Investigating Biomarkers for Inborn Errors of Immunity in a Prospective Study of Patients With Autoimmune Cytopenia

Quantitative immunoglobulin levels and naïve T cells remain valuable indicators of IEI in AIC. Our findings highlight the diagnostic value of emerging cellular and serum biomarkers in identifying IEI, including dysregulation of early B-cell subsets (transitional B cells and CD19^hiCD21^lo B cells), expansion of T_FH cells, and elevated levels of BAFF and sIL2R.