Azathioprine-induced vanishing bile duct syndrome: The value of early thiopurine metabolism assessment.

About 15% to 28% of patients treated with thiopurines experienced adverse drug reactions, such as haematological and hepatic toxicities. Some of these related to the polymorphic activity of the thiopurine S-methyltransferase (TPMT), the key detoxifying enzyme of thiopurine metabolism. We report here a case of thiopurine-induced ductopenia with a comprehensive pharmacological analysis on thiopurine metabolism. A 34-year-old woman, with a medical history of severe systemic lupus erythematosus with recent introduction of azathioprine therapy, presented with mild fluctuating transaminase blood levels consistent with a hepatocellular pattern, which evolved to a cholestatic pattern over the next weeks. A blood thiopurine metabolite assay revealed low 6-thioguanine nucleotides (6-TGN) level and a dramatically increased 6-methylmercaptopurine ribonucleotides (6-MMPN) level, together with an unfavourable [6-MMPN:6-TGN] metabolite ratio and a high TPMT activity. After a total of about 6 months of thiopurine therapy, a transjugular liver biopsy revealed a ductopenia, and azathioprine discontinuation led to further clinical improvement. In line with previous reports from the literature, our case supports the fact that ductopenia is a rare adverse drug reaction of azathioprine. The mechanism of reaction is unknown but may involve high 6-MMPN blood level, due to unusual thiopurine metabolism (switched metabolism). Early therapeutic drug monitoring with measurement of 6-TGN and 6-MMPN blood levels may help physicians to identify patients at risk of similar duct injury.

Belimumabe intravenoso para o tratamento adjuvante de pacientes adultos com lúpus eritematoso sistêmico com alto grau de atividade apesar da terapia padrão e que apresentem falha terapêutica a dois imunossupressores prévios / Intravenous belimumab for the adjuvant treatment of adult patients with systemic lupus erythematosus with a high degree of activity despite standard therapy and who experience treatment failure in two cases previous immunosuppressants

INTRODUÇÃO: O lúpus eritematoso sistêmico (LES) é uma doença autoimune multissistêmica crônica, que apresenta características polimórficas, com destaque para sintomas constitucionais, erupção cutânea e artrite. Também pode levar a complicações graves, como nefrite lúpica, citopenias autoimunes e doenças do sistema nervoso. Além da atividade de doença, o uso contínuo de corticoide em altas doses é associado a maiores danos acumulados e óbitos. O objetivo do tratamento é controlar a atividade da doença e evitar o surgimento de fatores de risco para complicações,sendo utilizados medicamentos como antimaláricos, corticoides e imunossupressores. Após a remissão clínica, recomenda-se a redução gradual das doses dos medicamentos, mantendo o uso da hidroxicloroquina. RECOMENDAÇÕES ANTERIORES DA CONITEC: Em 2018, o Plenário da Conitec deliberou por unanimidade pela não incorporação do belimumabe para o tratamento de LES no âmbito do Sistema Único de Saúde (SUS), conforme Relatório de Recomendação nº 344. Na ocasião, a pergunta de pesquisa se diferiu em relação aos desfechos e tipo de estudo, considerando-se apenas a melhora no Systemic Lupus Erythemathosus Response Index (SRI) e meta-análises de ensaios clínicos randomizados (ECRs), respectivamente. A

Citrato de tofacitinibe para o tratamento de retocolite ulcerativa ativa moderada a grave em pacientes adultos com resposta inadequada, perda de resposta ou intolerantes ao tratamento prévio com medicamentos sintéticos convencionais / Tofacitinib citrate for the treatment of moderate to severe active ulcerative colitis in adult patients with inadequate response, loss of response, or intolerant to prior treatment with conventional synthetic drugs

