Post-COVID­19 complications in hospitalized and nonhospitalized patients: the Silesian database of COVID­19 complications (SILCOV­19).

INTRODUCTION: Due to the extent of the pandemic, high prevalence and severity of complications in the early post­recovery period are expected. OBJECTIVES: This study aimed to compare the scope of early post-COVID­19 complications in patients who had the disease and were or were not hospitalized. PATIENTS AND METHODS: This was a prospective, observational, registry­based cohort study conducted at a tertiary cardiovascular hospital in Silesia, Poland. Interdisciplinary diagnostics, including cardiovascular, pneumatological, respiratory, neurological, and psychiatric tests, was performed during the study visit. All patients completed the study. Two­hundred unselected, adult, white men and women with the symptoms of acute COVID­19 were included, of which 86 patients had the disease but did not require hospitalization. RESULTS: The median (interquartile range) time from symptom onset to the study visit was 107 (87-117) and 105 (79-127) days in nonhospitalized and hospitalized patients, respectively. Lung lesions on high­resolution computed tomography were found in 10 (8.8%) and 33 (39.3%) of nonhospitalized and hospitalized patients, respectively (P <0.01); no lesions were visualized on chest X­ray images. Elevated platelet distribution width was found in more than 70% of the patients in both groups. More than half of the patients had insomnia, regardless of the hospitalization status. CONCLUSIONS: The abnormal platelet parameters, functional and radiological findings in the lungs, and insomnia were the most frequent short­term COVID­19 complications in hospitalized and nonhospitalized patients. Considering the number of patients who have had COVID­19 worldwide, a high burden of the post-COVID­19 complications might be expected.

Lung Transplant as a Treatment for Patients with End-Stage Respiratory Failure Due to COVID-19.

BACKGROUND: COVID-19 may lead to development of irreversible acute respiratory distress syndrome. Some patients sustain severe respiratory failure after infection subsides. They may require lung transplant as a last resort treatment. The aim of the study is to assess the effect and feasibility of lung transplant as a treatment for patients with severe irreversible respiratory failure due to COVID-19. METHODS: This retrospective study pertains to analysis of 119 patients in critical condition who were referred to Lung Transplant Ward (Zabrze, Poland). between July 2020 and June 2021 after developing respiratory failure requiring extracorporeal membrane oxygenation, invasive ventilation, or both, as well as a few patients on high-flow oxygen therapy. Inclusion criteria for referral were confirmed lack of viral disease and exhaustion of other therapeutic options. RESULTS: Of the referred patients, 21.84% were disqualified from such treatment owing to existing contraindications. Among the suitable patients, 75.8% died without transplant. Among all patients who were qualified for lung transplant, only 9 patients became double lung transplant recipients. Intraoperative mortality for this procedure was 33%. Four patients were discharged after the procedure and are currently self-reliant with full respiratory capacity. CONCLUSIONS: Patients with severe irreversible respiratory failure after COVID-19 present significantly high mortality without lung transplant. This procedure may present satisfactory results but must be performed in a timely fashion owing to critical condition and scarcity of lung donors, only aggravated around the time of peak infection waves.

COVID-19 Among Lung Transplant Recipients: A Single Center Study.

BACKGROUND: When COVID-19 became a pandemic, it was difficult to predict how it would affect lung transplant recipients. The aim of this study was to assess the mortality, influence on graft function as well as attitude toward SARS-CoV-2 vaccination among lung transplant recipients from a single center. METHODS: We analyzed medical data pertaining to 124 recipients who received lung transplants between 2008-2021 from a single center and original questionnaire on the COVID-19 severity classification system and the patients' attitude toward SARS-CoV-2 vaccination. Graft function was assessed by spirometry and a 6-minute walk test (6MWT), at least at the first postCOVID-19 visit. RESULTS: Among 29 patients who were confirmed to have COVID-19, 6 people died during or directly after contracting this infectious disease. The significant decrease in spirometry and distance in a 6MWT has been rarely observed in COVID-19 survivors. After vaccination ( n=107 patients) , most patients reported mild symptoms with slight pain and discomfort at the injection site being the most common (51.4%). 67.7% of all studiedpatients did not have any fears regarding the vaccination. Others reported being significantly worried about its effects (19.4% agreed to receive a vaccination anyway and 12.9% refused to be vaccinated). CONCLUSIONS: COVID-19 may present significant mortality among lung transplant recipients. The short-term safety and outcomes of vaccinations among these patients seemed encouraging. We are aware of the small study group limitations and hope to research this issue further.

