mercaptopurine and Hepatitis--Autoimmune

The utility of measuring thiopurine metabolites (TM) to individualize therapy in autoimmune hepatitis (AIH) has not been defined, and the evidence regarding its use in clinical practice is heterogeneous. This systematic review and meta-analysis aimed to compare the mean concentration of TM between patients in biochemical remission and those not in remission.. A systematic literature search was conducted using PubMed, Scopus, the Cochrane Library, and Google Scholar for keywords related to TM and AIH. Two reviewers independently searched and selected studies comparing the levels of 6-methyl mercaptopurine (6-MMP) and 6-thioguanine nucleotide (6-TGN) and their ratio in cases of AIH in remission and otherwise. Meta-analysis was performed by calculating the weighted mean difference using the inverse variance heterogeneity model.. A total of 1066 records were identified through systematic search; of which, 7 (n = 3 pediatric, n = 4 adults) were considered for inclusion, and 442 TM measurements (n = 128 in children) were analyzed. Mean 6-TGN levels were significantly higher among patients in remission than in those who were not, with a pooled weighted mean difference (WMD) of 15.67 [95% confidence interval (CI), 6.68-24.66] pmol/8 × 108 red blood cells (RBC). The difference was higher in the pediatric age group (WMD, 56.11; 95% CI, 13.60-98.62) than in adults (WMD, 13.77; 95% CI, 4.58-22.97). There was no significant difference in the 6-MMP levels (WMD, -431.7; 95% CI, -1237.4 to 373.9 pmol/8 × 108 RBC; I2 = 82%; n = 3 studies) or 6-MMP/6-TGN ratio among the patients who were in biochemical remission and those who were not (WMD, -0.97; 95% CI, -5.77 to 3.84; I2 = 82%; n = 3 studies).. This meta-analysis suggests a link between 6-TGN levels and biochemical remission in AIH. Further high-quality studies are required to determine the therapeutic cutoff of 6-TGN.

Topics: Adult; Azathioprine; Child; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Mercaptopurine; Thioguanine

Thiopurines in combination with glucocorticoids are used as first-line, second-line and maintenance therapies in autoimmune hepatitis and opportunities exist to improve and expand their use.. To describe the metabolic pathways and key factors implicated in the efficacy and toxicity of the thiopurine drugs and to indicate the opportunities to improve outcomes by monitoring and manipulating metabolic pathways, individualising dosage and strengthening the response.. English abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed.. Thiopurine methyltransferase activity and 6-tioguanine (6-thioguanine) nucleotide levels influence drug efficacy and safety, and they can be manipulated to improve treatment response and prevent myelosuppression. Methylated thiopurine metabolites are associated with hepatotoxicity, drug intolerance and nonresponse and their production can be reduced or bypassed. Universal pre-treatment assessment of thiopurine methyltransferase activity and individualisation of dosage to manipulate metabolite thresholds could improve outcomes. Early detection of thiopurine resistance by metabolite testing, accurate estimations of drug onset and strength by surrogate markers and adjunctive use of allopurinol could improve the management of refractory disease. Dose-restricted tioguanine (thioguanine) could expand treatment options by reducing methylated metabolites, increasing the bioavailability of 6-tioguanine nucleotides and ameliorating thiopurine intolerance or resistance.. The efficacy and safety of thiopurines in autoimmune hepatitis can be improved by investigational efforts that establish monitoring strategies that allow individualisation of dosage and prediction of outcome, increase bioavailability of the active metabolites and demonstrate superiority to alternative agents.

Topics: Allopurinol; Azathioprine; Drug-Related Side Effects and Adverse Reactions; Guanine Nucleotides; Hepatitis, Autoimmune; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Purines; Quality Improvement; Thioguanine; Thionucleotides; Treatment Outcome

Autoimmune hepatitis is a rare and chronic liver disease that is characterised by increased serum transaminases and immunoglobulin G, inflammatory liver histology and presence of circulating autoantibodies. An autoimmune hepatitis diagnosis justifies life-long treatment in most patients in order to prevent development of cirrhosis and end-stage liver disease. The cornerstone of treatment is steroid induction therapy followed by maintenance therapy with azathioprine, which is effective in most cases. For patients who do not respond to standard treatment, second-line treatment with other immunosuppressants can be effective. Treatment should be aimed at biochemical remission of the disease, which is defined as normalization of transaminases and immunoglobulin G. Patients should be monitored intensively during the first months of treatment in order to monitor side-effects, assess symptoms and individualise treatment. Specialist consultation should be sought in difficult-to-treat patients. Future studies and networking initiatives should result in optimization of current treatment strategies in autoimmune hepatitis.

