Direct hemoperfusion with a polymyxin B-immobilized fiber column eliminates neutrophils and improves pulmonary oxygenation--a comparison of two cases with acute exacerbation of idiopathic pulmonary fibrosis]

Idiopathic pulmonary fibrosis (IPF) is characterized by radiographically evident interstitial infiltrates predominantly affecting the lung bases and by progressive dyspnea and worsening pulmonary function. Acute exacerbation of IPF is recognized widely as an accelerated phase occurring suddenly in the course of IPF, which leads to a catastrophic outcome. No treatment has proven to be effective so far. We describe two cases of acute exacerbation of IPF which were treated by direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX) after steroid pulse therapy. One patient died on the 21st day after direct hemoperfusion and the other is alive at present. The survivor showed significant improvement of pulmonary oxygenation correlating with a decrease in the neutrophil count, SP-D and KL-6 after direct hemoperfusion with PMX. On the other hand, the non-survivor showed no improvement of pulmonary oxygenation, SP-D and KL-6 despite a decrease in neutrophil count comparable with that of the survivor. Neutrophil count which decreased temporarily after direct hemoperfusion with PMX soon convert to increase in the non-survivor, which is a characteristic difference between two. We reached the conclusions that (1) direct hemoperfusion with PMX absorbs neutrophils and this mechanism is effective to improve pulmonary oxygenation, (2) sometimes neutrophil absorption is not enough to control pulmonary inflammation in patients with acute exacerbation of IPF.