Thiopurine S-methyltransferase (TPMT) polymorphisms in children with acute lymphoblastic leukemia, and the need for reduction or cessation of 6-mercaptopurine doses during maintenance therapy: the Polish multicenter analysis.
Pediatr Blood Cancer
; 57(4): 578-82, 2011 Oct.
Article
em En
| MEDLINE
| ID: mdl-21319286
ABSTRACT
BACKGROUND:
6-Mercaptopurine (6-MP) is used for the treatment of pediatric acute lymphoblastic leukemia (ALL). Mutations in the TPMT gene may influence the efficacy and safety of 6-MP treatment. This multicenter study investigated the association between TPMT genotype, 6-MP dose adjustments, and the incidence of adverse effects in patients. PROCEDURE A total of 203 ALL children were genotyped using PCR/allele-specific amplification and PCR/RFLP. The control group consisted of 394 healthy volunteers.RESULTS:
The TPMT*3A variant allele was found in 16 patients (15 TPMT*1/*3A, 1 TPMT*3A/*3A) and the TPMT*3C (A719G) allele in 1 patient. No TPMT*2 (G238C) or TPMT*3B (G460A) alleles were detected in the study group. TPMT*3A, TPMT*1 (wild-type), and TPMT*3C alleles were detected at frequencies of 3.94%, 95.81%, and 0.25%, respectively. The genotype and allele distributions were similar in the ALL and control groups. The 6-MP dose was reduced more frequently in patients with TPMT*3A and TPMT*3C alleles, compared with wild-type alleles (P = 0.042). Reductions because of leucopenia with respiratory tract infection, or because of leucopenia, anemia and/or thrombocytopenia were four (P = 0.007) and five (P = 0.03) times more common, respectively. The groups differed with regard to the rates of 6-MP dose reduction (P = 0.028). 6-MP was discontinued more often in patients with TPMT*3A and TPMT*3C alleles (14-fold) as a result of leucopenia, anemia, and/or thrombocytopenia (P = 0.004).CONCLUSIONS:
The results indicate that TPMT genotype influences the safety and efficacy of ALL treatment and genotype information may therefore be useful for optimizing 6-MP therapy.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
1_ASSA2030
/
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Polimorfismo de Nucleotídeo Único
/
Leucemia-Linfoma Linfoblástico de Células Precursoras
/
Mercaptopurina
/
Metiltransferases
/
Antimetabólitos Antineoplásicos
Tipo de estudo:
Clinical_trials
/
Etiology_studies
/
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Child
/
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
País/Região como assunto:
Europa
Idioma:
En
Revista:
Pediatr Blood Cancer
Ano de publicação:
2011
Tipo de documento:
Article