Parathyroid hormone-related protein and lung injury after pulmonary thromboendarterectomy

Parathyroid hormone-related protein (PTHrP) is an autocrine growth and diff erentiation factor for alveolar type II epithelial cells. Type II cells sec rete pulmonary surfactant and are pluripotent cells with a role in alveolar epithelial repair after lung injury. The goals of this study were to inves tigate whether the levels of PTHrP in bronchoalveolar lavage liquid (BAL) v aried between patients who did and did not develop lung injury after pulmon ary thromboendarterectomy (PTE). BAL was performed in 48 patients undergoin g PTE for unresolved pulmonary emboli. Samples were obtained following indu ction of anesthesia, following separation from cardiopulmonary bypass, and 48 h postoperatively. PTHrP was measured by radioimmunoassay. Lung injury w as diagnosed in 23 patients on the basis of hypoxemia (PaO2/FIO2 < 300) and the presence of lung infiltrates in the absence of infection or atelectasi s. Patients with lung injury had significantly lower preoperative BAL level s of PTHrP, 21 (21-30) pg/ml (median, interquartile gap), compared to patie nts without lung injury, 34 (21-41) pg/ml (P < 0.05). Preoperative BAL PTHr P levels < 32 pg/ml predicted lung injury with a positive predictive value of 60% and negative predictive value of 82%. The odds of developing lung in jury for patients with preoperative PTHrP levels below this cutpoint were 6 times the odds for patients with higher levels. (C) 2001 Elsevier Science BN. All rights reserved.