Mutations in BTK in humans cause a more severe defect in B-cell development characterized by almost complete absence of B cells in the peripheral circulation, profound hypogammaglobulinemia and an inability to produce antibodies to any antigens.
Flow cytometric analysis of the peripheral monocytes using the anti-BTK antibody was used to characterize a 27 year old male patient with mild hypogammaglobulinemia (IgG, 635 mg/dl; IgM, 11 mg/dl; IgA, <5 mg/dl).
Viruses and bacteria in bronchoalveolar lavage fluids, protected specimen brush samples, and bronchial biopsies from 14 patients with primary hypogammaglobulinemia (11 patients with common variable immunodeficiency [CVID] and three patients with X-linked agammaglobulinemia [XLA]) were analyzed.
BPK was evaluated as a candidate for human X-linked agammaglobulinemia (XLA), an inherited immunodeficiency characterized by a severe deficit of B and plasma cells and profound hypogammaglobulinemia.