Elevated Levels of HMGB1 in Cancerous and Inflammatory Effusions

Background: Recently, it has become obvious that the HMGB1 protein can act as a proinflammatory and proangiogenic mediator when actively secreted by macrophages or passively released front necrotic cells playing an important role in the pathogenesis of several diseases including cancer. Materials and Methods: The absolute and relative amount of HMGB1 was measured with an ELISA in different effusion types. Results: The amount of HMGB1 protein in the samples differed between 0.0004% and 0.0025% of the total sample protein. The mean values of transudates were significantly (p<0.001) lower than the mean values of exudates. Conclusion: HMGB1, a so-called danger signalling protein, was found to be highly expressed in human pleural and peritoneal effusions due to cancer and inflammation. Compared to transudates the average level of HMGB1 was significantly higher in exudates. These results underline the characteristics of HMGB1 as a possible target for treatment in advanced cancer as well.