Meta-analysis of the association between NUDT15 gene polymorphism and 6-MP toxicity during chemotherapy in childhood acute lymphoblastic leukemia / 国际儿科学杂志

Objective:To evaluate systematically the association between the c. 415>C polymorphism of NUDT15 gene and the toxicity of 6-mercaptopurine(6-MP)in children with acute lymphoblastic leukemia(ALL).Methods:The literatures in domestic and foreign databases were retrieved: PubMed, EmBase, Cochrane Library, CNKI, CBM, VIP Chinese Sci-tech Journal Database, and Wanfang Database.The language was limited to Chinese or English.A case-control study or cohort study of 6-MP treatment in pediatric ALL related to the toxicity of the NUDT15 gene c. 415>C polymorphism was included.The time of search was set from the establishment of the database to October 1st, 2020.Two researchers screened the literature independently, extracted data from the literature that met the inclusion criteria, and evaluated the quality of the included studies.The association between locus polymorphism and toxicity during 6-MP chemotherapy was analyzed by Meta analysis with Rev Man 5.3 and Stata 12.0 software.Results:Nine studies were finally included, eight of which were cohort studies and one was a case-control study, with a total of 1 068 patients.The results showed that under the five genetic models, the mutation at c. 415>C of NUDT15 gene was significantly associated with the risk of leukopenia and neutropenia( P<0.01), while hepatotoxicity was with no significant association between the occurrence risk of damage( P>0.05). Conclusion:The mutation at c. 415>C of NUDT15 gene significantly increased the incidence of leukopenia and neutropenia during 6-MP chemotherapy, while there was no significant effect on the occurrence of hepatotoxicity.

Relationship between NUDT15 gene polymorphism and tolerance to treatment with 6-mercaptopurine in children with acute lymphoblastic leukemia / 白血病·淋巴瘤

Objective:To investigate the relationship between NUDT15 gene polymorphism and tolerance to treatment with 6-mercaptopurine (6-MP) in children with acute lymphoblastic leukemia (ALL).Methods:Fifty-eight children diagnosed with ALL in Shanxi Children's Hospital from January 2019 to December 2020 were recruited. All of them were treated with CCLG-ALL2018 chemotherapy regimen and the bone marrow showed complete remission. They received 6-MP oral treatment during maintenance treatment. Single nucleotide polymorphism of NUDT15 gene was detected by real-time fluorescence quantitative polymerase chain reaction. The bone marrow suppression after 6-MP treatment and 6-MP tolerance dose in patients with different NUDT15 genotypes were analyzed.Results:Among 58 patients, 3 patients had NUDT15 TT genotype, 46 patients had CC genotype and 9 patients had TC genotype. During maintenance treatment with 6-MP, the differences in leukocyte count, hemoglobin and platelet count among the three groups of patients with different NUDT15 genotypes were statistically significant (all P < 0.05). Among 58 patients, 23 (39.66%) patients had varying degrees of neutropenia after medication, including 16 cases of NUDT15 CC genotype, 5 cases of TC genotype and 2 cases of TT genotype. There was a statistically significant difference in bone marrow suppression among the three groups ( H = 29.10, P < 0.05). The dosages of 6-MP used in patients with TT, CC and TC genotypes were (10.4±8.8) mg·m -2·d -1, (41.5±1.3) mg·m -2·d -1 and (36.7±2.4) mg·m -2·d -1, respectively, and the difference was statistically significant ( F = 16.95, P < 0.05). Conclusions:Children with different NUDT15 genotypes have different tolerance to 6-MP, and NUDT15 gene polymorphism is associated with 6-MP intolerance during maintenance treatment in children with ALL, which may affect the treatment of the disease.

