Therapeutic drug monitoring of thiopurine drugs in patients with inflammatory bowel disease or autoimmune hepatitis.

Objective: Thiopurine drugs are commonly used immunosuppressants in the treatment of inflammatory bowel disease (IBD) as well as in autoimmune hepatitis (AIH), rheumatic diseases and in transplantation medicine. The relatively narrow therapeutic range requires useful therapy control. Therefore, the purpose of this study was to further investigate the rationale and usefulness of therapeutic drug monitoring in the surveillance of thiopurine drug therapy in Crohn's disease, ulcerative colitis and autoimmune hepatitis.

Detection of the Arg702Trp, Gly908Arg and Leu1007fsinsC polymorphisms of the NOD2/CARD15 gene by real-time PCR with melting curve analysis.

Crohn's disease is a complex disorder, with multiple genetic traits. A frameshift mutation (Leu1007fsinsC) and two missense mutations (Gly908Arg and Arg702Trp) in the NOD2/CARD15 gene are strongly associated with susceptibility to Crohn's disease. The presence of one of these risk alleles confers a 2- to 4-fold increase in the risk of developing Crohn's disease, and the presence of two mutant alleles increases the risk over 20-fold.

Thiopurine S-methyltransferase polymorphisms: efficient screening method for patients considering taking thiopurine drugs.

Objective: More than 11% of the Caucasian population are heterozygous or homozygous carriers of thiopurine S-methyltransferase (TPMT) mutants and are at risk for toxic side effects when treated with thiopurine drugs. Therefore, screening for TPMT polymorphisms in a patient prior to prescribing these agents is recommended. The goal of this study was to determine a cut-off concentration of the TPMT activity assay beyond which genotyping of the TPMT gene should be performed.