Commensal bacteria promote azathioprine therapy failure in inflammatory bowel disease via decreasing 6-mercaptopurine bioavailability.

Azathioprine (AZA) therapy failure, though not the primary cause, contributes to disease relapse and progression in inflammatory bowel disease (IBD). However, the role of gut microbiota in AZA therapy failure remains poorly understood. We found a high prevalence of Blautia wexlerae in patients with IBD with AZA therapy failure, associated with shorter disease flare survival time. Colonization of B. wexlerae increased inflammatory macrophages and compromised AZA's therapeutic efficacy in mice with intestinal colitis. B. wexlerae colonization reduced 6-mercaptopurine (6-MP) bioavailability by enhancing selenium-dependent xanthine dehydrogenase (sd-XDH) activity. The enzyme sd-XDH converts 6-MP into its inactive metabolite, 6-thioxanthine (6-TX), thereby impairing its ability to inhibit inflammation in mice. Supplementation with Bacillus (B.) subtilis enriched in hypoxanthine phosphoribosyltransferase (HPRT) effectively mitigated B. wexlerae-induced AZA treatment failure in mice with intestinal colitis. These findings emphasize the need for tailored management strategies based on B. wexlerae levels in patients with IBD.

Impact of Chronotherapy on 6-Mercaptopurine Metabolites in Inflammatory Bowel Disease: A Pilot Crossover Trial.

INTRODUCTION: Chronotherapy is the timing of medication according to biological rhythms of the host to optimize drug efficacy and minimize toxicity. Efficacy and myelosuppression of azathioprine/6-mercaptopurine (AZA/6-MP) are correlated with the metabolite 6-thioguanine, while the metabolite 6-methylmercaptopurine correlates with hepatotoxicity. METHODS: This was a single-center, 10-week prospective crossover trial involving 26 participants with inactive inflammatory bowel disease (IBD) on a stable dose and time of AZA or 6-MP therapy. Participants were switched to the opposite delivery time (morning or evening) for 10 weeks, and metabolite measurements were at both time points. RESULTS: In the morning vs evening dosing, 6-thioguanine levels were 225.7 ± 155.1 vs 175.0 ± 106.9 ( P < 0.01), and 6-methylmercaptopurine levels were 825.1 ± 1,023.3 vs 2,395.3 ± 2,880.3 ( P < 0.01), with 69% (18 out of 26) of participants had better metabolite profiles in the morning. Participants with optimal dosing in the morning had an earlier chronotype by corrected midpoint of sleep. DISCUSSION: In the first study on a potential role of chronotherapy in IBD, we found (i) morning dosing of AZA or 6-MP resulted in more optimal metabolite profiles and (ii) host chronotype could help identify one-third of patients who would benefit from evening dosing. Circadian regulation of metabolic enzymes of AZA/6-MP activity in the liver is the likely cause of these differences. This pilot study confirms the need to incorporate chronotherapy in future multicenter clinical trials on IBD disease.

Temporal Changes in the Treatment Paradigm and Long-term Prognosis of Patients With Crohn's Disease: A Hospital-Based Cohort Study in China.

BACKGROUND: The temporal trends in medical treatment and long-term outcomes of patients with Crohn's disease (CD) have not been well elucidated in China over the past 2 decades. Accordingly, we aimed to evaluate the treatment paradigm and long-term clinical course of Chinese patients with CD in a hospital-based cohort. METHODS: All adult patients newly diagnosed with CD (n = 1338) between 1999 and 2019 in the Sir Run Run Shaw Hospital were included in this cohort. Medication utilization, disease outcomes, and risk factors were investigated. RESULTS: Overall, 48.7%, 35.6%, 67.8%, and 61.6% of patients used 5-aminosalicylates (5-ASA), corticosteroids, thiopurines, and infliximab (IFX), respectively. The cumulative risk of 5-ASA and corticosteroid initiation decreased during follow-up, whereas that of IFX initiation increased. Throughout a median follow-up duration of 26.4 (interquartile range, 12.0-49.2) months, a total of 486 and 300 patients underwent hospitalization and surgery, respectively. Of the 1097 patients with B1/B2 disease behavior at diagnosis, 10.3% experienced phenotype progression. The hospitalization rate decreased after 2015; however, surgery and phenotype progression rates did not significantly change. A Cox regression analysis indicated that IFX use since diagnosis was a contributing factor for lower rates of hospitalization and phenotype progression, whereas thiopurine use was associated with a lower surgery rate. CONCLUSIONS: Infliximab use was observed to increase as 5-ASA and corticosteroid use decreased. Additionally, hospitalization rates decreased following temporal changes in IFX management, yet the surgery and phenotype progression rates remained the same.

