A Prospective Study of Airway Reactivity Before Bone Marrow Transplantation

The purposes of this study were to assess baseline airway function and to determine the frequency of airway reactivity in patients before bone marrow transplantation (BMT). The ratio of the forced expiratory volume at 1 second to the forced vital capacity (FEV₁/FVC) was the measure of baseline airflow. Using methacholine challenge, we tested 53 patients before conditioning chemotherapy, total-body irradiation, and BMT. All patients had a baseline FEV₁/FVC of 70% or more. The mean baseline FEV₁/FVC was 84 ± 6%. The response to methacholine challenge was defined by the change in FEV₁ from baseline (ΔFEV₁). A positive response (ΔFEV₁ of 20% or more) occurred in 11 of 53 patients (21%), a borderline response (ΔFEV₁ of less than 20% but greater than or equal to 10%) was found in 10 (19%), and no response (ΔFEV₁ of less than 10%) was elicited in 32 (60%). In our group of patients with a positive or borderline response to methacholine, we found no significant relationship to baseline FEV₁/FVC, smoking history, hematologic diagnosis or study, or major post-BMT pulmonary complications including bronchiolitis obliterans. We concluded that pretransplantation airway reactivity, as measured by methacholine challenge and in the setting of normal baseline FEV₁/FVC, was common before BMT. The presence of a borderline or positive response to methacholine challenge before transplantation was not associated with the development of either clinical or pathologically proven posttransplantation bronchiolitis obliterans.