Association of COVID-19 and other viral infections with interstitial lung diseases, pulmonary fibrosis, and pulmonary hypertension: A narrative review

COVID-19 and Comorbidities: What Has Been Unveiled by Metabolomics?

The COVID-19 pandemic has brought about diverse impacts on the global population. Individuals with comorbidities were more susceptible to the severe symptoms caused by the virus. Within the crisis scenario, metabolomics represents a potential area of science capable of providing relevant information for understanding the metabolic pathways associated with the intricate interaction between the viral disease and previous comorbidities. This work aims to provide a comprehensive description of the scientific production pertaining to metabolomics within the specific context of COVID-19 and comorbidities, while highlighting promising areas for exploration by those interested in the subject. In this review, we highlighted the studies of metabolomics that indicated a variety of metabolites associated with comorbidities and COVID-19. Furthermore, we observed that the understanding of the metabolic processes involved between comorbidities and COVID-19 is limited due to the urgent need to report disease outcomes in individuals with comorbidities. The overlap of two or more comorbidities associated with the severity of COVID-19 hinders the comprehension of the significance of each condition. Most identified studies are observational, with a restricted number of patients, due to challenges in sample collection amidst the emergent situation.

Assisted mobilisation in critical patients with COVID-19

The therapeutic value of early physiotherapeutic treatment in critical respiratory settings has already been clearly outlined in the last fifteen years by several authors. However, there is still a controversial perception of mobilisation by healthcare professions. In-bed cycling has attracted increasing attention having been demonstrated as a feasible and safe intervention in critical settings. Patients with respiratory diseases are typically prone to fatigue and exertional dyspnoea, as we observe in COVID-19 pandemic; in fact, these patients manifest respiratory and motor damage that can even be associated with cognitive and mental limitations. COVID-19 is at risk of becoming a chronic disease if the clinical sequelae such as pulmonary fibrosis are confirmed as permanent outcomes by further analysis, particularly in those cases with overlapping pre-existent pulmonary alterations. In the present article, we propose a practical analysis of the effects of in-bed cycling, and further discuss its potential advantages if used in critical patients with COVID-19 in intensive care settings.

Interstitial lung changes and persistent COVID-19 in a patient with follicular lymphoma: A case report

We herein report a case of interstitial lung changes in a patient with prolonged coronavirus disease 2019 (COVID-19) with follicular lymphoma receiving rituximab and bendamustine who recovered after treatment with a combination therapy consisting of corticosteroids and immunosuppressive agents. There is currently no treatment strategy for prolonged pneumonitis following COVID-19, which can be life-threatening for immunocompromised patients. Thus, further investigation is warranted.

Clinicopathological Outlines of Post-COVID-19 Pulmonary Fibrosis Compared with Idiopathic Pulmonary Fibrosis

This review brings together the current knowledge regarding the risk factors and the clinical, radiologic, and histological features of both post-COVID-19 pulmonary fibrosis (PCPF) and idiopathic pulmonary fibrosis (IPF), describing the similarities and the disparities between these two diseases, using numerous databases to identify relevant articles published in English through October 2022. This review would help clinicians, pathologists, and researchers make an accurate diagnosis, which can help identify the group of patients selected for anti-fibrotic therapies and future therapeutic perspectives.

The Evolving Phenotypes of Cardiovascular Disease during COVID-19 Pandemic

COVID-19 pandemic has negatively impacted the management of patients with acute and chronic cardiovascular disease: acute coronary syndrome patients were often not timely reperfused, heart failure patients not adequately followed up and titrated, atrial arrhythmias not efficaciously treated and became chronic. New phenotypes of cardiovascular patients were more and more frequent during COVID-19 pandemic and are expected to be even more frequent in the next future in the new world shaped by the pandemic. We therefore aimed to briefly summarize the main changes in the phenotype of cardiovascular patients in the COVID-19 era, focusing on new clinical challenges and possible therapeutic options.

Post-COVID interstitial lung disease in symptomatic patients after COVID-19 disease

