The Annals of Thoracic Surgery, Vol 51, 76-80, Copyright © 1991 by The Society of Thoracic Surgeons
Altered cellular immune function in the atelectatic lung
DM Nguyen, DS Mulder and H Shennib
McGill University Lung Transplant Program, Montreal, Quebec, Canada.
Pulmonary atelectasis is common and may predispose the lung to infection.
We have previously shown that atelectasis impairs alveolar macrophage
antibacterial function. This study examines the effect of atelectasis on
the cytotoxic function of lymphocytes harvested from the bronchoalveolar
space of atelectatic lung segments by bronchoalveolar lavage. Specifically,
we studied natural killer and lectin-dependent cell-mediated cytotoxicity
in peripheral blood and bronchoalveolar lavage lymphocytes from the
atelectatic lower lobes and contralateral normal lobes in a group of 8
dogs. We observed a decline of natural killer and lectin-dependent
cell-mediated cytotoxicity to 62.7% and 61.5%, respectively, of
preatelectasis control values in the affected lung lobes (p less than
0.01). Simultaneous measurements of cytotoxic activity of bronchoalveolar
lavage lymphocytes harvested from the unaffected contralateral normal lungs
were comparable with control values. On the other hand, natural killer and
lectin-dependent cell- mediated cytotoxicity activities in peripheral blood
lymphocytes were significantly increased in animals having right lower lobe
atelectasis (166.7% and 154.7% of pretreated normal control, respectively,
p less than 0.01). Atelectasis was also associated with an influx of
polymorphonuclear leukocytes into the bronchoalveolar compartment. These
findings confirm the presence of natural killer cells and cytotoxic
lymphocytes in the bronchoalveolar compartment and demonstrate an
atelectasis-induced impairment of local bronchoalveolar lymphocyte
function. Such a dysfunction of local lung cellular host defenses may
render the atelectatic lung susceptible to infection.
