Prevalence rates and risk factors associated with non-adherence to tacrolimusin outpatient pediatric hematopoietic stem cell transplant patients

Abstract

Hematopoietic stem cell transplant (HSCT) is an aggressive medical treatment associated with high morbidity and mortality. Recipients of HSCTs need to adhere to complex outpatient medication regimens. The rates of medication adherence in pediatric HSCT are currently unknown. Sub-therapeutic doses of immunosuppressant medications due to non-adherence cause adverse outcome and increase mortality. The purpose of this study was to describe adherence to tacrolimus during the acute phase in outpatient pediatric stem cell transplant patients and examine the potential predictive value of the Medication Level Variability Index (MLVI) biomarker. In our study, subjective adherence goes underreported. Approximately 60% of patients had non-therapeutic levels. The MLVI was associated with graft versus host disease. Using a criterion of MLVI > 3, there was a statistically significant increased likelihood of GVHD (p = 0.013). The MLVI area under the curve (AUC) for GVHD was statistically significant (p=. 024). This is the first known study to report the use of the MLVI in hematopoietic stem cell transplant patients. These are the first known results reporting adherence to immunosuppressive therapy in the acute post-transplant phase in pediatric hematopoietic stem cell transplant patients.