Thirty-two recipients of single, double, or heart-lung transplantation
followed-up for at least 3 months post-transplant were retrospectivel
y reviewed to assess the frequency, predictors, and risk factors assoc
iated with the development of bronchiolitis obliterans (BO). A clinica
l definition for the diagnosis of BO was made using the following crit
eria: persistent and progressive decline in FEF25-75, associated with
normal results of cytologic and microbiologic studies for significant
pathogens in bronchoalveolar lavage fluid, with a normal chest radiogr
aph. This was correlated with histologic diagnosis and patient outcome
. Sixteen (50%) of the patients developed BO, and this was associated
with a 56% mortality. All but 1 patient with histologic BO had a clini
cal diagnosis of BO made (often months) prior to diagnostic biopsy. No
patients with normal histologic findings had a clinical diagnosis of
BO. More than 3 episodes of histologically documented acute rejections
in any 12-month period were eventually associated with a 100%, incide
nce of BO. Cytomegalovirus occurred with greater frequency in patients
with BO, and in most cases, preceded or occurred concomitantly with t
he diagnosis of acute rejection or BO.