Yield of surveillance transbronchial biopsies performed beyond two years after lung transplantation.

BACKGROUND

Acute lung rejection after transplantation may lead to significant graft dysfunction. Hence surveillance protocols which include transbronchial biopsies have been established to monitor for early findings suggestive of acute rejection. However, the frequency of acute rejection diminishes as time from the transplant procedure increases. We therefore sought to examine the incidence of acute rejection seen on surveillance transbronchial biopsy performed at least 2 years after transplantation.

METHODS

A retrospective review of all transbronchial biopsy was conducted. Forced expiratory volume in 1 second at the time of transbronchial biopsy and in the preceding 6 months was recorded.

RESULTS

A total of 102 transbronchial biopsy procedures were assessed. Histologic evidence of at least grade 2 rejection (including three judged as grade 1 to 2) occurred in biopsy samples from 10 procedures (9.8%). Five of the episodes occurred at 2 years, three occurred at 3 years, and two occurred at 4 years. Inadequate biopsies occurred on 22 occasions (21.6%). A corresponding significant change in forced expiratory volume in 1 second ( >or= 10% decline) compared with the preceding 6 months was seen in 4 of 10 episodes of grade 2 acute rejection. Only one of five episodes occurring at least 3 years after transplantation was associated with a decline in forced expiratory volume in 1 second. No evidence of acute rejection was found in any of 15 transbronchial biopsy procedures beyond 4 years after transplantation where adequate material for histologic interpretation was obtained. However, no statistically significant change was found in the proportion of transbronchial biopsy procedures showing acute rejection as a function of time.

CONCLUSIONS

We conclude that transbronchial biopsy-proven acute rejection may occur in patients with asymptomatic, stable conditions who have survived at least 2 years, but the yield of transbronchial biopsy performed beyond 4 years is exceedingly low.