Complications after discharge with COVID-19 infection and risk factors associated with development of post-COVID pulmonary fibrosis

Risk Factors and Predictors for Persistent Dyspnea Post-COVID-19: A Systematic Review

The most frequently reported post-coronavirus disease of 2019 (COVID-19) symptoms include shortness of breath, fatigue, and cognitive disturbances, with reports of persistent dyspnea ranging between 26% and 41%. There is an urgent need to understand the risk factors and predictors for persistent COVID-19 dyspnea in individuals at all levels of COVID-19 illness severity, to enable the implementation of targeted interventions for those likely to be most affected with persistent dyspnea. Thus, the purpose of this systematic review is to explore the risk factors and predictors that are associated with persistent dyspnea in the post-COVID-19 population. This review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines and registered prospectively in PROSPERO as CRD42023466713. A search strategy was conducted across PubMed, CINAHL, Web of Science, and EMBASE databases, that included studies conducted from 2020 to March 2024. The Covidence platform was used for screening studies, scoring methodologic quality, and performing data extraction using a two-step independent review process. This review included 33 studies, addressing 83,920 participants across 20 countries. The strongest predictive risk factors for persistent dyspnea included the following: female sex, elevated body mass index, pulmonary comorbidities, pre-existing anxiety and depression, pre-COVID-19 physical limitations, the severity of the COVID-19 illness, and socioeconomic differences. Potential risk factors included increased age, smoking history, and COVID-19 variant type. The presence of biomarkers for persistent dyspnea in the post-COVID-19 population can be used by clinicians to prospectively identify those individuals who should be flagged. Early identification may then be leveraged for timely referral for prophylactic and rehabilitative interventions for dyspnea. A personalized plan to target those risk factors that are modifiable should follow.

Diagnostic value of lung function tests in long COVID: analysis of positive bronchial provocation test outcomes

Background

Long COVID patients are prone to bronchial hyperresponsiveness and respiratory symptoms like coughing and breathing difficulties, often with positive bronchial provocation test (BPT) results.

Objective

This study aims to evaluate the diagnostic value of various lung function tests in patients with long-term COVID-19, explicitly focusing on positive BPT outcomes.

Methods

Our study analyzed the BPT outcomes and various pulmonary function parameters of all 9,406 COVID-19 patients who met the inclusion criteria and visited our hospital between February 24, 2022, and April 28, 2024. Key indicators included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), and single-breath diffusing capacity for carbon monoxide (DLCOc SB). A logistic regression model was employed to identify factors influencing positive BPT results, while the receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of these indicators.

Results

A total of 4211 valid samples were analyzed, with 3388 patients (80.46%) testing positive for BPT. Significant differences were observed between positive and negative groups regarding age, gender, smoking status (all P < 0.05), and specific lung function indicators, including FVC, FEV1/FVC ratio, maximum of vital capacity (VC max), and DLCOc SB (all P < 0.001). Logistic regression identified age, MEF50, and DLCOc SB as independent factors influencing positive BPT results. The area under the ROC curve for all assessed factors was <0.700, indicating limited diagnostic value.

Conclusion

Age, the small airway function indicator MEF50, and the pulmonary diffusion function indicator DLCOc SB are independent influencing factors for BPT positivity in long-term COVID patients. However, baseline data and lung function indicators have limited utility for diagnosing positive BPT in this population, highlighting the complex nature of post-COVID respiratory symptoms.

Surviving COVID-19 and Battling Fibrosis: A Retrospective Cohort Study Across Three Pandemic Waves

BACKGROUND/OBJECTIVES

We aimed to characterize the fibrosis following COVID-19 pneumonia, using quantitative analysis, after three months and subsequently, after two years of patients' release from the hospital, and to identify the risk factors for pulmonary fibrosis.

METHODS

We performed a retrospective, observational cohort study on 420 patients with severe forms of COVID-19. For all patients, we registered demographic, inflammatory and biochemical parameters, complete blood count and D-dimers; all patients underwent three computed tomography scans (at admittance, at 3 months and at 2 years).

RESULTS

We found fibrosis in 67.9% of patients at the 3-month evaluation and in 42.4% of patients at the 2-year evaluation, registering a significant decrease in the severe and moderate fibrosis cases, with a slight increase in the mild fibrosis cases. The risk of fibrosis was found to be proportional to the values of age, duration of hospital stay, inflammatory markers (ESR, fibrinogen), cytolytic markers (LDH, AST) and D-dimers. The highest correlations with lung fibrosis were registered for interstitial pulmonary involvement (for the 3-month evaluation) and total pulmonary involvement (for the 2-year evaluation).

CONCLUSIONS

Lung fibrosis represents a significant post-COVID-19 complication found in 42% of patients with severe forms of pneumonia at the 2-year evaluation. A significant overall decrease in the severity of lung fibrosis was registered at the 2-year evaluation compared to the 3-month evaluation. We consider that the amount of interstitial pulmonary involvement represents the optimal parameter to estimate the risk of lung fibrosis following SARS-CoV-2 pneumonia.

Pulmonary fibrosis followed by severe pneumonia in patients with COVID-19 infection requiring mechanical ventilation: a prospective multicentre study

BACKGROUNDS

The management of lung complications, especially fibrosis, after COVID-19 pneumonia, is an important issue in the COVID-19 post-pandemic era. We aimed to investigate risk factors for pulmonary fibrosis development in patients with severe COVID-19 pneumonia.

METHODS

Clinical and radiological data were prospectively collected from 64 patients who required mechanical ventilation due to COVID-19 pneumonia and were enrolled from eight hospitals in South Korea. Fibrotic changes on chest CT were evaluated by visual assessment, and extent of fibrosis (mixed disease score) was measured using automatic quantification system.

RESULTS

64 patients were enrolled, and their mean age was 58.2 years (64.1% were males). On chest CT (median interval: 60 days [IQR; 41-78 days] from enrolment), 35 (54.7%) patients showed ≥3 fibrotic lesions. The most frequent fibrotic change was traction bronchiectasis (47 patients, 73.4 %). Median extent of fibrosis measured by automatic quantification was 10.6% (IQR, 3.8-40.7%). In a multivariable Cox proportional hazard model, which included nine variables with a p value of <0.10 in an unadjusted analysis as well as age, sex and Body Mass Index, male sex (HR, 3.01; 95% CI, 1.27 to 7.11) and higher initial Sequential Organ Failure Assessment (SOFA) score (HR, 1.18; 95% CI, 1.02 to 1.37) were independently associated with pulmonary fibrosis (≥3 fibrotic lesions).

CONCLUSION

Our data suggests that male gender and higher SOFA score at intensive care unit admission were associated with pulmonary fibrosis in patients with severe COVID-19 pneumonia requiring mechanical ventilation.