Susceptibility to thiopurine toxicity by TPMT and NUDT15 variants in Colombian children with acute lymphoblastic leukemia / Asociación de variantes genéticas en TPMT y NUDT15 con los eventos de toxicidad durante la terapia de mantenimiento en niños colombianos con Leucemia Linfoide Aguda

Abstract Objective: This study aimed to correlate the genetic profile of the NUDT15 and TPMT genes with the side effects of the treatment of pediatric patients with acute lymphoid leukemia who were undergoing maintenance therapy at a tertiary care hospital in 2017. Methods: This was an analytical, longitudinal, observational study in which the genotypes of the genes of interest were determined by PCR allelic discrimination with TaqMan® probes in patients receiving chemotherapy during the maintenance phase in the Pediatric Hematology and Oncology Unit in 2017. Sociodemographic and clinical data corresponding to the first six months of their maintenance chemotherapy were collected, and the correlation between the genotypes obtained and the development of side effects during the maintenance phase of chemotherapy in these patients was evaluated. Results: Seventy pediatric patients were included in the study. Genetic analyses were carried out of these for NUDT15 and TPMT (rs1800462 and rs1800460) on 68 patients, while for the rs1142345 polymorphism, typing was achieved in 42 patients. 4/68 patients were heterozygous for NUDT15, and the same number of patients were heterozygous for rs1800462 and rs1142345, while for rs1800460, 6 heterozygous patients were identified. No statistically significant association was identified between the genetic variants and the outcomes of interest. Conclusion: Studies with a larger population size are needed and the evaluation of other genetic variants that may influence the development of side effects during maintenance chemotherapy.

Resumen Objetivo: la finalidad de este estudio fue evaluar las asociaciones entre los perfiles de los genes NUDT15 y TPMT con los efectos adversos del tratamiento de mantenimiento en pacientes pediátricos con Leucemia Linfoblástica Aguda atendidos en un hospital de referencia durante el 2017. Métodos: Este fue un estudio observacional analítico, de corte longitudinal en el que los genotipos de los genes de interés fueron determinados mediante PCR de discriminación alélica con sondas TaqMan® en pacientes que estaban recibiendo quimioterapia de mantenimiento en la Unidad de Oncohematología Pediátrica durante el 2017. Los datos clínicos y sociodemográficos correspondientes a los primeros 6 meses de sus tratamientos de mantenimiento fueron colectados, y se evaluó la correlación entre los genotipos identificados y el desarrollo de efectos secundarios en estos pacientes. Resultados: setenta pacientes fueron incluidos en el estudio, de estos, los análisis genéticos para NUDT15 y TPMT (rs1800462 and rs1800460) fueron realizados en 68 pacientes, en tanto que para el polimorfismo rs1142345 se logró la tipificación en 42 pacientes. 4/68 pacientes fueron heterocigotos para NUDT15 y el mismo número de pacientes fueron heterocigotos para rs1800462 and rs1142345, mientras que para rs1800460, 6 pacientes heterocigotos fueron identificados. No se identificaron asociaciones estadísticamente significantes entre las variants genéticas y los resultados clínicos de interés. Conclusiones: Estos hallazgos resaltan la importancia de realizar estudios de este tipo con un mayor número de sujetos de estudio, así como plantean la necesidad de evaluar otras variantes genéticas que podrían tener algún impacto en el desarrollo de efectos secundarios durante la quimioterapia de mantenimiento.

Gene Detection Improving Safety of Thiopurine Drugs in Treatment of Inflammatory Bowel Disease / 胃肠病学

Thiopurine drugs such as azathioprine and 6-mercaptopurine, are often used in the treatment of inflammatory bowel disease (IBD). However, patients treated with these drugs are prone to adverse drug reactions, in which myelosuppression is the most important and potentially fatal. Currently, multiple genetic markers have been used to identify patients with IBD who are sensitive to thiopurine drugs. This article reviewed the improving of safety of thiopurine drugs in treatment of IBD by gene detection.

Association between polymorphism of NDUT15 gene and leucopenia induced by 6-mercaptopurine in children with acute lymphoblastic leukemia / 临床儿科杂志

Objective To investigate the association between single nucleotide polymorphisms (SNP) (rs116855232 in NDUT15 gene)and acute lymphocytic leukemia(ALL)in Chinese Han children.Methods A total of 133 children with ALL were recruited in this study, and were divided into two groups based on white blood cell count (WBC) as of WBC≤2.0×109 group and WBC>2.0×109group. Genotypes of each patient were detected using PCR-RFLP. WBC, initial and average dose of 6-mercaptopurine (6-MP) were collected. Results In this study, we found 4 patients with TT genotype, 31 patients with CT genotype and 98 patients with CC genotype; and there is a difference in genotypes between the two groups in initial stage (P=0.007) and in maintenance therapy stage (P=0.005). In maintenance therapy stage, patients with TT genotype received a lower dose of 6-MP than that for patients with other genotypes(P<0.01).Conclusions The polymorphism of rs116855232 in NDUT15 gene was associated with leucopenia induced by 6-mercaptopurine in children with ALL, and patients with TT genotype were suggested to use a lower dose of 6-MP to avoided serious leucopenia.