Complexation of uranyl (UO2)2+ with bidentate ligands: XRD, spectroscopic, computational, and biological studies.

Three new uranyl complexes [(UO2)(OAc)2(CMZ)], [(UO2)(OAc)2(MP)] and [(UO2)(OAc)2(SCZ)] were synthesized and characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, powder XRD analysis, and molar conductivity. The IR analysis confirmed binding to the metal ion by the sulfur and ethoxy oxygen atoms in the carbimazole (CMZ) ligand, while in the 6-mercaptopurine (MP) ligand, the sulfur and the N7 nitrogen atom of a purine coordinated binding to the metal ion. The third ligand showed a 1:1 molar ratio and bound via sulfonamide oxygen and the nitrogen of the pyrimidine ring. Analysis of the synthesized complexes also showed that acetate groups had monodentate binding to the (UO22+). Density Functional Theory (DFT) calculations at the B3LYP level showed similar structures to the experimental results. Theoretical quantum parameters predicted the reactivity of the complexes in the order, [(UO2)(OAc)2(SCZ)] > [(UO2)(OAc)2(MP)]> [(UO2)(OAc)2(CMZ)]. DNA binding studies revealed that [(UO2)(OAc)2(SCZ)] and [(UO2)(OAc)2(CMZ)] have the highest binding constant (Kb) among the uranyl complexes. Additionally, strong binding of the MP and CMZ metal complexes to human serum albumin (HSA) were observed by both absorbance and fluorescence approaches. The antibacterial activity of the complexes was also evaluated against four bacterial strains: two gram-negative; Escherichia coli and Klebsiella pneumonia, and two gram-positive; Staphylococcus aureus and Streptococcus mutans. [(UO2)(OAc)2(MP)] had the greatest antibacterial activity against Klebsiella pneumonia, the gram-positive bacteria, with even higher activity than the standard antibiotic. In vitro cytotoxicity tests were also performed against three human cancer lines, and revealed the most cytotoxic complexes to be [(UO2)(OAc)2(SCZ)], which showed moderate activity against a colon cancer cell line. Thus, uranyl addition enhances the antibacterial and anticancer properties of the free ligands.

[Effect of genetic polymorphism of TPMT and NUDT15 on the tolerance of 6-mercaptopurine therapy in adult acute lymphoblastic leukemia].

Objective: To investigate the effect of genetic polymorphisms of TPMT*2 rs1800462, TPMT*3B rs1800460, TPMT*3C rs1142345, and NUDT15 rs116855232 on the tolerance of 6-mercaptopurine (6-MP) therapy in adult acute lymphoblastic leukemia (ALL) . Methods: A total of 216 adult patients who were diagnosed with ALL and treated with cyclophosphamide, cytarabine, and 6-MP [complementary and alternative medicine (CAM) regimen] from September 2015 to December 2019 were included. Polymorphisms were detected by TaqMan SNP Genotyping Assay. Combined with clinical data, the influence of genetic polymorphism on the tolerance of 6-MP in the treatment of ALL was analyzed. Results: Among the 216 patients, 185 (85.65%) patients had B-ALL and 31 (14.35%) patients had T-ALL. 216 (100%) patients had CC genotype for both TPMT*2 rs1800462 and TPMT*3B rs1800460. The number of TT and TC genotypes for TPMT*3C rs1142345 was 209 (96.76%) and 7 (3.24%) , respectively. The allele frequency was 1.62% for TPMT*3C rs1142345. The number of CC, CT, and TT genotypes for NUDT15 rs116855232 was 166 (76.85%) , 48 (22.22%) , and 2 (0.93%) , respectively. The allele frequency was 12.04% for NUDT15 rs116855232. The TPMT*3C rs1142345 mutant group (TC+CC genotype) had less transfusion volume of packed red blood cell than the wild group (CC genotype) (P=0.036) , and the mutant group (TC+CC genotype) had a higher risk to develop hepatotoxicity (increased aspartate aminotransferase) than the wild group (CC genotype) (OR=9.559, 95% CI 1.135-80.475, P=0.038) . The durations of white blood cells (WBC) <1×10(9)/L and absolute neutrophil count (ANC) <0.5×10(9)/L in the NUDT15 rs116855232 mutation group (CT+TT genotype) were longer than that in the wild group (CC genotype) (P=0.005, P=0.007) , and the transfusion volume of apheresis-derived platelets in the mutant group (CT+TT type) was greater than that in the wild group (CC genotype) (P=0.014) . Conclusion: Genetic polymorphism of TMPT and NUDT15 has an effect on the tolerance of 6-MP in the treatment of adult ALL. Detecting genotypes of patients with ALL before treatment helps to optimize the dosage of 6-MP, which may help shorten the bone marrow suppression duration and reduce blood transfusion volume.