Topics: Alanine Transaminase; Aspartate Aminotransferases; Autoantibodies; Azathioprine; Disease Progression; Glucocorticoids; Hepatitis, Autoimmune; Humans; Immunoglobulin G; Immunosuppressive Agents; Induction Chemotherapy; Maintenance Chemotherapy; Mercaptopurine; Mycophenolic Acid; Prednisolone

Topics: Anti-Inflammatory Agents; Antimetabolites; Azathioprine; Calcineurin Inhibitors; Cyclophosphamide; Cyclosporine; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Mercaptopurine; Methotrexate; Mycophenolic Acid; Recurrence; Remission Induction; Risk Factors; Steroids; Tacrolimus; Treatment Outcome

Azathioprine (AZA) and mercaptopurine (MP) are the cornerstone of steroid-sparing strategies in autoimmune hepatitis (AIH). Up to 20% of patients do not tolerate or respond to these regimens.. To evaluate retrospectively the tolerability and efficacy of tioguanine (thioguanine) (TG) therapy in selected patients with AIH and AIH variant syndromes.. Records of 52 patients who received TG therapy were retrieved from nine hospitals in the Netherlands. Indications for TG treatment were intolerable side effects on AZA or MP (n = 38), insufficient response (n = 11) or first-line treatment (n = 3). Treatment efficacy was defined as normalisation of serum aminotransferases and serum immunoglobulin G.. No serious adverse events occurred in patients treated with TG during a median follow-up of 18 months (range 1-194). Treatment was well tolerated in 41 patients (79%), whereas four had tolerable (8%) and seven (13%) intolerable side effects. Thirty-eight patients were treated with TG after intolerable side effects on AZA or MP; 29 patients continued TG therapy of whom 24 (83%) achieved complete biochemical remission, four (14%) had incomplete and one (3%) had no response; nine discontinued treatment. Seven of 11 patients with insufficient response to AZA or MP were responsive to TG, three with complete and four with incomplete biochemical remission; four discontinued due to intolerance (n = 2) and non-response (n = 2). TG was effective in all AIH patients as first-line maintenance treatment.. In our retrospective review of TG therapy in selected patients with AIH or AIH variants who previously failed on AZA or MP, TG appeared tolerable with biochemical efficacy.

Topics: Adolescent; Adult; Aged; Azathioprine; Biomarkers; Child; Drug-Related Side Effects and Adverse Reactions; Female; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Male; Mercaptopurine; Middle Aged; Netherlands; Remission Induction; Retrospective Studies; Thioguanine; Treatment Outcome; Young Adult

Azathioprine (AZA) is the mainstay of maintenance therapy in pediatric autoimmune hepatitis (AIH). The use of thiopurines metabolites to individualize therapy and avoid toxicity has not, however, been clearly defined.. Retrospective analysis of children ≤18 years diagnosed with AIH between January 2001 and 2016. Standard definitions were used for treatment response and disease flare. Thiopurine metabolite levels were correlated with the corresponding liver function test.. A total of 56 children (32 girls) were diagnosed with AIH at a median age of 11 years (interquartile range [IQR] 9). No difference in 6-thioguanine-nucleotide (6-TG) levels (271[IQR 251] pmol/8 × 10 red blood cell vs 224 [IQR 147] pmol/8 × 10 red blood cell, P = 0.06) was observed in children in remission when compared with those who were not in remission. No correlation was observed between the 6-TG and alanine aminotransferase levels (r = -0.179, P = 0.109) or between 6-methyl-mercaptopurine (6-MMP) and alanine aminotransferase levels (r = 0.139, P = 0.213). The 6-MMP/6-TG ratio was significantly lower in patients who were in remission (2[7] vs 5 (10), P = 0.04). Using a quartile analysis, we found that having a ratio of <4 was significantly associated with being in remission with OR 2.50 (95% confidence interval 1.02-6.10), P = 0.047. Use of allopurinol with low-dose AZA in 6 children with preferential 6-MMP production brought about remission in 5/6 (83.3%).. Thiopurine metabolite levels should be measured in patients with AIH who have experienced a loss of remission. A 6-MMP/6-TG ratio of <4 with the addition of allopurinol could be considered in these patients.

