Life-threatening “breakthrough” cases of critical COVID-19 are attributed to poor or waning antibody (Ab) response to SARS-CoV-2 vaccines in individuals already at risk. Preexisting auto-Abs neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; their contribution to hypoxemic breakthrough cases in vaccinated people is unknown. We studied a cohort of 48 individuals (aged 20 to 86 years) who received two doses of a messenger RNA (mRNA) vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Ab levels to the vaccine, neutralization of the virus, and auto-Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal Ab response to the vaccine. Among them, 10 (24%) had auto-Abs neutralizing type I IFNs (aged 43 to 86 years). Eight of these 10 patients had auto-Abs neutralizing both IFN-α2 and IFN-ω, whereas two neutralized IFN-ω only. No patient neutralized IFN-β. Seven neutralized type I IFNs at 10 ng/ml and three at 100 pg/ml only. Seven patients neutralized SARS-CoV-2 D614G and Delta efficiently, whereas one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only type I IFNs at 100 pg/ml neutralized both D614G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating Abs capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a notable proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population.

Performance of the QuantiFERON-TB Gold Plus (QFT-Plus) assay could be affected by conditions of immune dysregulation. Little is known about the reliability of QTF-Plus in COVID-19 patients. Our aim was to determine the prevalence and the factors related to an indeterminate QFT-Plus test in COVID-19 hospitalized patients, and to analyze its relationship with in-hospital mortality. A retrospective analysis of all hospitalized COVID-19 patients on whom a QTF-Plus assay was performed in a tertiary care public hospital during the first epidemic wave in Spain (March–April 2020). Out of a total of 96 patients included, 34 (35.4%) had an indeterminate result, in all cases due to a lack of response in the mitogen control. Factors related to COVID-19 severity, such as higher lactate dehydrogenase (LDH) (odds ratio [OR] 1.005 [95% confidence interval [CI] 1.002–1.008]) and previous administration of corticosteroids (OR 4.477 [95% CI 1.397–14.345]), were independent predictors for indeterminate QFT-Plus assay. Furthermore, indeterminate results were more frequent among COVID-19 patients who died during hospitalization (29.1% vs. 64.7%; p = 0.005). We conclude that QFT-Plus assay yielded an unexpected, high prevalence of indeterminate results in severe COVID-19 patients. Factors related to worse COVID-19 outcome, such as LDH, as well as corticosteroid use before the QFT-Plus assay, seem to be predictors for an indeterminate result. The role of an indeterminate QFT-Plus result in predicting COVID-19 severity and mortality should be evaluated.

Background: COVID-19 has quickly become a global pandemic with a substantial number of deaths and is a considerable burden for healthcare systems worldwide. Although most cases are paucisymptomatic and limited to the viral infection-related symptoms, some patients evolve to a second phase, with an impaired inflammatory response (cytokine storm) that may lead to acute respiratory distress syndrome and death. This is thought to be caused by increased bradykinin synthesis. Methods: ICAT-COVID is a multicenter, randomized, open-label, proof-of-concept phase II clinical trial assessing the clinical efficacy and safety of adding icatibant to the standard of care in patients hospitalized with COVID-19 without invasive mechanical ventilation. Patients hospitalized with a confirmed COVID-19 pneumonia diagnosis (RT-PCR or antigen test ≤ 10 days prior to randomization, and radiographic evidence of pulmonary infiltrates), rated “4” or “5” on the WHO’s clinical status scale, are eligible. Patients will be randomized on a 1:1 ratio to either standard of care-plus-icatibant (experimental group) or to standard of care alone (control group). The experimental group will receive 30 mg of icatibant subcutaneously 3 times a day for 3 days (for a total of 9 doses). The expected sample size is 120 patients (60 per group) from 2 sites in Spain. Primary outcomes are the efficacy and safety of Icatibant. The main efficacy outcome is the number of patients reaching grades “2” or “1” on the WHO scale within 10 days of starting treatment. Secondary outcomes include “long-term efficacy”: number of patients discharged who do not present COVID-19-related relapse or comorbidity up until 28 days after discharge, and mortality. Discussion: Icatibant, a bradykinin type 2 receptor antagonist with proven effectiveness and safety against hereditary angioedema attacks, may be beneficial for COVID-19 patients by inhibiting bradykinin’s action on endothelial cells and by inhibiting the SARS-CoV-2 M protease. Our working hypothesis is that treatment with standard of care-plus-icatibant is effective and safe to treat patients infected with SARS-CoV-2 admitted to hospital for pneumonia without invasive mechanical ventilation. Trial registration: EudraCT 2020-002166-13. ClinicalTrials.gov NCT04978051

Introduction: On the basis of the preliminary report from the RECOVERY trial, the use of dexamethasone or alternative corticosteroids (CS) is currently recommended in severe COVID-19 patients requiring supplemental oxygen. However, last updated recommendations have not taken a position either for or against the use of other immunomodulators such as tocilizumab (TCZ), with or without CS, since results are still limited. Methods: From March 17 to April 7, 2020, a real-world observational retrospective analysis was conducted at our 750-bed university hospital to study the characteristics and risk factors for mortality in patients with severe COVID-19 treated with TCZ +/-CS, in addition to standard of care (SOC). Data were obtained from routine clinical practice, stored in electronic medical records. The main outcome was all-cause in-hospital mortality. Results: A total of 1,092 COVID-19 patients were admitted during the study period. Of them, 186 (17%) were treated with TCZ, of which 129 (87.8%) in combination with CS. Of the total 186, 155 (83.3 %) patients were receiving non-invasive ventilation when TCZ +/-CS was initiated. Mean time from symptoms onset and hospital admission to TCZ use was 12 (± 4.3) and 4.3 days (± 3.4), respectively. Overall, 147 (79%) survived and 39 (21%) died. By multivariate analysis, mortality was associated with older age (HR=1.09, p<0.001), chronic heart failure (HR=4.4, p=0.003), and chronic liver disease (HR=4.69, p=0.004). The use of CS, in combination with TCZ, was the main protective factor against mortality (HR=0.26, p<0.001) in such severe COVID-19 patients receiving TCZ. No serious superinfections were observed after a 30-day follow-up. Conclusions: In severe COVID-19 patients receiving TCZ due to systemic host-immune inflammatory response syndrome, the use of CS in addition to TCZ therapy, showed beneficial effect in preventing in-hospital mortality.

Late onset combined immunodeficiency (LOCID) is a rare variant of common variable immunodeficiency (CVID), typically affecting adult patients who present with opportunistic infections (OI) and/or low CD4+ T lymphocytes. Diagnostic delay is common due to the rareness of this entity, increasing morbidity and mortality. We report on a 66-year-old male who developed a severe gastrointestinal cytomegalovirus (CMV) infection, refractory to antiviral treatment and anti-cytomegalovirus specific human immunoglobulin administration, with a fatal outcome due to an undiagnosed LOCID.