The lung and primary immunodeficiency.

Primary immunodeficiences (ID), once considered to be very rare, are now increasingly recognized thanks to more knowledge in the immunological field and to the availability of more sophisticated diagnostic techniques. The respiratory tract and especially the lung are the most common targets of primary ID, and respiratory infections and/or failure are the most frequent causes of early death when the immune defect is not corrected with HLA-identical bone-marrow trans lant or, in few selected cases, with thymic extracts. Many patients with Ig deficiency are severely affected by chronic and recurrent respiratory infections, unfortunately leading to bronchiectasis in the majority of such patients. Today early i.v. gammaglobulin administration can prevent bronchiectasis, and this increases the chances of a better prognosis and of an improved quality of life as well.