Long-term safety of azathioprine for treatment of neuromyelitis optica spectrum disorders / Segurança a longo prazo da azatioprina no tratamento dos transtornos do espectro da neuromielite óptica

ABSTRACT Background: Azathioprine is a common first-line therapy for neuromyelitis optica spectrum disorder (NMOSD). Objective: The aim of this study was to determine whether long-term treatment (>10 years) with azathioprine is safe in NMOSD. Methods: We conducted a retrospective medical record review of all patients at the School of Medicine of the University of São Paulo (São Paulo, Brazil) who fulfilled the 2015 international consensus diagnostic criteria for NMOSD and were treated with azathioprine for at least 10 years. Results: Out of 375 patients assessed for eligibility, 19 were included in this analysis. These patients' median age was 44 years (range=28-61); they were mostly female (17/19) and AQP4-IgG seropositive (18/19). The median disease duration was 15 years (range=10-39) and most patients presented a relapsing clinical course (84.2%). The median duration of treatment was 11.9 years (range=10.0-23.8). The median annualized relapse rates (ARR) pre- and post-treatment with azathioprine were 1 (range=0.1-2) and 0.1 (range=0-0.35); p=0.09. Three patients (15.7%) had records of adverse events during the follow-up, which consisted of chronic B12 vitamin deficiency, pulmonary tuberculosis and breast cancer. Conclusion: Azathioprine may be considered a safe agent for long-term treatment (>10 years) of NMOSD, but continuous vigilance for infections and malignancies is required.

RESUMO Introdução: A azatioprina é um tratamento comum de primeira linha para os transtornos do espectro neuromielite óptica (NMOSD). Objetivo: Este estudo visou determinar a segurança do tratamento a longo prazo (>10 anos) da NMOSD com a azatioprina. Métodos: Foi realizada revisão retrospectiva de todos os prontuários de pacientes que preenchiam critérios de NMOSD de acordo com o "International Consensus Diagnostic Criteria for NMOSD" de 2015 em uso de azatioprina por ao menos 10 anos matriculados no ambulatório de Doenças Desmielinizantes do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Resultados: De 375 pacientes avaliados, 19 preencheram critérios de inclusão para análise. A mediana de idade foi de 44 anos (variância=28-61); os pacientes eram predominantemente do sexo feminino (17/19) e AQP4-IgG soropositivos (18/19). A mediana do tempo de duração de doença foi 11,9 anos (variância=10,0-23,8), a mediana da taxa anualizada de surtos pré e pós-tratamento foi de 1 (variância=0,1-2) e 0,1 (variância=0-0,35), p=0,09. Três pacientes (15,7%) apresentaram registro de eventos adversos durante o seguimento: deficiência crônica de vitamina B12, tuberculose pulmonar e câncer de mama. Conclusão: A azatioprina provavelmente pode ser considerada segura para o tratamento a longo prazo (>10 anos) da NMOSD, porém vigilância contínua de neoplasias e infecções é necessária.

Hepatotoxicidade induzida por azatioprina em portadora da síndrome de Vogt-Koyanagi-Harada / Azathioprine-induced hepatotoxicity in a Vogt-Koyanagi-Harada syndrome patient

Este relato teve como objetivo apresentar um caso de hepatotoxicidade colestática induzida por azatioprina em portadora da síndrome de Vogt-Koyanagi-Harada. À admissão, apresentava icterícia +3/+4, acolia fecal e colúria, além de aumento de marcadores hepáticos, sendo compatível com síndrome colestática, cuja etiologia foi confirmada após exclusão de outras causas possíveis e retirada da azatioprina. A paciente evoluiu, após 1 semana de retirada do fármaco, com diurese livre de coloração menos escura e evacuação presente, sem acolia. Além disso, houve melhora nos exames que precederam a alta hospitalar

This report aimed at presenting a case of azathioprine-induced cholestatic hepatotoxicity in a patient with Vogt-Koyanagi-Harada syndrome. On admission, she presented with jaundice +3/+4, acholic feces, and choluria, as well as increased hepatic markers, all consistent with cholestatic syndrome, the etiology of which was confirmed after other possible causes were ruled out and azathioprine was discontinued. After 1 week of the drug discontinuation, the patient progressed with free diuresis of lighter color and defecation, with no acholia. In addition, tests performed before discharge were improved.

