MUlticenter STudy of tissue plasminogen activator (alteplase) use in COVID-19 severe respiratory failure (MUST COVID): A retrospective cohort study.

Background: Few therapies exist to treat severe COVID-19 respiratory failure once it develops. Given known diffuse pulmonary microthrombi on autopsy studies of COVID-19 patients, we hypothesized that tissue plasminogen activator (tPA) may improve pulmonary function in COVID-19 respiratory failure. Methods: A multicenter, retrospective, observational study of patients with confirmed COVID-19 and severe respiratory failure who received systemic tPA (alteplase) was performed. Seventy-nine adults from seven medical centers were included in the final analysis after institutional review boards' approval; 23 were excluded from analysis because tPA was administered for pulmonary macroembolism or deep venous thrombosis. The primary outcome was improvement in the PaO2/FiO2 ratio from baseline to 48 h after tPA. Linear mixed modeling was used for analysis. Results: tPA was associated with significant PaO2/FiO2 improvement at 48 h (estimated paired difference = 23.1 ± 6.7), which was sustained at 72 h (interaction term p < 0.00). tPA administration was also associated with improved National Early Warning Score 2 scores at 24, 48, and 72 h after receiving tPA (interaction term p = 0.00). D-dimer was significantly elevated immediately after tPA, consistent with lysis of formed clot. Patients with declining respiratory status preceding tPA administration had more marked improvement in PaO2/FiO2 ratios than those who had poor but stable (not declining) respiratory status. There was one intracranial hemorrhage, which occurred within 24 h following tPA administration. Conclusions: These data suggest tPA is associated with significant improvement in pulmonary function in severe COVID-19 respiratory failure, especially in patients whose pulmonary function is in decline, and has an acceptable safety profile in this patient population.

The clinical impact of the Covid-19 pandemic first wave on patients with cystic fibrosis in New York.

BACKGROUND: People with cystic fibrosis (pwCF) may be at risk of complications from COVID-19 but the impact of COVID-19 on pwCF remains unknown. METHODS: We conducted a multicenter retrospective cohort study to assess the impact of the COVID-19 pandemic first wave on pwCF in the New York metropolitan area (NY) from March 1, 2020 to August 31, 2020. Objectives were to determine (1) the prevalence of COVID-19 by PCR and IgG antibody testing, (2) the clinical characteristics of COVID-19, (3) delay in routine outpatient care, and (4) the effect on anxiety and depression in pwCF. RESULTS: There were 26 COVID-19 cases diagnosed by PCR or antibody testing among the study cohort of 810 pwCF. The prevalence of COVID-19 by PCR (1.6%) and IgG antibody (12.2%) testing was low. 58% of cases were asymptomatic and 82% were managed at home. 8% were hospitalized and 1 person died. 89% of pwCF experienced delay in care. The prevalence of anxiety increased from 43% baseline to 58% during the pandemic (P<0.01). In post-hoc analysis, the proportion of patients with diabetes (38% versus 16%, P<0.01) and pancreatic insufficiency (96% versus 66%, P<0.01) were higher while CFTR modulator use was lower (46% versus 65%, P = 0.05) in pwCF who tested positive for COVID-19. CONCLUSIONS: The prevalence of COVID-19 among pwCF in NY during the pandemic first wave was low and most cases were managed at home. CFTR modulators may be protective. PwCF experienced delay in routine care and increased anxiety.

Study of Alteplase for Respiratory Failure in SARS-CoV-2 COVID-19: A Vanguard Multicenter, Rapidly Adaptive, Pragmatic, Randomized Controlled Trial.