Temporal trend of disease recognition, treatment paradigm, and clinical outcomes of Crohn disease in Thailand from 2000 through 2017: Is early use of thiopurines beneficial?

The prevalence of Crohn disease (CD) is increasing in Asia, but data from Southeast Asian population are scarce.The databases of 2 university-based national tertiary referral centers located in Bangkok, Thailand, were retrospectively reviewed for adult patients diagnosed with CD during January 2000 to December 2017. Disease characteristics, diagnosis, treatment, and outcomes were described and compared between the 2000 to 2009 cohort (cohort A) and the 2010 to 2017 cohort (cohort B).One hundred eighty-two patients (mean age: 46.4 years, 50% male) with 993 patient-years of follow-up were included. Thirteen percent had a history of intestinal resection, but were not diagnosed until disease recurrence. Another 6% were diagnosed at the time of first surgery. There was no improvement in diagnostic proficiency between cohorts. Mesalamine, corticosteroids, thiopurines, and biologics were prescribed in 75.8%, 81.3%, 84.6%, and 13.7% of patients, respectively (P > .05 between cohorts). Notably, thiopurines were started earlier in cohort B. Median time to the start of thiopurines was 6.2 and 1.65 months in cohort A and B, respectively (P < .01). However, the cumulative 5-year rates of disease behavior progression (P = .43), hospitalization (P = .14), and bowel surgery (P = .29) were not significantly different between cohorts. Subgroup analysis including only patients who required thiopurines showed the early use of thiopurines to be associated with lower risk of intestinal surgery after diagnosis (hazard ratio: 0.30, 95% confidence interval: 0.11-0.85).Early disease recognition and early introduction of immunomodulators may prevent long-term complications and reduce unnecessary surgery in CD.

Thiopurine Therapy for Inflammatory Bowel Disease During Pregnancy Is Not Associated with Anemia in the Infant.

INTRODUCTION: Thiopurine exposure throughout pregnancy in patients with inflammatory bowel diseases (IBD) is common and teratogenically safe. Late consequences of in utero exposure to thiopurines and its metabolite, 6-thioguanine nucleotides (6-TGN), such as neonatal and infant anemia are still disputed. AIM: To evaluate whether 6-TGN exposure during pregnancy influences anemia in infants at 1 year of life. METHODS: A comparative observational study was performed between 2009 and 2015 at a multidisciplinary IBD clinic dedicated to pregnant women. The hemoglobin level and signs of anemia between 9 and 15 months after birth of infants born to women exposed to thiopurines throughout the entire pregnancy was compared to infants of women with no thiopurine exposure during pregnancy. RESULTS: Altogether, 34 patients, 21 in the study group and 13 in the control group, were included. The median duration of maternal thiopurine exposure prior to pregnancy was 24 months (range 12-72 months), and median dosage was 100 mg (range 50-175 mg). Maternal IBD activity, infants' iron supplementation, and iron deficiency diagnoses were similar between both groups. The infants' mean hemoglobin level (gr/dL) in the thiopurine-exposed women versus the control group was 11.48 ± 0.8 versus 11.54 ± 0.6, respectively, p = 0.81. The composite risk of any sign of infant anemia was numerically higher in the thiopurine-exposed women, 10 (47%), compared to non-exposed women, 3 (23%), p = 0.17. The mean corpuscular volume, red cell distribution width, white blood cell, and platelet counts were similar among groups. CONCLUSIONS: Thiopurine therapy during pregnancy in women with IBD is safe for long-term neonatal outcomes; still large-scale confirmatory studies are required.