Variantes genéticas de la tiopurina metiltransferasa e incidencia de eventos adversos en pacientes con indicación de azatioprina / Genetic polymorphisms of thiopurine methyltransferase and incidence of adverse events in patients with medical indication of azathioprine

La azatioprina es una tiopurina que presenta rango terapéutico estrecho y marcada toxicidad hematológica y hepática. La tiopurina S-metiltransferasa es una enzima que metaboliza ese grupo de drogas. Mutaciones en el gen que codifica dicha enzima aumentan el riesgo de presentar eventos adversos, por lo que su estudio farmacogenético permite contar con información para el diseño de la estrategia terapéutica. Sin embargo, su utilidad en el medio local no está completamente establecida. Fueron incluidos 45 sujetos (13 hombres) con indicación de azatioprina. Se determinó la presencia de las mutaciones *2, *3A, *3B y *3C de TMPT por PCR-RFLP y se analizó la relación entre el genotipo y la incidencia de eventos adversos relacionados al fármaco. Nueve portaban al menos un alelo no funcional, uno de ellos con genotipo *3A/*3A. Se detectó toxicidad en 3 de los 18 que iniciaron tratamiento con azatioprina: 2 pacientes con genotipo normal presentaron eventos adversos leves, y el único evento adverso de gravedad (aplasia medular) ocurrió en el sujeto con genotipo homocigota mutado. El único que presentó genotipo homocigota mutado desarrolló el más grave de los eventos adversos registrados, a pesar de estar en tratamiento con dosis bajas de azatioprina. Por este motivo, la determinación del genotipo de la tiopurina metiltransferasa pareciera ser de utilidad, pero no reemplaza la necesidad de seguimiento clínico y bioquímico en pacientes en tratamiento con tiopurinas.

Azathioprine is a thiopurine which has a narrow therapeutic index and marked hematological and hepatic toxicity. Thiopurine s-methyltransferase is an enzyme involved in the metabolism of thiopurines. Mutations in the gene that encodes the enzyme may augment the risk of adverse events. For that reason, pharmacogenetic determinations prior to the initiation of therapy can provide useful information for the future therapeutic strategy. Nevertheless, its utility in the local environment is not completely established. Forty-five subjects (13 men) who had been prescribed azathioprine were included. The presence of *2, *3A, *3B and *3C mutations were determined by PCR-RFLP, and the relationship between genotype and incidence of adverse events related to the drug was analyzed. Nine carried at least one non-functional allele, one of them with *3A/*3A genotype. Among the eighteen patients who initiated treatment with azathioprine, toxicity was detected in 3 cases: 2 mild events were observed in patients with normal genotype, and the only serious event (bone marrow suppression) occurred in the individual with homozygous mutant genotype. The only homozygous mutant patient developed the most severe of the registered events, in spite of being under treatment with low doses of azathioprine. This is the reason why enzymatic determination could be of utility, even though it does not replace clinical and biochemical follow-up in patients under thiopurine treatment.

Terapia combinada en enfermedad inflamatoria intestinal: ¿una asociación necesaria? / Combination therapy in inflammatory bowel disease: a necessary association?

The management of inflammatory bowel disease (IBD) is constantly changing due to the arrival of new therapeutic agents. Combined therapy (biological associated with immunosuppressive therapy) has proven to be effective, reducing immunogenicity (antibody formation), optimizing the pharmacokinetics of biological therapy with anti-TNF. This therapeutic strategy has associated risks (neoplasia and intercurrent infections) that are not only explained by the use of drugs but also by the increase of cases in older ages. It is essential for the medical team to be familiar with the optimization and personalization of the therapy to achieve clear therapeutic objectives with the lowest possible risks.

El manejo de la enfermedad inflamatoria intestinal (EII) está en constante cambio, debido a la llegada de nuevos agentes terapéuticos. La terapia combinada (terapia biológica asociada a inmunosupresores) ha demostrado ser efectiva al disminuir la inmunogenicidad (formación de anticuerpos) permitiendo la optimización farmacocinética. Esta estrategia terapéutica tiene riesgos asociados (neoplasias e infecciones intercurrentes) que no sólo se explican por el uso de fármacos sino también por el aumento de casos en edades más avanzadas. Es fundamental que el equipo tratante este familiarizado con la optimización y personalización de la terapia para así lograr objetivos terapéuticos claros con los menores riesgos posibles.

