COVID-19 progression and convalescence in common variable immunodeficiency patients show dysregulated adaptive immune responses and persistent type I interferon and inflammasome activation.

Common variable immunodeficiency (CVID) is the most prevalent primary immunodeficiency, marked by hypogammaglobulinemia, poor antibody responses, and increased infection susceptibility. The COVID-19 pandemic provided a unique opportunity to study the effects of prolonged viral infections on the immune responses of CVID patients. Here we use single-cell RNA-seq and spectral flow cytometry of peripheral blood samples before, during, and after SARS-CoV-2 infection showing that COVID-19 CVID patients display a persistent type I interferon signature at convalescence across immune compartments. Alterations in adaptive immunity include sustained activation of naïve B cells, increased CD21low B cells, impaired Th1 polarization, CD4+ T central memory exhaustion, and increased CD8+ T cell cytotoxicity. NK cell differentiation is defective, although cytotoxicity remains intact. Monocytes show persistent activation of inflammasome-related genes. These findings suggest the involvement of intact humoral immunity in regulating these processes and might indicate the need for early intervention to manage viral infections in CVID patients.