Topics: Allopurinol; Antimetabolites; Azathioprine; Child; Female; Guanine Nucleotides; Hepatitis, Autoimmune; Humans; Liver Function Tests; Maintenance Chemotherapy; Male; Mercaptopurine; Retrospective Studies; Thionucleotides; Treatment Outcome

Autoimmune hepatitis (AIH) is an immune-mediated liver disease, which requires long-term immunosuppression. Ten to fifteen percent of patients experience insufficient/intolerance response to standard therapy. Although alternate immunosuppression has been applied, there is little long-term data reported on safety, efficacy, steroid-dose reduction and disease evolution in patients with difficult AIH who were on Tacrolimus therapy.. Clinical, biochemical, immunological profiles, treatment response and side effects of 17 AIH patients treated with Tacrolimus between 2003 and 2014 were analyzed from two tertiary referral liver centers.. Tacrolimus was started on 16/17 (94%) patients due to insufficient response to standard therapy. The median duration of treatment was 24 months and patients were followed up for median of 60 months. Tacrolimus dosage was 2 mg/day (median). During first year of therapy, there was a significant improvement in immunoglobulin G and Aspartate transaminase level. 9/17 (52%) compliant and definite AIH patients remained on Tacrolimus at end of follow-up and prednisolone dose reduction was achieved from 10 to 5 mg. All patients are alive and one patient underwent liver transplantation. 4/17 (24%) patients developed overlap with primary sclerosing cholangitis over follow-up period. No significant side effects were observed with Tacrolimus therapy.. Tacrolimus could be used in compliant patients with difficult to treat AIH in experienced centers. Its use is safe and can improve liver biochemistry, IgG and reduce steroid requirement. However, due to the lack of immunomodulatory effect, unmet need for effective immune-regulatory therapies still remain for AIH patients.

Topics: Adolescent; Adult; Aged; Anti-Inflammatory Agents; Aspartate Aminotransferases; Azathioprine; Cholangitis, Sclerosing; Cyclosporine; Female; Follow-Up Studies; Hepatitis, Autoimmune; Humans; Immunoglobulin G; Immunosuppressive Agents; Male; Mercaptopurine; Middle Aged; Mycophenolic Acid; Prednisolone; Retreatment; Tacrolimus; Time Factors; Treatment Outcome; Young Adult

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease that requires long-term immunosuppressive therapy. Although most patients have an excellent response to standard therapy (azathioprine in combination with corticosteroids), approximately 10%-15% have intolerance or an insufficient response to azathioprine treatment. We investigated whether 6-mercaptopurine (6-MP) is an effective second-line therapy for patients with AIH.. We performed a retrospective study of 22 patients with AIH who were switched to 6-MP therapy after treatment with the combination of azathioprine and prednisolone at 2 tertiary care institutions in Europe (Germany and the United Kingdom) before November 15, 2014. We performed statistical analyses of data on clinical and biochemical responses collected 4 weeks after 6-MP treatment and then at regular physician visits.. A total of 15 of 20 patients with prior azathioprine intolerance (75%) responded to 6-MP treatment; 8 of these patients had a complete response and 7 had partial remission, based on biochemical features. In these 15 patients, 6-MP was well tolerated, whereas the 5 remaining patients had to be switched to different immunosuppressive regimes because of 6-MP intolerance. The 2 patients with insufficient response to azathioprine treatment also showed no response to 6-MP.. In patients with AIH and azathioprine intolerance, 6-MP seems to be an effective and well-tolerated second-line treatment. 6-MP might be ineffective in patients with insufficient response to azathioprine.

