CD19+IgD+CD27- Naïve B Cells as Predictors of Humoral Response to COVID 19 mRNA Vaccination in Immunocompromised Patients.

Immunocompromised patients are considered high-risk and prioritized for vaccination against COVID-19. We aimed to analyze B-cell subsets in these patients to identify potential predictors of humoral vaccination response. Patients (n=120) suffering from hematologic malignancies or other causes of immunodeficiency and healthy controls (n=79) received a full vaccination series with an mRNA vaccine. B-cell subsets were analyzed prior to vaccination. Two independent anti-SARS-CoV-2 immunoassays targeting the receptor-binding domain (RBD) or trimeric S protein (TSP) were performed three to four weeks after the second vaccination. Seroconversion occurred in 100% of healthy controls, in contrast to 67% (RBD) and 82% (TSP) of immunocompromised patients, while only 32% (RBD) and 22% (TSP) achieved antibody levels comparable to those of healthy controls. The number of circulating CD19+IgD+CD27- naïve B cells was strongly associated with antibody levels (ρ=0.761, P<0.001) and the only independent predictor for achieving antibody levels comparable to healthy controls (OR 1.07 per 10-µL increase, 95%CI 1.02-1.12, P=0.009). Receiver operating characteristic analysis identified a cut-off at ≥61 naïve B cells per µl to discriminate between patients with and without an optimal antibody response. Consequently, measuring of naïve B cells in immunocompromised hematologic patients could be useful in predicting their humoral vaccination response.

Convalescent plasma therapy and mortality in COVID-19 patients admitted to the ICU: a prospective observational study.

BACKGROUND: This study aimed to quantify the potential survival benefit of convalescent plasma therapy (CVP) in critically ill patients with acute respiratory failure related to coronavirus disease-2019 (COVID-19). METHODS: This is a single-center prospective observational cohort study in COVID-19 patients with acute respiratory failure. Immediately after intensive care unit (ICU) admission patients were allocated to CVP treatment following pre-specified criteria to rapidly identify those patients potentially susceptible for this treatment. A propensity score adjustment [inverse probability of treatment weighted (IPTW) analysis] was implemented to account rigorously for imbalances in prognostic variables between the treatment groups. RESULTS: We included 120 patients of whom 48 received CVP. Thirty percent were female with a median age of 66 years [25th-75th percentile 54-75]. Eighty-eight percent of patients presented with severe acute respiratory failure as displayed by a median paO2/FiO2 ratio (Horowitz Index) of 92 [77-150]. All patients required any kind of ventilatory support with more than half of them (52%) receiving invasive ventilation. Thirty-day ICU overall survival (OS) was 69% in the CVP group and 54% in the non-CVP group (log-rank p = 0.049), respectively. After weighing the time-to-event data for the IPTW, the favorable association between CVP and OS became even stronger (log-rank p = 0.035). Moreover, an exploratory analysis showed an overall survival benefit of CVP therapy for patients with non-invasive ventilation (Hazard ratio 0.12 95% CI 0.03-0.57, p = 0.007) CONCLUSION: Administration of CVP in patients with acute respiratory failure related to COVID-19 is associated with improved ICU survival rates.

Changes in Hematopoietic Cell Transplantation Practices in Response to COVID-19: A Survey from the Worldwide Network for Blood & Marrow Transplantation.

SARS-CoV-2 has spread rapidly worldwide, but the full impact of the COVID-19 pandemic on the field of hematopoietic cell transplantation (HCT) remains unknown. To understand this better, an 18-item online survey was disseminated by the Worldwide Network for Blood & Marrow Transplantation with questions exploring SARS-CoV-2 testing algorithms, mobilization, and cryopreservation strategies and COVID-19 infections in allogeneic related and autologous hematopoietic progenitor cell (HPC) donors. The aim of this survey was to assess the impact of the outbreak on policies relating to HPC mobilization, collection, and processing with respect to changes in daily routine. A total of 91 individual responses from distinct centers in 6 continents were available for analysis. In these centers, the majority (72%) of allogeneic related and autologous donors are routinely tested for SARS-CoV-2 before HPC collection, and 80% of centers implement cryopreservation of allogeneic HPC grafts before commencing conditioning regimens in patients. Five related and 14 autologous donors who tested positive for COVID-19 did not experience any unexpected adverse events or reactions during growth factor administration (eg, hyperinflammatory syndrome). These data are limited by the small number of survey respondents but nonetheless suggest that centers are following the recommendations of appropriate scientific organizations and provide some preliminary data to suggest areas of further study.