Advance in the mechanism and clinical research of myalgia in long COVID

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, mortality rates of coronavirus disease 2019 (COVID-19) have significantly decreased. However, a variable proportion of patients exhibit persistent prolonged symptoms of COVID-19 infection (long COVID). This virus primarily attacks respiratory system, but numerous individuals complain persistent skeletal muscle pain or worsening pre-existing muscle pain post COVID-19, which severely affects the quality of life and recovery. Currently, there is limited research on the skeletal muscle pain in long COVID. In this brief review, we review potential pathological mechanisms of skeletal muscle pain in long COVID, and summarize the various auxiliary examinations and treatments for skeletal muscle pain in long COVID. We consider abnormal activation of inflammatory response, myopathy, and neurological damages as pivotal pathological mechanisms of skeletal muscle pain in long COVID. A comprehensive examination is significantly important in order to work out effective treatment plans and relieve skeletal muscle pain. So far, rehabilitation interventions for myalgia in long COVID contain but are not limited to drug, nutraceutical therapy, gut microbiome-targeted therapy, interventional therapy and strength training. Our study provides a potential mechanism reference for clinical researches, highlighting the importance of comprehensive approach and management of skeletal muscle pain in long COVID. The relief of skeletal muscle pain will accelerate rehabilitation process, improve activities of daily living and enhance the quality of life, promoting individuals return to society with profound significance.

Evaluation of Long-Coronavirus Disease 2019 Cases Readmitted to Intensive Care Units Due to Acute Respiratory Failure: Point Prevalence Study

OBJECTIVE

 Coronavirus disease 2019 (COVID-19) caused morbidity and mortality worldwide. Besides the acute effects, subacute and long-term effects are defined as long-COVID causing morbidity. The intensive care unit (ICU) data of long-COVID-19 cases were evaluated with the participation of 11 centers.

MATERIAL AND METHODS

 Study was designed by Turkish Thoracic Society Respiratory Failure and Intensive Care Working Group to evaluate long COVID-19 patients. All patients followed up in the ICU with long-COVID diagnosis were included in point prevelance study.

RESULTS

 A total of 41 long COVID-19 patients from 11 centers were included in the study. Half of the patients were male, mean age was 66 ± 14, body mass index was 27 ± 5. Hypertension, diabetes mellitus, lung cancer, malignancy, and heart failure rates were 27%, 51%, 34%, 34%, and 27%, respectively. Eighty percent had received COVID vaccine. Patients had moderate hypoxemic respiratory failure. APACHE II, SOFA score was 18 (14-26), 6 (3-8), respectively. Forty-six percent received invasive mechanical ventilator support, 42% were sepsis, 17% were septic shock. Bilateral (67%), interstitial involvement (37%) were most common in chest x-ray. Fibrosis (27%) was detected in thorax tomography. Seventy-one percent of patients received antibiotherapy (42% carbapenem, 22% linezolid). Sixty-one percent of the patients received corticosteroid treatment.

CONCLUSION

 More than half of the patients had pneumonia and the majority of them used broad-spectrum antibiotics. Presence of comorbidities and malignancies, intensive care severity scores, intubation, and sepsis rates were high. Receiving corticosteroid treatment and extensive bilateral radiologic involvement due to COVID-19 might be the reasons for the high re-admission rate for the ICUs.

Outcomes and Management After COVID-19 Critical Illness

TOPIC IMPORTANCE

COVID-19 has caused > 7 million deaths worldwide since its onset in 2019. Although the severity of illness has varied throughout the pandemic, critical illness related to COVID-19 persists. Survivors of COVID-19 critical illness can be left with sequelae of both the SARS-CoV-2 virus and long-term effects of critical illness included within post-intensive care syndrome. Given the complexity and heterogeneity of COVID-19 critical illness, the biopsychosocial-ecological model can aid in evaluation and treatment of survivors, integrating interactions among physical, cognitive, and psychological domains, as well as social systems and environments.

REVIEW FINDINGS

Prolonged illness after COVID-19 critical illness generally can be classified into effects on physical, cognitive, and psychosocial function, with much interaction among the various effects, and includes a wide range of symptoms such as ICU-acquired weakness, prolonged respiratory symptoms, cognitive changes, post-traumatic stress disorder post-traumatic stress disorder, anxiety, and depression. Risk factors for COVID-19 critical illness developing are complex and include preexisting factors, disease course, and specifics of hospitalization in addition to psychological comorbidities and socioenvironmental factors. Recovery trajectories are not well defined, and management requires a comprehensive, interdisciplinary, and individualized approach to care.

SUMMARY

The onset of vaccinations, new therapeutics, and new strains of SARS-CoV-2 virus have decreased COVID-19 mortality; however, the number of survivors of COVID-19 critical illness remains high. A biopsychosocial-ecological approach is recommended to guide care of COVID-19 critical illness survivors.

COVID-19 Chest Manifestation on CT Scan and Associated Risk Factors for Developing Pulmonary Fibrosis

PURPOSE

This retrospective study describes the imaging findings on chest computed tomography (CT) scans of coronavirus disease 2019 (COVID-19) patients as well as the prevalence of pulmonary fibrosis and the potential risk factors for the disease.

METHODS

One of the major COVID-19 centers in the western province of Saudi Arabia, the King Abdullah Medical Complex in Jeddah, was the site of this study. All adult COVID-19 patients who got a CT chest scan between January 2020 and April 2022 were included in the trial. The imaging findings and pulmonary severity scores (PSS) were obtained from the patients' CT chest. Patients were divided into two groups according to the evidence of fibrotic-like lung changes; clinical and radiological data between the two groups were subsequently compared. Data from the patients' electronic records was collected.

RESULTS

The average patient age was 56.4 years, and most (73.5%) patients were men. Two-thirds of the patients had comorbidities (69.1%). CT scans revealed that diffuse lung infiltration is reported in 61% of cases, followed by lower lobes in 19.9%. Ground glass opacity (94.1%), consolidation (76.5%), septal thickening, and/or reticulation (24.4%) were the main chest findings during the initial CT scan. Fibrotic-like lung changes were developed in 9.6% of patients. Patients known to have a positive history of hypertension (p-value = 0.031) and coronary artery disease (CAD) (p-value = 0.011) were found to be significantly more likely to develop lung fibrosis. The patients' pneumonia severity score was significantly higher among the lung fibrotic patients (p-value = 0.026). Also, patients who were diagnosed with pulmonary fibrosis stayed longer in the hospital (p-value 0.001). Sex and age did not correlate significantly with risk of lung fibrosis.

CONCLUSION

Pulmonary fibrosis was observed in 9.6% of COVID-19 patients. A close follow-up of patients with severe pneumonia, prolonged hospitalization, and pre-existing CAD and hypertension was necessary, as pulmonary fibrosis was more likely to occur as a result of these factors. There is a need for a thorough, long-term investigation with a large sample size.

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.

