Branchial hyperreactivity after lung transplantation predicts early bronchiolitis obliterans

Nonspecific bronchial hyperreactivity (NSBHR) has been observed in patients who have undergone lung transplantation, but studies have provided conflic ting reports as to the incidence and significance of this finding. To delin eate more clearly the natural history of NSBHR after lung transplantation, data from 111 consecutive patients undergoing double lung transplantation b etween February 1988 and May 1994 were reviewed. Methacholine challenge tes ting was requested in conjunction with regular postoperative follow-up. Amo ng 60 patients tested at 3 mo, 18 (30%) had a positive methacholine challen ge; at 6 mo, the incidence was 14 of 59 (24%). Of 21 patients for whom comp lete testing was performed for 12 mo or longer, 13 (62%) had exclusively ne gative challenges. Patients with a positive challenge at 3 mo were signific antly more likely to develop bronchiolitis obliterans syndrome (BOS) (p < 0 .006). Mean time to development of BOS was 16.9 mo in the group with positi ve challenges versus 43.9 mo for those with negative challenges, We conclud e that increased NSBHR is a common, but by no means universal, finding afte r lung transplantation. Furthermore, early positive methacholine challenges are associated with development of BOS, We hypothesize that NSBHR may repr esent an early marker of chronic rejection in these patients.