Background: After an allogeneic hematopoietic stem cell transplant (HSCT), the donor genome is found in the recipient s circulation and tissues. Post-HSCT recipients may receive a medication in which the dosing needs to be adjusted based on genetic variation. While genes in donor genome may influence dosing and administration of some agents, the majority of established gene-drug pairs in pharmacogenetics are related to expression of metabolic or transporting enzymes located in recipients tissues, often the liver. Determining which genetic variants influence drug disposition in HSCT recipients is complicated by chimerism in samples that are routinely collected for determining genotype. However, chimerism in tissues is poorly studied in this patient population.

Objectives: To determine the most reliable host genomic source for pharmacogenetic testing in participants that have received allogeneic HSCT.

Eligibility: People ages 18 years and older who are enrolled on a clinical trial at the NIH Clinical Center under which they will donate or receive an allogeneic HSCT.

Design: DNA is collected prior to HSCT and for two years after HSCT. Blood will be collected and skin fibroblast cell lines will be established prior to HSCT to serve as a reference genome. Blood, buccal cells, skin, and hair will be monitored for the development of mixed chimerism via detection of short tandem repeats. Liver biopsies will be collected from participants undergoing hepatic surgery. Pharmacoscan arrays will be conducted to determine which samples are useful for pharmacogenetic testing in participants who receive allogeneic HSCT. A probe drug cocktail will be administered pre- and post-HSCT to determine if transplantation alters the metabolic phenotype of liver enzymes. ...