APEX1 Polymorphism and Mercaptopurine-Related Early Onset Neutropenia in Pediatric Acute Lymphoblastic Leukemia / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Mercaptopurine (MP) is one of the main chemotherapeutics for acute lymphoblastic leukemia (ALL). To improve treatment outcomes, constant MP dose titration is essential to maintain steady drug exposure, while minimizing myelosuppression. We performed two-stage analyses to identify genetic determinants of MP-related neutropenia in Korean pediatric ALL patients. MATERIALS AND METHODS: Targeted sequencing of 40 patients who exhibited definite MP intolerance was conducted using a novel panel of 211 pharmacogenetic-related genes, and subsequent analysis was performed with 185 patients. RESULTS: Using bioinformatics tools and genetic data, four functionally interesting variants were selected (ABCC4, APEX1, CYP1A1, and CYP4F2). Including four variants, 23 variants in 12 genes potentially linked to MP adverse reactions were selected as final candidates for subsequent analysis in 185 patients. Ultimately, a variant allele in APEX1 rs2307486was found to be strongly associated with MP-induced neutropenia that occurred within 28 days of initiating MP (odds ratio, 3.44; p=0.02). Moreover, the cumulative incidence of MP-related neutropenia was significantly higher in patients with APEX1 rs2307486 variants, as GG genotypes were associated with the highest cumulative incidence (p < 0.01). NUDT15 rs116855232 variants were strongly associated with a higher cumulative incidence of neutropenia (p < 0.01), and a lower median dose of tolerated MP throughout maintenance treatment (p < 0.01). CONCLUSION: We have identified that APEX1 rs2307486 variants conferred an increased risk of MP-related early onset neutropenia. APEX1 and NUDT15 both contribute to cell protection from DNA damage or misincorporation, so alleles that impair the function of either gene may affect MP sensitivities, thereby inducing MP-related neutropenia.

NUDT15 Variants Cause Hematopoietic Toxicity with Low 6-TGN Levels in Children with Acute Lymphoblastic Leukemia / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We aimed to identify the impact of NUDT15 variants on thiopurine intolerance and 6-thioguanine nucleotide (6-TGN) levels in Korean children with acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: Genotyping of NUDT15 was tested in 258 patients with ALL registered at Samsung Medical Center. Patients were classified into normal-activity (wild-type), intermediate-activity (heterozygous variant), and low-activity groups (homozygous or compound heterozygous variant). Clinical and laboratory features during the first year of maintenance therapy were investigated. RESULTS: A total of 182 patients were included in the final analysis. There were five (2.7%), 46 (25.3%), and 131 (72.0%) patients in low-, intermediate-, and normal-activity groups, respectively. The lowest 6-mercaptopurine (6-MP) dose (mg/m2/day) was administered to the low-activity group (low-activity group 7.5 vs. intermediate-activity group 24.4 vs. normalactivity group 31.1, p < 0.01) from three months to a year after beginning maintenance therapy. The low-activity group experienced the longest duration of therapy interruption during the first year (low-activity group 169 days vs. intermediate-activity group 30 days vs. normal-activity group 16 days, p < 0.01). They also showed the lowest blood cell counts and had a longer duration of leukopenia (low-activity group 131 days vs. intermediate-activity group 92 days vs. normal-activity group 59 days, p < 0.01). 6-TGN level and its ratio to 6-MP dose were lowest in the low-activity group. CONCLUSION: NUDT15 variants cause hematopoietic toxicity with low 6-TGN levels. NUDT15 genotyping should be conducted before administering thiopurine, and dose adjustments require caution regardless of 6-TGN levels.

