Does COVID-19 pneumonia signify secondary organizing pneumonia?: A narrative review comparing the similarities between these two distinct entities

Prolonged COVID-19 Pneumonia in Patients with Hematologic Malignancies: Clinical Significance and Serial CT Findings

(1) Background: Hematologic malignancy patients have a heightened risk for prolonged COVID-19 pneumonia. (2) Methods: We retrospectively investigated the clinical significance and serial CT findings of prolonged COVID-19 pneumonia in hematologic malignancy patients. Hematologic malignancy patients with persistent SARS-CoV-2 polymerase chain reaction (PCR) positivity >30 days and more than one chest CT after initial positivity were reviewed. Serial CT images were analyzed for the presence of COVID-19 pneumonia, patterns and distribution of CT findings, and severity scores of lung involvement. Clinical characteristics of the patients, including treatments for underlying hematologic malignancy prior to and after COVID-19 and COVID-19-related factors, were compared according to the presence of COVID-19 pneumonia. (3) Results: A total of 55 patients (36 male, median age 60 years) were included in the study. A total of 56.4% had received B-cell-directed therapies, such as rituximab or teclistamab, within one year of COVID-19 diagnosis. A total of 76.4% of patients had the presence of COVID-19 pneumonia on CT, with a median CT duration of pneumonia of 35.5 days, and they experienced more frequent (p = 0.005) and longer (p = 0.002) hospital stays and longer delays in treatment for underlying malignancy (p = 0.03), compared to those without evidence of COVID-19 pneumonia on CT. The development of COVID-19 pneumonia was significantly related to B-cell-directed antibody therapies (p = 0.02). Median CT severity scores during <30 days, 30-59 days, 60-89 days, and ≥90 days from initial diagnosis were 2.0, 2.0, 2.0, and 1.0, respectively. (4) Conclusions: Patients with hematologic malignancies may experience prolonged COVID-19 pneumonia, which is associated with the use of B-cell-directed antibody-based drugs and can result in longer hospital stays and delays in treatments for underlying malignancy.

Trans-bronchial forceps biopsy for COVID-19 related diffuse parenchymal lung abnormalities

PURPOSE

The role of lung biopsy for evaluation of persistent chest radiographic abnormalities including secondary organizing pneumonia (OP) in COVID-19 remains uncertain. This study aimed to evaluate the diagnostic value of trans-bronchial forceps biopsy (TBFB) in patients with persistent lung abnormalities on thoracic computed tomography (CT) scan following SARS-CoV-2 infection with particular focus on cases with OP and immunocompromised (IC) patients.

METHODS

Descriptive retrospective single center analysis of all TBFB performed for diffuse lung parenchymal changes after COVID-19 03-2020 to 06-2023.

RESULTS

Twenty seven consecutive TBFB including 23 in IC patients resulted in 100% samples with alveolar tissue showing a high frequency of 12/27 (44%) histological pattern of OP. Steroids were used in 21/27 patients (78%) including 11/12 (92%) with OP. Clinical outcome at discharge was favorable in 89% (92% with OP).

CONCLUSION

TBFB contributes to the diagnosis of diffuse parenchymal lung abnormalities in the context of COVID-19 including a frequent OP pattern particularly in IC patients. Larger studies are necessary to confirm our data and elucidate on the optimal steroid treatment modality.

TRIAL REGISTRATION

Clinical trial number: not applicable. The study was approved by the Ethics Committee of the University Medicine Carl Gustav Carus, TU Dresden (BO-EK-309072023). Waiver of informed consent was granted because of the retrospective nature of the study.

Risk Factors for Secondary Organizing Pneumonia and Acute Fibrinous and Organizing Pneumonia in Patients with COVID-19 Pneumonia

Purpose

Secondary organizing pneumonia (OP) and acute fibrinous and organizing pneumonia (AFOP) are frequently observed in cases of COVID-19 pneumonia. Nevertheless, the identification of risk factors related to OP/AFOP and their impact on patient outcomes remain inadequately elucidated.

Patients and Methods

This retrospective study aimed to identify risk factors associated with OP/AFOP in patients with COVID-19 pneumonia and to compare clinical outcomes between patients with and without OP/AFOP. The study included hospitalized patients with COVID-19 pneumonia admitted between July 1 and September 30, 2021. Factors associated with OP/AFOP were identified using multivariable regression analysis. Additionally, a multivariable Cox proportional hazard model was used to evaluate the association of OP/AFOP with 90-day mortality.

