Advances in Endotoxin Adsorption Therapy Using Polymyxin B Immobilized Fiber Columns

Abstract

Researchers have been accumulating evidence of endotoxin removal therapy with polymyxin B immobilized column (PMXP) for the past two decades. However, the strength of the evidence remains limited. Currently, a randomized controlled trial (RCT) is underway in the US. This trial aims to identify the specific patient population with elevated blood endotoxin levels and organ dysfunction scores, within a defined range, that would likely benefit from PMX therapy. Recently, PMX has been used for different kinds of patients population such as acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) and septic shock due to viral infections such as H1N1. Improvements in hemodynamics and oxygenation have been reported in these patients’ populations, especially in those with endotoxemic septic shock. It was also reported that PMX was applied for COVID-19 patients. COVID-19 patients who underwent PMX therapy showed a reduction of inflammatory state and improvement in chest radiographic findings. Interestingly, PMX therapy appears to have a similar beneficial effect across various patient populations. However, there is a pressing need to conduct comprehensive studies to understand the underlying mechanism that explains this clinical effectiveness. PMX therapy exhibits a range of actions including endotoxin removal, elimination of both pro- and anti-inflammatory mediators, enhancement of coagulation balance, elimination of proapoptotic factors, and immunomodulation via monocyte and neutrophil removal. There is a need to investigate how these actions collectively contribute to the improvement of specific organ dysfunctions.