT Improves Prognostication in Non-ICU COVID-19 Patients beyond Conventional Biomarkers of Disease

(1) Background: COVID-19 continues to represent a worrying pandemic. Despite the high percentage of non-severe illness, a wide clinical variability is often reported in real-world practice. Accurate predictors of disease aggressiveness, however, are still lacking. The purpose of our study was to evaluate the impact of quantitative analysis of lung computed tomography (CT) on non-intensive care unit (ICU) COVID-19 patients' prognostication; (2) Methods: Our historical prospective study included fifty-five COVID-19 patients consecutively submitted to unenhanced lung CT. Primary outcomes were recorded during hospitalization, including composite ICU admission for the need of mechanical ventilation and/or death occurrence. CT examinations were retrospectively evaluated to automatically calculate differently aerated lung tissues (i.e., overinflated, well-aerated, poorly aerated, and non-aerated tissue). Scores based on the percentage of lung weight and volume were also calculated; (3) Results: Patients who reported disease progression showed lower total lung volume. Inflammatory indices correlated with indices of respiratory failure and high-density areas. Moreover, non-aerated and poorly aerated lung tissue resulted significantly higher in patients with disease progression. Notably, non-aerated lung tissue was independently associated with disease progression (HR: 1.02; p-value: 0.046). When different predictive models including clinical, laboratoristic, and CT findings were analyzed, the best predictive validity was reached by the model that included non-aerated tissue (C-index: 0.97; p-value: 0.0001); (4) Conclusions: Quantitative lung CT offers wide advantages in COVID-19 disease stratification. Non-aerated lung tissue is more likely to occur with severe inflammation status, turning out to be a strong predictor for disease aggressiveness; therefore, it should be included in the predictive model of COVID-19 patients.

Pulmonary vascular system: A vulnerable target for COVID-19

The number of coronavirus disease 2019 (COVID‐19) cases has been increasing significantly, and the disease has evolved into a global pandemic, posing an unprecedented challenge to the healthcare community. Angiotensin‐converting enzyme 2, the binding and entry receptor of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in hosts, is also expressed on pulmonary vascular endothelium; thus, pulmonary vasculature is a potential target in COVID‐19. Indeed, pulmonary vascular thickening is observed by early clinical imaging, implying a tropism of SARS‐CoV‐2 for pulmonary vasculature. Recent studies reported that COVID‐19 is associated with vascular endothelial damage and dysfunction along with inflammation, coagulopathy, and microthrombosis; all of these pathologic changes are the hallmarks of pulmonary vascular diseases. Notwithstanding the not fully elucidated effects of COVID‐19 on pulmonary vasculature, the vascular endotheliopathy that occurs after infection is attributed to direct infection and indirect damage mainly caused by renin‐angiotensin‐aldosterone system imbalance, coagulation cascade, oxidative stress, immune dysregulation, and intussusceptive angiogenesis. Degradation of endothelial glycocalyx exposes endothelial cell (EC) surface receptors to the vascular lumen, which renders pulmonary ECs more susceptible to SARS‐CoV‐2 infection. The present article reviews the potential pulmonary vascular pathophysiology and clinical presentations in COVID‐19 to provide a basis for clinicians and scientists, providing insights into the development of therapeutic strategies targeting pulmonary vasculature.

The MiR-320 Family Is Strongly Downregulated in Patients with COVID-19 Induced Severe Respiratory Failure

A high incidence of thromboembolic events associated with high mortality has been reported in severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infections with respiratory failure. The present study characterized post-transcriptional gene regulation by global microRNA (miRNA) expression in relation to activated coagulation and inflammation in 21 critically ill SARS-CoV-2 patients. The cohort consisted of patients with moderate respiratory failure (n = 11) and severe respiratory failure (n = 10) at an acute stage (day 0-3) and in the later course of the disease (>7 days). All patients needed supplemental oxygen and severe patients were defined by the requirement of positive pressure ventilation (intubation). Levels of D-dimers, activated partial thromboplastin time (aPTT), C-reactive protein (CRP), and interleukin (IL)-6 were significantly higher in patients with severe compared with moderate respiratory failure. Concurrently, next generation sequencing (NGS) analysis demonstrated increased dysregulation of miRNA expression with progression of disease severity connected to extreme downregulation of miR-320a, miR-320b and miR-320c. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed involvement in the Hippo signaling pathway, the transforming growth factor (TGF)-β signaling pathway and in the regulation of adherens junctions. The expression of all miR-320 family members was significantly correlated with CRP, IL-6, and D-dimer levels. In conclusion, our analysis underlines the importance of thromboembolic processes in patients with respiratory failure and emphasizes miRNA-320s as potential biomarkers for severe progressive SARS-CoV-2 infection.