Results

Among the 666 hospitalized patients with COVID-19 pneumonia, 53 (8%) developed OP/AFOP during their admission. When compared to patients younger than 50 years old, those aged 50-70 and over 70 years old exhibited an increased risk of developing OP/AFOP, with adjusted odds ratios (aOR) of 3.87 (95% CI, 1.24-12.11; P=0.02) and 5.74 (95% CI, 1.80-18.27; P=0.003), respectively. Other factors associated with OP/AFOP included a history of diabetes mellitus (aOR 2.37; 95% CI, 1.27-4.44; P=0.01) and patients with oxygen saturation at admission below 88% (aOR 4.52; 95% CI, 1.22-16.67; P=0.02). Furthermore, the presence of OP/AFOP was correlated with an increased risk of various complications, such as respiratory failure, acute kidney injury, secondary infections, pneumothorax, pneumomediastinum, and pulmonary embolism. Lastly, patients with OP/AFOP exhibited significantly higher 90-day mortality (adjusted hazard ratio 3.40; 95% CI, 1.68-6.92; P=0.001) compared to those without OP/AFOP.

Conclusion

We identified factors associated with an increased risk of OP/AFOP in patients with COVID-19 pneumonia, which included age ≥50 years, a history of DM, and hypoxemia on admission (SpO2 <88%). Furthermore, our study revealed that OP/AFOP was significantly linked to higher 90-day mortality.

A Child with COVID-19 Complicated by Rapidly Progressive Severe Organizing Pneumonia: A Case Report

A 2-year-old boy tested positive for SARS-CoV-2 and, after 30 days of mild-moderate respiratory symptoms, suddenly deteriorated and required extracorporeal membrane oxygenation. Lung biopsy was performed with findings consistent with organizing pneumonia. He received intensive therapy with high-dose methylprednisolone, intravenous immune globulin, rituximab, and plasmapheresis without improvement. He died after 85 days hospitalization. This case highlights unique presentations of COVID-19 and reaffirms the concept that, while rare in Hawai'i, pediatric COVID-19 is an ongoing problem and that severe, even fatal, disease can occur.

Lung Ultrasound Efficacy in Monitoring Post-SARS-CoV-2 Pneumonia and Inflammatory Biomarkers in Pediatric Patients

Background and Objectives: Recognizing the crucial gaps in our understanding of pediatric pneumonia post-SARS-CoV-2 infection, this study aimed to assess the relationship between Pediatric Pneumonia Ultrasound Scores (PedPne) and inflammatory biomarkers. The primary objective of this study is to evaluate the predictive value of PedPne in comparison with inflammatory biomarkers (IL-6 and dNLR) for the development of pneumonia in pediatric patients following SARS-CoV-2 infection. Materials and Methods: This longitudinal observational study collected data from pediatric patients diagnosed with pneumonia after an acute SARS-CoV2 infection. The study focused on analyzing changes in PedPne scores and inflammatory markers such as IL-6 and dNLR from initial admission to follow-up at 7 days. Statistical analysis involved calculating the sensitivity, specificity, and Area Under the Curve (AUC) for each biomarker, alongside regression analysis to determine their hazard ratios for predicting pneumonia development. Results: The analysis identified significant cutoff values for dNLR at 1.88 (sensitivity 77.0%, specificity 85.7%, AUC 0.802, p < 0.001), IL-6 at 6.1 pg/mL (sensitivity 70.3%, specificity 92.9%, AUC 0.869, p < 0.001), and PedPne score at 3.3 (sensitivity 75.7%, specificity 78.6%, AUC 0.794, p < 0.001). Conversely, NLR showed lower diagnostic performance (AUC 0.485, p = 0.327). Regression analysis further highlighted the strong predictive power of these markers, with IL-6 showing a fourfold increase in pneumonia risk (HR = 4.25, CI: 2.07-9.53, p < 0.001), dNLR indicating more than a twofold increase (HR = 2.53, CI: 1.19-6.97, p = 0.006), and PedPne score associated with more than a doubling of the risk (HR = 2.60, CI: 1.33-5.18, p < 0.001). Conclusions: The study conclusively demonstrated that both PedPne ultrasound scores and specific inflammatory biomarkers such as dNLR and IL-6 are significant predictors of pneumonia development in pediatric patients post-COVID-19 infection. These findings advocate for the integration of these biomarkers in routine clinical assessments to enhance the diagnostic accuracy and management of pneumonia in children following SARS-CoV-2 infection.