Severe recurrent nocturnal hypoglycemia during chemotherapy with 6-mercaptopurine in a child with acute lymphoblastic leukemia

Various endocrine dysfunctions occur during chemotherapy, including hypoglycemia. However, reports of hypoglycemia associated with 6-mercaptopurine (6-MP) are rare. Herein, we report an 8-year-old boy with severe symptomatic hypoglycemia likely due to 6-MP during chemotherapy. He had been diagnosed with acute lymphoblastic leukemia 3 years previously and was in the maintenance chemotherapy period. Treatment included oral dexamethasone, methotrexate, and 6-MP, of which only 6-MP was administered daily. Hypoglycemic symptoms appeared mainly at dawn, and his serum glucose dropped to a minimum of 37 mg/dL. Laboratory findings showed nothing specific other than increased serum cortisol, free fatty acids, ketone, alanine aminotransferase, and aspartate aminotransferase. Under the hypothesis of hypoglycemia due to chemotherapy drugs, we changed the time of 6-MP from evening to morning and recommended him to ingest carbohydrate-rich foods before bedtime. Hypoglycemia improved dramatically, and there was no further episode during the remaining maintenance chemotherapy period. To the best of our knowledge, this is the first report of this type of hypoglycemia occurring in an Asian child including Korean.

Effect of Immunomodulators and Biologic Agents on Malignancy in Patients with Inflammatory Bowel Disease / 대한소화기학회지

Immunosuppressive agents and biological agents are widely used for therapy in patients with inflammatory bowel disease (IBD). However, these therapies may be associated with an increased risk of malignancy. There is evidence that exposure of the therapeutic agents such as thiopurine and anti-tumor necrosis factor for IBD is associated with an increased risk of lymphoproliferative disorders, skin cancers, or uterine cervical cancers. This article reviews the malignancies associated with the use of immunosuppressive agents and biological agents in IBD.

Design and optimization of novel in situ gel of mercaptopurine for sustained drug delivery

Mercaptopurine is a purine antagonist, belonging to the class of antimetabolites. Its oral absorption is erratic and variable throughout GIT, with bioavailability of 5-37% and belongs to Biopharmaceutical Classification System (BCS) class IV. The focus of the present study was to improve solubility of mercaptopurine and to release the drug uniformly throughout the GIT by formulating into a novel in situ gel tablet. By in vitro swelling studies, xanthan gum was selected as the best gelling polymer and the tablets were prepared by direct compression. Sodium chloride was used as a release modifier to improve the release of drug from the tablet. A 32 full factorial design was applied to optimize the percentage of xanthan gum and sodium chloride to get desired swelling index and release profile. Tablets were evaluated for weight variation, hardness, friability, disintegration time, drug content, in vitro swelling studies and in vitro dissolution studies. The best optimized formulation showed good swelling index and extended the release up to 12 h, where as conventional tablet released the drug within 45 min. The results indicate that mercaptopurine loaded in situ gel tablet could be effective in sustaining drug release for a prolonged period of time throughout the GIT, which can possibly improve the oral bioavailability.

Mercaptopurine é um antagonista da purina, pertencente à a classe dos antimetabólitos. A sua absorção oral é errática e variável através do TGI, com biodisponibilidade de 5-37 % e pertence à classe IV, de acordo com o Sistema de Classificação Biofarmacêutica. O foco do presente estudo foi melhorar a solubilidade da mercaptopurina e liberar o fármaco uniformemente através do TGI, por meio da nova formulação de comprimidos que se tornam gel in situ. Por meio de estudos de inchamento, a goma xantana foi selecionada como o o melhor polímero gelificante e os comprimidos foram preparados por compressão direta. O cloreto de sódio também foi usado como agente modificador de liberação para aprimorar a liberação do fármaco do comprimido. Aplicou-se planejamento fatorial 32 para otimizar a porcentagem de goma xantana e de cloreto de sódio para se alcançar o índice de inchamento e o perfil de liberação desejáveis. Os comprimidos foram avaliados quanto à variação de peso, dureza, friabilidade, tempo de desintegração, conteúdo de fármaco, estudos in vitro de inchamento e de dissolução. A formulação mais bem otimizada mostrou bom índice de inchamento e liberação prolongada acima de 12 h, em comparação com um comprimido convencional, que libera o fármaco em 45 minutos. Os resultados indicam que a 6-mercaptopurina carregada no comprimido de gelificação in situ poderia ser eficaz para a liberação controlada por período de tempo prolongado através do TGI, o que pode, possivelmente, aprimorar a biodisponibilidade oral.