Looking at the Data on Smoking and Post-COVID-19 Syndrome-A Literature Review

Long COVID is a recently described entity that is responsible for significant morbidity and that has consequences ranging from mild to life-threatening. The underlying mechanisms are not completely understood, and treatment options are currently limited, as existing data focus more on risk factors and predictors. Smoking has been reported as a risk factor for poor outcomes of acute SARS-CoV-2 infection and seems to also play a role in mediating post-COVID-19 symptoms. We aimed to review relevant work addressing the interaction between smoking and long COVID in order to characterize smoking's role as a risk factor and possibly identify new research directions. Methods: The PubMed/MEDLINE database was searched using the keywords 'smoking', 'long COVID', and 'post-acute COVID' to identify relevant English-language articles published up to October 2023. Results and conclusions: From the 374 initial hits, a total of 36 papers were deemed relevant to the aim of the review. There was significant variability concerning the ways in which tobacco usage was quantified and reported; still, there is compelling evidence linking smoking to an increased risk of developing manifestations of post-acute-COVID disease. Some clinical conditions, such as dyspnea, cardiovascular symptoms, and cognitive or mental-health impairment, seem to be relatively strongly associated with smoking, while the connection between smoking and upper-airway involvement seems less certain. The available data support recommending smoking cessation as a clinical tool for the prevention of long COVID.

Persistence of Symptoms Following Hospitalization for COVID-19 in Oman: A Bidirectional Observational Study

Objectives

This study sought to assess the prevalence of persistent COVID-19-related symptoms in patients with mild, severe, and critical disease.

Methods

We conducted a bidirectional cohort observational study that included all adult patients ≥ 18 years, admitted to Armed Forces Hospital, Muscat between July 2020 and June 2022, with COVID-19 infection and discharged alive. Patients were requested to attend outpatient clinic at weeks six and 12 post-discharge, where they filled out a questionnaire and underwent a chest X-ray. Additionally, blood tests were performed if necessary. Healthcare workers with mild infections were also requested to fill out a questionnaire about their initial symptoms, persistent symptoms, and comorbidities.

Results

The study included 468 patients, comprising 261 hospitalized patients and 207 healthcare workers. On follow-up, 39.7% of patients presented with residual symptoms, such as cough, breathlessness, and joint pain. These symptoms were more common in patients with medical comorbidities, particularly hypertension, diabetes, and dyslipidemia. Notably, these symptoms were also observed in patients with mild disease. Post-COVID-19 pulmonary fibrosis was observed in 21 patients, mainly among those admitted to the intensive care unit or requiring prolonged hospitalization.

Conclusions

This study highlights the persistence of symptoms and the prevalence of post-COVID-19 syndrome at two months post-discharge, especially among patients with severe and critical disease during the acute phase. Various predictors of post-COVID-19 syndrome were identified, including female gender, older age, presence of comorbidities, disease severity, and hypertension. Therefore, patients in these categories require thorough evaluation and long-term follow-up to manage residual symptoms.

Risk of subsequent lower respiratory tract infection (LRTI) after hospitalization for COVID-19 LRTI and non-COVID-19 LRTI: a retrospective cohort study

BACKGROUND

Respiratory pathogens, including SARS-CoV-2, can cause pulmonary structural damage and physiologic impairment, which may increase the risk of subsequent lower respiratory tract infections (LRTI). Prior hospitalization for any reason is a risk factor for LRTI, but data on the risk of subsequent new-onset LRTI following hospitalization for COVID-19 LRTI or non-COVID-19 LRTI are needed to inform strategies for immunizations targeting respiratory pathogens.

METHODS

We conducted a retrospective cohort study at Kaiser Permanente Southern California (KPSC) among adults hospitalized from 3/1/2020 to 5/31/2022, excluding labor and delivery. We categorized individuals into 3 mutually exclusive baseline exposure groups: those hospitalized for COVID-19 LRTI, those hospitalized for non-COVID-19 LRTI, and those hospitalized for all other causes without LRTI or COVID-19 ("non-LRTI"). Following hospital discharge, patients were followed up for new-onset LRTI, beginning 30 antibiotic-free days after hospital discharge until 8/31/2022. We used multivariable cause-specific Cox regression with time-varying covariates to estimate hazard ratios (HR) of new-onset LRTI comparing those hospitalized for COVID-19 LRTI or non-COVID-19 LRTI to those hospitalized for non-LRTI, adjusting for demographic and clinical characteristics.

RESULTS

The study included 22,417 individuals hospitalized for COVID-19 LRTI, 12,795 individuals hospitalized for non-COVID-19 LRTI, and 176,788 individuals hospitalized for non-LRTI. Individuals hospitalized for non-COVID-19 LRTI were older and had more comorbidities than those hospitalized for COVID-19 LRTI or non-LRTI. Incidence rates per 1,000 person-years (95% CI) of new-onset LRTI were 52.5 (51.4-53.6) among individuals hospitalized for COVID-19 LRTI, 253.5 (243.7-263.6) among those hospitalized for non-COVID-19 LRTI, and 52.5 (51.4-53.6) among those hospitalized for non-LRTI. The adjusted hazard of new-onset LRTI during follow-up was 20% higher among individuals hospitalized for COVID-19 LRTI (HR 1.20 [95% CI: 1.12-1.28]) and 301% higher among individuals hospitalized for non-COVID-19 LRTI (HR 3.01 [95% CI: 2.87-3.15]) compared to those hospitalized for non-LRTI.

CONCLUSION

The risk of new-onset LRTI following hospital discharge was high, particularly among those hospitalized for non-COVID-19 LRTI, but also for COVID-19 LRTI. These data suggest that immunizations targeting respiratory pathogens, including COVID-19, should be considered for adults hospitalized for LRTI prior to hospital discharge.

SARS-CoV-2 post-acute sequelae in previously hospitalised patients: systematic literature review and meta-analysis

BACKGROUND

Many individuals hospitalised with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection experience post-acute sequelae of SARS-CoV-2 infection (PASC), sometimes referred to as "long COVID". Our objective was to conduct a systematic literature review and meta-analysis to identify PASC-associated symptoms in previously hospitalised patients and determine the frequency and temporal nature of PASC.

METHODS

Searches of MEDLINE, Embase, Cochrane Library (2019-2021), World Health Organization International Clinical Trials Registry Platform and reference lists were performed from November to December 2021. Articles were assessed by two reviewers against eligibility criteria and a risk of bias tool. Symptom data were synthesised by random effects meta-analyses.

RESULTS

Of 6942 records, 52 studies with at least 100 patients were analysed; ∼70% were Europe-based studies. Most data were from the first wave of the pandemic. PASC symptoms were analysed from 28 days after hospital discharge. At 1-4 months post-acute SARS-CoV-2 infection, the most frequent individual symptoms were fatigue (29.3% (95% CI 20.1-40.6%)) and dyspnoea (19.6% (95% CI 12.8-28.7%)). Many patients experienced at least one symptom at 4-8 months (73.1% (95% CI 44.2-90.3%)) and 8-12 months (75.0% (95% CI 56.4-87.4%)).

CONCLUSIONS

A wide spectrum of persistent PASC-associated symptoms were reported over the 1-year follow-up period in a significant proportion of participants. Further research is needed to better define PASC duration and determine whether factors such as disease severity, vaccination and treatments have an impact on PASC.