Linfoma difuso de células grandes B rectal en un paciente con colitis ulcerosa / Rectal diffuse large B cell lymphoma appearing after immunosuppression for ulcerative colitis: report of one case

Primary colorectal lymphoma is a rare form of presentation of gastrointestinal tract lymphomas. Inflammatory bowel disease and its treatment are risk factors for its development. We report a 47-year-old male patient with Ulcerative Colitis of two years of evolution, treated initially with azathioprine and later on with infliximab. Due to a relapse in symptoms after the second dose of infliximab, a new coloncoscopy was performed showing a rectal ulcerative lesion, corresponding to a large cell Non-Hodgkin's Lymphoma. The patient was successfully treated with RCHOP chemotherapy (Rituximab cyclophosphamide doxorubicin vincristine prednisone). He is currently in disease remission.

Hepatitis autoinmune refractaria: ¿cómo escoger el tratamiento de segunda línea o de rescate? / Refractory autoimmune hepatitis: how to choose second-line or rescue therapy?

Autoimmune hepatitis (AIH) is a liver disease of unknown etiology, with a breakdown in peripheral selftolerance against hepatocytes with both genetic and environmental factors involved. It is characterized by an immune mediated liver injury, with detectable autoantibodies, elevated levels of immunoglobulin G and histological criteria including, necroinflammation, lymphoplasmacytic infiltrates and hepatitis interface. It can be asymptomatic or can present as acute hepatitis or liver cirrhosis. Most patients (70-80%) respond to first line therapy (based on steroids ± azathioprine). In those patients not tolerating azatioprine, in steroid resistant, and those with repeated relapses (20-40%), a long-term second line therapy must be considered to avoid progression of liver disease. This last medications include other immunosuppressants like mycophenolate mophetil, calcineurin inhibitors (cyclosporine or tacrolimus), biologic agents (infliximab and rituximab), and other immunosuppressive agents (sirolimus, everolimus), all with good overall clinical results, but not exempt of side effects. Other difficult scenarios include fulminant AIH, end-stage AIH cirrhosis and the management of post-transplant AIH. In this article we will review the literature related to second- line therapy especially of steroid resistant AIH. Future directions in the treatment of HAI should be guided to the individual patient (personalized) and may include cell therapies, such as infusion of autologous, antigen-specific, and liver-homing regulatory T cells to restore hepatic immune tolerance

La hepatitis autoinmune (HAI) es una hepatopatía de etiología desconocida, con pérdida de la tolerancia inmune contra los hepatocitos con factores genéticos y ambientales asociados. Se caracteriza por fenómenos de daño inmunológicos, con autoanticuerpos circulantes, una concentración elevada de gammaglobulina sérica y en la biopsia de hígado actividad necroinflamatoria, infiltrados linfoplasmocitarios y daño de interfase. La HAI es una entidad que se puede presentar en forma asintomática, como hepatitis aguda o como cirrosis hepática. El 70-80% de los pacientes responden adecuadamente al tratamiento inmunosupresor de primera línea (corticoides ± azatioprina). En los pacientes que no toleran azatioprina, en los corticorresistentes o en aquellos con recaídas repetidas a pesar de terapia (20-40%), es necesario recurrir a terapias de segunda línea de largo plazo, para evitar la progresión de la hepatopatía. Estas últimas incluyen micofenolato mofetil, inhibidores calcineurínicos (ciclosporina o tacrolimus), agentes biológicos (infliximab y rituximab), y otros fármacos inmunosupresores (sirolimus, everolimus), con resultados alentadores, pero no exentos de efectos colaterales. Otros escenarios complejos incluyen: la HAI de presentación aguda grave y fulminante, la cirrosis terminal autoinmune y la HAI post-trasplante. En este trabajo se revisa la literatura en relación a terapias de segunda línea especialmente en HAI corticoide resistente. El futuro del tratamiento de la HAI va encaminado a una terapia personalizada y que podría incluir terapias celulares como la infusión de células T regulatorias, antígeno específicas y autólogas, para reestablecer los mecanismos de tolerancia inmune hepática.