Uso de azatioprina en enfermedad de Crohn ¿En qué estamos? / Current state of the use of azathioprine in Crohn’s disease

Crohn´s disease (CD) is an intestinal pathology that may have a torpid and disabling course. One of the purposes of the pharmalogical therapy is to prevent progression of the disease and keep the patient in clinical remission. Thiopurines (azathioprine (AZT)/6-mercaptopurine (6-MP)) correspond to a group of drugs so far recommended in all current consensus for maintaining remission of the disease. Recent publications have questioned its effectiveness as a maintenance treatment. We reviewed the literature to date and the aforementioned publications trying to clarify the current status of the use of AZT/6-MP in CD. We emphasize the importance of thiopurine therapy guided by levels of its metabolites, 6-thioguanines and 6-metilmercaptopurines and usefulness of Allopurinol in selected cases. It is still pending to determine whether thiopurines have the potential to modify the disease at an early stage. Further studies are needed before conclusions can modify our clinical behavior to continue using AZT/6-MP in patients with CD.

La enfermedad de Crohn (EC) es una enfermedad intestinal que puede tener un curso tórpido e invalidan. Uno de los objetivos del tratamiento farmacológico es evitar la progresión de la enfermedad y mantener al paciente en remisión. Las tiopurinas (azatioprina (AZT)/6-mercaptopurina (6-MP) corresponden a un grupo de fármacos hasta ahora recomendados en todos los consensos para mantener la remisión de esta enfermedad. Publicaciones recientes han cuestionado su efectividad como tratamiento de mantención. Revisamos la literatura disponible hasta la fecha y las mencionadas publicaciones, intentando esclarecer el estatus actual del uso de AZT/6-MP en EC. Recalcamos la importancia de realizar la terapia con tiopurinas guiada según los niveles de sus metabolitos 6-tioguaninas y 6-metilmercaptopurinas y la utilidad del uso de alopurinol en casos seleccionados. Conclusión: Está pendiente determinar si las tiopurinas tienen el potencial de modificar la enfermedad tempranamente. Se requieren mayores estudios antes de sacar conclusiones que modifiquen nuestra conducta clínica en lo que respecta a seguir usando AZT/6-MP en pacientes con EC.

Optimization and validation of an RP-HPLC method for the estimation of 6-mercaptopurine in bulk and pharmaceutical formulations

A reverse phase HPLC method is described for the determination of 6-mercaptopurine in bulk and tablets. Chromatography was carried on a C18 column using a mixture of acetonitrile and 0.05 mol/L sodium acetate buffer (10:90 v/v) as the mobile phase at a flow rate of 1 mL/min-1 with detection at 324 nm. The retention time of the drug was 3.25 min. The detector response was linear in the concentration of 0.01-5 μg/mL. The limit of detection and limit of quantification were 17 and 52 ng/mL respectively. The method was validated by determining its sensitivity, linearity, accuracy and precision. The proposed method is simple, economical, fast, accurate and precise and hence can be applied for routine quality control of mercaptopurine in bulk and tablets.

Descreve-se método de CLAE em fase reversa para a determinação de mercaptopurina a granel e em comprimidos. A cromatografia foi realizada em coluna C18, utilizando mistura de acetonitrila em tampão acetato de sódio 0,05 mol/L (10:90 v/v) como fase móvel, com fluxo de 1 mL/min e detecção a 324 nm. O tempo de retenção do fármaco foi de 3,25 min. A resposta do detector foi linear na concentração de 0,01-5 μg/mL. O limite de detecção e o limite de quantificação foram de 17e 52 ng/mL, respectivamente. O método foi validado pela determinação de sua sensibilidade, linearidade, acurácia e precisão. O método proposto é simples, econômico, rápido, acurado e preciso e, então, pode ser aplicado para controle de qualidade de rotina da mercaptopurina em batelada e em comprimidos.

Anti tumor activity of mercaptopurine in combination with trikatu and gomutra on 20-Methylcholantrene induced Carcinogenesis.

