The presence of chronic diarrhea, which is usually taken to mean diarrhea that has persisted for over 4 weeks.

A recurrent form of sinusitis.

Decreased levels of immunoglobulin A (IgA).

An abnormally decreased level of immunoglobulin M (IgM) in blood.

A skin abnormality characterized by redness and irritation, with thick, red skin that displays flaky, silver-white patches (scales).

Reduced functionality of the process in which a precursor cell type acquires the specialized features of a B cell. A B cell is a lymphocyte of B lineage with the phenotype CD19-positive and capable of B cell mediated immunity.

A group of phenotypically heterogeneous genetic disorders characterized by profound deficiencies of T- and B-cell function, which predispose the patients to both infectious and noninfectious complications.

A reduction in the normal proportion of class-switched memory B cells (CD19+/CD27+/IgM+/IgD+) 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.

A reduced ability to synthesize postvaccination antibodies against toxoids and polysaccharides in vaccines, as measured by antibody titer determination following vaccination.

An abnormally decreased level of immunoglobulin G (IgG) in blood.