Interindividual differences in thiopurine metabolism - studies with focus on inflammatory bowel disease

..................................................................................................................1 POPULÄRVETENSKAPLIG SAMMANFATTNING .............................................2 LIST OF PAPERS .........................................................................................................5 ABBREVIATIONS........................................................................................................7 INTRODUCTION .........................................................................................................9 Inflammatory bowel disease.....................................................................................9 Treatment of inflammatory bowel disease .............................................................11 Thiopurines.............................................................................................................12 Metabolism of thiopurine drugs .............................................................................14 Therapeutic drug monitoring..................................................................................18 Drugs interacting with thiopurine metabolism.......................................................20 Pharmacogenomics.................................................................................................21 Thiopurine S-methyltransferase .............................................................................22 Inosine 5 ́-monophosphate dehydrogenase ............................................................25 Other enzymes in the thiopurine metabolism.........................................................27 AIMS.............................................................................................................................31 MATERIALS AND METHODS................................................................................33 Patients and healthy volunteers ..............................................................................33 Methods ..................................................................................................................35 Preparation techniques .......................................................................................................35 Pyrosequencing..................................................................................................................36 Determination of enzyme activities....................................................................................38 Determination of metabolite concentrations ....................................................................39 Tissue culture and transfection ..........................................................................................40 Determination of mRNA expression..................................................................................41 Bioinformatic tools................................................................................................................43 Statistics ................................................................................................................................43 RESULTS AND DISCUSSION..................................................................................45 TPMT genotypes in Sweden ..................................................................................45 Concordance between TPMT genotype and phenotype........................................46 IMPDH in thiopurine metabolism..........................................................................52 Pharmacotranscriptomics in patients with different metabolite profiles...............60