The biological basis for the attenuation of mucositis: the example of interleukin-11.

Oral mucositis is common, painful, dose-limiting toxicity of drug and radiation therapy for cancer. In granulocytopenic patients, the ulcerations which accompany mucositis are frequent portals of entry for indigenous oral bacteria often leading to bacteremias or sepsis. The complexity of mucositis as a biological process has only recently been appreciated. The condition appears to represent a sequential interaction of the oral mucosal cells and tissues, pro-inflammatory cytokines, and local environmental factors in the mouth such as microorganisms and saliva. The recognition that the pathophysiology of mucositis is a multifactorial process has presented opportunities for intervention based on biological attenuation. Interleukin-11, a pleotropic cytokine, has a range of activities which is potentially relevant to mucositis. Consequently, it has been used successfully to modify the development, severity and course of mucositis in an animal model which closely mimics the equivalent human condition.