Direct hemoperfusion with polymyxin B immobilized fiber column (PMX) treatment for acute exacerbation of idiopathic pulmonary fibrosis: A prospective multicenter cohort study

The prognosis of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is extremely poor. However, recent clinical reports suggest that direct hemoperfusion with polymyxin B-immobilized fiber column (PMX) treatment may have beneficial effects in patients with AE-IPF. The aim of this multicenter prospective study was to investigate the effectiveness and safety of PMX treatment in AE-IPF. We conducted a prospective study of patients with AE-IPF treated by PMX at two institutions in Japan. Each patient received 2–3 sessions of PMX treatment with a target duration of 6–24 h. The primary endpoint was the survival rate at day 28 after the PMX treatment. The survival rate of the patients on day 28 after PMX treatment was 65% [95% confidence interval (CI): 40.3–81.5%]. The lower limit of 95% CI in the study was higher than the survival rate of 40%, which was the upper limit of the survival rate in AE-IPF receiving conventional treatments, as reported previously. The survival rate of the patients 12 weeks after PMX was 50% (95% CI: 27.1–69.2%). The changes in the difference between alveolar and arterial oxygen tension and the partial pressure of arterial oxygen/fraction of inspired oxygen improved as the number of PMX sessions increased, and significant improvements were observed at the end of the second PMX session. The safety of PMX was clinically acceptable. This prospective multicenter study suggests that PMX treatment is safe for patients with AE-IPF and may improve their oxygenation and prognosis.