Survival from acute exacerbation of idiopathic pulmonary fibrosis with or without direct hemoperfusion with polymyxin B-immobilized fiber column: A retrospective analysis

Background: Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) are fatal episodes of acute respiratory worsening of unknown etiology. Previous studies on acute respiratory distress syndrome have shown that direct hemoperfusion with polymyxin B-immobilized fiber column (PMX-DHP) beneficially impact respiratory status. Aimes: To investigate the prognosis and survival outcome of patients with AE-IPF who underwent PMX-DHP. Methods: We examined records of 50 patients with AE-IPF treated in our hospital. All patients received corticosteroid pulse therapy. We compared the disease outcome between 27 patients who underwent PMX-DHP (PMX group) and 23 patients who did not (non-PMX group). Independent predictors of survival were determined with Cox proportional hazards analyses. Results: A multivariate analysis of all patients revealed that PMX-DHP therapy was a significant predictor of survival (HR=0.442, p=0.019). Throughout the median observational period of 42.0 days (range, 1-1656 days) 38 patients (76.0%) died. Overall survival was significantly longer in the PMX group than the non-PMX group: median survival time, 192 days in the PMX vs. 29 days in the non-PMX (p=0.040, log rank test). The 12-month survival rate was also significantly better in the PMX group than the non-PMX group (41.7% vs. 9.8%). In a subanalysis of the PMX group, time from AE-IPF onset to PMX-DHP was a significant predictor of survival (HR=1.080, p=0.049). Conclusions: PMX-DHP improved the prognosis of AE-IPF. Time from AE-IPF onset to PMX-DHP may be informative for outcome prediction.