Nosocomial COVID-19: A Nationwide Spanish Study.

INTRODUCTION: SARS-CoV-2 is a highly contagious virus, and despite professionals' best efforts, nosocomial COVID-19 (NC) infections have been reported. This work aimed to describe differences in symptoms and outcomes between patients with NC and community-acquired COVID-19 (CAC) and to identify risk factors for severe outcomes among NC patients. METHODS: This is a nationwide, retrospective, multicenter, observational study that analyzed patients hospitalized with confirmed COVID-19 in 150 Spanish hospitals (SEMI-COVID-19 Registry) from March 1, 2020, to April 30, 2021. NC was defined as patients admitted for non-COVID-19 diseases with a positive SARS-CoV-2 test on the fifth day of hospitalization or later. The primary outcome was 30-day in-hospital mortality (IHM). The secondary outcome was other COVID-19-related complications. A multivariable logistic regression analysis was performed. RESULTS: Of the 23,219 patients hospitalized with COVID-19, 1,104 (4.8%) were NC. Compared to CAC patients, NC patients were older (median 76 vs. 69 years; p < 0.001), had more comorbidities (median Charlson Comorbidity Index 5 vs. 3; p < 0.001), were less symptomatic (p < 0.001), and had normal chest X-rays more frequently (30.8% vs. 12.5%, p < 0.001). After adjusting for sex, age, dependence, COVID-19 wave, and comorbidities, NC was associated with lower risk of moderate/severe acute respiratory distress syndrome (ARDS) (adjusted odds ratio [aOR]: 0.72; 95% confidence interval [CI]: 0.59-0.87; p < 0.001) and higher risk of acute heart failure (aOR: 1.40; 1.12-1.72; p = 0.003), sepsis (aOR: 1.73; 1.33-2.54; p < 0.001), and readmission (aOR: 1.35; 1.03-1.83; p = 0.028). NC was associated with a higher case fatality rate (39.1% vs. 19.2%) in all age groups. IHM was significantly higher among NC patients (aOR: 2.07; 1.81-2.68; p < 0.001). Risk factors for increased IHM in NC patients were age, moderate/severe dependence, malignancy, dyspnea, moderate/severe ARDS, multiple organ dysfunction syndrome, and shock; odynophagia was associated with lower IHM. CONCLUSIONS: NC is associated with greater mortality and complications compared to CAC. Hospital strategies to prevent NC must be strengthened.

Effective Natural Killer Cell Degranulation Is an Essential Key in COVID-19 Evolution.

NK degranulation plays an important role in the cytotoxic activity of innate immunity in the clearance of intracellular infections and is an important factor in the outcome of the disease. This work has studied NK degranulation and innate immunological profiles and functionalities in COVID-19 patients and its association with the severity of the disease. A prospective observational study with 99 COVID-19 patients was conducted. Patients were grouped according to hospital requirements and severity. Innate immune cell subpopulations and functionalities were analyzed. The profile and functionality of innate immune cells differ between healthy controls and severe patients; CD56dim NK cells increased and MAIT cells and NK degranulation rates decreased in the COVID-19 subjects. Higher degranulation rates were observed in the non-severe patients and in the healthy controls compared to the severe patients. Benign forms of the disease had a higher granzymeA/granzymeB ratio than complex forms. In a multivariate analysis, the degranulation capacity resulted in a protective factor against severe forms of the disease (OR: 0.86), whereas the permanent expression of NKG2D in NKT cells was an independent risk factor (OR: 3.81; AUC: 0.84). In conclusion, a prompt and efficient degranulation functionality in the early stages of infection could be used as a tool to identify patients who will have a better evolution.

T-Helper Cell Subset Response Is a Determining Factor in COVID-19 Progression.

The immune response type organized against viral infection is determinant in the prognosis of some infections. This work has aimed to study Th polarization in acute COVID-19 and its possible association with the outcome through an observational prospective study. Fifty-eight COVID-19 patients were recruited in the Medicine Department of the hospital "12 de Octubre," 55 patients remaining after losses to follow-up. Four groups were established according to maximum degree of disease progression. T-helper cell percentages and phenotypes, analyzed by flow cytometer, and serum cytokines levels, analyzed by Luminex, were evaluated when the microbiological diagnosis (acute phase) of the disease was obtained. Our study found a significant reduction of %Th1 and %Th17 cells with higher activated %Th2 cells in the COVID-19 patients compared with reference population. A higher percent of senescent Th2 cells was found in the patients who died than in those who survived. Senescent Th2 cell percentage was an independent risk factor for death (OR: 13.88) accompanied by the numbers of total lymphocytes (OR: 0.15) with an AUC of 0.879. COVID-19 patients showed a profile of pro-inflammatory serum cytokines compared to controls, with higher levels of IL-2, IL-6, IL-15, and IP-10. IL-10 and IL-13 were also elevated in patients compared to controls. Patients who did not survive presented significantly higher levels of IL-15 than those who recovered. No significant differences were observed according to disease progression groups. The study has shown that increased levels of IL-15 and a high Th2 response are associated with a fatal outcome of the disease.

