Bone marrow transplantation and the lung.

Bone marrow transplantation is a remarkably easy technical procedure with enormous therapeutic potential, which is as yet only partially tapped because of a paucity of suitable donors and a high complication rate. Nevertheless the procedure offers the hope of curing the many and diverse clinical disor- ders that result from malfunction of the progeny of haemopoietic pleuripotential stem cells. The technique is capable of restoring normal haematological function in primary red cell, white cell, or platelet dis- orders after ablation of aberrant cells and can be used to rescue patients with marrow failure secondary to chemical or radiation insult. Immunological com- petence can be restored as grafted haematological stem cells are able to differentiate into T and B lymphocytes. Possibly many immunological disorders will be treated with bone marrow transplantation in the forseeable future. Bone marrow transplantation is also being studied as a form of treatment for meta- bolic disorders, including mucopolysaccharidoses, Gaucher's disease, and adenosine deaminase deficiency.' By means of a graft of normal stem cells into an affected patient erythrocytes, granulocytes, and macrophages are produced and normal enzymes are manufactured, which then diffuse into enzyme deficient tissues. In 1986 two major difficulties, graft versus host disease and pulmonary damage, limit the widespread exploitation of bone marrow trans- plantation.24