COVID-19 is often associated with long-lasting pulmonary symptoms. Data are scarce about interstitial lung disease (ILD) in patients following COVID-19 hospitalization with persistent symptoms. We retrospectively reviewed all cases sent to pulmonary post-COVID evaluation due to persistent symptoms between February 2021 and February 2022 (N = 318). All patients with suspected ILD (N = 44) were reviewed at the multidisciplinary discussion. Patient characteristics, symptoms, time since hospitalization, detailed lung function measurements and 6-min walk test (6MWT) were evaluated. The post-COVID ILD suspected group included more men (68.2 vs. 31.8%) with significantly older age compared to the control group (64.0 ± 12.3 vs. 51.3 ± 14.9 years). Most patient needed hospital care for COVID-19 pneumonia (68.6% of all patients and 84.1% of ILD suspected group) and average time since hospitalization was 2.4 ± 2.3 months. Persisting symptoms included fatigue (34%), dyspnoea (25.2%), cough (22.6%), and sleep disorders (insomnia 13.2%; sleepiness 8.2%). Post-COVID ILD presented more often with new symptoms of cough and sleepiness. Functional impairment, especially decreased walking distance and desaturation during 6-min walk test (6MWT) were detected in the ILD-suspected group. Respiratory function test in the post-COVID ILD group showed slight restrictive ventilatory pattern (FVC: 76.7 ± 18.1%, FEV1: 83.5 ± 19.1%, TLC: 85.6 ± 28.1%) and desaturation during 6MWT were detected in 41% of patients. LDCT changes were mainly ground glass opacities (GGO) and/or reticular abnormalities in most cases affecting < 10% of the lungs. Our data indicate that suspected post-COVID ILD is affecting 13.8% of symptomatic patients. High resolution chest CT changes were mainly low extent GGO/reticulation, while long-term lung structural changes need further evaluation.

Cardiovascular, Pulmonary, and Neuropsychiatric Short- and Long-Term Complications of COVID-19

Beginning with the various strategies of the SARS-CoV-2 virus to invade our bodies and manifest infection, and ending with the recent long COVID, we are witnessing the evolving course of the disease in addition to the pandemic. Given the partially controlled course of the COVID-19 pandemic, the greatest challenge currently lies in managing the short- and long-term complications of COVID-19. We have assembled current knowledge of the broad spectrum of cardiovascular, pulmonary, and neuropsychiatric sequelae following SARS-CoV-2 infection to understand how these clinical manifestations collectively lead to a severe form of the disease. The ultimate goal would be to better understand these complications and find ways to prevent clinical deterioration.

The Role of DNA Damage and Repair in Idiopathic Pulmonary Fibrosis

The mortality rate of idiopathic pulmonary fibrosis (IPF) increases yearly due to ineffective treatment. Given that the lung is exposed to the external environment, it is likely that oxidative stress, especially the stimulation of DNA, would be of particular importance in pulmonary fibrosis. DNA damage is known to play an important role in idiopathic pulmonary fibrosis initiation, so DNA repair systems targeting damage are also crucial for the survival of lung cells. Although many contemporary reports have summarized the role of individual DNA damage and repair pathways in their hypotheses, they have not focused on idiopathic pulmonary fibrosis. This review, therefore, aims to provide a concise overview for researchers to understand the pathways of DNA damage and repair and their roles in IPF.

SARS-CoV-2 infection produces chronic pulmonary epithelial and immune cell dysfunction with fibrosis in mice

A subset of individuals who recover from coronavirus disease 2019 (COVID-19) develop post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal tissue samples. The mouse-adapted SARS-CoV-2 strain MA10 produces an acute respiratory distress syndrome in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute to clinical recovery phases. At 15 to 120 days after virus clearance, pulmonary histologic findings included subpleural lesions composed of collagen, proliferative fibroblasts, and chronic inflammation, including tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal up-regulation of profibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early antifibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

Postdischarge outcomes of COVID-19 patients from South Asia: a prospective study

BACKGROUND

Coronavirus disease 2019 (COVID-19) may cause clinical manifestations that last for weeks or months after hospital discharge. The manifestations are heterogeneous and vary in their frequency. Their multisystem nature requires a holistic approach to management. There are sparse data from the South Asian region on the outcomes of hospital-discharged COVID-19 patients. We assessed the posthospital discharge outcomes of a cohort of Sri Lankan COVID-19 patients and explored the factors that influenced these outcomes.

METHODS

Data were prospectively collected from patients who were discharged following an admission to the Nawaloka Hospital, Sri Lanka with COVID-19 from March to June 2021. At discharge, their demographic, clinical and laboratory findings were recorded. The patients were categorised as having mild, moderate and severe COVID-19, based on the Sri Lanka Ministry of Health COVID-19 guidelines. Following discharge, information on health status, complications and outcomes was collected through clinic visits and preplanned telephone interviews. A validated (in Sri Lanka) version of the Short Form 36 health survey questionnaire (SF-36) was used to assess multi-item dimensions health status of the patients at 1, 2 and 3 mo postdischarge.

RESULTS

We collected data on 203 patients (male, n=111 [54.7%]). The level of vaccination was significantly associated with disease severity (p<0.001). Early recovery was seen in the mild group compared with the moderate and severe groups. At 3 mo, on average 98% of mild and 90% of moderate/severe patients had recovered. Based on the SF-36, physical functioning dimensions, role limitation due to physical and emotional health, energy/ fatigue, emotional well-being, social functioning, pain and general health were significantly different in the moderate/severe vs mild COVID-19 groups at 1, 2 and 3 mo postdischarge (p<0.05). Twenty-three patients developed complications, of which the most common were myocardial infarction with heart failure (n=6/23; 26.1%), cerebrovascular accident (n=6/23; 26.1%) and respiratory tract infections (n=3/23; 13.01%) and there were six deaths.

