Inflammatory response to mucosal barrier injury after myeloablative therapy in allogeneic stem cell transplant recipients

We noted a significant increase of interleukin-8 (IL-8), LBP and CRP mirroring the pattern of mucosal barrier injury as measured by gut integrity (lactulose/rhamnose ratio), daily mucositis score (DMS) and serum citrulline concentrations of 32 haematopoietic stem cell transplant (HSCT) recipients following intensive myeloablative therapy. Concentrations of IL-8, LBP and CRP were already significantly elevated before the onset of fever or bacteraemia due to oral viridans streptococci (OVS) in the first week after transplant during profound neutropenia. These markers reached their peak when citrulline concentrations reached their nadir, the highest scores of DMS were attained and when there was significantly decreased gut integrity. This suggests that the degree of mucosal barrier injury rather than bacteraemia due to OVS determines the intensity of the inflammatory response.