label: Abnormal proportion of class-switched memory B cells
label_lc: abnormal proportion of class-switched memory b cells
description: "A deviation of the normal proportion of class-switched memory B cells (CD19+/CD27+/IgM-/IgD-) in circulation relative to the total number of B cells. Marginal zone B cells undergo limited somatic hypermutation and produce high-affinity IgM and some IgG, whereas class-switched memory B cells synthetize IgG, IgM, and IgA."