INTRODUÇÃO: A retocolite ulcerativa (RCU), ou colite ulcerativa, é uma doença caracterizada pela ocorrência de episódios de inflamação restrita à mucosa do cólon, podendo envolver o reto e se estender por outras partes proximais do cólon. Os pacientes apresentam diarreia, podendo ser associada com a presença de sangue. Os sintomas incluem dor abdominal, urgência, incontinência e tenesmo, que apresentam de forma gradual e progressiva, podendo estender-se por várias semanas. Febre, fadiga, perda de peso, dispneia, palpitação, anemia e deficiência de ferro podem ocorrer. A RCU pode ser dividida em fase ativa e estádio de remissão. A fase ativa é caracterizada pela presença de sintomas e lesões ativas da mucosa e a remissão é caracterizada pela resolução dos sintomas e desaparecimento de achados na mucosa. A doença ocorre gradualmente, seguida de períodos de remissão espontânea e recaídas subsequentes. A incidência da doença é semelhante entre homens e mulheres, sendo que a idade de início é entre 30 e 40 anos. O tratamento da RCU consiste em aminossalicilatos orais e por via retal, corticoides, imunossupressores e medicamentos biológicos, e é feito d

Citrato de tofacitinibe para o tratamento da retocolite ulcerativa moderada a grave em pacientes adultos com resposta inadequada, perda de resposta ou intolerantes ao tratamento prévio com medicamentos sintéticos convencionais ou biológicos / Tofacitinib citrate for the treatment of moderate to severe ulcerative colitis in adult patients with inadequate response, loss of response or intolerant to previous treatment with conventional synthetic or biological drugs

INTRODUÇÃO: A retocolite ulcerativa (RCU) é uma doença crônica que consiste na inflamação da camada mucosa do cólon, que afeta o reto e outras partes proximais do cólon. A diarreia sanguinolenta ou não, juntamente com o pequeno volume de cada evacuação e o aumento da frequência, caracterizam a doença. Além desses sintomas, observa-se febre, perda de peso, anemia, alterações laboratoriais, dores abdominais, dentre outros. A doença pode ser classificada de acordo com sua gravidade, o que auxilia no tratamento, em leve, moderada ou grave, a partir da aplicação de um índice específico. O tratamento atualmente preconizado no Sistema Único de Saúde é o uso de corticoides e aminossalicilatos. PERGUNTA: Citrato de tofacitinibe é eficaz e seguro para o tratamento da RCU ativa moderada a grave com resposta inadequada, perda de resposta ou intolerância a aminossalicilatos, corticosteroides, azatioprina, 6-mercaptopurina ou medicamentos biológicos da classe dos anti-TNF? TECNOLOGIA: Citrato de Tofacitinibe (Xeljanz®). EVIDÊNCIAS CI

Increased incidence of systemic serious viral infections in patients with inflammatory bowel disease associates with active disease and use of thiopurines.

Background: The magnitude and drivers of the risk of serious viral infections in Inflammatory Bowel diseases (IBD) are unclear. Objective: The objective of this study was to assess the incidence and risk factors for systemic serious viral infections in IBD patients. Methods: Using MICISTA, a database detailing prospective characteristics and complications of IBD, we identified patients that were followed for IBD in 2005-2014 outside the context of organ transplantation, HIV infection or chronic viral hepatitis. We estimated incidences of systemic serious viral infections, defined by the need for hospitalization or permanent organ damage. Standardized incidence ratios (SIRs) were calculated using the French hospital database. We performed a case-control study nested in MICISTA for assessing the role of exposure to IBD drugs and IBD clinical activity in the risk of developing infection. Results: We identified 31 patients with serious viral infections among 2645 patients followed for 15,383 person-years. We observed 13 cases of cytomegalovirus, 10 Epstein-Barr virus, 5 varicella zoster virus and 3 herpes simplex virus infections. No deaths occurred. The incidence rate of infections in patients with IBD was 2.02/1000 person-years, and the SIR was 3.09 (95% confidence interval (CI), 1.98-4.20; p = 0.0002) in the study population. By multivariate analysis, increased risk of infection was associated with exposure to thiopurines (odds ratio (OR), 3.48; 95% CI, 1.36-8.90; p = 0.009), and clinically active IBD at onset of infection (OR, 3.35; 95% CI, 1.23-9.23; p = 0.02). Conclusions: The incidence of systemic serious viral infections in patients with IBD is tripled compared to general population. Clinically active IBD and exposure to thiopurines are the main drivers of the risk.

