Chronic lung diseases in children are classified as primary and secondary lung disease. Secondary lung disease may develop due to several systemic disorders including primary ciliary dyskinesia, cystic fibrosis, due to oesophagus atresia and trachea–oesophagal fistula, neuromuscular disease and immunodeficiencies. In the lung, there are several different defence mechanisms against infections, both local and general. In this respect we relates to systemic causes of reduced immune defence.
Primary immunodeficiencies
Primary immunodeficiencies may present with different clinical pictures due to different pathogenic mechanisms involved. There are disorders of antibody function, T-cell disorders, phagocytic disorders and others including severe combined immunodeficiency (SCID).
Antibody function disorders
The antibody function disorders are the most common and include X-linked and non-X-linked a- and hypo-γ-globulinaemia, common variable hypo-γ-globulinaemia, immunoglobulin (Ig)G subclass deficiencies, IgA …