Fourteen to 15% of patients who develop chronic graft-versus-host disease after transplant develop bronchiolitis obliterans syndrome (BOS), a common manifestation of lung GVHD. Outcomes are best in patients diagnosed and properly treated early in the course of the disease.

Up to 50% of people develop lung problems after a transplant using donor cells. Some are caused by infection. Graft-versus-host disease can cause bronchiolitis obliterans syndrome (BOS). Frequent pulmonary function tests are important to catch breathing problems early after transplant.