Cost-effectiveness analysis of pretreatment screening for NUDT15 defective alleles.

BACKGROUND: Nucleotide triphosphate diphosphatase (NUDT15) genetic testing in addition to thiopurine methyl transferase (TPMT) is recommended to reduce the incidence of adverse severe myelotoxicity episodes induced by thiopurines. OBJECTIVE: We assessed the cost-effectiveness ratio of combined screening for TMPT and NUDT15 defective alleles by genotyping or next-generation sequencing (NGS) using TPMT genotyping as the reference. Because of the genetic differences in thiopurine toxicity, we tested the screening strategies on individuals of Caucasian and Asian descent. METHODS: A decision tree compared conventional TPMT genotyping with combined TPMT/NUDT15 genotyping or NGS using a Monte-Carlo microsimulation model of patients with inflammatory bowel disease. The main outcome was the incremental cost-effectiveness ratios (ICER) with effectiveness being one averted severe myelotoxicity requiring hospitalization. RESULTS: The mean estimated cost of the TPMT genotyping for one year is twice in Asian compared with Caucasian patients (980 euro/patient versus 488 euro/patient), and the effectiveness of TPMT genotyping in Caucasian avoided 43 severe myelosuppressions per 10 000 patients over a year compared with 3.6 per 10 000 patients in Asian. Combined TPMT/NUDT15 genotyping compared with TPMT genotyping had an ICER of 7 491 281 euro per severe myelotoxicity averted in Caucasian, compared to 619 euro in Asian. The ICER of the NGS-based screening strategy is disproportionally high compared with genotyping, irrespective of ethnic descent. CONCLUSION: With a low cost-effectiveness threshold, combined screening for NUDT15 and TPMT defective alleles is cost-effective compared to TMPT screening alone in patients of Asian descent, but is unrealistic from a cost-effectiveness point of view in Caucasians.

Maintenance immunosuppression for adults undergoing liver transplantation: a network meta-analysis.

