Comparison of various classifications for patients with common variable immunodeficiency (CVID) using measurement of B-cell subsets

Background Common variable immunodeficiency (CVID) is a heterogeneous disease, characterised by hypogammaglobulinaemia leading to recurrent infections and various complications. The aim of this study was to classify CVID patients based on four known classifications (Paris, Freiburg, EUROclass, and B-cell patterns) by measurement of B-cell subsets and to assess the relation of each classification with clinical manifestations. Methods We measured all B-cell subsets as both absolute count and percentage in 30 CVID patients and 30 healthy individuals using four-colour flow cytometry. Moreover, we evaluated antibody responses to pneumococcal vaccine in patients. Results A significant reduction in percentage of terminal B-cell subsets (total, marginal zone-like, switched memory, IgM-only memory, total memory B-cells and plasmablast) and absolute count of all B-cell subsets along with a strong increase in CD21low B-cells has been observed in patients. Patients with splenomegaly and hepatomegaly clustered in group Ia, smB + 21low and group 1 based on known classifications, and significantly tended to have a decreased transitional and marginal zone-like B-cells count, as well as an increase in CD21low B-cell counts. Patients with lymphadenopathy, bronchiectasis and allergy had a significant decrease in absolute count of total memory, switched memory and total B-cells, respectively. Conclusion Classification of patients could provide useful information to guide clinicians in long-term follow-up of CVID patients. Our data demonstrate that it may be more accurate to use absolute counts of B-cell subpopulations in CVID patients because absolute counts of B-cell subsets are more associated with clinical manifestations compared with their percentage and also four known classifications.