Pancitopenia inducida por azatioprina: Casos clínicos / Azathioprine-induced pancytopenia: Case series

La azatioprina es un fármaco inmunosupresor que ha demostrado efectividad en el tratamiento de la enfermedad inflamatoria intestinal. Su metabolito, la 6-mercaptopurina, es metaboliza-do a través de la tiopurina metiltransferasa. Los pacientes con baja actividad enzimática pueden presentar mayores efectos secundarios. El más frecuente es la leucopenia. Más raramente, aparece mielotoxicidad en forma de pancitopenia. La monitori-zación de la actividad de la tiopurina metiltransferasa permite obtener un perfil individualizado de la actividad enzimática, pero no debe reemplazar la monitorización mediante la realización de hemogramas seriados. Ante un paciente con neutropenia grave y fiebre, debe iniciarse un tratamiento antibiótico empírico precoz para evitar infecciones graves y diseminadas. Se presentan dos casos con esta complicación.

Azathioprine is an immunosuppressive drug that has shown effectiveness in inflammatory bowel disease treatment. Its metabolite, 6-mercaptopurine, is metabolized through thiopurine methyltransferase. Patients with low enzyme activity may have more frequent and severe side effects. The most common is leukopenia, and rarely pancytopenia. The thiopurine methyltransferase activity monitoring shows an individualized profile of enzymatic activity but it should not replace monitoring by performing serial blood counts. In patients with fever and severe neutropenia, early empirical antibiotic treatment should be initiated to prevent severe and disseminated infection. Two patients with this condition are reported.

Mycophenolate mofetil as an alternative treatment for autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immune-mediated chronic liver disease characterized by hepatocellular inflammation, necrosis, and fibrosis, which can progress to cirrhosis and fulminant hepatic failure. The standard treatment for AIH includes corticosteroids alone or in combination with azathioprine. Although most patients achieve remission using the standard regimen, some patients do not respond due to either drug intolerance or refractory disease; in such cases alternative immunosuppressive agents should be explored. The second-line therapies are cyclophilin inhibitors such as cyclosporine A or tacrolimus, and nowadays mycophenolate mofetil (MMF) is widely used if azathioprine-based therapies are not tolerated. Although these are recommended as an alternative to the first-line regimen, there is insufficient evidence for the efficacy of second-line therapies, with the evidence based mainly on expert opinion. Therefore, we report an AIH patient receiving the standard regimen in whom remission did not occur due to side effects to azathioprine, but was successfully treated with MMF in combination with corticosteroids as an alternative to the standard regimen.

Azathioprine-induced accelerated cutaneous and pulmonary nodulosis in a patient with rheumatoid arthritis

We report the case of a 42-year-old female with a 5-year history of rheumatoid arthritis treated with Rituximab and Azathioprine. Three months after the initiation of Azathioprine, the patient started with dry cough and noted the rapid development of multiple subcutaneous nodules on her right leg. CT scan of the chest demonstrates pulmonary nodulosis. Skin biopsy was compatible with rheumatoid nodule. A diagnosis of "accelerated cutaneous and pulmonary nodulosis" was considered. Azathioprine was discontinued and Rituximab was restarted. Two months later, most of the subcutaneous nodules had disappeared. This is the second case report of accelerated rheumatoid nodulosis in association with Azathioprine treatment.

Azathioprine for cortico-resistant noninfectious uveitis

The systemic steroids represent the first line treatment in the majority of the noninfectious uveitis, except some specific indications as the Behcet disease. Nevertheless, this treatment may be ineffective and immunosuppressive therapy is mandatory. To evaluate effectiveness and side effects of azathioprine [AZA] in corticosteroid resistant noninfectious uveitis [CRNIU]. This prospective study [2002- 2009], concerned 21 patients [mean age 37 years], 37 eyes, with CRNIU. Patients received oral AZA 2,5mg/kg/day, initiated in association with high dose steroids, with an end-point of 12 months. Response was defined as complete, partial response and failure, for each of the 3 following out-come measurements: improvement of BCVA, improvement of inflammation, steroids-sparing. Statistical analysis was considered significant if p value < 0,05. Side effects occurred in 42,8% [9/21] of patients, in which 5/9 patients stopped the treatment. Regarding BCVA, complete success was observed in 62,5%, partial response in 20,9%, and failure in 16,6% of cases. Regarding inflammation, complete success was noted in 70,8%, partial response in 29,1% and failure in 16,6 % of cases. Complete response of steroid sparing was observed in 85,7% of cases without failure. Complete success of the 3 criteria was observed in 57,1% of patients / 62,5% of eyes. Cataract [p=0,013] and pallor of optic nerve head [p=0,013] were associated to poor visual prognosis, BCVA of 20/40 or more [p=0,003, RR=2,38]] and papilledema [p=0,022, RR=2] to good visual prognosis. BCVA of 20/200 or less [p=0,001] was associated to failure of AZA on inflammatory response. AZA is safe and effective in corticosteroid-sparing and controlling inflammation in CRNIU. Its low cost and availability allow proposing it as a first-line option, especially when new biological treatments are difficult to obtain

