Respiratory Complications after COVID-19

Acute and post-acute respiratory complications of SARS-CoV-2 infection: population-based cohort study in South Korea and Japan

Considering the significant burden of post-acute COVID-19 conditions among patients infected with SARS-CoV-2, we aimed to identify the risk of acute respiratory complications or post-acute respiratory sequelae. A binational population-based cohort study was conducted to analyze the risk of acute respiratory complications or post-acute respiratory sequelae after SARS-CoV-2 infection. We used a Korean nationwide claim-based cohort (K-COV-N; n = 2,312,748; main cohort) and a Japanese claim-based cohort (JMDC; n = 3,115,606; replication cohort) after multi-to-one propensity score matching. Among 2,312,748 Korean participants (mean age, 47.2 years [SD, 15.6]; 1,109,708 [48.0%] female), 17.1% (394,598/2,312,748) were infected with SARS-CoV-2. The risk of acute respiratory complications or post-acute respiratory sequelae is significantly increased in people with SARS-CoV-2 infection compared to the general population (acute respiratory complications: HR, 8.06 [95% CI, 6.92-9.38]; post-acute respiratory sequelae: 1.68 [1.62-1.75]), and the risk increased with increasing COVID-19 severity. We identified COVID-19 vaccination as an attenuating factor, showing a protective association against acute or post-acute respiratory conditions. Furthermore, while the excess post-acute risk diminished with time following SARS-CoV-2 infection, it persisted beyond 6 months post-infection. The replication cohort showed a similar pattern in the association. Our study comprehensively evaluates respiratory complications in post-COVID-19 conditions, considering attenuating factors such as vaccination status, post-infection duration, COVID-19 severity, and specific respiratory conditions.

Lessons we learned during the past four challenging years in the COVID-19 era: pharmacotherapy, long COVID complications, and vaccine development

About four years have passed since the detection of the first cases of COVID-19 in China. During this lethal pandemic, millions of people have lost their lives around the world. Since the first waves of COVID-19 infection, various pharmacotherapeutic agents have been examined in the management of COVID-19. Despite all these efforts in pharmacotherapy, drug repurposing, and design and development of new drugs, multiple organ involvement and various complications occurred during COVID-19. Some of these complications became chronic and long-lasting which led to the "long COVID" syndrome appearance. Therefore, the best way to eradicate this pandemic is prophylaxis through mass vaccination. In this regard, various vaccine platforms including inactivated vaccines, nucleic acid-based vaccines (mRNA and DNA vaccines), adenovirus-vectored vaccines, and protein-based subunit vaccines have been designed and developed to prevent or reduce COVID-19 infection, hospitalization, and mortality rates. In this focused review, at first, the most commonly reported clinical presentations of COVID-19 during these four years have been summarized. In addition, different therapeutic regimens and their latest status in COVID-19 management have been listed. Furthermore, the "long COVID" and related signs, symptoms, and complications have been mentioned. At the end, the effectiveness of available COVID-19 vaccines with different platforms against early SARS-CoV-2 variants and currently circulating variants of interest (VOI) and the necessity of booster vaccine shots have been summarized and discussed in more detail.

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.

Substances of abuse and their effect on SAR-CoV-2 pathogenesis

Following the emergence of SARS-CoV-2, various reports suggest that there has been a significant increase in substance abuse due to social distancing and related issues. Several reports have suggested the impact of chronic substance use on individuals' physiological and psychological health. Therefore, there is a need to know the impact of SARS-CoV-2 on persons with substance use disorders. Individuals with substance use disorders are the most vulnerable groups and are at a high risk of SARS-CoV-2 infection due to their already existing health issues associated with substance use. This review discusses some of the molecular and systemic/organic effects chronic substance use such as alcohol, nicotine, marijuana (cannabis), opioids, methamphetamine, and cocaine have on SARS-CoV-2 infectivity and its potential cause for worsened disease outcomes in persons with substance use disorder. This will provide healthcare providers, public health policies, and researchers with the needed knowledge to address some of the many challenges faced during the Covid-19 pandemic to facilitate treatment strategies for persons with substance use disorders.

