RESUMEN
The conversion of azathioprine (AZA) to mercaptopurine (MP) is mediated by glutathione transferase Mu1 (GSTM1), alpha1 (GSTA1) and alpha2 (GSTA2). We designed a case-control study with data from the TOPIC trial to explore the effects of genetic variation on steady state 6-methylmercaptopurine ribonucleotide (6-MMPR) and 6-thioguanine nucleotide (6-TGN) metabolite levels. We included 199 patients with inflammatory bowel disease (126 on AZA and 73 on MP). GSTM1-null genotype carriers on AZA had two-fold lower 6-MMPR levels than AZA users carrying one or two copies of GSTM1 (2239 (1006-4587) versus 4371 (1897-7369) pmol/8 × 108 RBCs; P<0.01). In patients on MP (control group) 6-MMPR levels were comparable (6195 (1551-10712) versus 6544 (1717-11600) pmol/8 × 108 RBCs; P=0.84). The 6-TGN levels were not affected by the GSTM1 genotype. The presence of genetic variants in GSTA1 and GSTA2 was not related to the 6-MMPR and 6-TGN levels.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Azatioprina/uso terapéutico , Glutatión Transferasa/genética , Inmunosupresores/uso terapéutico , Tioinosina/análogos & derivados , Tionucleótidos/metabolismo , Adulto , Azatioprina/metabolismo , Estudios de Casos y Controles , Femenino , Genotipo , Nucleótidos de Guanina/genética , Humanos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/metabolismo , Isoenzimas/genética , Masculino , Mercaptopurina/metabolismo , Persona de Mediana Edad , Tioinosina/metabolismo , Tionucleótidos/genética , Adulto JovenRESUMEN
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 for infections. METHODS: Post hoc analysis of the Thiopurine response Optimisation by Pharmacogenetic testing in Inflammatory bowel disease Clinics (TOPIC) trial. For this analysis, patients without a variant in TPMT (*2, *3A or*3C) were included. Uni- and multivariate Cox-proportional hazard models were used to identify risk factors for leucopenia and infections. Leucopenia was defined as a white blood cell (WBC) count <3.0 × 109 /L and infections were classified according to the Common Terminology Criteria for Adverse Events. RESULTS: Sixty hundred and ninety-five patients (90.6%) included in the TOPIC-trial had no variant in TPMT, of which 45 (6.5%) developed leucopenia. Median time to leucopenia was 56 (29-112) days. Multivariate analysis showed that use of mercaptopurine compared to azathioprine was associated with leucopenia (hazard ratio [HR] 2.61 [95% CIs, 1.39-4.88; P < .01]) and a higher baseline WBC count was protective (HR 0.80 [95% CIs, 0.71-0.89; P < .01]). Risk factors for infections were older age (per 10 year; HR 2.07 [95% CIs, 1.18-3.63; P = .01]) and concomitant use of biologic drugs (HR 2.15 [95% CIs, 1.14-4.07; P = .02]). CONCLUSIONS: Low baseline WBC count and mercaptopurine, due to a relatively higher dose, were risk factors for thiopurine-induced leucopenia in patients without a TPMT variant.
Asunto(s)
Azatioprina/efectos adversos , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Mercaptopurina/efectos adversos , Metiltransferasas/genética , Adulto , Azatioprina/uso terapéutico , Estudios de Casos y Controles , Femenino , Genotipo , Humanos , Leucopenia/inducido químicamente , Masculino , Mercaptopurina/administración & dosificación , Persona de Mediana Edad , Polimorfismo Genético , Factores de RiesgoRESUMEN
In this new Dutch guideline for hepatitis C virus infection we provide recommendations for the management of hepatitis C infection. Until 2012 the standard for treatment consisted of pegylated interferon alpha (peg-IFNa) and ribavirin. The advent of first-generation direct antiviral agents such as boceprevir and telaprevir has changed the concept of treatment of adult chronic hepatitis C genotype 1 infected patients. There are three benefits of boceprevir and telaprevir. They increase the likelihood of cure in 1) naive genotype 1 patients and 2) in patients who did not respond to earlier treatment with peg-IFNa and ribavirin, while 3) allowing shortening of treatment duration from 48 weeks to 24 or 28 weeks, which is possible in 40-60% of non-cirrhotic naive (boceprevir and telaprevir) and relapsing patients (telaprevir). The use of boceprevir and telaprevir is associated with multiple side effects and awareness of these side effects is needed to guide the patient through the treatment process. This guideline, formulated on behalf of The Netherlands Association of Hepato-gastroenterologists, The Netherlands Association of Internal Medicine, and The Dutch Association for the Study of Liver Disease, serves as a manual for physicians for the management and treatment of acute and chronic hepatitis C virus monoinfection in adults.