Clinical Characteristics and Risk Factors of Respiratory Failure in a Cohort of Young Patients Requiring Hospital Admission with SARS-CoV2 Infection in Spain: Results of the Multicenter SEMI-COVID-19 Registry.

BACKGROUND: Age is a risk factor for COVID severity. Most studies performed in hospitalized patients with SARS-CoV2 infection have shown an over-representation of older patients and consequently few have properly defined COVID-19 in younger patients who require hospital admission. The aim of the present study was to analyze the clinical characteristics and risk factors for the development of respiratory failure among young (18 to 50 years) hospitalized patients with COVID-19. METHODS: This retrospective nationwide cohort study included hospitalized patients from 18 to 50 years old with confirmed COVID-19 between March 1, 2020, and July 2, 2020. All patient data were obtained from the SEMI-COVID Registry. Respiratory failure was defined as the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2 ratio) ≤200 mmHg or the need for mechanical ventilation and/or high-flow nasal cannula or the presence of acute respiratory distress syndrome. RESULTS: During the recruitment period, 15,034 patients were included in the SEMI-COVID-19 Registry, of whom 2327 (15.4%) were younger than 50 years. Respiratory failure developed in 343 (14.7%), while mortality occurred in 2.3%. Patients with respiratory failure showed a higher incidence of major adverse cardiac events (44 (13%) vs 14 (0.8%), p<0.001), venous thrombosis (23 (6.7%) vs 14 (0.8%), p<0.001), mortality (43 (12.5%) vs 7 (0.4%), p<0.001), and longer hospital stay (15 (9-24) vs 6 (4-9), p<0.001), than the remaining patients. In multivariate analysis, variables associated with the development of respiratory failure were obesity (odds ratio (OR), 2.42; 95% confidence interval (95% CI), 1.71 to 3.43; p<0.0001), alcohol abuse (OR, 2.40; 95% CI, 1.26 to 4.58; p=0.0076), sleep apnea syndrome (SAHS) (OR, 2.22; 95% CI, 1.07 to 3.43; p=0.032), Charlson index ≥1 (OR, 1.77; 95% CI, 1.25 to 2.52; p=0.0013), fever (OR, 1.58; 95% CI, 1.13 to 2.22; p=0.0075), lymphocytes ≤1100 cells/µL (OR, 1.67; 95% CI, 1.18 to 2.37; p=0.0033), LDH >320 U/I (OR, 1.69; 95% CI, 1.18 to 2.42; p=0.0039), AST >35 mg/dL (OR, 1.74; 95% CI, 1.2 to 2.52; p=0.003), sodium <135 mmol/L (OR, 2.32; 95% CI, 1.24 to 4.33; p=0.0079), and C-reactive protein >8 mg/dL (OR, 2.42; 95% CI, 1.72 to 3.41; p<0.0001). CONCLUSIONS: Young patients with COVID-19 requiring hospital admission showed a notable incidence of respiratory failure. Obesity, SAHS, alcohol abuse, and certain laboratory parameters were independently associated with the development of this complication. Patients who suffered respiratory failure had a higher mortality and a higher incidence of major cardiac events, venous thrombosis, and hospital stay.

Anti-Phospholipid Antibodies and COVID-19 Thrombosis: A Co-Star, Not a Supporting Actor.

BACKGROUND: COVID-19 clinical features include a hypercoagulable state that resembles the antiphospholipid syndrome (APS), a disease characterized by thrombosis and presence of antiphospholipid antibodies (aPL). The relationship between aPL-presence and the appearance of thrombi as well as the transience or permanence of aPL in COVID-19 patients is not sufficiently clear. METHODS: A group of 360 COVID-19 patients were followed-up for 6 months. Classic aPL, anti-B2GPI IgA, anti-phosphatidylserine/prothrombin IgG/M and anti-SARS-CoV-2 antibodies were determined at acute phase and >12 weeks later. The reference group included 143 healthy volunteers of the same age-range distribution. RESULTS: aPL prevalence was similar in COVID-19 patients and the reference population. aPL presence in both determinations was significantly associated with thrombosis (OR: 2.33 and 3.71), strong agreement being found for classic aPL and anti-B2GPI IgA (Weighted kappa: 0.85-0.91). Thrombosis-associated aPL occurred a median of 17 days after hospital admission (IQR: 6-28) vs. 4 days for the rest (IQR: 3-7). Although anti-SARS-CoV-2 antibodies levels increased during convalescence, aPL hardly changed. CONCLUSIONS: Most COVID-19 patients would carry these aPL before the infection. At least two mechanisms could be behind thrombosis, early immune-dysregulation-mediated thrombosis after infection and belated-aPL-mediated thrombosis, with SARS-CoV-2 behaving as a second hit.

A predictive score at admission for respiratory failure among hospitalized patients with confirmed 2019 Coronavirus Disease: a simple tool for a complex problem.