Topics: Adult; Aged; Aged, 80 and over; Female; Germany; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Male; Mercaptopurine; Middle Aged; Retrospective Studies; Tertiary Care Centers; Treatment Outcome; United Kingdom; Young Adult

Therapy for autoimmune hepatitis has been prednisone based for decades; however, budesonide may be equally effective with fewer side effects. Our aim was to evaluate quality-adjusted life years and health care costs of three different treatment regimens.. Treatment using prednisone, budesonide or a combination of both over a three-year period in newly diagnosed children with type I autoimmune hepatitis were simulated with a Markov model. Transition probabilities were calculated over consecutive three-month period. Costs were determined from a hospital database and health utilities were estimated from the literature. A Monte Carlo probabilistic sensitivity analysis was used to simulate the outcomes of 5000 patients in each treatment arm.. Compared to standard therapy, budesonide leads to a gain of 0.09 quality-adjusted life years, costing $17,722 per QALY over a three-year period. Standard therapy led to significantly lower QALY's compared to other strategies (p < 0.001). Health utilities of patients in remission in each treatment group had the greatest impact on the model. Budesonide remained the treatment of choice if the probability of inducing remission was 55% or greater.. Budesonide therapy in non-cirrhotic, treatment naïve patients with type I autoimmune hepatitis yielded greater QALY's compared to the current standard therapy with an acceptable increase in costs.

Topics: Adolescent; Anti-Inflammatory Agents; Budesonide; Child; Child, Preschool; Decision Support Techniques; Drug Administration Schedule; Drug Therapy, Combination; Follow-Up Studies; Health Care Costs; Hepatitis, Autoimmune; Humans; Illinois; Markov Chains; Mercaptopurine; Monte Carlo Method; Prednisone; Quality-Adjusted Life Years; Treatment Outcome

Topics: Azathioprine; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Mercaptopurine

Preferential conversion of azathioprine or 6-mercaptopurine into methylated metabolites is a major cause of thiopurine resistance. To seek potentially Mendelian causes of thiopurine hypermethylation, we recruited 12 individuals who exhibited extreme therapeutic resistance while taking azathioprine or 6-mercaptopurine and performed whole-exome sequencing (WES) and copy-number variant analysis by array-based comparative genomic hybridisation (aCGH). Exome-wide variant filtering highlighted four genes potentially associated with thiopurine metabolism (ENOSF1 and NFS1), transport (SLC17A4) or therapeutic action (RCC2). However, variants of each gene were found only in two or three patients, and it is unclear whether these genes could influence thiopurine hypermethylation. Analysis by aCGH did not identify any unusual or pathogenic copy-number variants. This suggests that if causative mutations for the hypermethylation phenotype exist they may be heterogeneous, occurring in several different genes, or they may lie within regulatory regions not captured by WES. Alternatively, hypermethylation may arise from the involvement of multiple genes with small effects. To test this hypothesis would require recruitment of large patient samples and application of genome-wide association studies.

Topics: Adult; Azathioprine; Colitis, Ulcerative; Comparative Genomic Hybridization; Crohn Disease; DNA Copy Number Variations; Drug Resistance; Exome; Female; Genome-Wide Association Study; Hepatitis, Autoimmune; High-Throughput Nucleotide Sequencing; Humans; Male; Mercaptopurine; Metabolic Networks and Pathways; Methyltransferases; Middle Aged; Mutation

Topics: Allopurinol; Antimetabolites; Female; Hepatitis, Autoimmune; Humans; Male; Mercaptopurine

Topics: Allopurinol; Antimetabolites; Female; Hepatitis, Autoimmune; Humans; Male; Mercaptopurine

