Endotoxin-mediated activation of cytokine production in human PBMCs by collagenase and Ficoll

Endotoxin-induced early inflammatory reactions may inhibit the function and survival of isolated cells or cell aggregates after transplantation. By th e chromogenic Limulus amebocyte lysate assay we found rather high but varia ble endotoxin concentrations in the chemicals used for islet isolation, i.e . collagenase and Ficoll. Liberase, a special collagenase preparation from Boehringer, was nearly endotoxin-free. Correlating to the endotoxin content , collagenase and Ficoll had the capacity to induce interleukin-1 beta rele ase from human peripheral blood mononuclear cells. Because collagenase and density gradient media are needed in most cell isolation procedures from so lid organs. each lot of these chemicals should be tested for endotoxin cont amination. In pancreatic islet transplantation, the use of endotoxin-free c hemicals may diminish early local inflammatory reactions at the graft site and thereby reduce the number of islets needed for successful islet transpl antation.