LYMPHOID AGGREGATES IN ENDOBRONCHIAL BIOPSIES FROM YOUNG ELITE CROSS-COUNTRY SKIERS

Observation of bronchus-associated lymphoid tissue (BALT) in whole lun g specimens from healthy nonsmoking adults has questioned the hypothes is that BALT is not constitutively present in healthy adult human lung s. In our study, we investigated endobronchial biopsies of the second- and third-generation carinae from 44 cross-country ski athletes and 1 2 healthy control subjects, all nonsmoking young adults. The skiers ha d a prevalence of respiratory allergy (18%), asthma-like symptoms (59% ), beta 2 agonist medication (25%), and methacholine bronchial hyperre sponsiveness (79%). Biopsy sections were stained by immunohistochemica l and hematoxylin-eosin-saffran methods. Lymphoid aggregates of more t han 50 cells were identified in 28 (64%) skiers and three (25%) contro l subjects (p = 0.02). They were small in comparison to those found in rabbits and rats, contained T and B lymphocytes and macrophages, and were seen more frequently in skiers using beta 2 agonists (p = 0.04) a nd with bronchial hyperresponsiveness to methacholine (p = 0.053). The frequency of these aggregates was not significantly different at the two carinal levels (p = 0.6). The aggregates were not associated with a history of respiratory allergy or asthma-like symptoms. These aggreg ates share some resemblance with what is usually defined as BALT. Howe ver, their exact nature and function await further clarification.