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.

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.

Respiratory sequelae of COVID-19: pulmonary and extrapulmonary origins, and approaches to clinical care and rehabilitation

Although the exact prevalence of post-COVID-19 condition (also known as long COVID) is unknown, more than a third of patients with COVID-19 develop symptoms that persist for more than 3 months after SARS-CoV-2 infection. These sequelae are highly heterogeneous in nature and adversely affect multiple biological systems, although breathlessness is a frequently cited symptom. Specific pulmonary sequelae, including pulmonary fibrosis and thromboembolic disease, need careful assessment and might require particular investigations and treatments. COVID-19 outcomes in people with pre-existing respiratory conditions vary according to the nature and severity of the respiratory disease and how well it is controlled. Extrapulmonary complications such as reduced exercise tolerance and frailty might contribute to breathlessness in post-COVID-19 condition. Non-pharmacological therapeutic options, including adapted pulmonary rehabilitation programmes and physiotherapy techniques for breathing management, might help to attenuate breathlessness in people with post-COVID-19 condition. Further research is needed to understand the origins and course of respiratory symptoms and to develop effective therapeutic and rehabilitative strategies.

Pulmonary function and exercise capacity six months after hospital discharge of patients with severe COVID-19

INTRODUCTION

The long-term consequences of COVID-19, especially pulmonary impairment, are frequent but not well understood. The knowledge about sequels or long COVID-19 are necessary, considering the high prevalence and need for specific public strategies.

METHOD

The study was conducted to evaluate symptoms (standardized questionnaire), pulmonary function (spirometry), and exercise capacity (6-minute-walk-test) at 30 (D30), 90 (D90), and 180 (D180) days after hospital discharge of patients surviving to severe COVID-19. We excluded in this follow up patients with comorbidities before COVID infection.

RESULTS

44 patients were included and 31 (26 men) completed the 6-month follow-up (age mean 53.6 ± 9.6 years). At D180, 28% presented still at least one symptom. The most common was dyspnea (17.2%), followed by cough (13.8%), and myalgia (10.3%). All spirometric parameters showed progressive improvement from D30 to D180. However, 16% maintained a restrictive pattern on spirometry test, 44% presented desaturation on the 6-minute walk-test, and 25% walked < 75% of the predicted value.

CONCLUSION

6-months after hospital discharge, reduced pulmonary function and reduced exercise capacity was founded frequently and more than a quarter remained symptomatic. The persistent symptoms and functional impairment suggest that sequels and development of Long COVID-19 are very common. The identification of these patients to provide the necessary health care is a challenging task, considering the large number of patients infected and surviving to COVID-19 disease.

Clinical Evolution and Risk Factors in Patients Infected during the First Wave of COVID-19: A Two-Year Longitudinal Study

A limited number of longitudinal studies have examined the symptoms associated with long-COVID-19. We conducted an assessment of symptom onset, severity and patient recovery, and determined the percentage of patients who experienced reinfection up to 2 years after the initial onset of the disease. Our cohort comprises 377 patients (≥18 years) with laboratory-confirmed COVID-19 in a secondary hospital (Madrid, Spain), throughout March 3-16, 2020. Disease outcomes and clinical data were followed-up until August 12, 2022. We reviewed the evolution of the 253 patients who had survived as of April 2020 (67.1%). Nine died between April 2020 and August 2022. A multivariate regression analysis performed to detect the risk factors associated with long-COVID-19 revealed that the increased likelihood was associated with chronic obstructive lung disease (OR 14.35, 95% CI 1.89-109.09; p = 0.010), dyspnea (5.02, 1.02-24.75; p = 0.048), higher LDH (3.23, 1.34-7.52; p = 0.006), and lower D-dimer levels (0.164, 0.04-0.678; p = 0.012). Reinfected patients (n = 45) (47.8 years; 39.7-67.2) were younger than non-reinfected patients (64.1 years; 48.6-74.4)) (p < 0.001). Patients who received a combination of vaccines exhibited fewer symptoms (44.4%) compared to those who received a single type of vaccine (77.8%) (p = 0.048). Long-COVID-19 was detected in 27.05% (66/244) of patients. The early detection of risk factors helps predict the clinical course of patients with COVID-19. Middle-aged adults could be susceptible to reinfection, highlighting the importance of prevention and control measures regardless of vaccination status.

Oxidative Biomarkers Associated with the Pulmonary Manifestation of Post-COVID-19 Complications

INTRODUCTION

The role of mitochondria in post coronavirus disease 2019 (post-COVID-19) complications is unclear, especially in the long-term pulmonary complications. This study aims to investigate the association between post-COVID-19 pulmonary complications and mitochondrial regulatory proteins in the context of oxidative stress.

METHODOLOGY

Patients who had recovered from COVID-19 were enrolled. According to the evidence of persistent interstitial lung lesions on computed tomography (CT), patients were divided into a long-term pulmonary complications group (P(+)) and a control group without long-term pulmonary complications (P(-)). We randomly selected 80 patients for investigation (40 subjects for each group). Biomarkers levels were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The serum concentrations of mitochondrial regulatory proteins were significantly higher in the P(+) group, including PTEN-induced kinase 1 (PINK1): 1.62 [1.02-2.29] ng/mL vs. 1.34 [0.94-1.74] ng/mL (p = 0.046); Dynamin-1-like protein (DNM1L): 1.6 [0.9-2.4] ng/mL IQR vs. 0.9 [0.5-1.6] ng/mL (p = 0.004); and Mitofusin-2 (MFN2): 0.3 [0.2-0.5] ng/mL vs. 0.2 [0.1-0.3] ng/mL IQR (p = 0.001). Patients from the P(+) group also had higher serum levels of chemokine ligand 18 (PARC, CCL18), IL-6, and tumour necrosis factor-alpha (TNF-α) cytokines than the P(-) group. The concentration of interferon alpha (IFN-α) was decreased in the P(+) group. Furthermore, we observed statistically significant correlations between the advanced glycation end product (sRAGE) and TNF-α (Pearson's factor R = 0.637; p < 0.001) and between serum levels of DNM1L and IFN-α (Pearson's factor R = 0.501; p = 0.002) in P(+) patients.

CONCLUSIONS

Elevated concentrations of mitochondrial biomarkers in post-COVID-19 patients with long-term pulmonary complications indicate their possible role in the pathobiology of COVID-19 pulmonary sequelae. Oxidative stress is associated with the immune response and inflammation after COVID-19. TNF-α could be a promising biomarker for predicting pulmonary complications and may be a potential target for therapeutic intervention in patients with post-COVID-19 complications.

Impact of impaired pulmonary function on clinical outcomes in survivors of severe COVID-19 without pre-existing respiratory disease

OBJECTIVE

To investigate the impact of impaired pulmonary function on patient-centered outcomes after hospital discharge due to severe COVID-19 in patients without preexisting respiratory disease.