Monitoring Thiopurine Metabolites in Korean Pediatric Patients with Inflammatory Bowel Disease

PURPOSE: This study aimed to assess the role of thiopurine S-methyltransferase (TPMT) and 6-thioguanine nucleotide (6-TGN) as predictors of clinical response and side effects to azathioprine (AZA), and estimate the optimal AZA dose in Korean pediatric inflammatory bowel disease (IBD) patients. MATERIALS AND METHODS: One hundred and nine pediatric IBD patients in whom AZA treatment was required were enrolled. Thiopurine metabolites were monitored since September 2010. Among them, 83 patients who had prescribed AZA for at least 3 months prior to September 2010 were enrolled and followed until October 2011 to evaluate optimal AZA dose, adverse effects and disease activity before and after thiopurine metabolite monitoring. RESULTS: The result of the TPMT genotype was that 102 patients were *1/*1 (wild type), four were *1/*3C, one was *1/*6, one was *1/*16 (heterozygote) and one was *3C/*3C (homozygote). Adverse effects happened in 31 patients pre-metabolite monitoring and in only nine patients post-metabolite monitoring. AZA dose was 1.4+/-0.31 mg/kg/day before monitoring and 1.1+/-0.46 mg/kg/day after monitoring (p<0.001). However, there were no statistical differences in disease activity during metabolite monitoring period (p=0.34). Adverse effects noticeably decreased although reduction of the AZA dose since monitoring. CONCLUSION: TPMT genotype and thiopurine metabolite monitoring could be helpful to examine TPMT genotypes before administering AZA and to measure 6-TGN concentrations during prescribing AZA in IBD patients.

Differences in the Adverse Effects of Azathioprine between Inflammatory Bowel Disease and Autoimmune Hepatitis in Korean Patients / 대한소화기학회지

BACKGROUND/AIMS: Azathioprine (AZA) has been widely used in the therapy of inflammatory bowel disease (IBD) and autoimmune hepatitis (AIH). However, studies evaluating the adverse effects of AZA in these two diseases are lacking. The aim of this study was to compare the adverse effects of AZA in Korean IBD and AIH patients. METHODS: Patients with IBD or AIH who were treated with AZA at Keimyung University Dongsan Medical Center (Daegu, Korea) between January 2002 and March 2011 were enrolled. Their medical records were reviewed retrospectively in terms of clinical characteristics and adverse effects of AZA. RESULTS: A total of 139 IBD patients and 55 AIH patients were finally enrolled. Thirty IBD patients (21.6%) and eight AIH patients (14.5%) experienced adverse effects of AZA. In particular, the prevalence of leukopenia was significantly higher in the IBD group than in the AIH group (p=0.026). T474C mutation was observed in three of 10 patients who were assessed for thiopurine methyltransferase (TPMT) genotype. CONCLUSIONS: IBD patients are at increased risk for the adverse effects of AZA compared with AIH patients, of which leukopenia was the most commonly observed. Therefore, IBD patients receiving AZA therapy should be carefully monitored.