Case report: Suspected organizing pneumonia secondary to severe respiratory syncytial virus pneumonia in an elderly patient

Respiratory syncytial virus (RSV) usually causes acute respiratory tract infection in infants. In recent years, it has gradually become an important pathogen of lower respiratory tract infection in elderly people with an underlying disease. However, at present, the treatment of severe RSV pneumonia in adults is unclear, and organizing pneumonia (OP) after severe RSV infection has rarely been reported. We reported a 76-year-old man with multiple chronic heart and lung diseases who presented with fever, cough and progressive dyspnea. Finally, severe RSV pneumonia was diagnosed after his nasopharyngeal swabs and bronchoalveolar lavage metagenomic next-generation sequencing tests were positive for RSV. After combined treatment with oral ribavirin, intravenous immunoglobulin and corticosteroids, the patient's condition largely resolved, and he was discharged. However, when the corticosteroids were gradually tapered, the disease relapsed twice, and the patient experienced fever and aggravated dyspnea. Despite the lack of pathological evidence, we highly suspected organizing pneumonia secondary to severe RSV pneumonia based on the typical imaging manifestations and the clinical characteristics of a good response to corticosteroids. Finally, this patient was successfully treated with a course of corticosteroids and followed up for 14 months in total.

Radiologic Abnormalities in Prolonged SARS-CoV-2 Infection: A Systematic Review

We systematically reviewed radiological abnormalities in patients with prolonged SARS-CoV-2 infection, defined as persistently positive polymerase chain reaction (PCR) results for SARS-CoV-2 for > 21 days, with either persistent or relapsed symptoms. We extracted data from 24 patients (median age, 54.5 [interquartile range, 44-64 years]) reported in the literature and analyzed their representative CT images based on the timing of the CT scan relative to the initial PCR positivity. Our analysis focused on the patterns and distribution of CT findings, severity scores of lung involvement on a scale of 0-4, and the presence of migration. All patients were immunocompromised, including 62.5% (15/24) with underlying lymphoma and 83.3% (20/24) who had received anti-CD20 therapy within one year. Median duration of infection was 90 days. Most patients exhibited typical CT appearance of coronavirus disease 19 (COVID-19), including ground-glass opacities with or without consolidation, throughout the follow-up period. Notably, CT severity scores were significantly lower during ≤ 21 days than during > 21 days (P < 0.001). Migration was observed on CT in 22.7% (5/22) of patients at ≤ 21 days and in 68.2% (15/22) to 87.5% (14/16) of patients at > 21 days, with rare instances of parenchymal bands in previously affected areas. Prolonged SARS-CoV-2 infection usually presents as migrating typical COVID-19 pneumonia in immunocompromised patients, especially those with impaired B-cell immunity.

Rapidly Progressing Secondary Organizing Pneumonia Due to Underlying Immunosuppression With Rituximab in SARS-CoV-2 Patients

Secondary organizing pneumonia (SOP) as a sequela to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) usually has a prolonged benign course with a good response to corticosteroids. We present a case series of three patients who developed rapid progression to organizing pneumonia, after initial presentation with SARS-CoV-2. Imaging revealed rapid interval progression of bilateral subpleural ground glass opacities, and lung biopsy showed dense fibroblastic plugs within the alveoli. Two patients were steroid-responsive, and one patient succumbed to his illness despite maximal therapy. We postulate that B-cell depletion and immunosuppression may cause rapid progression to SOP, as all three patients were immunosuppressed and on chronic rituximab therapy.

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.

Organizing Pneumonia Associated with Pneumocystis jirovecii in a Patient Receiving Dose-Dense Chemotherapy for Breast Cancer: A Case Report

In patients not infected by HIV, Pneumocystis jirovecii pneumonia (PCP) is characterized by rapid disease progression, difficulty in confirming the diagnosis, and poor prognosis. PCP has also been reported in immunocompromised patients receiving chemotherapy, most often for hematologic tumors, although some patients receiving treatment for breast cancer have been affected. Dose-dense chemotherapy (DDC) which is performed with shorter dosing intervals than standard chemotherapy and is now widely used in clinical practice. However, adverse events have been reported, including infections associated with decreased immune status. PCP infection is considerably more challenging to diagnose and treat than bacterial or viral infections. Furthermore, organizing pneumonia (OP), a pulmonary lesion of PCP, is infrequent and requires caution on the part of clinicians, as protozoan infections require different forms of treatment. Although we initially suspected bacterial, viral, and drug-induced pneumonia in our patient and started treatment with antibiotics, antifungals, and prednisolone, the final diagnosis was OP. The pulmonary lesion of PCP was treated with systemic corticosteroids, leading to recovery. There have been no similar reports of PCP during chemotherapy for malignant disease; however, the possibility of OP should be considered during chemotherapy. Herein, we report a case of PCP during preoperative DDC for advanced breast cancer.

