IRF2BP2 deficiency: An important form of common variable immunodeficiency with inflammation

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• IRF2BP2 is a transcription factor crucial for immune regulation, angiogenesis, apoptosis, and cell differentiation.
• IRF2BP2 gene defects are linked to primary immunodeficiency disorders.

Purpose of the Study:

• To investigate the clinical spectrum and functional consequences of IRF2BP2 variants.
• To characterize 34 individuals from 18 families harboring IRF2BP2 mutations.

Main Methods:

• Clinical data abstraction for phenotype correlation.
• Functional assays using peripheral blood mononuclear cells (PBMCs).
• Evaluation of IRF2BP2 repressor activity on NFAT signaling in Jurkat cells using reporter constructs.

Main Results:

• 91% of subjects presented with immunodeficiency, alongside frequent gastrointestinal (65%) and inflammatory/autoimmune (57%) features.
• Reduced memory B cells, impaired immunoglobulin production, and decreased calcium flux were observed.
• Patient-derived IRF2BP2 mutants showed impaired repression of NFAT activation and elevated TNF-α transcript levels.

Conclusions:

• IRF2BP2 deficiency results in a complex immunodeficiency syndrome with multi-systemic manifestations.
• Impaired IRF2BP2 function disrupts B-cell maturation and promotes pro-inflammatory signaling via the NFAT pathway.