The expanded CD19(+)IgM(+)CD27(-)CD21(low)CD38(low)CD24(-)B cell population in CVID patients shows the signs of antigen-driven selection and affinity maturation
2009
Abstract
A novel CD19+(I)gM+(C)D27(-)CD21(low)CD38(low)CD24(-) B cell population was found to be significantly increased in the peripheral blood of CVID patients as compared to controls. The differentiation status of these B cells and their capacity to produce immunoglobulins is still unknown.
The aim of the study was to provide detailed molecular analysis of gene repertoire, mutational frequency and amino acid composition of immunoglobulins produced by these B cells at the IgM/IgG mRNA level using single-cell RT-PCR. The signs of antigen-driven selection, affinity maturation and isotype switching were detected in B cells from CVID patients as well as controls.
The results suggest that these cells might represent a novel memory B cell subset.