METHODS

This is an ongoing prospective cohort study evaluating patients (> 18 years of age) 2-6 months after hospital discharge due to severe COVID-19. Respiratory symptoms, health-related quality of life, lung function, and the six-minute walk test were assessed. A restrictive ventilatory defect was defined as TLC below the lower limit of normal, as assessed by plethysmography. Chest CT scans performed during hospitalization were scored for the presence and extent of parenchymal abnormalities.

RESULTS

At a mean follow-up of 17.2 ± 5.9 weeks after the diagnosis of COVID-19, 120 patients were assessed. Of those, 23 (19.2%) reported preexisting chronic respiratory diseases and presented with worse lung function and exertional dyspnea at the follow-up visit in comparison with their counterparts. When we excluded the 23 patients with preexisting respiratory disease plus another 2 patients without lung volume measurements, a restrictive ventilatory defect was observed in 42/95 patients (44%). This subgroup of patients (52.4% of whom were male; mean age, 53.9 ± 11.3 years) showed reduced resting gas exchange efficiency (DLCO), increased daily-life dyspnea, increased exertional dyspnea and oxygen desaturation, and reduced health-related quality of life in comparison with those without reduced TLC (50.9% of whom were male; mean age, 58.4 ± 11.3 years). Intensive care need and higher chest CT scores were associated with a subsequent restrictive ventilatory defect.

CONCLUSIONS

The presence of a restrictive ventilatory defect approximately 4 months after severe COVID-19 in patients without prior respiratory comorbidities implies worse clinical outcomes.

Corrigendum to "The prevalence and long-term health effects of long Covid among hospitalised and non-hospitalised populations: a systematic review and meta-analysis"

[This corrects the article DOI: 10.1016/j.eclinm.2022.101762.].

Fatigue outcomes following COVID-19: a systematic review and meta-analysis

OBJECTIVES

Fatigue is a pervasive clinical symptom in coronaviruses and may continue beyond the acute phase, lasting for several months or years. This systematic review and meta-analysis aimed to incorporate the current evidence for postinfection fatigue among survivors of SARS-CoV-2 and investigate associated factors.

METHODS

Embase, PsyINFO, Medline, CINAHL, CDSR, Open Grey, BioRxiv and MedRxiv were systematically searched from January 2019 to December 2021. Eligible records included all study designs in English. Outcomes were fatigue or vitality in adults with a confirmed diagnosis of SARS-CoV-2 measured at >30 days post infection. Non-confirmed cases were excluded. JBI risk of bias was assessed by three reviewers. Random effects model was used for the pooled proportion with 95% CIs. A mixed effects meta-regression of 35 prospective articles calculated change in fatigue overtime. Subgroup analyses explored specific group characteristics of study methodology. Heterogeneity was assessed using Cochran's Q and I2 statistic. Egger's tests for publication bias.

RESULTS

Database searches returned 14 262 records. Following deduplication and screening, 178 records were identified. 147 (n=48 466 participants) were included for the meta-analyses. Pooled prevalence was 41% (95% CI: 37% to 45%, k=147, I2=98%). Fatigue significantly reduced over time (-0.057, 95% CI: -107 to -0.008, k=35, I2=99.3%, p=0.05). A higher proportion of fatigue was found in studies using a valid scale (51%, 95% CI: 43% to 58%, k=36, I2=96.2%, p=0.004). No significant difference was found for fatigue by study design (p=0.272). Egger's test indicated publication bias for all analyses except valid scales. Quality assessments indicated 4% at low risk of bias, 78% at moderate risk and 18% at high risk. Frequently reported associations were female gender, age, physical functioning, breathlessness and psychological distress.

CONCLUSION

This study revealed that a significant proportion of survivors experienced fatigue following SARS-CoV-2 and their fatigue reduced overtime. Non-modifiable factors and psychological morbidity may contribute to ongoing fatigue and impede recovery.

PROSPERO REGISTRATION NUMBER

CRD42020201247.

Systematic review of overlapping microRNA patterns in COVID-19 and idiopathic pulmonary fibrosis

BACKGROUND

Pulmonary fibrosis is an emerging complication of SARS-CoV-2 infection. In this study, we speculate that patients with COVID-19 and idiopathic pulmonary fibrosis (IPF) may share aberrant expressed microRNAs (miRNAs) associated to the progression of lung fibrosis.

OBJECTIVE

To identify miRNAs presenting similar alteration in COVID-19 and IPF, and describe their impact on fibrogenesis.

METHODS

A systematic review of the literature published between 2010 and January 2022 (PROSPERO, CRD42022341016) was conducted using the key words (COVID-19 OR SARS-CoV-2) AND (microRNA OR miRNA) or (idiopathic pulmonary fibrosis OR IPF) AND (microRNA OR miRNA) in Title/Abstract.

RESULTS

Of the 1988 references considered, 70 original articles were appropriate for data extraction: 27 studies focused on miRNAs in COVID-19, and 43 on miRNAs in IPF. 34 miRNAs were overlapping in COVID-19 and IPF, 7 miRNAs presenting an upregulation (miR-19a-3p, miR-200c-3p, miR-21-5p, miR-145-5p, miR-199a-5p, miR-23b and miR-424) and 9 miRNAs a downregulation (miR-17-5p, miR-20a-5p, miR-92a-3p, miR-141-3p, miR-16-5p, miR-142-5p, miR-486-5p, miR-708-3p and miR-150-5p).

CONCLUSION

Several studies reported elevated levels of profibrotic miRNAs in COVID-19 context. In addition, the balance of antifibrotic miRNAs responsible of the modulation of fibrotic processes is impaired in COVID-19. This evidence suggests that the deregulation of fibrotic-related miRNAs participates in the development of fibrotic lesions in the lung of post-COVID-19 patients.

Long-term respiratory follow-up of ICU hospitalized COVID-19 patients: Prospective cohort study

BACKGROUND

Coronavirus disease (COVID-19) survivors exhibit multisystemic alterations after hospitalization. Little is known about long-term imaging and pulmonary function of hospitalized patients intensive care unit (ICU) who survive COVID-19. We aimed to investigate long-term consequences of COVID-19 on the respiratory system of patients discharged from hospital ICU and identify risk factors associated with chest computed tomography (CT) lesion severity.

METHODS

A prospective cohort study of COVID-19 patients admitted to a tertiary hospital ICU in Brazil (March-August/2020), and followed-up six-twelve months after hospital admission. Initial assessment included: modified Medical Research Council dyspnea scale, SpO2 evaluation, forced vital capacity, and chest X-Ray. Patients with alterations in at least one of these examinations were eligible for CT and pulmonary function tests (PFTs) approximately 16 months after hospital admission. Primary outcome: CT lesion severity (fibrotic-like or non-fibrotic-like). Baseline clinical variables were used to build a machine learning model (ML) to predict the severity of CT lesion.