Cancer is one of the most life threatening diseases and serious health problem in both developing and developed countries. Many synthetic and chemotherapeutic agents used in cancer therapy are having low bioavailability and involve the risk of life threatening host toxicity. Modern researchers are increasingly showing interest toward the improvement of bioavailability of a large number of drugs by addition of various herbs with bioenhancing properties. In oral drug delivery system, the co-administration of therapeutic agents with natural compounds possessing absorption improving activities, has also garnered great interest. Hence the present study was conducted to evaluate the anti-tumor activity of Mercaptopurine in combination with Trikatu and Gomutra. 20- Methylcholanthrene a Polycyclic aromatic hydrocarbons was used to induce tumor in albino mice. Haematological and endogenous antioxidant parameters were evaluated in the study. Individual treatment with Mercaptopurine (5mg/kg) and trikatu (100mg/kg) significantly restored the altered haematological and antioxidant parameters to normal values. Even Mercaptopurine (2.5mg/kg) at its sub therapeutic dose showed equivalent effects as that of therapeutic dose of Mercaptopurine (5mg/kg) when it was co administered along with trikatu compared to the positive tumor control group.

The Association between the Therapeutic Agent and the Compliance of the Patients with Inflammatory Bowel Diseases / 대한소화기학회지

BACKGROUND/AIMS: Adherence of the patients with inflammatory bowel diseases is important to maintain the remission. However, the patients do not always keep their appointments for treatment. The aim of this study was to investigate the clinical factors associated with adherence of patients in terms of appointment keeping. METHODS: A total of 73 subjects were retrospectively investigated from September 2005 to January 2012 at Dongguk University Ilsan Hospital (Goyang, Korea). We reviewed medical records including the age, sex, residence, medications, the disease activity, and the rate of keeping the date. A punctual visit was defined as outpatient visit on the scheduled date +/-7 days. Punctual patients for the visit were defined as their punctual visit rates exceed 90%. RESULTS: Male to female ratio was 2.4:1. Mean age was 41.5+/-15.4 years (range, 20 to 78 years). Ulcerative colitis was 53 cases (72.6%) and Crohn's disease was 20 cases (27.4%). Mean duration of disease was 42.0+/-41.6 months (range, 4 to 226 months). Mean puntual visit rate was 86.7+/-16.0% (range, 27 to 100). Thirty-eight patients (52.1%) were punctual patients for the visit. Azathioprine/6-mercaptopurine treatment was associated with punctual patients for the visit (odd ratio, 3.19; 95% confidence interval, 1.12 to 9.09; p=0.03). However, other clinical factors did not influence the punctual visit rates. CONCLUSIONS: Our study demonstrated that the use of azathioprine/6-mercaptopurine was associated with keeping the appointment for meeting the doctor. Further prospective study would be necessary.

Toxicity of azathioprine: why and when? analysis of the prevalence of polymorphism in Joinville, SC, Brazil / Toxicidade da azatioprina: por que e quando? análise da prevalência de polimorfismo em Joinville, SC

CONTEXT: The use of thiopurine drugs such as azathioprine and 6-mercaptopurine has become quite common in the treatment of inflammatory bowel disease, transplantation and acute leukemias. Despite their effectiveness, these drugs are capable of causing drug-induced toxicity with the risk of death by myelosuppression. It is now known that these complications occur because of genetic polymorphisms of the thiopurinemethyltransferase (TPMT) enzyme, responsible for its metabolism. OBJECTIVE: To assess the prevalence of thiopurine methyltransferase polymorphisms in the population of Joinville, SC, Brazil. METHODS: We analyzed the frequency of four main allelic variants of the TPMT gene in 199 blood donors from Joinville, from February to April 2010. RESULTS: The normal allele ("wild-type") was found in 93.9% of subjects studied. TPMT variants were detected in 12 subjects (6.03%). CONCLUSIONS: From this study, it was estimated at 6% the risk of toxicity by the administration of azathioprine and 6-mercaptopurine to patients in Joinville.

CONTEXTO: A utilização de drogas tiopurinas como a azatioprina e a 6-mercaptopurina tem se tornado bastante frequente no tratamento de doenças inflamatórias intestinais, transplantes e leucemias agudas. Apesar de sua efetividade, estas drogas são capazes de causar toxicidade droga-induzida com risco de morte através de mielossupressão. Sabe-se hoje que estas complicações ocorrem em decorrência de polimorfismos genéticos da enzima tiopurina metiltransferase (TPMT), responsável por sua metabolização. OBJETIVOS: Avaliar a prevalência do polimorfismo do gene da TPMT na população de Joinville, SC. MÉTODOS: Foi analisada a frequência das quatro principais variantes alélicas do gene da TPMT em 199 doadores de sangue da cidade de Joinville, SC, no período de fevereiro a abril de 2010. RESULTADOS: O alelo normal ("selvagem") foi encontrado em 93,9% dos indivíduos estudados. Variantes da TPMT foram detectadas em 12 sujeitos (6,03%). CONCLUSÕES: A partir do presente estudo, pode-se estimar em cerca de 6% o risco de toxicidade na administração de azatioprina e 6-mercaptopurina a pacientes em Joinville.