Post-Infection Oscillometry and Pulmonary Metrics in SARS-CoV-2 Patients: A 40-Day Follow-Up Study

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had significant impacts on pulmonary function. This study aimed to comprehensively evaluate pulmonary function and structure in patients 40 days post-SARS-CoV-2 infection, employing an array of testing methodologies including spirometry, plethysmography, forced oscillometry, and CT scanning. It also sought to establish potential correlations between these metrics and evaluate if forced oscillometry could provide additional value in post-infective lung function assessment. A 40-day post-infection follow-up observational study was conducted involving 66 patients with confirmed SARS-CoV-2 infection. The results revealed decreases in FVC and FEF25-75 with the increasing severity of COVID-19. Specifically, patients with severe symptoms exhibited statistically significant decreases in FVC (mean = 86.8) compared with those with mild symptoms (mean = 106.0; p = 0.018). The FEF25-75 showed a similar trend, with severe patients exhibiting a mean of 77.7 compared with 82.9 in the mild group (p = 0.017). Furthermore, resonant frequency (RF) increased with disease severity, with the severe group exhibiting a statistically significant increase (mean = 17.4) compared with the mild group (mean = 14.3; p = 0.042). CT scans showed an increase in ground-glass opacities with disease severity, with 81.8% of severe patients demonstrating this finding (p = 0.037). Multiple regression analysis revealed that Reactance at 4 Hz (X4), Forced Expiratory Flow 25-75% (FEF25-75), and Resonant Frequency (RF) were significantly related to COVID-19 severity. Specifically, for each unit increase in these factors, the risk of the event was estimated to increase by a factor of 3.16, 2.09, and 1.90, respectively. Conversely, Resistance at 4 Hz (R4) and Airway Resistance (RAW) were found to significantly decrease the event hazard, highlighting their potential protective role. Spirometry, plethysmography, and forced oscillometry are effective in assessing these changes. Forced oscillometry may be particularly beneficial in identifying subtle changes in lung function post-COVID-19. Further studies are warranted to validate these findings and develop strategies to manage post-infective pulmonary changes in SARS-CoV-2 patients.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

SARS-CoV-2 infection and multi-organ system damage: A review

The SARS-CoV-2 infection causes COVID-19, which has affected approximately six hundred million people globally as of August 2022. Organs and cells harboring angiotensin-converting enzyme 2 (ACE2) surface receptors are the primary targets of the virus. However, once it enters the body through the respiratory system, the virus can spread hematogenously to infect other body organs. Therefore, COVID-19 affects many organs, causing severe and long-term complications, even after the disease has ended, thus worsening the quality of life. Although it is known that the respiratory system is most affected by the SARS-CoV-2 infection, many organs/systems are affected in the short and long term. Since the COVID-19 disease simultaneously affects many organs, redesigning diagnostic and therapy policies to fit the damaged organs is strongly recommended. Even though the pathophysiology of many problems the infection causes is unknown, the frequency of COVID-19 cases rises with age and the existence of preexisting symptoms. This study aims to update our knowledge of SARS-CoV-2 infection and multi-organ dysfunction interaction based on clinical and theoretical evidence. For this purpose, the study comprehensively elucidates the most recent studies on the effects of SARS-CoV-2 infection on multiple organs and systems, including respiratory, cardiovascular, gastrointestinal, renal, nervous, endocrine, reproductive, immune, and parts of the integumentary system. Understanding the range of atypical COVID-19 symptoms could improve disease surveillance, limit transmission, and avoid additional multi-organ-system problems.

Gas6/TAM Axis Involvement in Modulating Inflammation and Fibrosis in COVID-19 Patients

Gas6 (growth arrest-specific gene 6) is a widely expressed vitamin K-dependent protein that is involved in many biological processes such as homeostatic regulation, inflammation and repair/fibrotic processes. It is known that it is the main ligand of TAMs, a tyrosine kinase receptor family of three members, namely MerTK, Tyro-3 and Axl, for which it displays the highest affinity. Gas6/TAM axis activation is known to be involved in modulating inflammatory responses as well as fibrotic evolution in many different pathological conditions. Due to the rapidly evolving COVID-19 pandemic, this review will focus on Gas6/TAM axis activation in SARS-CoV-2 infection, where de-regulated inflammatory responses and fibrosis represent a relevant feature of severe disease manifestation. Furthermore, this review will highlight the most recent scientific evidence supporting an unsuspected role of Axl as a SARS-CoV-2 infection driver, and the potential therapeutic advantages of the use of existing Axl inhibitors in COVID-19 management. From a physiological point of view, the Gas6/TAM axis plays a dual role, fostering the tissue repair processes or leading to organ damage and loss of function, depending on the prevalence of its anti-inflammatory or profibrotic properties. This review makes a strong case for further research focusing on the Gas6/TAM axis as a pharmacological target to manage different disease conditions, such as chronic fibrosis or COVID-19.

Post-COVID-19 syndrome symptoms after mild and moderate SARS-CoV-2 infection

Background

Post-COVID-19 Syndrome (PCS) is characterized by residual symptoms following the initial recovery from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The prevalence of PCS is known to be the highest among severe and critical forms of the disease. However, the occurrence and risk factors for PCS after mild or moderate SARS-CoV-2 infection has not been extensively investigated.

