Ontology highlight
ABSTRACT: Background
Genetic variants of TPMT and NUDT15 have been reported to predict the inter-patient variability in response and toxicity profiles of patients receiving thiopurine therapy. However, the clinical utility of TPMT genotyping in guiding thiopurine doses has been questionable, in part due to underlying differences in the prevalence of TPMT variants in both Caucasian and Asian populations. Several NUDT15 variants have been associated with thiopurine-induced leukopenia, particularly in Asian cohorts. So far, none have been reported in a multiethnic Asian population.Aim
To investigate the associations between TPMT and NUDT15 variants with thiopurine-induced myelotoxicity in 129 Asian inflammatory bowel disease patients.Materials & methods
Pyrosequencing was performed to screen for TPMT and NUDT15 variants. Intracellular steady-state metabolite concentrations were quantified using liquid chromatography-tandem mass spectrometry.Results
Significant declines in nadir white blood cell, absolute neutrophil count and platelet counts were observed with increasing copy numbers of the risk T allele at NUDT15 c.415C>T locus (overall p < 0.05) within 4, 8 and 12 weeks and 6 months after thiopurine initiation. Patients with low and intermediate NUDT15 activity, as inferred from haplotype pairs, had significantly higher risks of leukopenia (p = 0.000253) and neutropenia (p = 0.002) compared with patients with normal NUDT15 activity.Conclusion
These findings highlight the critical relevance of NUDT15 pharmacogenetics in predicting for thiopurine-induced myelotoxicity and confirm the lack of significance of TPMT variants in Asian inflammatory bowel disease patients.
SUBMITTER: Sutiman N
PROVIDER: S-EPMC5753614 | biostudies-literature | 2018 Jan
REPOSITORIES: biostudies-literature
Sutiman Natalia N Chen Sylvia S Ling Khoon Lin KL Chuah Sai Wei SW Leong Wai Fook WF Leong Wai Fook WF Nadiger Vinayak V Tjai Madeline M Choon Kong Chris San CS Schwender Brian John BJ Chan Webber W Shim Hang Hock HH Lim Wee Chian WC Khor Chiea Chuen CC Cheung Yin Bun YB Chowbay Balram B
Pharmacogenomics 20171206 1
<h4>Background</h4>Genetic variants of TPMT and NUDT15 have been reported to predict the inter-patient variability in response and toxicity profiles of patients receiving thiopurine therapy. However, the clinical utility of TPMT genotyping in guiding thiopurine doses has been questionable, in part due to underlying differences in the prevalence of TPMT variants in both Caucasian and Asian populations. Several NUDT15 variants have been associated with thiopurine-induced leukopenia, particularly i ...[more]