Acute Pancreatitis Induced by Azathioprine and 6-mercaptopurine Proven by Single and Low Dose Challenge Testing in a Child with Crohn Disease / 대한소아소화기영양학회지

We report here a case of drug-induced acute pancreatitis proved by elimination and single, low dose challenge test in a child with Crohn disease. A 14-year-old boy with moderate/severe Crohn disease was admitted due to high fever and severe epigastric pain during administration of mesalazine and azathioprine. Blood test and abdominal ultrasonography revealed acute pancreatitis. After discontinuance of the medication and supportive care, the symptoms and laboratory findings improved. A single, low dose challenge test was done to confirm the relationship of the adverse drug reaction and acute pancreatitis, and to discriminate the responsible drug. Azathioprine and 6-mercaptopurine showed positive responses, and mesalazine showed a negative response. We introduce the method of single, low dose challenge test and its interpretation for drug-induced pancreatitis.

Inflammatory Bowel Disease and Lymphoproliferative Disorders / 대한소화기학회지

The risk of lymphoproliferative disorders (LPDs) has been reported to be increased in autoimmune diseases and chronic inflammatory diseases. Similar with other chronic inflammatory diseases such as rheumatoid arthritis, there is a concern about the risk of LPDs in patients with inflammatory bowel disease (IBD). Generally, in IBD patients, the risk of LPDs appears to be similar with or very slightly higher, compared to the general population. The association of therapeutic agents with the risk of LPDs is difficult to evaluate due to multiple other potentially involved factors and co-treatment with other agents. To date, data show that thiopurine is associated with a moderately increased risk of LPDs in patients with IBD. Evidence regarding the risk of LPDs in IBD patients using methotrexate is not sufficient, but the risk of LPDs seems low. The responsibility of anti-TNF-alpha agents on the risk of LPDs is difficult to determine, because most of IBD patients receiving anti-TNF-alpha agents are co-treated with thiopurines. Attention should be given to the high risk of hepatosplenic T-cell lymphoma in young male patients treated with anti-TNF-alpha agents together with thiopurines. The risk and benefit of immunosuppressive therapy for IBD should be carefully evaluated and individualized considering the risk of LPDs.

The Safety and Efficacy of Azathioprine and 6-Mercaptopurine in the Treatment of Korean Patients with Crohn's Disease

BACKGROUND/AIMS: This study aimed to evaluate the adverse events and efficacy of azathioprine (AZA) and 6-mercaptopurine (6-MP) in Korean patients with Crohn's disease (CD). METHODS: We retrospectively analyzed 700 patients with CD (male : female=469 : 231; median age at diagnosis, 22 years; agerange, 9-74 years) who were treated at the Asan Medical Center between January 1997 and January 2006. RESULTS: Of 700 patients, 372 (53.1%) were treated with AZA/6-MP. The cumulative rates of AZA/6-MP treatment at 1, 5, 10, and 20 years were 17.4%, 51.6%, 73.1%, and 94.5%, respectively. Of 372 patients treated with AZA/6-MP, 217 patients (58.3%) experienced 291 adverse events, requiring discontinuation of therapy in 41 patients (11%). Nausea occurred in 120 patients (32.3%) and led to discontinuation of therapy in 11 patients (3.0%). Leukopenia developed in 116 patients (31.2%), requiring dose adjustments in 100 patients (26.9%) and discontinuation of medications in 16 patients (4.3%). Other adverse events included infections (2.7%), abnormal liver function tests (2.7%), fever (0.8%), hair loss (0.8%), arthralgias (0.5%), pancreatitis (0.5%), headaches (0.5%), and skin rashes (0.3%). Complete corticosteroids withdrawal was achieved in 70.9% of the patients based on an intention-to-treat analysis. The remission rate of perianal fistulas was 32.6%. CONCLUSIONS: The risk of leukopenia by AZA/6-MP is higher in Korean patients with CD than in Western patients. Although the adverse events of AZA/6-MP are not uncommon in Korean patients with CD, the actual discontinuation rate of the treatment is low. Therefore, AZA/6-MP can be administered to most Korean patients with CD without serious adverse events.