Towards improved control of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is characterized by activation of both the innate and adaptive immune system in genetically susceptible individuals, resulting in chronic intestinal inflammation. The triggers that initiate and perpetuate this continuous inflammation are the subject of much speculation and research, although the central role of the intestinal microbiota is recognized, and is even a target for treatment in some circumstances. The mainstay of modern IBD treatment is suppression of the immune response towards as yet unspecified antigens, and conventional therapy includes corticosteroids, 5-aminosalicylic acid (5-ASA), thiopurines and methotrexate. Reducing activity of specific mediators has proven efficacious, including adhesion molecules, such as the gut-homing integrin α4 ß7 expressed on the surface of circulating immune cells, and cytokines, such as tumour necrosis factor α (TNF-α). This has been achieved using biologic agents including monoclonal antibodies. Recent discoveries in immunology and neuroscience have revealed that signals in the peripheral nervous system regulate inflammation, including levels of TNF-α. The understanding of the mechanisms of the neuro-immune communication involved in inflammation control in the gut is evolving, but is as yet incomplete. Clinical studies using implanted vagus nerve stimulators for treatment of IBD show encouraging results. Accordingly, the neural reflex control of inflammation is emerging as a potential therapeutic target in treatment of IBD. Here, we review current therapeutic options and neural reflex control of gut immunity in the context of intestinal inflammation.

Discovery of novel multidrug resistance protein 4 (MRP4) inhibitors as active agents reducing resistance to anticancer drug 6-Mercaptopurine (6-MP) by structure and ligand-based virtual screening.

Multidrug resistance protein 4 (MRP4/ABCC4) is an ATP-binding cassette (ABC) transporter. It is associated with multidrug resistance (MDR), which is becoming a growing challenge to the treatment of cancer and infections. In the context of several types of cancer in which MRP4 is overexpressed, MRP4 inhibition manifests striking effects against cancer progression and drug resistance. In this study, we combined ligand-based and structure-based drug design strategy, by searching the SPECS chemical library to find compounds that are most likely to bind to MRP4. Clustering analysis based on a two-dimensional fingerprint was performed to help with visual selection of potential compounds. Cell viability assays with potential inhibitors and the anticancer drug 6-MP were carried out to identify their bioactivity. As a result, 39 compounds were tested and seven of them reached inhibition above 55% with 6-MP. Then compound Cpd23 was discovered to improve HEK293/MRP4 cell sensibility to 6-MP dramatically, and low concentration Cpd23 (5 µM) achieved the equivalent effect of 50 µM MK571. The accumulation of 6-MP was determined by validated high-performance liquid chromatography methods, and pretreatment of the HEK293/MRP4 cells with 50 µM MK571 or Cpd23 resulted in significantly increased accumulation of 6-MP by approximately 1.5 times. This compound was first reported with a novel scaffold compared with previously known MRP4 inhibitors, which is a hopeful molecular tool that can be used for overcoming multidrug resistance research.

Analytical and Sample Preparation Protocol for Therapeutic Drug Monitoring of 12 Thiopurine Metabolites Related to Clinical Treatment of Inflammatory Bowel Disease.

Thiopurines (TP) represent an important therapeutic tool for the treatment of inflammatory bowel diseases (IBD) in the current situation of rising incidence and health care costs. The results of multiple clinical studies aimed at finding correlations between levels of TP metabolites and response of IBD patients to the treatment are, however, often controversial due to variability in analytical and sample preparation procedures among these studies. In this work, therefore, an updated analytical and sample preparation procedure for therapeutic drug monitoring (TDM) of TP metabolites in blood samples obtained from patients with IBD was proposed to establish a unified protocol. An advanced analytical method based on ion-exchange liquid chromatography hyphenated with tandem mass spectrometry (IEC-ESI-MS/MS) was used for the determination of the profiles of 12 individual TP metabolites in the particular steps of sample preparation procedure including blood collection, red blood cells (RBC) isolation, lysis, and storage. Favorable performance parameters of the IEC-ESI-MS/MS method (LLOQs 1⁻10 nmol/L, accuracy 95⁻105%, intra-day and inter-day precision < 10%, selectivity demonstrated via no sample matrix interferences) and acceptable stability (peak area fluctuations < 15%) of clinical samples under the proposed sample preparation conditions {(i) EDTA anticoagulant tube for the blood collection; (ii) 4 °C and 4 h between the sample collection and RBC isolation; (iii) phosphate-buffered saline for RBC washing and re-suspendation; (iv) -20 °C for RBC lysis and short-term storage; (v) 50 mmol/L phosphate buffer, pH 7.4, 10 mmol/L DTT as a stabilizing medium for TPN in RBC lysates} demonstrated the suitability of such protocol for a well-defined and reliable routine use in studies on thiopurines TDM.

