Diffusing lung capacity and cyclosporine in patients with heart transplants.

Pulmonary function studies were performed in 10 patients undergoing surgery for heart transplantation. The study was repeated 6 to 12 months after surgery. The comparison between data before and after transplantation showed an overall improvement in lung function indices, except for the lung diffusing capacity (DLCO). A mean 14% reduction (p less than 0.01) of DLCO was observed. In the absence of evidence of other lung disease or rejection reaction in these patients, this finding may be related to a side effect of cyclosporine on the lung and deserves further investigation.