BACKGROUND: As part of liver transplantation, immunosuppression (suppressing the host immunity) is given to prevent graft rejections resulting from the immune response of the body against transplanted organ or tissues from a different person whose tissue antigens are not compatible with those of the recipient. The optimal maintenance immunosuppressive regimen after liver transplantation remains uncertain. OBJECTIVES: To assess the comparative benefits and harms of different maintenance immunosuppressive regimens in adults undergoing liver transplantation through a network meta-analysis and to generate rankings of the different immunosuppressive regimens according to their safety and efficacy. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until October 2016 to identify randomised clinical trials on immunosuppression for liver transplantation. SELECTION CRITERIA: We included only randomised clinical trials (irrespective of language, blinding, or publication status) in adult participants undergoing liver transplantation (or liver retransplantation) for any reason. We excluded trials in which participants had undergone multivisceral transplantation or participants with established graft rejections. We considered any of the various maintenance immunosuppressive regimens compared with each other. DATA COLLECTION AND ANALYSIS: We performed a network meta-analysis with OpenBUGS using Bayesian methods and calculated the odds ratio, rate ratio, and hazard ratio (HR) with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. MAIN RESULTS: We included a total of 26 trials (3842 participants) in the review, and 23 trials (3693 participants) were included in one or more outcomes in the review. The vast majority of the participants underwent primary liver transplantation. All of the trials were at high risk of bias, and all of the evidence was of low or very low quality. In addition, because of sparse data involving trials at high risk of bias, it is not possible to entirely rely on the results of the network meta-analysis. The trials included mainly participants undergoing primary liver transplantation of varied aetiologies. The follow-up in the trials ranged from 3 to 144 months. The most common maintenance immunosuppression used as a control was tacrolimus. There was no evidence of difference in mortality (21 trials; 3492 participants) or graft loss (15 trials; 2961 participants) at maximal follow-up between the different maintenance immunosuppressive regimens based on the network meta-analysis. In the direct comparison, based on a single trial including 222 participants, tacrolimus plus sirolimus had increased mortality (HR 2.76, 95% CrI 1.30 to 6.69) and graft loss (HR 2.34, 95% CrI 1.28 to 4.61) at maximal follow-up compared with tacrolimus. There was no evidence of differences in the proportion of people with serious adverse events (1 trial; 719 participants), proportion of people with any adverse events (2 trials; 940 participants), renal impairment (8 trials; 2233 participants), chronic kidney disease (1 trial; 100 participants), graft rejections (any) (16 trials; 2726 participants), and graft rejections requiring treatment (5 trials; 1025 participants) between the different immunosuppressive regimens. The network meta-analysis showed that the number of adverse events was lower with cyclosporine A than with many other immunosuppressive regimens (12 trials; 1748 participants), and the risk of retransplantation (13 trials; 1994 participants) was higher with cyclosporine A than with tacrolimus (HR 3.08, 95% CrI 1.13 to 9.90). None of the trials reported number of serious adverse events, health-related quality of life, or costs. FUNDING: 14 trials were funded by pharmaceutical companies who would benefit from the results of the trial; two trials were funded by parties who had no vested interest in the results of the trial; and 10 trials did not report the source of funding. AUTHORS' CONCLUSIONS: Based on low-quality evidence from a single small trial from direct comparison, tacrolimus plus sirolimus increases mortality and graft loss at maximal follow-up compared with tacrolimus. Based on very low-quality evidence from network meta-analysis, we found no evidence of difference between different immunosuppressive regimens. We found very low-quality evidence from network meta-analysis and low-quality evidence from direct comparison that cyclosporine A causes more retransplantation compared with tacrolimus. Future randomised clinical trials should be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid postrandomisation dropouts or planned cross-overs; and use clinically important outcomes such as mortality, graft loss, renal impairment, chronic kidney disease, and retransplantation. Such trials should use tacrolimus as one of the control groups. Moreover, such trials ought to be designed in such a way as to ensure low risk of bias and low risks of random errors.

Early Assessment of Thiopurine Metabolites Identifies Patients at Risk of Thiopurine-induced Leukopenia in Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Only a quarter of thiopurine-induced myelotoxicity in inflammatory bowel disease [IBD] patients is related to thiopurine S-methyltransferase deficiency. We determined the predictive value of 6-thioguanine nucleotide [6-TGN] and 6-methylmercaptopurine ribonucleotide [6-MMPR] concentrations 1 week after initiation [T1] for development of leukopenia during the first 8 weeks of thiopurine treatment. METHODS: The study was performed in IBD patients starting thiopurine therapy as part of the Dutch randomized controlled TOPIC trial [ClinicalTrials.gov NCT00521950]. Blood samples for metabolite measurement were collected at T1. Leukopenia was defined by leukocyte counts of <3.0 × 109/L. For comparison, patients without leukopenia who completed the 8 weeks on the stable dose were selected from the first 272 patients of the TOPIC trial. RESULTS: Thirty-two patients with, and 162 patients without leukopenia were analysed. T1 threshold 6-TGN concentrations of 213 pmol/8 × 108 erythrocytes and 3525 pmol/8 × 108 erythrocytes for 6-MMPR were defined: patients exceeding these values were at increased leukopenia risk (odds ratio [OR] 6.2 [95% CI: 2.8-13.8] and 5.9 [95% CI: 2.7-13.3], respectively). Leukopenia rates were higher in patients treated with mercaptopurine, compared with azathioprine (OR 7.3 [95% CI: 3.1-17.0]), and concurrent anti-TNF therapy (OR 5.1 [95% CI: 1.6-16.4]). Logistic regression analysis of thiopurine type, threshold concentrations, and concurrent anti-tumour necrosis factor [TNF] therapy revealed that elevations of both T1 6-TGN and 6-MMPR resulted in the highest risk for leukopenia, followed by exceeding only the T1 6-MMPR or 6-TGN threshold concentration (area under the curve 0.84 [95% CI: 0.76-0.92]). CONCLUSIONS: In ~80% of patients, leukopenia could be explained by T1 6-TGN and/or 6-MMPR elevations. Validation of the predictive model is needed before implementing in clinical practice.

