Polymyxin B-immobilized Fiber Column (PMX) Treatment for Idiopathic Pulmonary Fibrosis with Acute Exacerbation: A Multicenter Retrospective Analysis

Objective The prognosis of idiopathic pulmonary fibrosis (IPF) patients with acute exacerbation (AE) is reported to be extremely poor. Several clinical studies suggest that direct hemoperfusion with polymyxin Bimmobilized fiber (PMX) may have beneficial effects on AE in patients with interstitial pneumonia (IP). The aim of this multicenter retrospective analysis was to investigate whether PMX treatment could provide improvement of oxygenation and survival benefits in IPF patients with AE. Methods We conducted a retrospective study of 160 IP patients (including 73 IPF) with AE treated by PMX at 18 institutions in Japan. PMX treatment was carried out twice. The total hemoperfusion time of PMX treatment was, on average, 12 hours. Data concerning oxygenation on PMX treatment and survival after AE were collected and analyzed. Results In IPF patients with AE, arterial oxygen tension (PaO2)/inspiratory oxygen fraction (FiO(2)), (P/F) ratio was significantly improved at the end of the 2nd treatment with PMX (173.9 +/- 105.4 to 195.2 +/- 106.8 Torr, p=0.003). White blood cell count was significantly reduced at the end of the 2nd treatment (13,330 +/- 7,002 to 9,426 +/- 5,188/mm(3), p<0.001). These clinical changes were also observed on analysis of all 160 IP patients with AE. The one-and three-month survival rates of IPF patients after AE were 70.1% and 34.4%, respectively. Conclusion PMX treatment may improve oxygenation and survival in IPF patients with AE. Prospective, controlled trials of PMX treatment for IPF with AE are warranted to verify this potential benefit.