Ten percent of patients with autoimmune hepatitis (AIH) are nonresponsive or intolerant to thiopurine therapy. A skewed metabolism, leading to the preferential generation of (hepato)toxic thiopurine metabolites (6-MMPs) instead of the metabolic active 6-tioguanine (thioguanine) nucleotides (6-TGNs), may explain this unfavourable outcome. Co-administration of allopurinol to low-dose thiopurine therapy may effectively revert this deviant metabolism, as has been shown in inflammatory bowel disease.. To describe the effect of adding allopurinol to low-dose thiopurine therapy in patients with AIH with intolerance or nonresponse to normal thiopurine dosages due to a skewed metabolism.. We describe the clinical efficacy and tolerability of allopurinol-thiopurine combination therapy with allopurinol 100 mg and low-dose thiopurine (25-33% of the original dosage) in eight AIH patients with a skewed thiopurine metabolism. Patients were switched because of dose-limiting intolerance (n = 3), nonresponse (n = 3) or loss of response (n = 2) to conventional thiopurine treatment.. All eight patients showed biochemical improvement with a reduction in median alanine aminotransferase (ALT) levels of 62 U/L at start to 35 U/L at 1 month (P = 0.03). This clinical benefit was sustained in seven patients. Allopurinol-thiopurine combination therapy effectively bypassed thiopurine side effects in four of five patients. Median 6-tioguanine nucleotides levels increased from 100 to 200 pmol/8 × 10(8) red blood cells (RBC) at 3 months (P = 0.04). Median 6-MMP levels decreased in all patients from 6090 to 175 pmol/8 × 10(8) RBC (P = 0.01).. Allopurinol safely and effectively optimises thiopurine therapy in patients with autoimmune hepatitis with intolerance and/or nonresponse due to an unfavourable thiopurine metabolism.

Topics: Adult; Aged; Alanine Transaminase; Allopurinol; Antimetabolites; Drug Interactions; Drug Therapy, Combination; Female; Hepatitis, Autoimmune; Humans; Male; Mercaptopurine; Methyltransferases; Middle Aged; Salvage Therapy; Thioguanine

In autoimmune hepatitis (AIH) patients treated with azathioprine, the utility of measuring thiopurine methyltransferase (TPMT) and azathioprine metabolites has been limited.. To evaluate the association between TPMT genotype and enzyme activity, and the impact of TPMT enzyme activity on levels of azathioprine metabolites and leukopenia to assess the clinical utility of monitoring azathioprine metabolites in Alaska Native and other non-Caucasian AIH patients.. Individuals with AIH were recruited at the Alaska Native Medical Center (Alaska, USA) and the University of Texas Southwestern Medical Center (Texas, USA). Identification of TPMT genotype and measurement of enzyme activity were performed. The metabolites 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP) were measured in participants who were on azathioprine, and the associations with disease remission and leukopenia were assessed.. Seventy-one patients with AIH were included. The distribution of TPMT genotypes was similar to that reported in other populationbased studies. TPMT genotype and phenotype were strongly associated (P<0.0001). Levels of 6-TGN and 6-MMP correlated with azathioprine dose only in individuals with normal TPMT enzyme activity. Patients with leukopenia due to azathioprine were no more likely to have abnormal TPMT enzyme levels than those without leukopenia (P=1.0). No specific level of 6-TGN metabolites was associated with remission or leukopenia.. Results of the present study were consistent with previous studies in Caucasian populations. TPMT genotype and phenotype correlated well, and levels of 6-TGN and 6-MMP metabolites were not associated with remission of AIH or toxicity of azathioprine.. The present study confirmed the limited utility of monitoring levels of azathioprine metabolites in AIH patients.

Topics: Adult; Alaska; Azathioprine; Biomarkers; Female; Genetic Association Studies; Hepatitis, Autoimmune; Humans; Indians, North American; Male; Mercaptopurine; Methyltransferases; Middle Aged

