Thiopurines are an important therapy for the maintenance of remission in inflammatory bowel disease (IBD). However, the use of thioguanine has been limited by concerns regarding its toxicity. We performed a systematic review to evaluate its effectiveness and safety in IBD.
Electronic databases were searched to identify studies reporting clinical responses and/or adverse events of thioguanine therapy in IBD. We calculated the pooled clinical response and clinical remission rates of thioguanine in IBD. Subgroup analyses were done for the dosage of thioguanine and the type of studies (prospective or retrospective). Meta-Regression was used to analyze the impact of dose on clinical efficacy and occurrence of nodular regenerative hyperplasia.
A total of 32 studies were included. The pooled clinical response rate of thioguanine therapy in IBD was 0.66 (95% C.I. 0.62 - 0.70; I2 = 16%). The pooled clinical response rate with low-dose was similar to high-dose thioguanine therapy [0.65 (95% C.I. 0.59 - 0.70; I2 = 24%) and 0.68 (95% C.I. 0.61 - 0.75; I2 = 18%) respectively]. The pooled remission maintenance rate was 0.71 (95% C.I. 0.58 - 0.81; I2 = 86%). The pooled rates of occurrence of nodular regenerative hyperplasia, liver function tests abnormalities and cytopenia were 0.04 (95% C.I. 0.02 - 0.08; I2 = 75%), 0.11 (95% C.I. 0.08 - 0.16; I2 = 72%) and 0.06 (95% C.I. 0.04 - 0.09; I2 = 62%) respectively. Meta-regression suggested that the risk of nodular regenerative hyperplasia is related to the dose of thioguanine.
TG is an efficacious and well-tolerated drug in most patients with IBD. Nodular regenerative hyperplasia, cytopenias, and liver function abnormalities occur in a small subset. Future studies should look into TG as primary therapy in IBD.

Inosine monophosphate dehydrogenase (IMPDH) is a crucial enzyme involved in the de novo synthesis of purine nucleotides. IMPDH activity is used to evaluate the pharmacodynamics/pharmacokinetics of immunosuppressant drugs such as mycophenolic acid and thiopurines. These drugs are often used to prevent organ transplant rejection and as steroid-sparing agents in autoinflammatory diseases such as inflammatory bowel disease and rheumatoid arthritis. Numerous analytical techniques have been employed to evaluate IMPDH activity in biological matrices. However, hyphenated LC techniques were most widely used in the literature. This review focuses on hyphenated LC methods used to measure IMPDH activity and provides detailed insight into the sample preparation techniques, chromatographic conditions, enzymatic assay conditions, detectors and normalization factors employed in those methods.

There is an increasing trend of malignancy worldwide. Disease-modifying antirheumatic drugs (DMARDs) are the cornerstones for the treatment of immune-mediated inflammatory diseases (IMIDs), but risk of malignancy is a major concern for patients receiving DMARDs. In addition, many IMIDs already carry higher background risks of neoplasms. Recently, the black box warning of malignancies has been added for Janus kinase inhibitors. Also, the use of biologic DMARDs in patients with established malignancies is usually discouraged owing to exclusion of such patients in pivotal studies and, hence, lack of evidence. In contrast, some conventional synthetic DMARDs (csDMARDs) have been reported to show antineoplastic properties and can be beneficial for patients with cancer. Among the csDMARDs, chloroquine and hydroxychloroquine have been the most extensively studied, and methotrexate is an established chemotherapeutic agent. Even cyclosporine A, a well-known drug associated with cancer risk, can potentiate the effect of some chemotherapeutic agents. We review the possible mechanisms behind and clinical evidence of the antineoplastic activities of csDMARDs, including chloroquine and hydroxychloroquine, cyclosporine, leflunomide, mycophenolate mofetil, mycophenolic acid, methotrexate, sulfasalazine, and thiopurines. This knowledge may guide physicians in the choice of csDMARDs for patients with concurrent IMIDs and malignancies.

During the 3rd congress of the European Society of Pharmacogenomics and Personalised Therapy (ESPT) in Budapest in 2015, a preliminary meeting was held aimed at establishing a pediatric individualized treatment in oncology and hematology committees. The main purpose was to facilitate the transfer and harmonization of pharmacogenetic testing from research into clinics, to bring together basic and translational research and to educate health professionals throughout Europe. The objective of this review was to provide the attendees of the meeting as well as the larger scientific community an insight into the compiled evidence regarding current pharmacogenomics knowledge in pediatric oncology. This preliminary evaluation will help steer the committee\'s work and should give the reader an idea at which stage researchers and clinicians are, in terms of personalizing medicine for children with cancer. From the evidence presented here, future recommendations to achieve this goal will also be suggested.