Organizing pneumonia and COVID-19

Organizing pneumonia (OP) is an interstitial lung disease, and can be cryptogenic, if no cause is identified, or secondary to several conditions. COVID-19-induced persistent inflammation can be associated with interstitial lung disease. We present a review of literature of OP and COVID-19-induced OP with an illustrative case. A 38-year-old man was admitted with COVID-19 that required mechanical ventilation for 56 days. Initial chest computed tomography (CT) revealed diffuse bilateral ground-glass opacities in the lungs with consolidation areas involving 75 % of the parenchyma. After weaning from MV, the patient still required oxygen supplementation. A new chest CT scan also showed extensive diffuse areas of consolidation and ground-glass opacity. OP was hypothesized and 40 mg/day prednisone initiated and continued for six months with resolution of lung functional and image abnormalities. Organizing pneumonia should be included in the differential diagnosis of COVID-19 patients with respiratory symptoms after partial pulmonary recovery.

Efficacy of Additional Corticosteroids After Dexamethasone Treatment for Moderate to Severe COVID-19: An Observational Study

Background Previous studies have demonstrated dexamethasone (DEX)'s efficacy for coronavirus disease 2019 (COVID-19). In contrast, patients with residual lung field shading and symptoms after DEX treatment have been observed, and the efficacy of additional corticosteroids (AC) is unknown. Objectives We aimed to investigate the efficacy of AC in patients with COVID-19 with residual respiratory symptoms or who required oxygen therapy or invasive mechanical ventilation after DEX treatment. Methods This was a single-center, retrospective observational study including 261 patients with community-onset COVID-19, aged ≥ 18 years, admitted to our hospital between March 1, 2020, and May 31, 2021. Finally, 34 patients were included in the study who met all four of the following criteria: (1) required oxygen therapy or invasive ventilation, (2) were treated with DEX, (3) had residual shading on chest imaging after DEX treatment, or (4) had unimproved respiratory symptoms or oxygen saturation < 90%. We reviewed the medical records and clinical courses of 14 patients who received AC therapy (AC group) and 20 patients who did not (non-additional corticosteroids or NC group). Results The 90-day mortality rate was 35.7% in the AC group and 25.0% in the NC group. There was no statistically significant difference between the two groups (p = 0.797). In addition, there was no difference between groups in the proportion of patients who required oxygen therapy at discharge (64% vs. 35%, p = 0.162). The time from the end of DEX therapy to discharge was significantly longer in the AC group (median 7.5 vs. 33 days, p = 0.019). Regarding serious adverse events, infection was statistically more common in the AC group than in the NC group (p = 0.005). Conclusions AC after DEX treatment does not improve clinical outcomes and may prolong hospital stay.

Influence of radiologic pattern and the presence of diffuse parenchymal lung disease on outcome in ventilated patients with COVID-19 pneumonia: impact on prognosis

BACKGROUND

Suspected organising pneumonia (OP) is a common finding in patients with severe coronavirus disease 2019 (COVID-19), but the impact on outcomes of the radiological patterns of diffuse parenchymal lung disease on outcome of these patients is still uncertain.

AIMS

Investigate the presence of radiological images compatible with OP and its association with clinical outcomes in patients with COVID-19 submitted to invasive mechanical ventilation (IMV).

METHODS

Retrospective, unicentric cohort study composed of patients who required IMV and underwent chest computerized tomography to investigate secondary complications of COVID-19. We compared patients with radiological findings characteristic of suspected OP with those without this condition. The main outcome was hospital mortality.

RESULTS

Two hundred and ten patients were included, and 65 had signals compatible with OP. All patients with suspected OP were treated with corticosteroids. There was no difference in IVM-free days until day 28 between the groups (median, 0 days; interquartile range [IQR], 0-14.8) in the group with suspected OP vs 0 days (IQR, 0-11) in the group without suspected OP (P = 0.14). In univariate analysis, the presence of suspected OP was associated with lower hospital mortality; however, after correction for potential confounding variables, it was not associated with the outcome, even after matching by propensity score in patients without this condition.

