Treatment of presumed and proven acute rejection following six months of lung transplant survival.

The gold standard for the diagnosis and subsequent treatment of acute rejection of lung allografts is the demonstration of rejection on transbronchial biopsy specimens. However, treatment may be initiated in the case of a compatible clinical scenario in the absence of definitive histologic documentation. In the Toronto Lung Transplant Program, we have treated patients with a decline in FEV1 and no evidence of infection with augmented systemic steroids for a presumed diagnosis of rejection. We retrospectively reviewed all episodes of acute rejection that occurred beyond 6 mo after transplant where treatment with augmented steroids had been initiated. A total of 72 treatments with augmented steroids were initiated in 45 patients who underwent 47 transplant procedures. FEV1 showed at least a 10% improvement following steroids in 14 of 72 (19%). FEV1 continued to decline by at least 10% in 32 of 72 (44%). Changes in FEV1 between +10 and -10% occurred in 26 of 72 (36%); of those episodes, 19 showed a decline of < 10%. Histologic evidence of at least grade II rejection was documented in only 16 cases. In those cases, FEV1 improved by at least 10% in 7 of 16 (44%), whereas it declined by at least 10% in 4 of 16 (25%). Spirometric evidence of bronchiolitis obliterans syndrome developed within 3 mo of the treated rejection episode in at least 20 of 47 transplants (43%). We conclude that treatment with augmented systemic steroids for presumed and histologically proven acute rejection beyond 6 mo after transplant is often ineffective in improving spirometry.