BACKGROUND: Pulmonary vascular microthrombi are a proposed mechanism of COVID-19 respiratory failure. We hypothesized that early administration of tissue plasminogen activator (tPA) followed by therapeutic heparin would improve pulmonary function in these patients. RESEARCH QUESTION: Does tPA improve pulmonary function in severe COVID-19 respiratory failure, and is it safe? STUDY DESIGN AND METHODS: Adults with COVID-19-induced respiratory failure were randomized from May14, 2020 through March 3, 2021, in two phases. Phase 1 (n = 36) comprised a control group (standard-of-care treatment) vs a tPA bolus (50-mg tPA IV bolus followed by 7 days of heparin; goal activated partial thromboplastin time [aPTT], 60-80 s) group. Phase 2 (n = 14) comprised a control group vs a tPA drip (50-mg tPA IV bolus, followed by tPA drip 2 mg/h plus heparin 500 units/h over 24 h, then heparin to maintain aPTT of 60-80 s for 7 days) group. Patients were excluded from enrollment if they had not undergone a neurologic examination or cross-sectional brain imaging within the previous 4.5 h to rule out stroke and potential for hemorrhagic conversion. The primary outcome was Pao2 to Fio2 ratio improvement from baseline at 48 h after randomization. Secondary outcomes included Pao2 to Fio2 ratio improvement of > 50% or Pao2 to Fio2 ratio of ≥ 200 at 48 h (composite outcome), ventilator-free days (VFD), and mortality. RESULTS: Fifty patients were randomized: 17 in the control group and 19 in the tPA bolus group in phase 1 and eight in the control group and six in the tPA drip group in phase 2. No severe bleeding events occurred. In the tPA bolus group, the Pao2 to Fio2 ratio values were significantly (P < .017) higher than baseline at 6 through 168 h after randomization; the control group showed no significant improvements. Among patients receiving a tPA bolus, the percent change of Pao2 to Fio2 ratio at 48 h (16.9% control [interquartile range (IQR), -8.3% to 36.8%] vs 29.8% tPA bolus [IQR, 4.5%-88.7%]; P = .11), the composite outcome (11.8% vs 47.4%; P = .03), VFD (0.0 [IQR, 0.0-9.0] vs 12.0 [IQR, 0.0-19.0]; P = .11), and in-hospital mortality (41.2% vs 21.1%; P = .19) did not reach statistically significant differences when compared with those of control participants. The patients who received a tPA drip did not experience benefit. INTERPRETATION: The combination of tPA bolus plus heparin is safe in severe COVID-19 respiratory failure. A phase 3 study is warranted given the improvements in oxygenation and promising observations in VFD and mortality. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT04357730; URL: www. CLINICALTRIALS: gov.

The number and function of T regulatory cells in obese atopic female asthmatics.

BACKGROUND: Mechanisms underlying the association between asthma and obesity remain poorly understood. Obesity appears to be a risk factor for asthma, and obese asthmatics fare poorly compared to lean asthmatics. OBJECTIVES: To explore the possibility that reduced regulatory T cell (Treg) number and function contribute to the obesity-asthma association. We concentrated on obese females with childhood-onset asthma, since Treg may be involved in this phenotype. METHODS: We recruited 64 women (ages 18-50) into four groups: lean (BMI 18-25 kg/m2) controls (n = 17) and asthmatics (n = 13), and obese (BMI ≥ 35 kg/m2) controls (n = 17) and asthmatics (n = 17). Asthmatics had atopy and childhood-diagnosed asthma. We assessed lung function, asthma control and quality of life. Peripheral blood CD4+/CD25+/FoxP3+ Treg cells were identified and counted by flow cytometry and expressed as % total CD4+ T cells. We assessed Treg cell function by the ability of CD4+/CD25+ Treg cells to suppress autologous CD4+/CD25- responder T cell (Tresp) proliferation and measured as % suppression of Tresp cell proliferation. RESULTS: Obese asthmatics had worse lung function, asthma control, and quality of life compared to lean asthmatics. Compared to lean or obese control groups, the number of Treg cells in the obese asthmatics was approximately 1.58- or 1.73-fold higher. The ability of Treg cells from obese-asthmatics to suppress Tresp cell proliferation was reduced. CONCLUSIONS: Obese, atopic women with childhood diagnosed asthma demonstrate increased Treg cell number and mildly decreased Treg cell function. Our data do not support the view that reduced Treg cell number contributes to this obese-asthma phenotype.

Relationship of adipokines with immune response and lung function in obese asthmatic and non-asthmatic women.

BACKGROUND: Obesity is a risk factor for asthma. Studies in mice suggest that the adipokines leptin and adiponectin affect asthmatic responses. The purpose of this study was to determine if adipokines associated with obesity are (1) altered in obese women with asthma compared to controls and (2) associated with increased cytokines and chemokines involved in allergic inflammation. METHODS: We performed a cross-sectional study of asthmatic and non-asthmatic obese premenopausal women. Participants answered questionnaires and performed lung function tests. Serum and peripheral blood mononuclear cells (PBMCs) were collected for analysis of cytokines and adipokines. RESULTS: A total of 22 asthmatic (mean body mass index 40.0 ± 5.1 kg/m(2)) and 20 non-asthmatic women (mean body mass index 41.3 ± 5.6 kg/m(2)) participated. We found no difference in serum adipokine concentrations between asthmatics and non-asthmatics. Serum adiponectin correlated positively with PBMC eotaxin (r(s) = 0.55, p = .0003) and RANTES (regulated upon activation, normal T-cell expressed, and secreted) (r(s) = 0.36, p = .03), whereas serum leptin correlated negatively with PBMC eotaxin (r(s) = -0.34, p = .04). There was a negative correlation between serum adiponectin and PBMC interferon-γ (r(s) = -0.41, p = .01). CONCLUSIONS: Perturbations of adipokines that occur in obesity were correlated with decreased cytokine production typically associated with allergic responses in PBMC of obese premenopausal women. This study suggests that although obese asthmatics may have elements of Th2-mediated inflammation, adipokine derangements in obesity are associated with Th1 rather than Th2 bias. Obesity has complex effects on allergic inflammation and is likely to be important modifier of the pathogenesis of airway disease in asthma.