The benefit-to-risk balance of combining infliximab with azathioprine varies with age: a markov model.

BACKGROUND & AIMS: Combination therapy with infliximab and azathioprine has demonstrated benefit over monotherapy for moderate-to-severe Crohn's disease. Clinical trials and models have not accounted for age-specific risks associated with these therapies, including the risk of immunosuppression-related cancer and infection. After accounting for these risks, the strategy yielding the greatest benefit may vary with age. METHODS: We assessed age-specific risks and benefits of combination therapy compared with infliximab monotherapy by using Markov modeling. The base case was a 35-year-old male patient with a 1-year time horizon. We assumed the incidence of lymphoma to be 5.28-fold higher with combination therapy. Secondary analyses accounted for life expectancy, therapy beyond 1 year, and age-specific surgical and infection risks. Quality-adjusted life years (QALYs) were calculated for 25- to 75-year old individuals. RESULTS: Combination therapy was found to be of greater benefit in the base case (0.7522 QALYs for combination therapy vs 0.7426 QALYs for monotherapy). Accounting for life years lost, monotherapy was the best approach if the hazard ratio for lymphoma with combination therapy was >8.1 patients who were 75 years old. Monotherapy provided greater net benefit to patients 55, 65, or 75 years old if therapy was extended for 9, 7, or 5 years, respectively. For 25-year-old men, monotherapy resulted in fewer deaths but only yielded greater QALYs if the annual incidence of hepatosplenic T-cell lymphoma exceeded 36/100,000 persons. CONCLUSIONS: After accounting for age-specific risks of lymphoma, infection, and surgical complications, benefits of combination therapy outweighed the risks as a short-term and intermediate-term strategy for most patients with moderate-to-severe Crohn's disease who were younger than 65 years. For young male patients, combination therapy yields greater QALYs but at cost of an increased risk of death from lymphoma.

Assessment of the adjuvant effect of tacrolimus in the management of pemphigus vulgaris: A randomized controlled trial.

UNLABELLED: Introduction: To investigate the therapeutic efficacy of tacrolimus compared with azathioprine in the treatment of pemphigus vulgaris. METHODS: About 23 patients received prednisolone and azathioprine, and 23 patients prednisolone and tacrolimus for 6 months. Pemphigus activity scores, the time that new bulla formation stopped, the time corticosteroid was tapered, cumulative steroid dosage and medication side effects were analyzed. RESULTS: In the control group, the new bulla formation was ceased after a mean ± SD of 11.8 ± 4.7 days, and steroid tapering was done after a mean ± SD of 28.3 ± 5.45 days. Of the 23 patients receiving prednisolone and tacrolimus, the new bulla formation was ceased after a mean ± SD of 12.9 ± 5.26 days, and steroid tapering was done after a mean ± SD of 28.2 ± 5.39 days. About 8.6% of patients did not reach remission in each group. In patients receiving azathioprine, life-threatening side effects were seen in 1 (4.7%), moderate side effects in 2 (9.5%) and mild side effects in 1 (4.7%). In patients receiving tacrolimus, moderate side effect was seen in 1 (5%) and mild in 1 (5%). CONCLUSION: Tacrolimus effects are comparable to azathioprine as pemphigus vulgaris adjuvant treatment, also it has less severe side effects. Trial registration No. IRCT2012073010450N1 available at www.IRCT.ir.

