||B lymphocytes are essential for protective humoral immunity against infectious pathogens. Defects in the differentiation, responsiveness, or composition of different B cell subsets can lead to a wide spectrum of clinical immunodeficiencies such as primary (PID) and common variable (CVID) immunodeficiencies. These diseases are characterized by variably defective immunoglobulin production, susceptibility to recurrent infection, and ineffective vaccine responses. Secondary immunodeficiency due to immunotherapy directed against B cells (e.g. rituximab) for treatment of autoimmune diseases and various B cell malignancies can show selective loss of B cell subsets and may predict outcome.
This assay analyzes the expression of CD19, CD20, CD27, CD21, CD10, CD38, CD24, IgM, and IgD to characterize the different B cell compartments to aid in the diagnosis and classification of primary and secondary immunodeficiencies.