Abstract
Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amoebocyte lysate test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested before and after treatment with cellulase, using three lysates and four Limulus amoebocyte lysate methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified by chromatographic methods. Results indicate that the Limulus amoebocyte lysate reactive material is cellulose derived and not pyrogenic.