Recent clinical trials in lupus nephritis.

Recent clinical trials have provided evidence for the efficacy of low-dose intravenous cyclophosphamide and mycophenolate mofetil as induction treatment for patients with proliferative lupus nephritis in comparative trials with standard-dose intravenous cyclophosphamide. Trials of maintenance treatments have had more variable results, but suggest that the efficacy of mycophenolate mofetil may be similar to that of quarterly standard-dose intravenous cyclophosphamide and somewhat more efficacious than azathioprine. Differential responses to mycophenolate mofetil based on ethnicity suggest that it may be more effective in black and Hispanic patients. Rituximab was not efficacious as an adjunct to induction treatment with mycophenolate mofetil.

Implementation of TPMT testing.

The activity of the enzyme thiopurine methyltransferase (TPMT) is regulated by a common genetic polymorphism. One in 300 individuals lack enzyme activity and 11% are heterozygous for a variant low activity allele and have an intermediate activity. The thiopurine drugs azathioprine, mercaptopurine and thioguanine are substrates for TPMT; these drugs exhibit well documented myelosuppressive effects on haematopoietic cells and have a track record of idiosyncratic drug reactions. The development of severe bone marrow toxicity, in patients taking standard doses of thiopurine drugs, is associated with TPMT deficiency whilst the TPMT heterozygote is at an increased risk of developing myelosuppression. Factors influencing TPMT enzyme activity, as measured in the surrogate red blood cell, are discussed in this review to enable an appreciation of why concordance between TPMT genotype and phenotype is not 100%. This is particularly important for lower/intermediate TPMT activities to avoid misclassification of TPMT status. TPMT testing is now widely available in routine service laboratories. The British National Formulary suggests TPMT testing before starting thiopurine drugs. Dermatologists were quick to adopt routine TPMT testing whilst gastroenterologists do not specifically recommend TPMT screening. TPMT testing is mandatory prior to the use of mercaptopurine in childhood leukaemia. Thiopurine drug dose and other treatment related influences on cell counts explain some of the differing recommendations between clinical specialities. TPMT testing is cost-effective and the major role is in the identification of the TPMT deficient individual prior to the start of thiopurine drugs.

Adverse events do not outweigh benefits of combination therapy for Crohn's disease in a decision analytic model.

BACKGROUND & AIMS: The Study of Biologic and Immunomodulator-Naïve Patients With Crohn's Disease (SONIC) showed that combination therapy with infliximab and azathioprine (IFX/AZA) is more effective than treatment with IFX alone. Numbers and types of adverse events were roughly equivalent among groups, although enrollment was limited, so it was not clear how rare adverse events might affect overall outcomes in practice. We sought to define the frequency at which a rare adverse event would have to occur for the risks of combination therapy to outweigh the benefits of treatment. METHODS: We constructed a decision model to compare the risks and benefits of IFX/AZA with IFX monotherapy. Model parameters were taken from SONIC and other published literature. The base-case analysis was patients with active Crohn's disease who are naïve to both medications (similar to those in SONIC) who were treated for 1 year. We used sensitivity analyses to determine the thresholds at which the risks of side effects from IFX/AZA outweigh its benefits. RESULTS: During 1 year, the benefits of IFX/AZA would outweigh the risks, unless serious infections occurred in 20% or more of the population or lymphoma in 3.9% or more. These thresholds are 5-fold and 65-fold higher than base-case estimates, respectively. CONCLUSIONS: On the basis of data from 1 year of SONIC, the combination of IFX/AZA was more effective than IFX alone in patients with Crohn's disease who are naïve to either drug. For the risks of combination therapy to outweigh the benefits in this time frame, the incidence of serious adverse events would have to be higher than seems clinically realistic.