Preclinical evaluation of NUDT15-guided thiopurine therapy and its effects on toxicity and antileukemic efficacy.

Thiopurines (eg, 6-mercaptopurine [MP]) are highly efficacious antileukemic agents, but they are also associated with dose-limiting toxicities. Recent studies by us and others have identified inherited NUDT15 deficiency as a novel genetic cause of thiopurine toxicity, and there is a strong rationale for NUDT15-guided dose individualization to preemptively mitigate adverse effects of these drugs. Using CRISPR-Cas9 genome editing, we established a Nudt15-/- mouse model to evaluate the effectiveness of this strategy in vivo. Across MP dosages, Nudt15-/- mice experienced severe leukopenia, rapid weight loss, earlier death resulting from toxicity, and more bone marrow hypocellularity compared with wild-type mice. Nudt15-/- mice also showed excessive accumulation of a thiopurine active metabolite (ie, DNA-incorporated thioguanine nucleotides [DNA-TG]) in an MP dose-dependent fashion, as a plausible cause of increased toxicity. MP dose reduction effectively normalized systemic exposure to DNA-TG in Nudt15-/- mice and largely eliminated Nudt15 deficiency-mediated toxicity. In 95 children with acute lymphoblastic leukemia, MP dose adjustment also directly led to alteration in DNA-TG levels, the effects of which were proportional to the degree of NUDT15 deficiency. Using leukemia-bearing mice with concordant Nudt15 genotype in leukemia and host, we also confirmed that therapeutic efficacy was preserved in Nudt15-/- mice receiving a reduced MP dose compared with Nudt15+/+ counterparts exposed to a standard dose. In conclusion, we demonstrated that NUDT15 genotype-guided MP dose individualization can preemptively mitigate toxicity without compromising therapeutic efficacy.

Cost-utility Analysis: Thiopurines Plus Endoscopy-guided Biological Step-up Therapy is the Optimal Management of Postoperative Crohn's Disease.

BACKGROUND: Postoperative recurrence of Crohn's disease is common. This study sought to assess whether the postoperative management should be based on biological therapy alone or combined with thiopurines and whether the therapy should be started immediately after surgery or guided by either endoscopic or clinical recurrence. METHODS: A Markov model was developed to estimate expected health outcomes in quality-adjusted life years (QALYs) and costs in Canadian dollars (CAD$) accrued by hypothetical patients with high recurrence risk after ileocolic resection. Eight strategies of postoperative management were evaluated. A lifetime time horizon, an annual discount rate of 5%, a societal perspective, and a cost-effectiveness threshold of 50,000 CAD$/QALY were assumed. Deterministic and probabilistic sensitivity analyses were conducted. The model was validated against randomized trials and historical cohorts. RESULTS: Three strategies dominated the others: endoscopy-guided full step-up therapy (14.80 QALYs, CAD$ 462,180), thiopurines immediately post-surgery plus endoscopy-guided biological step-up therapy (14.89 QALYs, CAD$ 464,099) and combination therapy immediately post-surgery (14.94 QALYs, CAD$ 483,685). The second strategy was the most cost-effective, assuming a cost-effectiveness threshold of 50,000 CAD$/QALY. Probabilistic sensitivity analysis showed that the second strategy has the highest probability of being the optimal alternative in all comparisons at cost-effectiveness thresholds from 30,000 to 100,000 CAD$/QALY. The strategies guided only by clinical recurrence and those using biologics alone were dominated. CONCLUSIONS: According to this decision analysis, thiopurines immediately after surgery and addition of biologics guided by endoscopic recurrence is the optimal strategy of postoperative management in patients with Crohn's disease with high risk of recurrence (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B654).

Arsenic Trioxide Consolidation Allows Anthracycline Dose Reduction for Pediatric Patients With Acute Promyelocytic Leukemia: Report From the Children's Oncology Group Phase III Historically Controlled Trial AAML0631.

