Common Variable Immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency. A significant proportion of patients present decreased number of circulating B cells, and defective or deregulated pre-germinal center B cell compartment.
We aim to precisely trace the maturation pathway of the pre-germinal center compartment in CVID patients, to identify if a deregulated or derailed maturation could already indicate an impaired early development in bone marrow, or suggest alterations in peripheral B cell homeostasis in a proportion of patients.
A total of 100 CVID patients and 56 HD were studied with standardized protocols within the collaborative and multicenter frame of the PID-group of the EuroFlow consortium. Patients samples and clinical data were collected at 7 different sites.
The distribution of distinct B-cell subsets were analyzed by flow cytometry, with the EuroFlow 8-color pre GC B-cell tube. CD19+ B-cells were subclassified into 11 different subpopulations.
We created a normal maturation B cell pathway focused in the pre GC B cell compartment of HD with the maturation tool of the Infinicyt software. We performed the same analysis to a cohort of 100 CVID patients and plotted the individual results to the normal, in order to detect aberrant populations in preGC in CVID that may have followed a diverse maturation pathway, and identify aberrant expression of markers in CVID patients.
We sought for correlations among alterations in the preGC compartment (absolute counts and expression markers) with clinical data records looking for potential implications of phenotypic aberrancies and clinical complications.