RESULTS

In total, 326 patients (72%) were eligible for CT and PFTs. COVID-19 CT lesions were identified in 81.8% of patients, and half of them showed mild restrictive lung impairment and impaired lung diffusion capacity. Patients with COVID-19 CT findings were stratified into two categories of lesion severity: non-fibrotic-like (50.8%-ground-glass opacities/reticulations) and fibrotic-like (49.2%-traction bronchiectasis/architectural distortion). No association between CT feature severity and altered lung diffusion or functional restrictive/obstructive patterns was found. The ML detected that male sex, ICU and invasive mechanic ventilation (IMV) period, tracheostomy and vasoactive drug need during hospitalization were predictors of CT lesion severity(sensitivity,0.78±0.02;specificity,0.79±0.01;F1-score,0.78±0.02;positive predictive rate,0.78±0.02; accuracy,0.78±0.02; and area under the curve,0.83±0.01).

CONCLUSION

ICU hospitalization due to COVID-19 led to respiratory system alterations six-twelve months after hospital admission. Male sex and critical disease acute phase, characterized by a longer ICU and IMV period, and need for tracheostomy and vasoactive drugs, were risk factors for severe CT lesions six-twelve months after hospital admission.

Prevalence, risk factors and treatments for post-COVID-19 breathlessness: a systematic review and meta-analysis

Persistent breathlessness >28 days after acute COVID-19 infection has been identified as a highly debilitating post-COVID symptom. However, the prevalence, risk factors, mechanisms and treatments for post-COVID breathlessness remain poorly understood. We systematically searched PubMed and Embase for relevant studies published from 1 January 2020 to 1 November 2021 (PROSPERO registration number: CRD42021285733) and included 119 eligible papers. Random-effects meta-analysis of 42 872 patients with COVID-19 reported in 102 papers found an overall prevalence of post-COVID breathlessness of 26% (95% CI 23-29) when measuring the presence/absence of the symptom, and 41% (95% CI 34-48) when using Medical Research Council (MRC)/modified MRC dyspnoea scale. The pooled prevalence decreased significantly from 1-6 months to 7-12 months post-infection. Post-COVID breathlessness was more common in those with severe/critical acute infection, those who were hospitalised and females, and was less likely to be reported by patients in Asia than those in Europe or North America. Multiple pathophysiological mechanisms have been proposed (including deconditioning, restrictive/obstructive airflow limitation, systemic inflammation, impaired mental health), but the body of evidence remains inconclusive. Seven cohort studies and one randomised controlled trial suggested rehabilitation exercises may reduce post-COVID breathlessness. There is an urgent need for mechanistic research and development of interventions for the prevention and treatment of post-COVID breathlessness.

Evaluation of Blood Biochemistry and Cardiopulmonary status of Hospitalized Covid-19 Patients in 3 Months Post Discharged Follow up Survey

BACKGROUND

The new coronavirus causes systemic inflammation and damage to various organs. So, this study aimed to follow up patients with COVID -19 after recovery for three months by performing cardiac, pulmonary and laboratory tests.

MATERIALS AND METHODS

This was a prospective cohort study of COVID-19 patients who were discharged from Baharloo Hospital. The diagnosis of COVID-19 was confirmed by PCR or long CT scan. Inclusion criteria were age over 18 years and patients with more than 50% of pulmonary involvement in lung CT scan. The patients were called to Baharloo hospital three months after recovery and were examined for cardiac, pulmonary and blood tests.

RESULT

Our study included 178 participants with mean age of 55.70, and 50.6% of them were male. Among pulmonary factors in the hospital, 71.9%, 15.7%,1.7%,19.1% and 53.4% had positive GGO, consolidation, reverse halo sign, traction bronchiectasis and vascular enlargement, respectively. After three months follow up, percentage of patients who had reticulation, honeycombing, fibrotic brand and bullae were 12%, 1.1%,8.4% and 0%, respectively. The Mean values of FVC and FEV1 were reported 4.21 and 3.01, respectively. Among Cardiac factors, positive PVC, PAC and mean Pap were decreased after three months. Only Growth in myalgia and Decreased sense of taste were statistically significant. Also, D dimer, UA protein, PMN, Ferritin CRP, PMN, LDH and HB amounts had decreased significantly.

CONCLUSION

Our study indicated that in addition to pulmonary changes, rapid damage to other organs and the occurrence of cardiac symptoms and changes in laboratory result were also reported in patients recovered from COVID-19.

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.

Cardiopulmonary disease as sequelae of long-term COVID-19: Current perspectives and challenges

COVID-19 infection primarily targets the lungs, which in severe cases progresses to cytokine storm, acute respiratory distress syndrome, multiorgan dysfunction, and shock. Survivors are now presenting evidence of cardiopulmonary sequelae such as persistent right ventricular dysfunction, chronic thrombosis, lung fibrosis, and pulmonary hypertension. This review will summarize the current knowledge on long-term cardiopulmonary sequelae of COVID-19 and provide a framework for approaching the diagnosis and management of these entities. We will also identify research priorities to address areas of uncertainty and improve the quality of care provided to these patients.

Autoimmunity, cancer and COVID-19 abnormally activate wound healing pathways: critical role of inflammation

Recent evidence indicates that targeting IL-6 provides broad therapeutic approaches to several diseases. In patients with cancer, autoimmune diseases, severe respiratory infections [e.g. coronavirus disease 2019 (COVID-19)] and wound healing, IL-6 plays a critical role in modulating the systemic and local microenvironment. Elevated serum levels of IL-6 interfere with the systemic immune response and are associated with disease progression and prognosis. As already noted, monoclonal antibodies blocking either IL-6 or binding of IL-6 to receptors have been used/tested successfully in the treatment of rheumatoid arthritis, many cancer types, and COVID-19. Therefore, in the present review, we compare the impact of IL-6 and anti-IL-6 therapy to demonstrate common (pathological) features of the studied diseases such as formation of granulation tissue with the presence of myofibroblasts and deposition of new extracellular matrix. We also discuss abnormal activation of other wound-healing-related pathways that have been implicated in autoimmune disorders, cancer or COVID-19.

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.

Post-COVID kortikosteroid kullanımı ve pulmoner fibrozis: 1 yıllık izlem

Purpose: Depending on the prevalence and severity of COVID-19 disease, pulmonary sequelae and fibrotic lung disease continue to pose significant problems for patients in the post-COVID period. In our study, we aimed to determine the risk factors for pulmonary sequelae and fibrosis with post-COVID patient management. Materials and Methods: The study comprised 67 post-COVID patients who were released from the hospital after receiving low-dose corticosteroids (0.5 mg/kg daily methylprednisolone) as a result of COVID-19. Socio-demographic data, radiological and laboratory findings of the patients were recorded. All patients were followed up at 3, 6, and 12 months after discharge, and the diagnosis of pulmonary fibrosis was made according to high resolution computed tomography (HRCT) findings, by evaluating with detailed biochemical blood tests and HRCT. Results: Thirtyfour (50.7%) of the 67 patients were male and the mean age was 57±16.33 (min.19–max.90). At 3 months, there were 59 patients (88.1%) with aberrant thoracic computed tomography (CT) findings, 28 (41.8%) at 6 months, and 21 (31.3%) at 12 months. In the 12th month follow-up, pulmonary fibrosis was detected in a total of 9 (13.4%) patients according to thorax CT findings. Conclusion: In our study, the most important risk factors for the development of post-COVID pulmonary fibrosis were intensive care unit (ICU) follow-up, lymphocyte count