Purpose The Children's Oncology Group AAML0631 trial for newly diagnosed pediatric acute promyelocytic leukemia (APL) was a phase III historically controlled trial to determine the survival of patients receiving arsenic trioxide (ATO) consolidation and reduced doses of anthracyclines. Patients and Methods Patients age 2 to 21 years with de novo APL confirmed by PML-RARα polymerase chain reaction were stratified as standard risk (SR) or high risk (HR) on the basis of diagnostic WBC count. All patients received all-trans retinoic acid (ATRA) during induction, each consolidation course, and maintenance. All patients received two cycles of ATO therapy during consolidation 1, an additional two (SR) or three (HR) consolidation courses that included high-dose cytarabine and anthracycline, and maintenance therapy comprising ATRA, oral methotrexate, and mercaptopurine. Results One hundred one patients (66 SR and 35 HR) were evaluable for outcome. The 3-year overall survival was 94%, and event-free survival (EFS) was 91%. For SR and HR patients with APL, the overall survival was 98% versus 86% ( P = .003), and EFS was 95% versus 83% ( P = .03), respectively. The EFS for SR patients in AAML0631 was noninferior to that of patients in the AIDA 0493 historical control, which used a significantly higher anthracycline dose and did not include ATO consolidation. Relapse risk for patients in AAML0631 from end consolidation 1 (after ATO treatment) was only 4% at 3 years and did not differ significantly between SR and HR patients. Conclusion ATO consolidation cycles were well tolerated in pediatric patients with APL and allowed significant reduction in cumulative anthracycline doses while maintaining excellent survival and a low relapse risk for both SR and HR patients with APL.

Successful Treatment of Generalized Essential Telangiectasia With 6-Mercaptopurine.

Generalized essential telangiectasia (GET) is a notoriously difficult to treat disorder with no current satisfactory treatments. This case and discussion report the use of 6-mercaptopurine (6-MP) as a successful treatment for GET. Moreover, we show that GET may represent a state of increased angiogenesis, a paradigm shift from the current understanding that these telangiectasias represent dilatations of only pre-existing vessels. This new view of GET may drive others to look at novel agents for treatment.

J Drugs Dermatol. 2017;16(3):280-282.

Plasmonic, Targeted, and Dual Drugs-Loaded Polypeptide Composite Nanoparticles for Synergistic Cocktail Chemotherapy with Photothermal Therapy.

To integrate cocktail chemotherapy with photothermal therapy into one biocompatible and biodegradable nanocarrier, the plasmonic, lactose-targeted, and dual anticancer drugs-loaded polypeptide composite nanoparticles were for the first time fabricated under mild conditions. The glyco-PEGylated polypeptide micelles that self-assembled from the lactose (LAC) and PEG grafted polycysteine terpolymer were used as templates to generate the plasmonic composite nanoparticles, as mainly characterized by DLS, TEM, SEM, and XPS. These composite nanoparticles showed a broad and strong near-infrared (NIR) absorption at 650-1100 nm and increased the temperature of phosphate buffer solution by 30.1 °C upon a continuous-wave laser irradiation (808 nm, 5 min, 2 W·cm(-2)), while the same dose of NIR-mediated heating completely killed HepG2 cancer cells in vitro, presenting excellent photothermal properties. Two anticancer drugs, doxorubicin (DOX) and 6-mercaptopurine (6-MP), were loaded into the composite nanoparticles through physical interactions and Au-S bond, respectively. The dual drugs-loaded composite nanoparticles exhibited reduction-sensitive and NIR-triggered cocktail drugs release profiles and trigger-enhanced cytotoxicity. As evidenced by flow cytometry, fluorescence microscopy, and MTT assay, the LAC-coated composite nanoparticles were more internalized by the HepG2 than the HeLa cell line, demonstrating a LAC-targeting enhanced cytotoxicity toward HepG2. The combination cocktail chemo-photothermal therapy produced a lower half maximal inhibitory concentration than cocktail chemotherapy or photothermal therapy alone, displaying a good synergistic antitumor effect.

A purine antimetabolite attenuates toll-like receptor-2, -4, and subarachnoid hemorrhage-induced brain apoptosis.