Hiperplasia nodular regenerativa del hígado secundaria a uso de azatioprina por trasplante renal previo, tratado con trasplante combinado hepático y renal / Combined hepatic and renal transplant after nodular regenerative hyperplasia of the liver secondary to azathioprine in renal transplant patient

Nodular regenerative hyperplasia is an uncommon condition, characterized by the presence of regenerative nodules with minimal or absence of fibrosis, which can lead to non-cirrhotic portal hypertension. There are numerous diseases, conditions and drugs that can cause it. Thiopurines, a group of immunosuppressors used in transplanted patients, has been linked to this entity. We report a case of a renal transplant woman, who has been on chronic therapy with azathioprine and that develops portal hypertension and end-stage renal disease, undergoing combined hepatic and renal transplant. Histological examination of the explanted liver was compatible with nodular regenerative hyperplasia. How azathioprine causes this entity is unknown, but endothelial vascular damage in a dose-dependent manner is postulated as the main mechanism. To our knowledge, this is the first case report of a renal transplant patient who develops nodular regenerative hyperplasia of the liver in association with azathioprine, and undergoes combined hepatic and renal transplant, with a favorable outcome 5 years post procedure.

La hiperplasia nodular regenerativa es una entidad infrecuente, que se caracteriza por la presencia de nódulos hepáticos con ausencia o mínima fibrosis y que puede llevar a hipertensión portal de origen no cirrótico. Existen diversas enfermedades, condiciones y medicamentos que la causan, destacando entre estos últimos las tiopurinas, inmunosupresores utilizados habitualmente en trasplantados. Se presenta el caso de una paciente trasplantada renal usuaria crónica de azatioprina, que desarrolla hipertensión portal además de deterioro de la función renal, requiriendo de un doble trasplante hepático y renal, destacando en la biopsia del explante hallazgos histológicos compatibles con hiperplasia nodular regenerativa. Los mecanismos de daño por azatioprina en esta entidad son desconocidos, pero se postula al daño endotelial dosis-dependiente como principal causa. La revisión de la literatura demuestra que este caso corresponde al primero de hiperplasia nodular regenerativa secundaria a azatioprina en trasplantado renal, que requiere de doble trasplante hepático y renal con evolución favorable hasta 5 años post trasplante.

Successful Azathioprine Treatment with Metabolite Monitoring in a Pediatric Inflammatory Bowel Disease Patient Homozygous for TPMT*3C

Thiopurine S-methyltransferase (TPMT) methylates purine analogues, showing TPMT activity in inverse relation to concentrations of active metabolites such as 6-thioguanine nucleotide (6-TGN). With conventional dosing of thiopurines, patients with homozygous variant TPMT alleles consistently suffer from severe myelosuppression. Here, we report a patient with TPMT*3C/*3C who managed successfully with monitoring of thiopurine metabolites. The patient was an 18-year-old male diagnosed with Crohn's disease. The standard dose of azathioprine (AZA) (1.8 mg/kg/day) with mesalazine (55.6 mg/kg/day) was prescribed. Two weeks after starting AZA treatment, the patient developed leukopenia. The DNA sequence analysis of TPMT identified a homozygous missense variation (NM_000367.2: c.719A>G; p.Tyr240Cys), TPMT*3C/*3C. He was treated with adjusted doses of azathioprine (0.1-0.2 mg/kg/day) and his metabolites were closely monitored. Leukopenia did not reoccur during the follow-up period of 24 months. To our knowledge, this is the first case of a patient homozygous for TPMT*3C successfully treated with azathioprine in Korea. While a TPMT genotyping test may be helpful to determine a safe starting dose, it may not completely prevent myelosuppression. Monitoring metabolites as well as routine laboratory tests can contribute to assessing drug metabolism and optimizing drug dosing with minimized drug-induced toxicity.

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.

Determinación de la tiopurina metiltransferasa para ajustar la dosis de azatioprina o mercaptopurina: [revisión] / Monitoring thiopurine methyltransferase activity to adjust dosages of azathioprine or mercaptopurine: [review]

