Asunto(s)
Periodoncia , Endodoncia , Ortodoncia , Prótesis e Implantes , Odontología Pediátrica , Toma de Decisiones , Protocolos ClínicosRESUMEN
Thiopurine methyltransferase deficiency, inherited as an autosomal codominant trait, is associated with aberrant mercaptopurine metabolism leading to excessive cellular accumulation of 6-thioguanine nucleotides, the active metabolites of mercaptopurine. We describe a case of severe thiopurine methyltransferase deficiency (activity less than 1 U/8 x 10(8) erythrocytes) in a young girl with acute lymphocytic leukemia. The level of 6-thioguanine nucleotide in the patient's erythrocytes was seven times the population median value, and she had intolerable hematologic toxic effects during postremission therapy with a standard dosage of mercaptopurine (75 mg/m2 per day). Subsequent therapy with 6% of this dosage (10 mg/m2 three times weekly) yielded erythrocytic 6-thioguanine nucleotide concentrations consistently above the population median but not associated with prohibitively toxic effects. This case demonstrates that thiopurine methyltransferase deficiency does not absolutely contraindicate mercaptopurine therapy, and it also provides insight into the mechanism of excessive toxic effects of mercaptopurine sometimes observed in children with acute lymphocytic leukemia.
Asunto(s)
Mercaptopurina/metabolismo , Mercaptopurina/uso terapéutico , Metiltransferasas/deficiencia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Niño , Eritrocitos/metabolismo , Femenino , Humanos , Mercaptopurina/administración & dosificación , Mercaptopurina/efectos adversos , Errores Innatos del Metabolismo/sangre , Errores Innatos del Metabolismo/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Nucleótidos de Purina/sangre , Tioguanina/análogos & derivados , Tioguanina/sangreRESUMEN
In the case reported here, compound composite odontoma was found in a 63-year-old man. Considering the growth characteristics of odontoma, it is likely that this lesion was of at least 45-50 years' duration. The typically asymptomatic nature of the odontoma and its location, apical to the canine and lateral incisor roots, explain why it was not noticed by the patient nor detected by a dentist for many years. Because definitive diagnosis of odontoma is possible only after histopathological examination of the lesion, surgical excision is advised.