Extracorporeal membrane oxygenation for severe COVID-19-associated acute respiratory distress syndrome in Poland: a multicenter cohort study.

BACKGROUND: In Poland, the clinical characteristics and outcomes of patients with COVID-19 requiring extracorporeal membrane oxygenation (ECMO) remain unknown. This study aimed to answer these unknowns by analyzing data collected from high-volume ECMO centers willing to participate in this project. METHODS: This retrospective, multicenter cohort study was completed between March 1, 2020, and May 31, 2021 (15 months). Data from all patients treated with ECMO for COVID-19 were analyzed. Pre-ECMO laboratory and treatment data were compared between non-survivors and survivors. Independent predictors for death in the intensive care unit (ICU) were identified. RESULTS: There were 171 patients admitted to participating centers requiring ECMO for refractory hypoxemia due to COVID-19 during the defined time period. A total of 158 patients (mean age: 46.3 ± 9.8 years) were analyzed, and 13 patients were still requiring ECMO at the end of the observation period. Most patients (88%) were treated after October 1, 2020, 77.8% were transferred to ECMO centers from another facility, and 31% were transferred on extracorporeal life support. The mean duration of ECMO therapy was 18.0 ± 13.5 days. The crude ICU mortality rate was 74.1%. In the group of 41 survivors, 37 patients were successfully weaned from ECMO support and four patients underwent a successful lung transplant. In-hospital death was independently associated with pre-ECMO lactate level (OR 2.10 per 1 mmol/L, p = 0.017) and BMI (OR 1.47 per 5 kg/m2, p = 0.050). CONCLUSIONS: The ICU mortality rate among patients requiring ECMO for COVID-19 in Poland was high. In-hospital death was independently associated with increased pre-ECMO lactate levels and BMI.

First lung transplantation as a treatment of a patient supported with extracorporeal membrane oxygenation (ECMO) after COVID-19 in Poland.

A 44-year-old male with no history of underlying diseases was referred to academic hospital due to ARDS with confirmed SARSCoV-2 infection after 7 days of mechanical ventilation. Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) was initiated as no improvement was noted in prone position. Mechanical ventilation was continued with TV of 3-4 mL/kg. A gradual decline of static lung compliance was observed from baseline 35 mL/cm H20 to 8 mL/cm H2O. The chest CT scan revealed extensive ground-glass areas with a significant amount of traction bronchiectasis after 3 weeks since admission. When the patient was negative for SARS-CoV-2 during the 4th week of ECMO, the decision to perform an emergency lung transplantation (LTx) was made based on the ongoing degradation of lung function and irreversible damage to lung structure. The patient was transferred to the transplant center where he was extubated, awaiting the transplant on passive oxygen therapy and ECMO. Double lung transplantation was performed on the day 30th of ECMO. Currently, the patient is self-reliant. He does not need oxygen therapy and continues physiotherapy. ECMO may be life-saving in severe cases of COVID-19 ARDS but some of these patients may require LTx, especially when weaning proves impossible. VV ECMO as a bridging method is more difficult but ultimately more beneficial due to insufficient number of donors, and consequently long waiting time in Poland.

HTCC as a Polymeric Inhibitor of SARS-CoV-2 and MERS-CoV.