Azathioprine is commonly used in the treatment of autoimmune hepatitis (AIH). Few data are available on drug monitoring of azathioprine metabolites in patients with AIH, especially in pediatric patients. The purpose of this study was to investigate intracellular thiopurine metabolites in children with AIH and to assess the relevance of drug monitoring compared with the efficacy and toxicity. Data from 28 patients with AIH treated by azathioprine for at least 3 months were recorded. 6-Thioguanine nucleotides (6-TGN) and 6-methyl mercaptopurine nucleotides (6-MeMPN) concentrations and TPMT activity were determined by high-performance liquid chromatography. Blood cell counts and liver function tests were also collected and the clinical outcome was documented. A wide interindividual variability in 6-TGN and 6-MeMPN concentrations was observed with values ranging from 51 to 1966 pmol/8 x 10(8) red blood cells (RBCs) for 6-TGN and from 42 to 8189 pmol/8 x 10(8) RBCs for 6-MeMPN. A total of 61.4% of the patients achieved remission and only 32.6% of these children had 6-TGN values within the target range proposed for inflammatory bowel disease (250-450 pmol/8 x 10(8) red blood cells). No difference in metabolite concentrations was observed between children in remission and those with active disease. Azathioprine dosage was significantly related to 6-TGN and 6-MeMPN levels (r = 0.308, P < 0.001 and r = 0.405, P < 0.001, respectively). A significant negative correlation was observed between 6-TGN concentrations and erythrocyte and lymphocyte counts, whereas 6-MeMPN was not related to blood cell counts. Although leukocyte counts were not related to 6-TGN concentrations, patients with leucopenia exhibited higher 6-TGN values than those without leucopenia (median values 438 pmol/8 x 10(8) RBCs versus 405 pmol/8 x 10(8) RBCs, respectively). Thiopurine metabolite monitoring appears useful in identifying the myelotoxicity and the hepatotoxicity as a result of azathioprine with disease recurrence and to assess adherence to therapy. A further larger study will be required to confirm the optimal recommended target for thiopurine metabolites to achieve remission in patients with AIH.

Topics: Adolescent; Adrenal Cortex Hormones; Anti-Inflammatory Agents; Azathioprine; Biotransformation; Blood Cell Count; Child; Child, Preschool; Chromatography, High Pressure Liquid; Drug Monitoring; Drug Therapy, Combination; Female; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Liver Function Tests; Male; Mercaptopurine; Thioguanine

Topics: Allopurinol; Antimetabolites; Child; Cholangitis, Sclerosing; Female; Follow-Up Studies; Hepatitis, Autoimmune; Humans; Male; Mercaptopurine; Salvage Therapy; Transaminases

Azathioprine is a thiopurine immunosuppressive antimetabolite used to chronically treat inflammatory bowel disease and autoimmune hepatitis. Azathioprine treatment is a long-term therapy and therefore it is at risk for non-adherence, which is considered an important determinant of treatment inefficacy. Measurement of 6-thioguanine and 6-methylmercaptopurine nucleotides has been recently suggested as a screener for non-adherence detection. We describe four young patients in which non-adherence to azathioprine therapy was detected only through the measurement of drug metabolite concentrations, and the criterion for non-adherence was undetectable metabolite levels. After the identification of non-adherence, patients and their families were approached and the importance of a correct drug administration was thoroughly enlightened and discussed; this allowed obtaining a full remission in all subjects. Our observations support the use of undetectable metabolite levels as indicators of non-adherence to therapy in azathioprine treated patients. The additional level of medical supervision given by this assay allows getting a better adherence to medical treatment, which results in an improvement in the response to therapy; these benefits may justify the costs associated with the assay.

Topics: Adolescent; Azathioprine; Child; Child, Preschool; Female; Guanine Nucleotides; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Male; Medication Adherence; Mercaptopurine; Thionucleotides; Young Adult

Individualised doses of azathioprine (AZA) may be prescribed by monitoring the levels of the enzyme thiopurine methyltransferase (TPMT). The measurements of thiopurine metabolites of AZA, 6-thioguanine (6-TGN) and 6-methylmercaptopurine (6-MMP), have also been reported as new markers of AZA activity.. To describe TPMT phenotype in our population and to establish a relationship between thiopurine metabolites,and therapeutic activity and adverse effects.. Data on TPMT were retrospectively collected from 107 patients, and 6-TGN and 6-MMP levels in 18 patients currently on treatment with AZA (Crohn's disease 5, ulcerative colitis 5, autoimmune hepatitis 5).. Mean value of TPMT was 20.19U/ml. None of the patients had a TPMT activity<5U/ml. Of the 18 patients on treatment, 13 showed sub-therapeutic levels of 6-TGN (<235pmol/8x10(8) red blood cells). Clinical remission was maintained in 45% of patients. Mean levels of 6-TGN in patients with clinical remission were 259pmol/8x10(8) red blood cells versus 209pmol/8x10(8) red blood cells in non-responders (p=0.37). There was an inverse relationship (r=-0.28) between TPMT and 6-TGN levels. Toxic effects occurred in 6 of 18 patients, with leukopenia in 5 and hyperamylasemia in 1.. Determination of TPMT and monitoring of thiopurine metabolites allows AZA treatment to be optimised, although further studies are necessary to establish therapeutic effectiveness and toxicity ranges.

