Utility of peripheral blood B cell subsets analysis in common variable immunodeficiency.

Area of Science:

• Immunology
• Hematology

Background:

• Peripheral blood B cell subset abnormalities are noted in common variable immunodeficiency (CVID).
• Classification systems for CVID based on B cell numbers have been proposed to predict clinical outcomes.

Purpose of the Study:

• To analyze B lymphocyte subsets in CVID patients using multi-colour flow cytometry.
• To assess the clinical relevance of B cell subsets and validate existing classification criteria (Freiburg, Paris, Euroclass) against clinical manifestations.

Main Methods:

• Multi-colour flow cytometry (MFC) was used to analyze B lymphocyte subsets.
• A cohort of well-characterized CVID patients was studied.
• B cell subset proportions and absolute numbers were compared to controls.

Main Results:

• CVID patients exhibited reduced proportions of total and switched memory B cells (MBC, swMBC) compared to controls.
• Freiburg Ia classification correlated with a higher prevalence of granulomatous diseases.
• Absolute B cell counts, including total B cells and MBCs, showed a significant linear correlation with granulomatous disease.
• Previously reported associations with autoimmune diseases were not confirmed; Euroclass classification was not predictive.

Conclusions:

• Absolute numbers of peripheral blood B cell subsets may be more clinically relevant than relative percentages for assessing granulomatous disease risk in CVID.
• Further investigation is needed to clarify the association between B cell subsets and autoimmune diseases in CVID.