The effect of bronchoalveolar lavage on bronchial responsiveness in patients with airflow obstruction.

This study assessed the effect of bronchoalveolar lavage (BAL) on nonspecific bronchial responsiveness in 31 patients. Of these, 20 had airflow obstruction; 11 control subjects had normal pulmonary function. Bronchial responsiveness to methacholine, expressed as the dose of inhaled methacholine required to provoke a 20 percent fall in forced expiratory volume in one second (PD20 FEV1), was measured before and after BAL. We found no evidence for the induction of responsiveness by BAL in 11 control subjects with negative methacholine tests prior to the procedure. There were small but significant falls in FEV1 following BAL in both the control group and in patients with airflow obstruction. Thus, BAL does not appear to induce nonspecific bronchial hyperresponsiveness in subjects without airflow obstruction, nor does it affect airway responsiveness in emphysema patients. Among asthmatics, bronchial responsiveness can be increased as a result of BAL; this increase was greatest in patients who were most responsive initially.