CONCLUSION

OP radiologic pattern in patients with severe COVID-19 is not associated with worse outcomes.

Dual Antiviral Therapy for Persistent Coronavirus Disease 2019 and Associated Organizing Pneumonia in an Immunocompromised Host

The management of patients with prolonged viral shedding and coronavirus disease 2019 symptoms remains unclear. Combining antivirals, as practiced in other infections, is theoretically advantageous. We present a case of persistent, symptomatic severe acute respiratory syndrome coronavirus 2 infection and associated organizing pneumonia that was successfully treated with an extended course of combination antiviral therapy.

A review of organizing pneumonia

ABSTRACT

Organizing pneumonia is a clinical and pathological syndrome that describes a lung injury caused by an inflammatory reaction in the alveolar connective tissue. Classified as an interstitial lung disease, it can be secondary to infection, drug toxicity, connective tissue disorders, inhalation injuries (cocaine), organ transplant, or radiotherapy, and also can be idiopathic. Although organizing pneumonia is not a new phenomenon, it has been noted to be a complication of COVID-19, and should be considered in patients who have had COVID-19 and have atypical chest imaging, because treatment includes corticosteroids instead of antimicrobials.

Treatment of Acquired von Willebrand Disease due to Extracorporeal Membrane Oxygenation in a Pediatric COVID-19 Patient with Vonicog Alfa: A Case Report and Literature Review

Acquired von Willebrand disease (aVWD) is frequently observed in patients with the need for extracorporeal membrane oxygenation (ECMO). aVWD can be treated by plasma-derived concentrates containing factor VIII (FVIII) and/or von Willebrand factor (VWF) and recombinant VWF concentrate as well as adjuvant therapies such as tranexamic acid and desmopressin. However, all of these therapeutic options possibly cause thromboembolism. Therefore, the optimal treatment remains uncertain. This report presents a case of a 16-year-old patient suffering from severe acute respiratory distress syndrome due to coronavirus disease 2019 with the need of ECMO support. Our patient developed aVWD under ECMO therapy characterized by loss of high-molecular-weight multimers (HMWM) and severe bleeding symptoms following endoscopic papillotomy due to sclerosing cholangitis. At the same time standard laboratory parameters showed hypercoagulability with increased fibrinogen level and platelet count. The patient was successfully treated with recombinant VWF concentrate (rVWF; vonicog alfa; Veyvondi) combined with topic tranexamic acid application and cortisone therapy. rVWF concentrate vonicog alfa is characterized by ultra-large multimers and absence of FVIII. Patient could be successfully weaned from ECMO support after 72 days. Multimer analysis 1 week after ECMO decannulation showed an adequate reappearance of HMWM.

Increase of mast cells in COVID-19 pneumonia may contribute to pulmonary fibrosis and thrombosis

AIMS

Lung tissue from COVID-19 patients shares similar histomorphological features with chronic lung allograft disease, also suggesting activation of autoimmune-related pathways in COVID-19. To more clearly understand the underlying spectrum of pathophysiology in COVID-19 pneumonia, we analysed mRNA expression of autoimmune-related genes in post-mortem lung tissue from COVID-19 patients.

METHODS AND RESULTS

Formalin-fixed, paraffin-embedded lung tissue samples of 18 COVID-19 patients and eight influenza patients were used for targeted gene expression profiling using NanoString technology. Multiplex immunofluorescence for tryptase and chymase was applied for validation. Genes related to mast cells were significantly increased in COVID-19. This finding was strengthened by multiplex immunofluorescence also showing a significant increase of tryptase- and chymase-positive cells in COVID-19. Furthermore, receptors for advanced glycation end-products (RAGE) and pro-platelet basic protein (PPBP) were up-regulated in COVID-19 compared to influenza. Genes associated with Type I interferon signalling showed a significant correlation to detected SARS-CoV2 pathway-related genes. The comparison of lung tissue samples from both groups based on the presence of histomorphological features indicative of acute respiratory distress syndrome did not result in finding any specific gene or pathways.

CONCLUSION

Two separate means of measuring show a significant increase of mast cells in SARS-CoV-2-infected lung tissue compared to influenza. Additionally, several genes involved in fibrosis and thrombosis, among which are RAGE and PPBP, are up-regulated in COVID-19. As mast cells are able to induce thrombosis and fibrosis, they may play an important role in the pathogenesis of COVID-19.

