6-Mercaptopurine (6MP) and methotrexate are the backbone of continuation therapy for childhood acute lymphoblastic leukemia (ALL). In studies of oral 6MP and methotrexate, indices of chronic systemic exposure to active metabolites of these agents, namely, red blood cell (RBC) concentrations of methotrexate polyglutamates (MTXPGs) and thioguanine nucleotides (TGNs) have positively correlated wit...

6-Mercaptopurine (6MP) and methotrexate are the backbone of continuation therapy for childhood acute lymphoblastic leukemia (ALL). In studies of oral 6MP and methotrexate, indices of chronic systemic exposure to active metabolites of these agents, namely, red blood cell (RBC) concentrations of methotrexate polyglutamates (MTXPGs) and thioguanine nucleotides (TGNs) have positively correlated wit...

PURPOSE Thioguanine nucleotides (TGNs) mediate the cytotoxicity of mercaptopurine (MP). Methylated MP metabolites (formed by thiopurine methyltransferase [TPMT]) and methotrexate (MTX) polyglutamates can inhibit de novo purine synthesis. We explored whether dose adjustment of MP and MTX by erythrocyte (E) levels of TGN and MTX (including polyglutamates) could improve outcome in childhood acute ...

Azathioprine is an immunomodulator commonly used in renal transplant recipients and to treat lupus erythematous, inflammatory bowel disease, as second-line therapy cases of rheumatoid arthritis. Here, we present a case non-segmental vitiligo treated with low-dose azathioprine developing life-threatening pancytopenia febrile neutropenia trephine biopsy-proven drug-induced myelosuppression. The p...

BACKGROUND An increased understanding of the genetic basis of disease creates a demand for personalized medicine and more genetic testing for diagnosis and treatment. The objective was to assess the incremental cost-effectiveness per life-month gained of thiopurine methyltransferase (TPMT) genotyping to guide doses of 6-mercaptopurine (6-MP) in children with acute lymphoblastic leukemia (ALL) c...

Genotyping of thiopurine S-methyltransferase (TPMT) is recommended for predicting the adverse drug response of thiopurines. In the current study, a novel version of allele-specific PCR (AS-PCR), termed competitive real-time fluorescent AS-PCR (CRAS-PCR) was developed to analyze the TPMT*2 genotype in ethnic Chinese. This technique simultaneously uses wild-type and mutant allele-specific scorpio...

Sir, We greatly appreciate your interest in our article. The study by Sayani et al. (2005) has shown that there is no correlation between the TPMT activity and the development of azathioprine induced adverse events. Therefore estimation of TPMT levels to predict adverse events seems unnecessary. The apprehension of using 300 mg pulse doses of azathioprine in the absence of TPMT assessment also ...

To the Editor, I read the paper by Belen et al. published in a recent issue of this journal with great interest [1]. They reported a 15-year-old girl with T-ALL who developed severe pancytopenia during consolidation and maintenance therapy despite dose reduction of 6-mercaptopurine (MP). They found thiopurine S-methyltransferase (TPMT) *3A/*3C polymorphisms upon TPMT genotyping. Prednisolone th...

Background: Azathioprine (AZA) has been proposed as an off-label option in treating moderateto-severe atopic dermatitis. Pre-treatment thiopurine methyltransferase (TPMT) assessment is commonly used in western countries, but TPMT test is not commonly available locally. Objective: We sought to evaluate the efficacy and tolerability of AZA in adult Chinese atopic dermatitis patients with pre-trea...