CONCLUSIONS

In our cohort, receiving two doses of the COVID-19 vaccine was associated with reduced disease severity. Those with mild disease recovered faster than those with moderate/severe disease. At 3 mo posthospital discharge, >90% had recovered.

Interrelation Between Fibroblasts and T Cells in Fibrosing Interstitial Lung Diseases

Interstitial lung diseases (ILDs) are a heterogeneous group of diseases characterized by varying degrees of inflammation and fibrosis of the pulmonary interstitium. The interrelations between multiple immune cells and stromal cells participate in the pathogenesis of ILDs. While fibroblasts contribute to the development of ILDs through secreting extracellular matrix and proinflammatory cytokines upon activation, T cells are major mediators of adaptive immunity, as well as inflammation and autoimmune tissue destruction in the lung of ILDs patients. Fibroblasts play important roles in modulating T cell recruitment, differentiation and function and conversely, T cells can balance fibrotic sequelae with protective immunity in the lung. A more precise understanding of the interrelation between fibroblasts and T cells will enable a better future therapeutic design by targeting this interrelationship. Here we highlight recent work on the interactions between fibroblasts and T cells in ILDs, and consider the implications of these interactions in the future development of therapies for ILDs.

Seven days treatment with the angiotensin II type 2 receptor agonist C21 in hospitalized COVID-19 patients; a placebo-controlled randomised multi-centre double-blind phase 2 trial

BACKGROUND

COVID-19 morbidity and mortality remains high and the need for safe and effective drugs continues despite vaccines.

METHODS

Double-blind, placebo-controlled, multi-centre, randomised, parallel group phase 2 trial to evaluate safety and efficacy of oral angiotensin II type 2 receptor agonist C21 in hospitalized patients with COVID-19 and CRP ≥ 50-150 mg/L conducted at eight sites in India (NCT04452435). Patients were randomly assigned 100 mg C21 bid or placebo for 7 days in addition to standard of care. Primary endpoint: reduction in CRP. The study period was 21 July to 13 October 2020.

FINDINGS

106 patients were randomised and included in the analysis (51 C21, 55 placebo). There was no significant group difference in reduction of CRP, 81% and 78% in the C21 and placebo groups, respectively, with a treatment effect ratio of 0.85 [90% CI 0.57, 1.26]. In a secondary analysis in patients requiring supplemental oxygen at randomisation, CRP was reduced in the C21 group compared to placebo. At the end of the 7-day treatment, 37 (72.5%) and 30 (54.5%) of the patients did not require supplemental oxygen in the C21 and placebo group, respectively (OR 2.20 [90% CI 1.12, 4.41]). A post hoc analysis showed that at day 14, the proportion of patients not requiring supplemental oxygen was 98% and 80% in the C21 group compared to placebo (OR 12.5 [90% CI 2.9, 126]). Fewer patients required mechanical ventilation (one C21 patient; four placebo patients), and C21 was associated with a numerical reduction in the mortality rate (one vs three in the C21 and placebo group, respectively). Treatment with C21 was safe and well tolerated.

INTERPRETATION

Among hospitalised patients with COVID-19 receiving C21 for 7 days there was no reduction in CRP compared to placebo. However, a post-hoc analysis indicated a marked reduction of requirement for oxygen at day 14. The day 14 results from this study justify further evaluation in a Phase 3 study and such a trial is currently underway.

FUNDING

Vicore Pharma AB and LifeArc, UK.

Perpetually Positive: Post-COVID Interstitial Lung Disease in an Immunocompromised Patient With Diffuse Large B-cell Lymphoma

As more patients recover from COVID-19 infection, long-term complications are beginning to arise. Our case report will explore a debilitating long-term complication, Post-COVID Interstitial Lung Disease (PC-ILD). We will introduce a patient who developed PC-ILD in the setting of diffuse large B-cell lymphoma, outlining a difficult hospital course, including a positive COVID-19 polymerase chain reaction (PCR) for more than 3 months. We will then discuss the human body’s physiological response to the virus and how our patient was not able to adequately mount an immune response. Finally, the pathophysiology of PC-ILD will be explored and correlated with the patient’s subsequent computed tomographic images obtained over a 3-month period. The difficult hospital course and complex medical decision-making outlined in this case report serve as a reminder for health care providers to maintain vigilance in protecting our most vulnerable patient population from such a devastating disease process.