Coronavirus Disease 2019 (COVID-19) pandemic has implacably stricken on the wellness of many countries and their health-care systems. The aim of the present study is to analyze the clinical characteristics of the initial wave of patients with COVID-19 attended in our center, and to identify the key variables predicting the development of respiratory failure. Prospective design study with concurrent data retrieval from automated medical records of all hospitalized adult patients who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rRT-PCR assay performed on respiratory samples from March 2nd to 18th, 2020. Patients were followed up to May 1st, 2020 or death. Respiratory failure was defined as a PaO2/FiO2 ratio ≤ 200 mm Hg or the need for mechanical ventilation (either non-invasive positive pressure ventilation or invasive mechanical ventilation). We included 521 patients of whom 416 (81%) had abnormal Chest X-ray on admission. Median age was 64.6 ± 18.2 years. One hundred eighty-one (34.7%) developed respiratory failure after a median time from onset of symptoms of 9 days (IQR 6-11). In-hospital mortality was 23.8% (124/521). The modeling process concluded into a logistic regression multivariable analysis and a predictive score at admission. Age, peripheral pulse oximetry, lymphocyte count, lactate dehydrogenase and C-reactive protein were the selected variables. The model has a good discriminative capacity with an area under the ROC curve of 0.85 (0.82-0.88). The application of a simple and reliable score at admission seems to be a useful tool to predict respiratory failure in hospitalized COVID-19 patients.

Beta-2-Glycoprotein-I Deficiency Could Precipitate an Antiphospholipid Syndrome-like Prothrombotic Situation in Patients With Coronavirus Disease 2019.

OBJECTIVE: Patients with coronavirus disease 2019 (COVID-19) present coagulation abnormalities and thromboembolic events that resemble antiphospholipid syndrome (APS). This work has aimed to study the prevalence of APS-related antigens, antibodies, and immune complexes in patients with COVID-19 and their association with clinical events. METHODS: A prospective study was conducted on 474 adults with severe acute respiratory syndrome coronavirus 2 infection hospitalized in two Spanish university hospitals. Patients were evaluated for classic and extra-criteria antiphospholipid antibodies (aPLs), immunoglobulin G (IgG)/immunoglobulin M (IgM) anticardiolipin, IgG/IgM/immunoglobulin A (IgA) anti-ß2-glicoprotein-I (aß2GPI), IgG/IgM antiphosphatidylserine/prothrombin (aPS/PT), the immune complex of IgA aß2GPI (IgA-aß2GPI), bounded to ß2-glicoprotein-1 (ß2GPI) and ß2GPI levels soon after COVID-19 diagnosis and were followed-up until medical discharge or death. RESULTS: Prevalence of aPLs in patients with COVID-19 was as follows: classic aPLs, 5.8%; aPS/PT, 4.6%; IgA-aß2GPI, 15%; and any aPL, 21%. When patients were compared with individuals of a control group of a similar age, the only significant difference found was the higher prevalence of IgA-aß2GPI (odds ratio: 2.31; 95% confidence interval: 1.16-4.09). No significant differences were observed in survival, thrombosis, or ventilatory failure in aPL-positive versus aPL-negative patients. ß2GPI median levels were much lower in patients with COVID-19 (15.9 mg/l) than in blood donors (168.8 mg/l; P < 0.001). Only 3.5% of patients with COVID-19 had normal levels of ß2GPI (>85 mg/l). Low levels of ß2GPI were significantly associated with ventilatory failure (P = 0.026). CONCLUSION: ß2GPI levels were much lower in patients with COVID-19 than in healthy people. Low ß2GPI-levels were associated with ventilatory failure. No differences were observed in the COVID-19 evolution between aPL-positive and aPL-negative patients. Functional ß2GPI deficiency could trigger a clinical process similar to that seen in APS but in the absence of aPLs.

Impact of viral load at admission on the development of respiratory failure in hospitalized patients with SARS-CoV-2 infection.

The aim of our study was to elucidate if SARS-CoV-2 viral load on admission, measured by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) cycle threshold (Ct) value on nasopharyngeal samples, was a marker of disease severity. All hospitalized adult patients with a diagnosis of SARS-CoV-2 infection by rRT-PCR performed on a nasopharingeal sample from March 1 to March 18 in our institution were included. The study population was divided according to the Ct value obtained upon admission in patients with high viral load (Ct < 25), intermediate viral load (Ct: 25-30) and low viral load (Ct > 30). Demographic, clinical and laboratory variables of the different groups were analyzed to assess the influence of viral load on the development of respiratory failure during admission. Overall, 455 sequential patients were included. The median Ct value was 28 (IQR: 24-32). One hundred and thirty patients (28.6%) had a high viral load, 175 (38.5%) an intermediate viral load and 150 (33%) a low viral load. Advanced age, male sex, presence of cardiovascular disease and laboratory markers such as lactate dehydrogenase, lymphocyte count and C-reactive protein, as well as a high viral load on admission, were predictive of respiratory failure. A Ct value < 25 was associated with a higher risk of respiratory failure during admission (OR: 2.99, 95%IC: 1.57-5.69). SARS-CoV-2 viral load, measured through the Ct value on admission, is a valuable tool to predict the development of respiratory failure in COVID-19 inpatients.