EFFECT OF CYCLOSPORINE ON LUNG DIFFUSING-CAPACITY IN RENAL-TRANSPLANTPATIENTS

A prospective lung function study pre- and postrenal transplantation w as performed on 21 patients in order to evaluate whether cyclosporin d ecreased the lung diffusing capacity due to lung toxicity. Initial inc lusion criteria were absence of respiratory symptoms and normal findin gs in both chest X-ray and pulmonary function tests. Participants had to be non-smokers. We determined spirometry including lung volumes, ar terial blood gases, carbon monoxide diffusing capacity by the single b reath method (DLCOSB), and rate of CO uptake per unit of lung volume ( KCO) before and 3, 6, and 12 months after transplantation. Immunosuppr ession consisted of prednisone and cyclosporin, maintaining total bloo d levels between 100 and 250 ng/ml. Spirometric and blood gases data r emained within reference levels during the follow-up. Hemoglobin (Hb) pretransplant concentrations remained low, returning to their normal l evels posttransplantation. Pretransplant DLCOSB levels were slightly d ecreased but fell within the therapeutic range after correction for Hb concentration, unlike the mean KCO levels which remained slightly dim inished despite their correction. In post-transplant controls, the val ues obtained for both DLCOSB and KCO were significantly higher at the different post-transplant intervals (P < 0.005) than pretransplantatio n but only when compared without Hb correction. No significant differe nces for DLCOSB were found when corrected values were compared, and an improvement in the KCO appeared to be significant at 12 months posttr ansplantation. Based on these findings, we feel that when serum levels are within the therapeutic range, cyclosporin fails to alter the resp iratory function or the pulmonary diffusing capacity of the lung.