Combination therapy with diltiazem plus CsA/MMF/Pred or CsA/Aza/Pred triple immunosuppressive regimens for use in clinical kidney transplantation in Northwestern China.

OBJECTIVE: The effects of diltiazem on 1692 kidney transplant recipients under the immunosuppressive regimen of cyclosporine A (CsA) in combination with either mycophenolate mofetil or azothioprine were assessed. The two treatment groups were compared for blood concentrations of CsA, the extent of acceptable dosage reduction for the maintenance of immunotherapy, potential effects of kidney protection, and promotion of graft function. METHOD: We monitored changes of blood concentrations of CsA in the two different patient treatment groups for post-transplant graft function, episodes of acute rejection, and hepatic and renal toxicity in 1640 renal transplant recipients after treatment with diltiazem. RESULTS: In patients treated with the triple immunosuppressive regimen consisting of CsA, azothioprine, and prednisolone (Pred), the sub-group of patients receiving the diltiazem treatment saw a significantly reduced CsA dosage in comparison to the non-diltiazem group (control group 1) (P < 0.05), but the blood concentrations of CsA of the diltiazem group were higher than those of control group 1 (P < 0.01). Of the patients treated with CsA, mycophenolate mofetil, and Pred, the sub-group of patients also treated with diltiazem showed similar effects: CsA dosage was reduced (P < 0.01) and the blood concentrations of CsA significantly increased (P < 0.01) in comparison with those of control group 2. In addition, recovery time of graft function decreased to 4.7 ± 1.8 days and 3.9 ± 1.4 days in the two diltiazem treatment groups, respectively (P < 0.05), and the rate of acute rejection decreased to 21 (p < 0.05) and 7.9% (P < 0.01), respectively. CONCLUSION: In our cohort of renal transplantation patients, co-administration of CsA and diltiazem increased CsA blood concentration, thereby resulting in a reduction in its required dosage treatment, which lightened the patients' economic burden while improving primary and long-term kidney function by promoting the recovery of graft function and decreasing hepatic and renal toxicity. The co-administration of diltiazem may also reduce the rate of acute rejection, especially in patients who also receive the triple immunosuppressive regimen consisting of CsA, mycophenolate mofetil, and Pred.

Assessment of non-cirrhotic portal hypertension associated with thiopurine therapy in inflammatory bowel disease.

Thiopurines represent an effective and widely used immunosuppressant in the therapeutic armamentarium of inflammatory bowel disease. However up to 25% of patients may be unable to continue the drug due to side effects. The incidence of hepatotoxicity associated with thiopurine use is reported between 0% and 32%. Veno-occlusive disease, peliosis hepatis, perisinusoidal fibrosis and nodular regenerative hyperplasia have all been described with thiopurines. Recent trials of 6-tioguanine, although successful in patients with allergies to azathioprine or mercaptopurine, have been compromised by increased hepatotoxicity, either veno-occlusive disease or nodular regenerative hyperplasia. We describe a report of nodular regenerative hyperplasia in a Crohn's disease patient associated with 6-mercaptopurine therapy and have reviewed the management and the literature regarding this complication. Our report strengthens the importance of further safety studies to evaluate the etiology, prevalence, risk factors and screening modalities for hepatotoxicity, in particular of nodular regenerative hyperplasia, in patients treated with thiopurines for inflammatory bowel disease.

Thiopurine S- methyltransferase [corrected] testing in idiopathic pulmonary fibrosis: a pharmacogenetic cost-effectiveness analysis.

