[Common variable immunodeficiency: a rare humoral immunodeficiency with frequent later change of diagnosis].

Common variable immunodeficiency (CVIS) is a condition associated with a deficiency of humoral immunity. The typical patient is an adolescent or adult with a history of recurrent upper respiratory tract infections over many years. Despite the long history the illness is not readily recognised and diagnosis is usually delayed until the patient is admitted to hospital for a severe respiratory tract infection and is being worked up for causes of immunodeficiency. The diagnosis of CVIS is based on the finding of an immunoglobulin deficiency in immunoelectrophoresis or documentation of reduced IgG subclasses. Typically this leads to upper respiratory tract infections and malabsorption, as illustrated by the case reports. Pathophysiologically this disease is characterised by malfunction of B cells with defective gammaglobulin production or secretion. 7 patients were substituted with IgG, leading to decreased susceptibility to infection and a reduction in hospital admissions due to severe infections.