Background: Patients with antibody deficiency suffer chronic respiratory symptoms, recurrent exacerbations, and progressive airways disease despite systemic replacement of IgG. Little is known about the respiratory tract biology of these patients.
Objective: We sought to measure immunoglobulin levels, inflammatory cytokines, and mediators of tissue damage in serum and sputum from patients with antibody deficiency and healthy controls; to analyze the respiratory microbiome in the same cohorts.