Endothelin in bronchoalveolar lavage fluid is increased in lung-transplanted patients.

Animal studies have shown increased endothelin in bronchoalveolar lavage (BAL) fluid during unmodified rejection. We performed radioimmunoassay of endothelin in 59 BAL fluid samples from ten patients at different times after lung transplantation. All patients received immunosuppressive therapy (cyclosporin, azathioprine and methylprednisolone). Reference BAL samples were obtained from six controls. Of the 59 test samples, five were collected during rejection episodes, confirmed by clinical outcome, BAL cytology and radiology (rejection group), and 19 were taken during bacterial, viral or fungal infection (infection group). The endothelin content of BAL (pg/ml) was significantly greater in the rejection group than in the infection group (61.1 +/- 3.8 vs 40.6 +/- 2.0) or in the 35 samples taken in uncomplicated course after lung transplantation (40.9 +/- 5.4), p < 0.01. The endothelin level in BAL fluid from the controls was only 3.0 +/- 1.4 pg/ml, significantly less (p < 0.005) than in all the lung-transplanted groups. Endothelin in BAL fluid thus was increased after lung transplantation, and still further during rejection.