Single cell meta-analysis of EndMT and EMT state in COVID-19

COVID-19 prognoses suggests that a proportion of patients develop fibrosis, but there is no evidence to indicate whether patients have progression of mesenchymal transition (MT) in the lungs. The role of MT during the COVID-19 pandemic remains poorly understood. Using single-cell RNA sequencing, we profiled the transcriptomes of cells from the lungs of healthy individuals (n = 45), COVID-19 patients (n = 58), and idiopathic pulmonary fibrosis (IPF) patients (n = 64) human lungs to map the entire MT change. This analysis enabled us to map all high-resolution matrix-producing cells and identify distinct subpopulations of endothelial cells (ECs) and epithelial cells as the primary cellular sources of MT clusters during COVID-19. For the first time, we have identied early and late subgroups of endothelial mesenchymal transition (EndMT) and epithelial-mesenchymal transition (EMT) using analysis of public databases for single-cell sequencing. We assessed epithelial subgroups by age, smoking status, and gender, and the data suggest that the proportional changes in EMT in COVID-19 are statistically significant. Further enumeration of early and late EMT suggests a correlation between invasive genes and COVID-19. Finally, EndMT is upregulated in COVID-19 patients and enriched for more inflammatory cytokines. Further, by classifying EndMT as early or late stages, we found that early EndMT was positively correlated with entry factors but this was not true for late EndMT. Exploring the MT state of may help to mitigate the fibrosis impact of SARS-CoV-2 infection.

Challenges in the Management of Post-COVID-19 Pulmonary Fibrosis for the Latin American Population

This commentary aims to highlight some of the major issues (with possible solutions) that the Latin American region is currently dealing with in managing post-COVID-19 pulmonary fibrosis. Overall, there is little evidence for successful long-term COVID-19 follow-up treatment. The lack of knowledge regarding proper treatment is exacerbated in Latin America by a general lack of resources devoted to healthcare, and a lack of availability and access to multidisciplinary teams. The discussion suggests that better infrastructure (primarily multicenter cohorts of COVID-19 survivors) and well-designed studies are required to develop scientific knowledge to improve treatment for the increasing prevalence of pulmonary fibrosis in Latin America.

Interstitial Lung Fibrosis Following COVID-19 Pneumonia

Background and Objectives: Pulmonary fibrosis represents a stage of normal physiologic response to inflammatory aggression, mostly self-limiting and reversible; however, numerous patients treated for SARS-CoV-2 pneumonia present after release from hospital residual lung fibrosis. In this article, we aim to present an optimization method for evaluating pulmonary fibrosis by quantitative analysis, to identify the risk factors/predictors for pulmonary fibrosis in patients with SARS-CoV-2 infection, and to characterize the impact of pulmonary fibrosis on the symptomatology of patients after release from the hospital. Materials and Methods: We performed a prospective observational study on 100 patients with severe forms of pneumonia, with a control group of 61 non-COVID normal patients. Results: We found persistent interstitial changes consistent with fibrotic changes in 69% of patients. The risk of fibrosis was proportional to the values of erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and lactate dehydrogenase (LDH), and to the duration of hospitalization. The imaging parameters correlated with increased risk for interstitial fibrosis were the number of affected pulmonary lobes and the percent of interstitial pulmonary fibrosis. Conclusions: The main risk factors for pulmonary fibrosis post-COVID-19 identified in our study are increased ESR, CRP, LDH, duration of hospitalization and the severity of pneumonia.

Managing Post COVID-19 Patient with Breathlessness

Background

Chronic respiratory disease may be associated with severity of coronavirus disease 2019 (COVID-19) infection. We review a case of chronic obstructive pulmonary disease (COPD) patient who developed acute breathlessness post COVID-19 infection, also focusing on the diagnostic approach.

Case

A 69-year-old gentleman with background history of COPD GOLD D and ischemic heart disease was admitted with severe COVID-19 infection. He required high-flow nasal cannula upon presentation. A computed tomography pulmonary angiography (CTPA) thorax at day 10 of illness revealed moderate organizing pneumonia (OP) with emphysematous changes, without pulmonary embolism. He received oral baricitinib and intravenous methylprednisolone for 3 days, which was then followed by tapering prednisolone starting dose of 1 mg/kg/day (60 mg/day) with reduction of 10 mg prednisolone every 3 days. COPD pharmacotherapy was optimized with early utilization of dual bronchodilators and inhaled corticosteroid was withheld. He underwent inpatient pulmonary rehabilitation and was discharged with home oxygen therapy. Unfortunately, he was re-admitted after 2 weeks with shortness of breath and fever for 3 days. Blood results revealed leucocytosis with raised C-reactive protein. A repeat CTPA showed increase reticulations and crazy paving pattern with reduction in lung volume. Multidisciplinary team discussion concluded it as interstitial pneumonia with COVID-19 OP and fibrosis progression. Prednisolone was stopped and he responded well with antibiotics. A follow-up at 3 months post COVID-19 infection showed improvement of clinical symptoms with radiological resolution of ground glass changes.

Conclusion

Corticosteroid inhaler should be cautioned in this case, in view of recent pneumonia and non-elevated serum eosinophil count. These groups of patients should be closely followed up to unmask interstitial lung disease that may present prior to COVID-19 and worsen post-infection. Optimizing pre-existing medical conditions should be the paramount intervention.

Predictors of post COVID complications in patients admitted with moderate to severe COVID symptoms: A single center, prospective, observational study

While the world was still busy battling active COVID-19 infections, a large subset of patients started showing prolonged symptoms or developing complications following an initial recovery from COVID-19. Post covid complications range from mild symptoms such as fatigue, headache, shortness of breath to serious, life threatening conditions like opportunistic infections, deep venous thrombosis, pulmonary embolism, pneumothorax and lung fibrosis. A single center, prospective, observational study was carried out in a tertiary respiratory care institute in North India from June 2021 to August 2021 where 224 cases of previously treated COVID-19/ongoing symptomatic COVID-19 (those patients who were manifesting symptoms beyond 4 weeks), were enrolled and followed up for a period of 3 months to estimate the prevalence of persistent symptoms, complications and any risk factors associated with it. Data analysis was done using SPSS software version 21. Univariate and multivariate analysis done among risk factors and outcome variables. ROC was done on predictor variables and area under curve (AUC) calculated. p value less than 0.05 was considered significant. Among the 24.6% symptomatic patients at follow up, the most common symptom was fatigue (51.8%) followed by dyspnea (43.8%) and anxiety (43.3%). Among the complications of COVID-19, the most common according to our study was fibrosis (15.2%), followed by pulmonary thromboembolism (PTE) (12.1%), echocardiographic abnormalities (11.2%) and pulmonary mucormycosis (5.4%). Female gender, presence of comorbidities, requirement of non-invasive or invasive ventilation during hospital stay emerged as independent risk factors for complications following COVID-19. This study brings forth the huge morbidity burden that COVID-19 brought upon seemingly cured individuals and lists the risk factors associated with persistence of symptoms and complications. This would help to better streamline health resources and standardize follow up guidance of COVID-19 patients.

