BACKGROUND Patients' beliefs about medicine may either reflect the necessity for treatment or concerns regarding the treatment. We explored the extent to which these beliefs have an effect on thiopurine metabolite levels and premature discontinuation in patients with inflammatory bowel disease (IBD). PATIENTS AND METHODS Patients enrolled in the 'Thiopurine response Optimization by Pharmacoge...

BACKGROUND Leucopenia is a common side effect in patients treated with thiopurines. Variants in the thiopurine S-methyltransferase (TPMT) gene are the best-known risk factor, but only explain up to 25% of leucopenia cases. AIM To identify the clinical risk factors for thiopurine-induced leucopenia in patients without a common TPMT variant, and explore if these patients are at increased risk f...

Only a few studies have addressed the cost-effectiveness of pharmacogenetics interventions in healthcare. Lack of health economics data on aspects of pharmacogenetics is perceived as one of the barriers hindering its implementation for improving drug safety. Thus, a recent Institute for Prospective Technological Studies (IPTS) study, entitled 'Pharmacogenetics and pharmacogenomics: state-of-the...

The association between the 6-thioguanine nucleotide (6-TGN) level and clinical remission in Crohn's disease (CD) remains controversial. Thiopurine-induced leukopenia is a life-threatening complication of CD in Asians that was recently shown to strongly correlate with NUDT15 genetic variants. This study aimed to determine the relationship between thiopurine metabolite levels and therapeutic res...

Thiopurines (azathioprine, 6-mercaptopurine and 6-thioguanine) are a class of genotoxic drugs extensively used in the treatment of various illnesses including leukemia. Their underlying molecular mechanism of action involves the activation of apoptosis and autophagy but remains widely unclear. Here we present evidence that autophagy induction by thiopurines is a survival mechanism that antagoni...

AIM To identify which blood and mucosal lymphocyte populations are specifically depleted by thiopurine use in vivo. METHODS The thiopurines azathioprine and 6-mercaptopurine have been a mainstay of inflammatory bowel disease (IBD) therapy for decades, but their mechanism of action in vivo remains obscure. Although thiopurines are lymphotoxic at high doses, and have been reported to cause T ce...

BACKGROUND/AIMS For decades, thiopurines have been the mainstay of inflammatory bowel disease (IBD) treatment and will play an important role in the future. However, complex metabolism and various side effects limit the use of these potent drugs in clinical practice. The Korean Association for the Study of Intestinal Diseases developed a set of consensus statements with the aim of guiding clini...

Background: The response to thiopurine treatment in inflammatory bowel disease patients differs greatly among individuals and nearly 50% of patients experience no benefit. Several factors have been implicated in determining this response, including individual genetic variation. Methods: Aiming to identify genes involved in the response to thiopurine drugs, a two-stage investigation of 20,000 co...

UNLABELLED Thiopurine S-methyltransferase (TPMT) metabolizes thiopurine medications, including azathioprine and 6-mercaptopurine. Absent TPMT activity (i.e., in individuals homozygous for a variant TPMT allele) is associated with an increased risk of myelosuppression in patients taking thiopurine drugs. However, it is not clear if there is also an increased risk for patients with intermediate T...