Long-term survival after lung transplantation depends on development and severity of bronchiolitis obliterans syndrome.

BACKGROUND

The objectives of this study were to describe the natural history of bronchiolitis obliterans syndrome (BOS) in a large consecutive series of patients from a national center in accordance with the most recent grading criteria, and to examine the prognosis with respect to onset and severity of BOS.

METHODS

All patients receiving a cadaveric lung transplant between 1992 and 2004 were included in the study (n = 389). Exclusion criteria were patients not surviving at least 3 months after transplantation (n = 39) and lack of available lung function measurements (n = 4).

RESULTS

The 1-, 3-, 5- and 10-year actuarial survival rates for the entire series were 81%, 67%, 60% and 36%, respectively. The 1-, 3-, 5- and 10-year actuarial freedom from BOS Grade > or = 1 was 81%, 53%, 38% and 15%, respectively. A Cox regression model with BOS grade as a time-dependent covariate was performed in a sub-group of patients surviving at least 3 years (n = 237). Both progression from BOS Grade 1 to 2 and from BOS Grade 2 to 3 were associated with a significant increase in mortality: hazard ratio (HR) = 3.1 (confidence interval [CI] 1.2 to 7.9) and HR = 2.9 (CI 1.6 to 5.3), respectively. The addition of a non-time-dependent covariate to signify early (within 18 months of transplantation) or late (after 18 months) development of BOS was not significant (p = 0.5).

CONCLUSIONS

The development and progression of chronic allograft rejection after lung transplantation (BOS Grades 2 and 3) is associated with a 3-fold increase in the risk of death at each stage, irrespective of whether BOS developed early or late.