Iron accumulation in lung allografts is associated with acute rejection but not with adverse outcome.

BACKGROUND

Iron content in lung allografts is increased after transplantation. It was hypothesized that this may lead to fibrosis and posttransplant bronchiolitis obliterans syndrome (BOS).

METHODS

In a prospective study, we evaluated 399 BAL fluid (BALF) and transbronchial lung biopsy samples obtained concurrently from 72 consecutive lung transplant recipients.

RESULTS

The hemosiderin scores (HSs) of the BALF samples increased steadily during the postoperative period (p < 0.001). Patients with at least one acute rejection episode (AR) grade > or = A2 event had higher mean HSs, the difference being significant after the second (p < 0.008) and the sixth postoperative months (p < 0.05). The HS correlated with the number of ARs (p < 0.004), and it significantly increased after the first AR (p < 0.04). Except for oral anticoagulation, no other risk factors for elevated iron content were found. There was no correlation between HS or number of ARs and the development of BOS or survival, respectively.

CONCLUSIONS

Progressive iron accumulation in lung allografts seems to be caused mainly by an AR, possibly due to perivascular leakage of erythrocytes. Neither increased HS nor the frequency of ARs were risk factors for subsequent development of BOS. Early detection and treatment of ARs might uncouple their association with BOS.