Topics: Adolescent; Azathioprine; Female; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Male; Mercaptopurine; Methyltransferases; Retrospective Studies; Thioguanine

Topics: Child; Endoscopy, Digestive System; Female; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Liver Cirrhosis; Mercaptopurine; Prednisone; Remission Induction; Ultrasonography

Azathioprine is a key drug in the management of autoimmune hepatitis (AIH), with effects mediated via conversion to 6-thioguanine (6-TG) and 6-methylmercaptopurine (6-MMP), the latter controlled by thiopurine methyltransferase (TPMT). Our aims were to evaluate the role of TPMT genotyping and phenotyping and to examine 6-TG and 6-MMP metabolite levels in patients with AIH.. TPMT genotyping and phenotyping was performed on 86 patients with AIH, and metabolites evaluated in assessable patients.. Eighty-six patients with AIH received azathioprine; 22 developed toxicity and 4/22 were heterozygous for TPMT alleles. Cirrhosis was more common amongst patients who developed toxicity (12/22 (54.5%) versus 19/64 (29.6%), P=0.043). Patients who required persistent prednisone at equivalent azathioprine doses had a higher mean fibrosis stage (P=0.044). TPMT activity, but not metabolites, was lower in patients with stage III/IV fibrosis versus stage I/II fibrosis (30+/-1.92 versus 35.2+/-1.93, P=0.044). Azathioprine dose significantly correlated with measured 6-TG levels (r=0.409, P<0.0001) and 6-MMP levels (r=0.387, P<0.001).. Advanced fibrosis but not TPMT genotype or activity predicts azathioprine toxicity in AIH. Overlap in 6-TG and 6-MMP metabolite levels is noted whether or not steroid therapy is used to maintain remission.

Topics: Adolescent; Adult; Aged; Anti-Inflammatory Agents; Azathioprine; Drug Monitoring; Female; Genotype; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Liver; Liver Cirrhosis; Male; Mercaptopurine; Methyltransferases; Middle Aged; Phenotype; Prednisone; Thioguanine

Thiopurine drugs are commonly used immunosuppressants in the treatment of inflammatory bowel disease (IBD) as well as in autoimmune hepatitis (AIH), rheumatic diseases and in transplantation medicine. The relatively narrow therapeutic range requires useful therapy control. Therefore, the purpose of this study was to further investigate the rationale and usefulness of therapeutic drug monitoring in the surveillance of thiopurine drug therapy in Crohn's disease, ulcerative colitis and autoimmune hepatitis.. 6-Thioguanine nucleotide (TGN) and 6-methylmercaptopurine nucleotide (MMPN) levels were measured in 182 IBD patients and 18 AIH patients using HPLC-UV.. In our cohort of IBD patients, 18% had TGN levels < 235 pmol/8 x 10 red blood cells (RBC) (recommended range, 235-450 pmol/8 x 10 RBC), 41% of these patients were sent for drug failure. Twenty-four per cent of the IBD patients had TGN levels > 450 pmol/8 x 10 RBC, but only 27% of these experienced adverse effects. Fifty-nine per cent of the patients having drug failure had TGN levels in the recommended range and could therefore be classified as non-responders. In the AIH cohort 33% of the patients had TGN levels below the recommended range but showed clinical response to therapy. MMPN levels increased with the duration of treatment and could be useful for controlling compliance. There was 8.8% of IBD patients who were heterozygous for non-functional TPMT alleles.. TGN monitoring did not identify significant differences between patient groups but allowed the identification of non-responders from non-compliant patients and allowed the differentiation of mild side effects, such as malaise, from genuine toxicity caused by highly increased TGN levels.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Chromatography, High Pressure Liquid; Cohort Studies; Colitis, Ulcerative; Crohn Disease; Drug Monitoring; Female; Guanine Nucleotides; Hepatitis, Autoimmune; Heterozygote; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Male; Mercaptopurine; Middle Aged; Purines; Thioguanine; Thionucleotides