Azathioprine in combination with N-acetylcysteine (NAC) and steroids is a standard therapy for idiopathic pulmonary fibrosis (IPF). Its use, however, is limited by its side effects, principally leukopenia. A genotypic assay, thiopurine S-methyltransferase (TPMT), has been developed that can potentially identify those at risk for developing leukopenia with azathioprine, and thereby limit its toxicity. In those with abnormal TPMT activity, azathioprine can be started at lower dose or an alternate regimen selected. Determine the cost-effectiveness of a treatment strategy using TPMT testing before initiation of azathioprine, NAC, and steroids in IPF by performing a computer-based simulation. We developed a decision analytic model comparing three strategies: azathioprine, NAC and steroids with and without prior TPMT testing, and conservative therapy, consisting of only supportive measures. Prevalence of abnormal TPMT alleles and complication rates of therapy were taken from the literature. We assumed a 12.5% incidence of abnormal TPMT alleles, 4% overall incidence of leukopenia while taking azathioprine, and that azathioprine, NAC, and steroids in combination reduced IPF disease progression by 14% during 12 months. TPMT testing before azathioprine, NAC, and steroids was the most effective and most costly strategy. The marginal cost-effectiveness of the TPMT testing strategy was $49,156 per quality adjusted life year (QALY) gained versus conservative treatment. Compared with azathioprine, NAC and steroids without prior testing, the TPMT testing strategy cost only $29,662 per QALY gained. In sensitivity analyses, when the prevalence of abnormal TPMT alleles was higher than our base case, TPMT was "cost-effective." At prevalence rates lower than our base case, it was not. TPMT testing before initiating therapy with azathioprine, NAC, and steroids is a cost-effective treatment strategy for IPF.

Impact of immunosuppressive medication on the risk of renal allograft failure due to recurrent glomerulonephritis.

Recurrent glomerulonephritis is a major problem in kidney transplantation but the role of immunosuppression in preventing this complication is not known. We used data from the United States Renal Data System to examine the effect of immunosuppressive medication on allograft failure due to recurrent glomerulonephritis for 41,272 patients undergoing kidney transplantation from 1990 to 2003. Ten-year incidence of graft loss due to recurrent glomerulonephritis was 2.6% (95% confidence interval [CI]: 2.3-2.8%). After adjusting for important covariates, the use of cyclosporine, tacrolimus, azathioprine, mycophenolate mofetil, sirolimus or prednisone was not associated with graft failure due to recurrent glomerulonephritis. There was no difference between cyclosporine and tacrolimus or between azathioprine and mycophenolate mofetil in the risk of graft failure due to recurrent glomerulonephritis. However, any change in immunosuppression during follow-up was independently associated with graft loss due to recurrence (adjusted hazard ratio 1.30, 95% CI: 1.06-1.58, p = 0.01). In patients with a pretransplant diagnosis of glomerulonephritis, the risk of graft loss due to recurrence was not associated with any specific immunosuppressive medication. The selection of immunosuppression for kidney transplant recipients should not be made with the goal of reducing graft failure due to recurrent glomerulonephritis.

Improving pharmacovigilance in Europe: TPMT genotyping and phenotyping in the UK and Spain.

Thiopurine S-methyltransferase (TPMT) is the rate-limiting step in the conversion of thiopurine drugs including azathioprine (AZA) to inactive metabolites. Heritable deficiency of TPMT activity increases risk for adverse events, most notably, myelosuppression leading to leukopenia and neutropenic sepsis. The reported European Commission study was undertaken to identify current evidence for the clinical utility of testing for TPMT status and extent of uptake, by either genotyping or phenotyping, in the clinical setting. Data presented here for the UK and Spain indicate that there has been a considerable increase in the uptake of TPMT testing in recent years. There are some data that support routine TPMT testing before AZA prescribing for reducing AZA-related adverse events. Key data include evidence in favor of TPMT testing in addition to the current practice of routine monitoring for reducing the number of AZA-related episodes of myelosuppression, averting deaths from neutropenic sepsis and improving health-related quality of life. Further data are needed for determining the cost-effectiveness of routine TPMT testing.