Currently, the interest of pediatricians in diseases associated with dysfunction of the immune system has increased. Among the variety of immunopathological processes , immunodeficiency states in children are of greatest clinical importance. Immunodeficiency syndrome (IDS) is characterized by increased susceptibility to infections, which usually take on a severe acute form or a chronic relapsing course. The possibility of immunodeficiency should be considered in all cases of recurrent infections. However, the diagnosis of immunodeficiency is often difficult due to the widespread use of antibiotics in modern therapeutic practice. Immunodeficiency diseases are divided into 2 groups.