Glucocorticoid Therapy in COVID-19-Induced Organizing Pneumonia: A Rare Occurrence

Background Although the incidence of post-COVID-19 organizing pneumonia (OP) is low, the mortality and morbidity in select patients appear to be high. Anticipating specific populations who may be at higher risk and initiating treatment earlier could reduce mortality. Research question Does treatment with high dose, standard dose, or no glucocorticoids for COVID-19 infection impact the incidence and clinical outcome in COVID-19-induced OP? Study design and methods This was a single-center, retrospective, observational cohort study conducted from 03/01/2020 to 06/30/2021 in hospitalized patients over the age of 18 with confirmed COVID-19 infection and computed tomography (CT) scan evidence of OP. Institutional review board (IRB) approval was obtained from the institution (STUDY00002241). Patients' demographics and oxygen requirements at the time of diagnosis, at the time of discharge, and at one, three, six, 10, and 12 months post-discharge were obtained. The dose, duration, and choice of glucocorticoid therapy were recorded for each subject, as well as oxygen requirements during hospitalization. Despite radiological evidence of OP, patients on minimal supplemental oxygen requirements did not receive high-dose or long-duration glucocorticoid therapy. Results A total of 881 patients were admitted with COVID-19, of which 42 met the study criteria. Three patients underwent a lung biopsy to confirm the diagnosis of organizing pneumonia. All other patients were diagnosed based on CT imaging and clinical presentation. Of the patients, 17% did not receive any steroid treatment, while 36% received dexamethasone and 43% received prednisone. The most common oxygen requirement at the time of discharge for steroid-treated patients was nasal cannula (55%) and room air (29%). The incidence of OP in this patient population was 0.05 with a mortality rate of 14%. Interpretation and relevance The incidence of post-COVID-19 OP appears to be lower than anticipated. Steroids for patients on lower supplemental oxygen requirements were discontinued although they had radiological evidence of OP. Patients who were on higher supplemental oxygen requirements at 10 days were continued on steroids regardless of imaging. The decision to continue steroids should be based on individual patient characteristics such as oxygen requirements. In the future, larger multicenter cohort studies would help understand further treatment of post-COVID-19-associated OP. Anticipating specific populations who may be at higher risk and starting treatment earlier could help reduce mortality.

Timeline of Oxygen Demand in Patients with COVID-19 Pneumonia

Objective In patients with coronavirus disease 2019 (COVID-19), understanding the timeline of oxygen demand and severe respiratory failure, such as intensive care unit (ICU) admission, may clarify the therapeutic window when home-care treatment is possible and help determine the timing of treatment in hospitalized patients to improve the respiratory status. We examined the timeline of respiratory status in hospitalized patients with moderate-to-severe COVID-19 in terms of oxygen demand and ICU admission. Methods We retrospectively assessed all patients with COVID-19 who were admitted to our hospital between February 2020 and February 2021 and required supplemental oxygen. This study included 66 patients who were transferred to the ICU (ICU patients) and 144 patients who were not transferred to the ICU (non-ICU patients). Results In the total cohort, the median duration from symptom onset to the need for supplemental oxygen was 8 [interquartile range (IQR) 6-10] days. This duration was significantly shorter in ICU patients than in non-ICU patients [8 (IQR 6-9) vs. 9 (IQR 6-10) days, p=0.02]. The median duration from symptom onset to ICU admission was 9 (IQR 8-11) days in severely ill patients. The median duration from the initiation of supplemental oxygen to ICU admission was 1.0 (IQR 1-2.75) days. Only 2 of 66 patients (3.0%) were admitted to the ICU six days or later after the initiation of supplemental oxygen. Conclusion Physicians should carefully monitor each patient's condition after eight days from symptom onset. New therapies and their early administration are needed to reduce the frequency of respiratory failure in COVID-19 patients.

Severe COVID-19 with persistent respiratory failure—A retrospective cohort study in a tertiary centre in Malaysia

Introduction

Management of severe COVID-19 patients with persistent respiratory failure after acute phase treatment is not only challenging, but evidence for treatment is scarce, despite some authors reporting favourable clinical responses to corticosteroid therapy in histologically proven secondary organising pneumonia (OP). This study aimed to report the course of the disease, radiological pattern and clinical outcomes of severe COVID-19 patients with persistent respiratory failure.

Methods

This was a retrospective cohort study of severe COVID-19 patients who were admitted to a single tertiary centre from 1 January 2021 to 30 June 2021. The clinical data of the patients during admission and clinic follow-up, including radiological images, were traced using electronic medical records.