Post-Coronavirus Disease 2019 Pulmonary Fibrosis: Wait or Needs Intervention

Coronavirus disease 2019 (COVID-19) has become a major health burden worldwide, with over 450 million confirmed cases and 6 million deaths. Although the acute phase of COVID-19 management has been established, there is still a long way to go to evaluate the long-term clinical course or manage complications due to the relatively short outbreak of the virus. Pulmonary fibrosis is one of the most common respiratory complications associated with COVID-19. Scarring throughout the lungs after viral or bacterial pulmonary infection have been commonly observed, but the prevalence of post-COVID-19 pulmonary fibrosis is rapidly increasing. However, there is limited information available about post-COVID-19 pulmonary fibrosis, and there is also a lack of consensus on what condition should be defined as post-COVID-19 pulmonary fibrosis. During a relatively short follow-up period of approximately 1 year, lesions considered related to pulmonary fibrosis often showed gradual improvement; therefore, it is questionable at what time point fibrosis should be evaluated. In this review, we investigated the epidemiology, risk factors, pathogenesis, and management of post-COVID-19 pulmonary fibrosis.

Chest CT-based Assessment of 1-year Outcomes after Moderate COVID-19 Pneumonia

Background

COVID-19 pneumonia may lead to pulmonary fibrosis in the long term. Chest CT is useful to evaluate changes in the lung parenchyma over time.

Purpose

To illustrate the temporal change of lung abnormalities on chest CT scans associated with COVID-19 pneumonia over 1 year.

Materials and Methods

In this prospective study, patients previously hospitalized due to COVID-19 pneumonia who visited the radiology department of a tertiary care center for imaging follow-up were consecutively enrolled between March 2020 and July 2021. Exclusion criteria were acute respiratory distress syndrome, requirement of intubation and/or mechanical ventilation, pulmonary embolism, and any interstitial lung disease. High-resolution volumetric noncontrast chest CT scans were acquired at 3, 6, and 12 months from the first diagnosis and were compared with baseline CT scans. The imaging features analyzed were ground-glass opacity (GGO), consolidation, pleuroparenchymal band, linear atelectasis, bronchiectasis and/or bronchiolectasis, reticulation, traction bronchiectasis and/or bronchiolectasis, and honeycombing. The prevalence distribution of lung abnormalities was recorded at all time points.

Results

Eighty-four participants (56 men; mean age, 61 years ± 11 [SD]) were studied. GGOs and consolidations represented the main baseline lung abnormalities, accounting for a median severity score of 9 (IQR, 7–12.7; maximum possible score, 20), which indicates moderate lung involvement. The baseline prevalence of GGOs decreased from 100% to 2% of participants at 1 year, and that of consolidations decreased from 71% to 0% at 6 months. Fibrotic-like abnormalities (pleuroparenchymal bands, linear atelectasis, bronchiectasis and/or bronchiolectasis) were detected at 3 months (50% of participants), 6 months (42% of participants), and 1 year (5% of participants). Among these, pleuroparenchymal bands were the most represented finding. Fibrotic changes (reticulation and traction bronchiectasis and/or bronchiolectasis) were detected at 3–6 months (2%) and remained stable at 1 year, with no evidence of honeycombing. At 1 year, lung abnormalities due to COVID-19 pneumonia were completely resolved in 78 of 84 (93%) participants.

Conclusion

Residual lung abnormalities in individuals hospitalized with moderate COVID-19 pneumonia were infrequent, with no evidence of fibrosis at 1-year chest CT.

© RSNA, 2022

Lung function six months after severe COVID-19: Does time, in fact, heal all wounds?

Background

COVID-19 has been associated with persistent symptoms and functional changes, especially in those surviving severe disease.

Methods

We conducted a prospective multicenter study in patients with severe COVID-19 to determine respiratory sequelae. Patients were stratified into two groups: ward admission (WA) and intensive care unit (ICU) admission. In each follow-up visit, the patients where inquired about cough and dyspnea, and performed spirometry, lung volumes, carbon monoxide diffusion capacity (DLCO), 6-minute walk test (6MWT), and respiratory muscle strength (MIP and MEP). Results of pulmonary function tests at 45 days and 6 months after hospital admission were compared using paired analysis.

Results

211 patients were included, 112 in WA and 99 in ICU. Dyspnea persisted in 64.7% in the WA and 66.7% in the ICU group after 6 months. Lung function measures showed significant improvement between 45 days and 6 months, both in WA and ICU groups in VC, FVC, FEV1, total lung capacity, and 6MW distance measures. The improvement in the proportions of the altered functional parameters was significant in the ICU group for VC (44.2% 45 d; 20.8% 6 m; p = 0,014), FVC (47.6% 45 d; 28% 6 m; p = 0,003), FEV1 (45.1% 45 d; 28% 6 m; p = 0,044), DLCO (33.8% 45 d; 7.7% 6 m; p < 0,0001).

Conclusion

Six months follow-up of patients with the severe forms of COVID-19 showed significant improvement in the lung function measures compared to 45 days post hospital discharge. The difference was more evident in those requiring ICU admission.

Dihydroartemisinin attenuates pulmonary inflammation and fibrosis in rats by suppressing JAK2/STAT3 signaling

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has induced a worldwide pandemic since early 2020. COVID-19 causes pulmonary inflammation, secondary pulmonary fibrosis (PF); however, there are still no effective treatments for PF. The present study aimed to explore the inhibitory effect of dihydroartemisinin (DHA) on pulmonary inflammation and PF, and its molecular mechanism. Morphological changes and collagen deposition were analyzed using hematoxylin-eosin staining, Masson staining, and the hydroxyproline content. DHA attenuated early alveolar inflammation and later PF in a bleomycin-induced rat PF model, and inhibited the expression of interleukin (IL)-1β, IL-6, tumor necrosis factor α (TNFα), and chemokine (C-C Motif) Ligand 3 (CCL3) in model rat serum. Further molecular analysis revealed that both pulmonary inflammation and PF were associated with increased transforming growth factor-β1 (TGF-β1), Janus activated kinase 2 (JAK2), and signal transducer and activator 3(STAT3) expression in the lung tissues of model rats. DHA reduced the inflammatory response and PF in the lungs by suppressing TGF-β1, JAK2, phosphorylated (p)-JAK2, STAT3, and p-STAT3. Thus, DHA exerts therapeutic effects against bleomycin-induced pulmonary inflammation and PF by inhibiting JAK2-STAT3 activation. DHA inhibits alveolar inflammation, and attenuates lung injury and fibrosis, possibly representing a therapeutic candidate to treat PF associated with COVID-19.