Clinical outcomes, immunogenicity, and safety of BNT162b22 Vaccine in Primary Antibody Deficiency (preprint)

Background: Common variable immunodeficiency (CVID) is characterized by an impaired post-vaccination response, high susceptibility to respiratory tract infections, and a broad spectrum of non-infectious complications. Thus, patients with CVID are at high risk of coronavirus disease 2019 (COVID-19), and vaccination’s role in prevention is questionable. The main aim of this study was to evaluate the clinical outcomes, safety, and dynamics of humoral and T-cell immune responses induced by the mRNA vaccine BNT162b2 in CVID. Methods: This prospective observational cohort study focused on the clinical outcomes (proportion of infected patients, disease severity), safety (adverse-event incidence, laboratory-parameter changes), and dynamics of humoral (specific post-vaccination and virus-neutralizing-antibody assessment) and T-cell immune responses (anti-SARS-CoV-2 specific T-cell detection) in 21 patients with CVID after a two-dose administration of BNT162b2. The patients were followed for 6 months. Results: Humoral response was observed in 52% (11/21) of patients at month 1 post-vaccination but continuously decreased to 33.3% (5/15) at month 6. Nevertheless, they had a remarkably lower anti-SARS-CoV-2 neutralizing antibody titer than healthy controls. The T-cell response was measurable in 33% (6/17) of patients with CVID at month 1, and it persisted for the study period. Mild infection occurred in three patients (14.3%) within the follow-up period. The vaccine also exhibited a favorable safety profile. Conclusions: The BNT162b2 vaccine elicited a measurable antibody response in a high proportion of patients, but it was limited by low titer of the virus-neutralizing antibodies and rapid waning of anti-RBD SARS-CoV-2 specific antibodies. T-cell response was detected in one-third of the patients and remained stable within the follow-up period. Vaccination has favorable safety and clinical-related outcomes in preventing severe COVID-19.

B cells, BAFF and interferons in MIS-C (preprint)

Multisystem Inflammatory Syndrome in Children associated with COVID-19 (MIS-C) is a late complication of pediatric COVID-19, which follows weeks after original SARS-CoV-2 infection, regardless of its severity. It is characterized by hyperinflammation, neutrophilia, lymphopenia and activation of T cells with elevated IFN-γ. Observing production of autoantibodies and parallels with systemic autoimmune disorders, such as systemic lupus erythematodes (SLE), we explored B cell phenotype and serum levels of type I, II and III interferons, as well as the cytokines BAFF and APRIL in a cohort of MIS-C patients and healthy children after COVID-19. We documented a significant elevation of IFN-γ, but not IFN-α and IFN-λ in MIS-C patients. BAFF was elevated in MIS-C patient sera and accompanied by decreased BAFFR expression on all B cell subtypes. The proportion of plasmablasts was significantly lower in patients compared to healthy post-COVID children. We noted the presence of ENA Ro60 autoantibodies in 4/35 tested MIS-C patients. Our work shows the involvement of humoral immunity in MIS-C and hints at parallels with the pathophysiology of SLE, with autoreactive B cells driven towards autoantibody production by elevated BAFF. Graphical abstract Summary sentence Elevated serum BAFF in children with MIS-C supports the state of polyclonal B cell activation and autoimmune phenomena characterizing this disease.

Complex Immuno-metabolic Profiling Reveals Activation of Cellular Immunity and Biliary Lesion in Patients with Severe COVID-19 (preprint)

The aim of this study was to assess the key laboratory features displayed by coronavirus disease 2019 (COVID-19) inpatients which associated with mild, moderate, severe and fatal course of the disease and, through longitudinal follow-up, to understand the dynamics of COVID-19 pathophysiology. All SARS-CoV-2 positive patients admitted to the University Hospital in Motol between March and June 2020 were included in this study. Severe course of COVID-19 was associated with elevation of proinflammatory markers, efflux of immature granulocytes into peripheral blood, activation of CD8 T cells, which infiltrate lungs, and transient liver disease. In particular, the elevation of serum gamma-glutamyl transferase (GGT) and histological signs of cholestasis were highly specific for patients with severe disease. In contrast, patients with fatal course of COVID-19 failed to upregulate markers of inflammation, showed dyscoordination of immune response and progressed towards acute kidney failure. COVID-19 is a disease with multi-organ affinity characterized by activation of innate and cellular adaptive immunity. Biliary lesion with elevation of GGT and organ-infiltration of IL-6 producing cells are defining characteristic for patients with fulminant disease.