Results

In our cohort, the mortality rate for those with severe COVID-19 was 23.1% (173/749). Among the survivors, 46.2% (266/576) had persistent respiratory failure (PRF) after 14 days of illness. Of them, 70.3% (187/266) were followed up, and 68% (128/187) received oral corticosteroid (prednisolone) maintenance treatment. OP pattern made up the majority (81%) of the radiological pattern with a mean severity CT score of 10 (SD±3). The mean prednisolone dose was 0.68mg/kg/day with a mean treatment duration of 47 days (SD±18). About one-third of patients (67/187) had respiratory symptoms at 4 weeks (SD±3). Among 78.1% (146/187) who had a repeated CXR during follow-up, only 12 patients (8.2%, SD±3) had radiological improvement of less than 50% at 6 weeks (SD±3), with 2 of them later diagnosed as pulmonary tuberculosis. Functional assessments, such as the 6-minute walk test and the spirometry, were only performed in 52.4% and 15.5% of the patients, respectively.

Conclusion

Almost half of the patients with severe COVID-19 had PRF, with a predominant radiological OP pattern. More than two-thirds of the PRF patients required prolonged oral corticosteroid treatment. Familiarising clinicians with the disease course, radiological patterns, and potential outcomes of this group of patients may better equip them to manage their patients.

Clinical Outcomes of Routine Awake Prone Positioning in COVID-19 Patients: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Before coronavirus disease 2019 (COVID-19) emerged, proning had been demonstrated to improve oxygenation in those with acute hypoxic respiratory failure and be performed in non-intensive care settings. This benefit was further exemplified by the COVID-19 pandemic, leading to awake prone positioning (APP). We assessed the efficacy of routine APP versus standard care in preventing death and invasive mechanical ventilation (IMV) in non-intubated hypoxic COVID-19 patients. PubMed, Cochrane Library, Scopus, and medRxiv databases were used from January 1st, 2020, to January 15th, 2022, to identify randomized controlled trials (RCTs). Routine APP group were encouraged to be self-prone, whereas the standard care group received care according to local clinical practice and allowed APP crossover as rescue therapy. We included eight COVID-19 RCTs assessing 809 APP vs. 822 standard care patients. APP group had less IMV requirement (26.5% vs. 30.9%; OR - odds ratio 0.77; P=0.03) than the standard care group, with subgroup analysis showing greater benefit (32.5% vs. 39.1%; OR 0.75; P=0.02) for those mainly requiring oxygen support of non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC). The time to IMV initiation was similar (mean 8.3 vs. 10.0 days; P=0.66) for patients requiring NIMV and HFNC. Patients mainly receiving supplemental oxygen and non-rebreather masks had improved oxygenation parameters, although not statistically significant. Other outcomes involving all-cause hospital mortality, hospital and ICU (intensive care unit) length of stay, and adverse events were comparable. APP appeared to be an important modality for reducing IMV requirements, especially in those requiring NIMV and HFNC.

A Case of Steroid-Responsive Severe Pneumonia Following a Recent COVID-19 Infection in a Patient With Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infection

A twenty-two-year-old woman with a history of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) on rituximab presented with fever, abdominal pain, and worsening shortness of breath requiring supplemental oxygen via nasal cannula one month after a severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection from which she was minimally symptomatic and had recovered. Radiographic studies revealed bilateral patchy consolidations interspersed with ground-glass opacities (GGO). She was started on antibiotics for presumed community-acquired pneumonia with no improvement. Echocardiography revealed preserved biventricular function and a suspected intracardiac mass. A cardiac magnetic resonance imaging (CMRI) revealed myocarditis and no intracardiac mass. Fever persisted and oxygen requirements increased from FiO2 0.4 to 1.0. Repeat CXR showed subtotal left hemithorax opacification. Bronchoscopic samples showed a negative Gram stain and an unremarkable cell count differential. In view of this and given her lack of response to antibiotics with worsening respiratory status, high-dose steroids were started. She improved rapidly, and six days later she was off oxygen. Transbronchial biopsies showed benign parenchyma with some intra-alveolar fibrin deposition with no definitive evidence of viral cytopathic effect, vasculitis, or diffuse alveolar damage (DAD). Follow-up imaging in the pulmonary clinic revealed improvement of prior airspace disease with some new migratory opacities that completely resolved after 12 weeks. Pulmonary function tests and repeat CMRI were normal three months after discharge. Multisystem inflammatory syndrome in adults (MISA), post-covid organizing pneumonia (OP), and immune reconstitution inflammatory syndrome (IRIS) are rare and potentially steroid-responsive causes of pneumonia, which were in our differential diagnosis. It is imperative to consider the rare possibility of steroid-responsive pneumonia-like MISA, post-COVID-OP, and IRIS in patients with worsening respiratory symptoms following a recent SARS-CoV 2 infection.

