No predictive value of TPMT genotyping for leukopenia or hepatotoxicity during azathioprine therapy in inflammatory bowel disease

Pharmacogenomics and IBD

“…In another study Curvers and colleagues determined the TPMT genotypes of 535 patients with IBD treated with AZA. 17 A case control study was performed in which the cases were patients with TPMT variant alleles and the controls were patients with the wild type alleles (2 controls for each case). Wild type alleles were present in 492 patients (90%), 53 patients were heterozygous for variant alleles (10%), and 2 patients were homozygous for variant alleles (0.4%).…”

Review article: monitoring of immunomodulators in inflammatory bowel disease

“…In a case–control study by Curvers et al . published as an abstract subjects with TPMT variant alleles were compared to subjects with normal alleles for the risk of developing leucopoenia and the OR was 1.5 (95% CI: 0.7–3.2) for developing leucopoenia 46 . In this study and others, the majority of myelosuppression cases occur with normal levels of TPMT enzyme activity.…”

American Gastroenterological Association Institute Technical Review on Corticosteroids, Immunomodulators, and Infliximab in Inflammatory Bowel Disease

“…82 Algunos estudios sugieren que los individuos con actividad enzimática intermedia (o aquéllos que sean heterocigotos para TPMT) son más proclives a desarrollar leucopenia, o a hacerlo en un periodo de tiempo más corto, 112 mientras que otros no han encontrado hallazgos similares. 84,86,91,[113][114][115] Hasta que se hayan realizado más estudios, las recomendaciones basadas en la evidencia con respecto al modo de inicio del tratamiento (eg, utilización de la dosis máxima o la rapidez con la cuál se llega a ésta) de acuerdo a si un individuo carece de alguna mutación (actividad enzimática de TPMT completa) o tiene actividad intermedia de TPMT, no pueden ser establecidas de manera formal.…”