The characterization of bronchoalveolar lavage fluid in very elderly patients with cerebrovascular disease

Background. Elderly patients with cerebrovascular disease have a high frequ ency of pneumonia due to impaired immune function and the occurrence of mic ro-aspiration. Methods. We performed bronchoalveolar lavage in I I very elderly subjects w ith cerebrovascular disease and 9 healthy volunteers to investigate whether there were changes of local immunity in the lungs of the elderly subjects. The total cell count. the cell characteristics, and the lymphocyte subsets in bronchoalveolar lavage fluid were compared between the two groups. Results. A significant increase in the total cell count as well as in the n umber of neutrophils and CD8(-) T cells was observed in the elderly group. In addition, the mean CD4/CD8 lymphocyte ratio was lower in the elderly pat ients than in the healthy volunteers. Conclusions. These observations suggest that silent micro-aspiration occurs in many elderly individuals with cerebrovascular disease and that pulmonar y defenses decrease with age.