Mortality rates are high among patients with idiopathic pulmonary fibrosis (IPF) awaiting lung transplantation (LTx). Gamma-Interferon 1b(IFN) has been used in these patients, with evidence suggesting an improvement in mortality in patients with mild to moderate disease. The role of IFN in LTx candidates was assessed by comparing outcomes of listed IPF patients who were treated with IFN and those who were not.
Retrospective review of all patients with IPF listed for LTx at two large centers (1992-2004). Endpoints were defined as mortality from listing to 90 days post LTx along with survival to LTx and survival post LTx. Outcomes were compared between those patients who did and did not receive IFN pretransplant.
During the study period, 101 patients with IPF were listed and 76 underwent LTx. Among the IFN+ cohort, 10% (n=2) died prior to LTx vs 21% (n=17) of the IFN- cohort (p=0.20). The median duration of IFN treatment was 359 days (range 42-867). The waiting list time was shorter for the IFN+ group, 86 vs 136 days in the IFN- group, (p=0.09). The mortality rates from listing to 90 days post LTx for the IFN+ and IFN- groups were 5% and 24%, respectively (p = 0.23). Survival from listing and post LTx are seen in the tables below.
Survival From Listing1-mo3-mo6-mo12-moγ-IFN+ group (n= 22)91%91%91%91%γ-IFN- group (n=78)94%82%77%69%
p = 0.12 by Gehan-Wilcoxon
Survival after LTx1-mo3-mo6-mo12-moγ-IFN+ group (n=17)100%100%100%100%γ-IFN- group (n=59)92%86%81%81%
p = 0.14 by Gehan-Wilcoxon
IFN appeared to have a clinically relevant reduction in mortality for IPF transplant candidates although statistical significance was not achieved. This study is limited by its retrospective design, small sample size, and historically different eras in the pooled dataset.
We speculate this trend to improved survival in IFN+ group may be due to a combination of improved pretransplant survival and the IFN+ patients being less ill at the time of transplant.
R.F. Browning, None.