Among seven coronaviruses that infect humans, three (severe acute respiratory syndrome coronavirus [SARS-CoV], Middle East respiratory syndrome coronavirus [MERS-CoV], and the newly identified severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) are associated with a severe, life-threatening respiratory infection and multiorgan failure. We previously proposed that the cationically modified chitosan N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC) is a potent inhibitor of human coronavirus NL63 (HCoV-NL63). Next, we demonstrated the broad-spectrum antiviral activity of the compound, as it inhibited all low-pathogenicity human coronaviruses (HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1). Here, using in vitro and ex vivo models of human airway epithelia, we show that HTCC effectively blocks MERS-CoV and SARS-CoV-2 infection. We also confirmed the mechanism of action for these two viruses, showing that the polymer blocks the virus entry into the host cell by interaction with the S protein.IMPORTANCE The beginning of 2020 brought us information about the novel coronavirus emerging in China. Rapid research resulted in the characterization of the pathogen, which appeared to be a member of the SARS-like cluster, commonly seen in bats. Despite the global and local efforts, the virus escaped the health care measures and rapidly spread in China and later globally, officially causing a pandemic and global crisis in March 2020. At present, different scenarios are being written to contain the virus, but the development of novel anticoronavirals for all highly pathogenic coronaviruses remains the major challenge. Here, we describe the antiviral activity of an HTCC compound, previously developed by us, which may be used as a potential inhibitor of currently circulating highly pathogenic coronaviruses-SARS-CoV-2 and MERS-CoV.

Visualization of SARS-CoV-2 using Immuno RNA-Fluorescence In Situ Hybridization.

This manuscript provides a protocol for in situ hybridization chain reaction (HCR) coupled with immunofluorescence to visualize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in cell line and three-dimensional (3D) cultures of human airway epithelium. The method allows highly specific and sensitive visualization of viral RNA by relying on HCR initiated by probe localization. Split-initiator probes help amplify the signal by fluorescently labeled amplifiers, resulting in negligible background fluorescence in confocal microscopy. Labeling amplifiers with different fluorescent dyes facilitates the simultaneous recognition of various targets. This, in turn, allows the mapping of the infection in tissues to better understand viral pathogenesis and replication at the single-cell level. Coupling this method with immunofluorescence may facilitate better understanding of host-virus interactions, including alternation of the host epigenome and immune response pathways. Owing to sensitive and specific HCR technology, this protocol can also be used as a diagnostic tool. It is also important to remember that the technique may be modified easily to enable detection of any RNA, including non-coding RNAs and RNA viruses that may emerge in the future.

Replication of SARS-CoV-2 in human respiratory epithelium

Currently, there are four seasonal coronaviruses associated with relatively mild respiratory tract disease in humans. However, there are also a plethora of animal coronaviruses, which have the potential to cross the species border. This regularly results in the emergence of new viruses in humans. In 2002 SARS-CoV emerged, to rapidly disappear in May 2003. In 2012 MERS-CoV was identified as a possible threat to humans, but its pandemic potential so far is minimal, as the human-to-human transmission is ineffective. The end of 2019 brought us information about the SARS-CoV-2 emergence, and the virus rapidly spread in 2020 causing an unprecedented pandemic. At present, the studies on the virus are carried out using a surrogate system based on the immortalized simian Vero E6 cell line. This model is convenient for diagnostics, but it has serious limitations and does not allow for the understanding of virus biology and evolution. Here we show that fully differentiated human airway epithelium cultures constitute an excellent model to study the infection with the novel human coronavirus SARS-CoV-2. We observed an efficient replication of the virus in the tissue, with the maximal replication at 2 days post-infection. The virus replicated in ciliated cells and was released apically. IMPORTANCE SARS-CoV-2 emerged by the end of 2019 to rapidly spread in 2020. At present, it is of utmost importance to understand the virus biology and to rapidly assess the potential of existing drugs and develop new active compounds. While some animal models for such studies are under development, most of the research is carried out in the Vero E6 cells. Here, we propose fully differentiated human airway epithelium cultures as a model for studies on the SARS-CoV-2.