Methods

Online and offline via both paper or mailed questionnaires distributed among Jordan collected between 1st and 21st August 2021, including a total number of 800 respondents, of whom 495 had previous mild to moderate COVID-19 infection. The Newcastle post-COVID syndrome Follow-up Screening Questionnaire was modified, translated, and used as a standard instrument for data collection regarding psychological, medical, and socio-economic symptoms post-infection. The primary outcome was the prevalence of PCS after mild to moderate COVID-19 in Jordan. Secondary outcome was the identification of PCS risk factors.

Results

The most common PCS symptom was mood disturbance followed by fatigue, anxiety, and myalgia. Female gender significantly increased the risk for multiple PCS symptoms. Age < 30 years was found to be an independent risk factor for myalgia (p = 0.001).

Conclusion

PCS is highly prevalent among COVID-19 survivors in Jordan, especially in females and patients with comorbidities. Planning physical and mental rehabilitation services is recommended for those patients with PCS symptoms after mild to moderate COVID-19 infection.

Evaluation of cardio-pulmonary functions of previously healthy adults with moderate-severe COVID-19 pneumonia after discharge

Aim: Persistent dyspnea is one of the most frequent post-COVID symptoms. We aimed to evaluate the cardiopulmonary functions of COVID-19 survivors with moderate to severe COVID-19 pneumonia without comorbidity, during the first wave of pandemics. Material and Method: The study was conducted retrospectively in a single center. The electronic data of patients applied with dyspnea one month after hospital discharge, without any comorbidities, and who were evaluated with pulmonary function test (PFT) and echocardiography were included in the study. A total of adult 88 patients who suffered from COVID-19 pneumonia (46 moderate and 42 severe) were enrolled. Results of biochemical, hematological and radiological examinations, PFT parameters and echocardiography were recorded and compared between moderate and severe cases. Results: The mean age of 88 patients included in the study was 48±13 years. Sixty-seven (74.4%) of the patients were male. Pulmonary thromboembolism was not detected in both groups. PFT parameters performed were similar in the two groups and there was no statistically significant difference. Pulmonary function test of the patients with moderate COVID-19 pneumonia revealed mild restriction in 21.7% and moderate restriction in 2% of the patients. In the severe group, 38.1% of the patients had mild and 4.8% of the patients had a moderate restrictive pattern. Small airway obstruction was detected in 37% of the moderate group and in 38.1% of the severe group. Conventional echocardiographic parameters of the two groups were normal. Pulmonary arterial pressures were 22.6±8.3 vs 22.1±6.8; p=0.8 was found. Tricuspid annular plane systolic excursion were within normal limits. Conclusıon: The persistent dyspnea following COVID-19 pneumonia may be related to disturbances in PFT even in patients without comorbidities. We concluded that; the detailed evaluation of the patients with prolonged respiratory symptoms might help to detect the cardiopulmonary functional disturbances.

Reinfection in patients with COVID-19: a systematic review

BACKGROUND

With the continuation of the COVID-19 pandemic, some COVID-19 patients have become reinfected with the virus. Viral gene sequencing has found that some of these patients were reinfected by the different and others by same strains. This has raised concerns about the effectiveness of immunity after infection and the reliability of vaccines. To this end, we conducted a systematic review to assess the characteristics of patients with reinfection and possible causes.

METHODS

A systematic search was conducted across eight databases: PubMed, Embase, Web of Science, The Cochrane Library, CNKI, WanFang, VIP and SinoMed from December 1, 2019 to September 1, 2021. The quality of included studies were assessed using JBI critical appraisal tools and Newcastle-Ottawa Scale.

RESULTS

This study included 50 studies from 20 countries. There were 118 cases of reinfection. Twenty-five patients were reported to have at least one complication. The shortest duration between the first infection and reinfection was 19 days and the longest was 293 days. During the first infection and reinfection, cough (51.6% and 43.9%) and fever (50% and 30.3%) were the most common symptoms respectively. Nine patients recovered, seven patients died, and five patients were hospitalized, but 97 patients' prognosis were unknown. B.1 is the most common variant strain at the first infection. B.1.1.7, B.1.128 and B.1.351 were the most common variant strains at reinfection. Thirty-three patients were infected by different strains and 9 patients were reported as being infected with the same strain.

CONCLUSIONS

Our research shows that it is possible for rehabilitated patients to be reinfected by SARS-COV-2. To date, the causes and risk factors of COVID-19 reinfection are not fully understood. For patients with reinfection, the diagnosis and management should be consistent with the treatment of the first infection. The public, including rehabilitated patients, should be fully vaccinated, wear masks in public places, and pay attention to maintaining social distance to avoid reinfection with the virus.