[Primary antibody deficiency syndrome. Improved life expectancy and immunoglobulin G substitution].

Recurrent pyogenic infections are the leading clinical symptom in patients with antibody deficiency syndromes. In accordance with the WHO-classification at least nine different diseases are differentiated. In some cases diagnosis can be made simply by determining the immunoglobulin serum levels. Some diseases, such as Ig-heavy chain gene deletions, are clearly characterized by molecular biological methods, while other terms, such as common variable immunodeficiency, cover a collection of different diseases with changes predominantly of B-cell functions. The main features of the antibody deficiency syndromes are described. In most cases adequate therapy can be achieved by IgG replacement therapy.