Monitoração terapêutica da azatioprina: uma revisão: [revisão] / Therapeutic drug monitoring of azathioprine: a review: [review]

Os nucleotídeos de tioguanina (6-TGN), metabólitos ativos da azatioprina (AZA) e da 6-mercaptopurina (6-MP), atuam como antagonistas das purinas, inibindo as sínteses de DNA, RNA e a protéica, e induzindo à citotoxicidade/imunossupressão. A enzima geneticamente determinada, tiopurina metiltransferase (TPMT), está envolvida no metabolismo desses agentes e, hipoteticamente, determina a resposta clínica às tiopurinas. A baixa atividade dessa enzima diminui a metilação das tiopurinas, resultando em potencial sobredose, enquanto altos níveis de TPMT levam à superprodução do metabólito tóxico 6-metilmercaptopurina (6-MMP) e à não-efetividade terapêutica da AZA e da 6-MP. Várias mutações no gene da TPMT têm sido identificadas e correlacionadas com fenótipos de baixa atividade. Neste artigo, também se discute a monitoração terapêutica desses fármacos por meio da medida dos níveis de 6-TGN intra-eritrocitários, os quais se correlacionam com imunossupressão e mielotoxicidade. Já a 6-MMP está diretamente relacionada com hepatotoxicidade. Esses ensaios estão associados ao uso de doses adequadas dessa droga, resultando num melhor controle da doença e menor uso de corticosteróides.

Thioguanine nucleotides (6-TGN), active metabolites of azathioprine (AZA) and 6-mercaptopurine (6-MP), act as purine antagonists, inhibiting DNA, RNA, and protein synthesis and inducing cytotoxicity and immunosuppression. The genetically determined thiopurine methyltransferase enzyme (TPMT) is involved in the metabolism of these agents and, theoretically, determines the clinical response to thiopurines. Low activity of this enzyme decreases the methylation of thiopurines, what results in potential overdosing, whereas high TPMT status leads to overproduction of toxic metabolite 6-methilmercaptopurine (6-MMP) and ineffectiveness of AZA and 6-MP. Several mutations in the TPMT gene have been identified and correlated with low activity phenotypes. In this study, we also discuss the therapeutic monitoring of these drugs by means of red blood cell 6-TGN levels, which correlate with immunosuppression and mielotoxicity. 6-MMP is directly connected with hepatotoxicity. These metabolites assays are associated with the use of appropriate doses of this drug, what results in a better control of the disease and a decreased use of corticosteroids.

The Frequency and the Course of the Adverse Effects of Azathioprine/6-Mercaptopurine Treatment in Patients with Inflammatory Bowel Disease / 대한소화기학회지

BACKGROUND/AIMS: This study was to evaluate the frequency and the course of the adverse effects of AZA/6-MP in Korean patients with inflammatory bowel disease (IBD). METHODS: Medical records of the patients with IBD treated with AZA/6-MP at Severance hospital from June 1996 to September 2006 were retrospectively analyzed. RESULTS: A total of 133 patients were studied. Male to female ratio was 1.3:1. The mean age was 31.7+/-10.9 year. Adverse effects included leukopenia occurred in 75 cases (56.4%), nausea/vomiting in 32 cases (24.1%), arthralgia in 6 cases (4.5%), hepatitis in 6 cases (4.5%), skin rash in 4 cases (3.0%), herpes zoster in 3 cases (2.3%), and headache in 1 case (0.8%). Most of leucopenia (58.7%) developed within 3 months after maximal tolerated dose of AZA/6-MP and nausea/vomiting frequently occurred within 3 months after start of AZA/6-MP treatment. Thirty-eight patients (28.6%) required the discontinuation of medication due to adverse effects. CONCLUSIONS: Leukopenia was the most common adverse effect of AZA/6-MP treatment. Leukopenia and nausea/vomiting developed frequently in the early period of treatment of AZA/6-MP in patients with IBD. AZA/6-MP should be used cautiously to scrutinize bone marrow suppression.