Busulfan Concentration in Saliva and Plasma, and Its Relationship With Salivary Changes and Mucositis in the Digestive Tract of Patients Submitted to Hematopoietic Stem Cell Transplantation

The first objective of this project is to verify the feasibility of using the analysis of salivary concentration of BU during individual adjustments of this drug in the period that precedes HSCT. Another question related to this project is with reference to the effects that the Bu concentration in saliva has on the mucosa of the digestive tract, particularly with regard to mucositis and salivary changes. Thus, the second objective of this project is to verify whether there is any association between salivary changes, cytological changes in the oral mucosa, degrees of mucositis and concentration of Bu in saliva. An analysis will be performed of the Bu concentration in saliva and in blood, as well as the salivary dosage of total proteins, albumin, amylase, antioxidant enzymes (superoxide dismutase, catalase, and glutathione reductase) and pro-inflammatory cytokines IL-1β, IL-6 and TNF-α. In addition, morphological analysis will be made, and rate of apoptosis of cells of the oral mucosa will be analyzed. If the efficacy of saliva for the individual adjustment of the dose of Bu is confirmed, this method could facilitate the dissemination of pharmacokinetic monitoring of this drug in chemotherapy and HSCT centers. In addition, it is expected that the results of the present project will allow establishment of the toxicity indicators of BU detected by analysis of saliva and the cells of the oral mucosa, thereby allowing the early adoption of preventive actions for reducing the frequency and severity of mucositis, a fact that may have a positive impact on the success of HSCT.