Effects of Exercise Training on Cardiopulmonary Function and Quality of Life in Elderly Patients with Pulmonary Fibrosis: A Meta-Analysis

(1) Objective: Our objective was to conduct a meta-analysis of randomized controlled trials that have evaluated the benefits of exercise training for elderly pulmonary fibrosis (PF) patients. (2) Methods: Studies in either English or Chinese were retrieved from the China National Knowledge Infrastructure (CNKI) and the Wanfang, PubMed, Web of Science and SPORTDiscus databases from inception until the first week of April 2021. Age, body mass index (BMI), and exercise frequency, intensity, type, and duration were considered for each participant. The specific data recorded were the six-minute walk distance (6MWD), maximal rate of oxygen consumption (peak VO2), predicted forced vital capacity (FVC% pred), predicted diffusing capacity of the lung for carbon monoxide (DLCO% pred), predicted total lung capacity (TLC% pred), St. George's respiratory questionnaire (SGRQ) total score and a modified medical research council score (mMRC). (3) Results: Thirteen studies comprised this meta-analysis (eleven randomized controlled trials and two prospective studies design), wherein 335 patients were exercised and 334 were controls. The results showed that exercise training increased the 6MWD (Cohen's d = 0.77, MD = 34.04 (95% CI, 26.50-41.58), p < 0.01), peak VO2 (Cohen's d = 0.45, MD = 1.13 (95% CI, 0.45-1.82), p = 0.0001) and FVC% pred (Cohen's d = 0.42, MD = 3.94 (95% CI, 0.91-6.96), p = 0.01). However, exercise training reduced scores for the SGRQ (Cohen's d = 0.89, MD = -8.79 (95% CI, -10.37 to -7.21), p < 0.01) and the mMRC (Cohen's d = 0.64, MD = -0.58 (95% CI, -0.79 to -0.36), p < 0.01). In contrast, exercise training could not increase DLCO% pred (Cohen's d = 0.16, MD = 1.86 (95% CI, -0.37-4.09), p = 0.10) and TLC% pred (Cohen's d = 0.02, MD = 0.07 (95% CI, -6.53-6.67), p = 0.98). Subgroup analysis showed significant differences in frequency, intensity, type, and age in the 6MWD results (p < 0.05), which were higher with low frequency, moderate intensity, aerobic-resistance-flexibility-breathing exercises and age ≤ 70. Meanwhile, the subgroup analysis showed significant differences in exercise intensity and types in the mMRC results (p < 0.05), which were lower with moderate intensity and aerobic-resistance exercises. (4) Conclusions: Exercise training during pulmonary rehabilitation can improved cardiopulmonary endurance and quality of life in elderly patients with PF. The 6MWDs were more noticeable with moderate exercise intensity, combined aerobic-resistance-flexibility-breathing exercises and in younger patients, which all were not affected by BMI levels or exercise durations. As to pulmonary function, exercise training can improve FVC% pred, but has no effect on DLCO% pred and TLC% pred.

Role of JAK/STAT in Interstitial Lung Diseases; Molecular and Cellular Mechanisms

Interstitial lung diseases (ILDs) comprise different fibrotic lung disorders characterized by cellular proliferation, interstitial inflammation, and fibrosis. The JAK/STAT molecular pathway is activated under the interaction of a broad number of profibrotic/pro-inflammatory cytokines, such as IL-6, IL-11, and IL-13, among others, which are increased in different ILDs. Similarly, several growth factors over-expressed in ILDs, such as platelet-derived growth factor (PDGF), transforming growth factor β1 (TGF-β1), and fibroblast growth factor (FGF) activate JAK/STAT by canonical or non-canonical pathways, which indicates a predominant role of JAK/STAT in ILDs. Between the different JAK/STAT isoforms, it appears that JAK2/STAT3 are predominant, initiating cellular changes observed in ILDs. This review analyzes the expression and distribution of different JAK/STAT isoforms in ILDs lung tissue and different cell types related to ILDs, such as lung fibroblasts and alveolar epithelial type II cells and analyzes JAK/STAT activation. The effect of JAK/STAT phosphorylation on cellular fibrotic processes, such as proliferation, senescence, autophagy, endoplasmic reticulum stress, or epithelial/fibroblast to mesenchymal transition will be described. The small molecules directed to inhibit JAK/STAT activation were assayed in vitro and in in vivo models of pulmonary fibrosis, and different JAK inhibitors are currently approved for myeloproliferative disorders. Recent evidence indicates that JAK inhibitors or monoclonal antibodies directed to block IL-6 are used as compassionate use to attenuate the excessive inflammation and lung fibrosis related to SARS-CoV-2 virus. These altogether indicate that JAK/STAT pathway is an attractive target to be proven in future clinical trials of lung fibrotic disorders.