Delayed-onset Organizing Pneumonia Emerging after Recovery from Coronavirus Disease 2019: A Report of Three Cases Diagnosed Using Transbronchial Cryobiopsy and a Review of the Literature

We present three cases with an atypical clinical course of organizing pneumonia (OP) secondary to coronavirus disease 2019 (COVID-19). Three patients were discharged with satisfactory improvement after standard steroid therapy for COVID-19. Shortly after the completion of treatment, the patients experienced a flare-up of symptoms. Imaging results showed new lesions in the lungs. Transbronchial lung cryobiopsy showed histological findings consistent with OP in all cases. Steroids were administered, and a good therapeutic response was observed. This report is the first to describe pathologically confirmed OP that developed after recovery from COVID-19. Careful follow-up is advisable for patients who have recovered from COVID-19.

重症COVID–19患者における侵襲的人工呼吸管理中のステロイドの投与終了と28日死亡率の関連の検討，後方視的コホート研究(Association between corticosteroid treatment termination during invasive mechanical ventilation and 28–day mortality in severe COVID–19 patients, a retrospective cohort study)

Aims: To investigate the association between corticosteroid treatment termination during invasive mechanical ventilation and 28–day mortality in severe COVID–19 patients.

Methods: The study was a single–center, retrospective cohort study of COVID–19 patients undergoing invasive mechanical ventilation on their scheduled corticosteroid termination day between March 1, 2020, and June 30, 2021. The scheduled corticosteroid termination day was scheduled 10 days after initiation of dexamethasone 6mg orally or 6.6mg intravenously. Patients who terminated corticosteroids during the ventilatory period and did not receive corticosteroids thereafter were defined as the termination group, whereas patients who continued to receive corticosteroids in some form after the scheduled corticosteroid termination day were defined as the continuation group. The primary endpoint was 28–day mortality, and the difference was evaluated using the log–rank test.

Results: The 28–day mortality was found to be 61% (14 of 23 patients) in the termination group, which was significantly higher than the 28–day mortality of 22% (5 of 23 patients) in the continuation group (Hazard Ratio: 3.82, 95% CI: 1.37–10.68; p=0.005).

Conclusions: In severe COVID–19 patients, corticosteroid termination during invasive ventilation is associated with an increased 28–day mortality.

A systematic review of Vaccine Breakthrough Infections by SARS-CoV-2 Delta Variant

Vaccines are proving to be highly effective in controlling hospitalization and deaths associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as shown by clinical trials and real-world evidence. However, a deadly second wave of coronavirus disease 2019 (COVID-19), infected by SARS-CoV-2 variants, especially the Delta (B.1.617.2) variant, with an increased number of post-vaccination breakthrough infections were reported in the world recently. Actually, Delta variant not only resulted in a severe surge of vaccine breakthrough infections which was accompanied with high viral load and transmissibility, but also challenged the development of effective vaccines. Therefore, the biological characteristics and epidemiological profile of Delta variant, the current status of Delta variant vaccine breakthrough infections and the mechanism of vaccine breakthrough infections were discussed in this article. In addition, the significant role of the Delta variant spike (S) protein in the mechanism of immune escape of SARS-CoV-2 was highlighted in this article. In particular, we further discussed key points on the future SARS-CoV-2 vaccine research and development, hoping to make a contribution to the early, accurate and rapid control of the COVID-19 epidemic.

Pneumonia rebound after stopping steroid in a patient with COVID-19: A case report

Patients with severe coronavirus disease 2019 (COVID-19) can develop a systemic inflammatory response that can lead to lung injury and multisystem organ dysfunction. The current treatment guideline recommends the use of corticosteroids in patients who require supplemental oxygen or are mechanically ventilated. This study reports a patient with severe COVID-19 pneumonia. Initially, the patient was treated with dexamethasone for 10 days and remdesivir for 5 days. There was clinical improvement following the treatments. However, on day 15, the patient experienced rebound pneumonia and clinical deterioration. His clinical condition improved until dexamethasone was re-administered. This case demonstrates the rebound phenomenon after the steroid was discontinued. The duration and timing of steroids are crucial to reduce the risk of prolonged systemic inflammation and rebound pneumonia.