La monitorización de la actividad de la tiopurina metiltransferasa (TPMT) se emplea para identificar a los pacientes tratados con azatioprina (AZA) y mercaptopurina (MP) que presentan mayor riesgo de mielotoxicidad. La actividad de la TPMT en la población general sigue una distribución trimodal, en la que aproximadamente el 11% de los individuos son heterocigotos y el 0.3% homocigotos para el alelo de baja actividad. Existen dos estrategias para identificar los pacientes con deficiencia de TPMT: la medición del fenotipo y del genotipo, con una elevada concordancia entre ambas técnicas. Se demostró una notable correlación entre el fenotipo o el genotipo de baja actividad de la TPMT y el riesgo de mielotoxicidad. Los pacientes con un genotipo homocigoto de alta actividad (o con actividad normal de la TPMT) deberían recibir dosis de inmunosupresores que hayan demostrado ser claramente eficaces. En aquellos enfermos con genotipo o fenotipo homocigoto de baja actividad de la TPMT se debería contraindicar el empleo de AZA/MP o, en todo caso, sería obligado administrar dosis muy reducidas de estos fármacos. En resumen, la determinación de la actividad de la TPMT constituye una atractiva opción para individualizar la dosis de AZA o MP y prevenir el riesgo de efectos adversos, aunque está por demostrarse si esta estrategia debe aplicarse rutinariamente en todos los pacientes. En cualquier caso, el fenotipo o el genotipo asociado con el déficit de TPMP explica únicamente un porcentaje de casos de mielotoxicidad, por lo que los controles analíticos periódicos deben seguir realizándose en estos pacientes a pesar de que la función de esta enzima sea normal.

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.

Toxicidade da azatioprina na doença de Crohn: incidência, abordagem e evolução / Azathioprine toxicity in Crohn's disease: incidence, approach and course

OBJETIVO: A azatioprina (AZA) tem sido usada freqüentemente no tratamento da doença de Crohn (DC). O objetivo do presente estudo foi avaliar a freqüência, evolução e abordagem dos efeitos adversos da AZA no tratamento de pacientes com DC. MÉTODOS: Foram incluídos prospectivamente 106 pacientes portadores de DC em uso de AZA, de janeiro de 2002 a dezembro de 2006. Registraram-se dados clínicos e demográficos, com controle laboratorial mensal dos efeitos hematológicos e supervisão de reações adversas por meio de avaliação clínica. Realizou-se comparação entre os grupos com e sem efeitos adversos. RESULTADOS: Cinqüenta e seis (52,7 por cento) dos pacientes estudados apresentaram pelo menos um efeito adverso, requerendo redução transitória da dose da droga; 18 (17 por cento) necessitaram suspender definitivamente o uso de AZA, geralmente devido a reações de hipersensibilidade. Náuseas e vômitos, freqüentemente leves, ocorreram em 29 (27,4 por cento); a raça negra e aqueles com comorbidades apresentaram mais intolerância gástrica do que os brancos e aqueles sem outras doenças associadas (p=0,04). Leucopenia foi o efeito adverso mais freqüente, ocorrendo em 36 (34 por cento). O tempo de uso de AZA foi maior em pacientes com leucopenia do que nos não leucopênicos (p=0,001), enquanto a dose média de AZA foi menor naqueles com leucopenia comparados aos não leucopênicos (p=0,005). Não houve infecções graves, neoplasias ou óbitos durante o tratamento com AZA. CONCLUSÃO: A AZA mostrou ser uma droga relativamente segura no tratamento da DC, desde que seja mantida supervisão clínica e laboratorial periódica durante todo o tratamento.

OBJECTIVE: Azathioprine (AZA) is frequently used in Crohn's disease (CD) therapy. This paper aimed to evaluate the frequency, evolution and management of AZA side effects in CD patients. METHODS: One hundred and six CD patients under AZA therapy were evaluated prospectively from January 2002 to December 2006. Clinical and demographic data were recorded, together with a monthly laboratory control of hematological or other adverse reactions by means of clinical evaluation. Comparison was carried out between groups with and without side effects. RESULTS: At least one adverse reaction was found in 56 (52.7 percent) of the patients studied and required a transient drug reduction; 18 (17 percent) had to definitely stop use of AZA, often because of hypersensitivity reactions. Nausea, vomit, although slight, occurred in 29 (27.4 percent). The black race and those with co-morbidities had more gastric intolerance than Caucasians and those without other associated disease (p=0.04). Leucopoenia was the more frequent side effect observed, occurring in 36 (34 percent). The period of AZA use was longer for patients with leucopoenia than for those without (p=0.001), while the mean dose of AZA was lower for those with leucopoenia when compared to non-leucopoenics (p=0.005). No serious infections, malignancy or death was noticed as a consequence of AZA use. CONCLUSION: In this study use of AZA in therapy for Crohn's disease disclosed that the drug is satisfactorily safe as long as periodical clinical and laboratory supervision is carried out during treatment.