The effectiveness of the tumor necrosis-α (TNF-α) blockade has changed the treatment of several chronic inflammatory diseases, including inflammatory bowel disease; however, this treatment also has disadvantages. The use of immunosuppressants in combination with infliximab has been associated with greater risk of developing malignant neoplasms. Herein, we report the case of a 33-year-old ethnic Korean man with Crohn disease (CD) who developed papillary thyroid carcinoma (PTC) and, subsequently, T-cell acute lymphoblastic leukemia (ALL) after approximately 16.0 years of immunosuppressant therapy and 5.5 years of infliximab therapy. To our knowledge, this is the first case described in the literature of 2 different malignant neoplasms, 1 of hematologic origin and the other involving the solid organs, in a patient with CD. Through a systematic literature review, we found 28 cases of acute leukemia in adult patients with CD, of whom 22 had myeloid leukemia and 6 had lymphoid leukemia. Half of the patients with ALL underwent TNF-α-blocker therapy in combination with thiopurines.

OBJECTIVE: Combination therapy with infliximab and azathioprine has been shown to be superior to either treatment alone in Crohn\'s disease (CD). However, the benefit of combining adalimumab with an immunomodulator remains controversial. The aim of this study was to compare the efficacy of adalimumab monotherapy with combination therapy for induction and maintenance of response and remission in CD using a meta-analysis of the current literature.
METHODS: We performed a systematic literature search using Medline, Embase, Cochrane and several other databases. Prospective randomized controlled trials, retrospective cohort and case-controlled studies were included. The primary outcomes included induction of response and remission (up to week 12), maintenance of clinical response and remission (1 year) and the need for dose escalation. Several subgroup and sensitivity analyses were performed.
RESULTS: Eighteen out of 2743 retrieved studies were included. A meta-analysis of 7 studies assessing induction of remission (n=1984) showed that ADA monotherapy was inferior to combination therapy [OR=0.78 (0.64-0.96), p=0.02]. A meta-analysis of 4 studies revealed that combination therapy was not statistically different from ADA for maintenance of remission [OR=1.08 (0.79-1.48), p=0.48]. Combination therapy was also not different from ADA monotherapy in terms of requirement for dose escalation [OR=1.13 (0.69-1.85), p=0.62].
CONCLUSIONS: Combination therapy with ADA and immunomodulator was mildly superior to ADA monotherapy for induction of remission in CD. The rate of remission at 1 year and the need for dose escalation were similar in both groups. These findings should be interpreted with caution in view of possible confounders and should be further validated by randomized controlled trials.

OBJECTIVE: The aim was to systematically review the evidence on the clinical usefulness of thiopurine metabolite and white blood count (WBC) monitoring in the assessment of clinical outcomes in children with inflammatory bowel disease (IBD).
METHODS: Medline, Embase, Cochrane Central Register of controlled trials and http://www.clinicaltrials.gov were screened in adherence to the PRISMA statement by two independent reviewers for identification of eligible studies. Eligible studies were randomized controlled trials (RCTs), cohort studies and large case series of children with inflammatory bowel disease (IBD) (<18 years) who underwent monitoring of thiopurine metabolites and/or WBC.
RESULTS: Fifteen papers were identified (n = 1026). None of the eligible studies were RCTs. High 6-thioguanine nucleotide (6TGN) concentrations were not consistently associated with leucopenia. Leucopenia was not associated with achievement of clinical remission. A positive but not consistent correlation between 6TGN and clinical remission was reported. Haematological toxicity could not be reliably assessed with 6TGN measurements only. A number of studies supported the use of high 6-methylmercaptopurine ribonucleotides (6MMPR) as an indicator of hepatotoxicity. Low thiopurine metabolite concentration may be indicative of non-compliance.
CONCLUSIONS: Thiopurine metabolite testing does not safely predict clinical outcome, but may facilitate toxicity surveillance and treatment optimization in poor responders. Current evidence favours the combination of thiopurine metabolite/WBC monitoring and clinic follow-up for prompt identification of haematologic/hepatic toxicity safe dose adjustment, and treatment modification in cases of suboptimal clinical outcome or non-compliance. Well designed RCTs for the identification of robust surrogate markers of thiopurine efficacy and toxicity are required.