BACKGROUND: Upregulation of high-level toll-like receptors (TLRs) is observed in the serum of animals following experimental subarachnoid hemorrhage (SAH) and is highly related to SAH-induced early brain injury (EBI). The present study was of interest to examine the effect of 6-mercaptopurine (6-MP) on alternation of TLR-2, -3, and -4 in this model. METHODS: A rodent SAH model was used. Administration with 6-MP (0.5/1/2 mg/kg/d) was initiated 1 h after the induction of SAH via an osmotic minipump. Cerebral cortex was harvested to measure TLRs messenger RNA and protein (reverse transcription polymerase chain reaction [rt-PCR] and Western blot). Cerebral cortex was harvested for activated caspases (rt-PCR) measurement. RESULTS: Cellular evaluation revealed increased neuronal nuclei(+) neurons with vacuolated nuclear and glial fibrillary acidic protein(+) astrocytes in the SAH group, but absent in the 6-MP treatment and healthy controls. The TLR-3 levels were not significantly increased in animals subject to SAH, compared with the controls (no SAH). The levels of TLR-2 and -4 in the SAH only and SAH plus vehicle groups were significantly elevated (P < 0.01), and treatment with 6-MP reduced TLR-2, -3 (at 2 mg/kg), and -4 (dose-dependently) protein expression following SAH. Likewise, the TLR-4 messenger RNA levels were also significantly reduced in the 6-MP (at 1 mg/kg and 2 mg/kg) groups. Cleaved caspase-3 and caspase-9a were reduced at 2-mg/kg 6-MP treatment group. CONCLUSIONS: These results show that 6-MP attenuates the expression of TLR-2, -4, especially TLR-4, which play an antiapoptotic effect on SAH-induced EBI. This finding supported that through modulating TLRs, 6-MP can attenuate SAH-induced EBI. Those results offer credit to the neuroprotective effect of 6-MP.

The protective effect of Capparis ovata on 6-mercaptopurine-induced hepatotoxicity and oxidative stress in rats.

Capparis ovata is a member of Capparidacaeae family has been used in phytomedicine with a lot of positive effects such as an antioxidative, antihyperlipidemic, anti-inflammatory, and antihepatotoxic agent. The aim of this study was to research the protective effect of C. ovata on 6-mercaptopurine (6-MP) induced to hepatotoxicity and oxidative stress in rats. The rats were divided into 4 groups: control, 6-MP, C. ovataovate, and 6-MP + C. ovata. A complete blood count was performed, liver function test and antioxidant enzymes levels such as superoxide dismutase, glutathione peroxidase, catalase, and malondialdehyde were measured in blood before and after a 14-day test period. White blood cell and platelet counts were lower in the 6-MP group than other 3 groups (P < 0.005). Hepatic transaminase levels were higher in 6-MP group than the 3 groups (P < 0.05). Superoxide dismutase, glutathione peroxidase, and CAT levels were lower and malondialdehyde was higher in blood samples in 6-MP group than other 3 groups (P < 0.005). In conclusion, our tests were showed that C. ovata may be useful in patients receiving 6-MP therapy to prevent hepatotoxicity and in order to maintain uninterrupted therapy possibly reducing the risk of relapse. Although additional studies ensure that Capparis does not affect 6-MP antileukemic activity. We believe these results are important contribution to the literature.

The management of an orbital diffuse large B-cell lymphoma.

BACKGROUND: The orbit represents a rare site of presentation of non-Hodgkin lymphoma. The diagnosis and management of orbital lymphomas may be challenging because these neoplasms present few specific features. METHODS: A 69-year-old woman presented with painless swelling of the left lower eyelid of 5 years' duration. Magnetic resonance imaging and incisional biopsy were necessary to establish a diagnosis of orbital diffuse large B-cell lymphoma. Staging was completed, thanks to a computed tomographic study of the chest and abdomen. RESULTS: The patient underwent systemic chemotherapy with 1 regimen (doxorubicin, vincristine, prednisone, 6-mercaptopurine, and methotrexate), followed by 1 R-COMP-14 regimen (rituximab, cyclophosphamide, nonpegylated liposome-encapsulated doxorubicin, vincristine, and prednisone). Complete resolution of the disease was obtained. CONCLUSIONS: Although not typically performed by the head and neck surgeon, an understanding of the staging process is crucial for multidisciplinary management of orbital lymphomas.

Fecal microbial composition of ulcerative colitis and Crohn's disease patients in remission and subsequent exacerbation.

BACKGROUND: Limited studies have examined the intestinal microbiota composition in relation to changes in disease course of IBD over time. We aimed to study prospectively the fecal microbiota in IBD patients developing an exacerbation during follow-up. DESIGN: Fecal samples from 10 Crohn's disease (CD) and 9 ulcerative colitis (UC) patients during remission and subsequent exacerbation were included. Active disease was determined by colonoscopy and/or fecal calprotectine levels. Exclusion criteria were pregnancy, antibiotic use, enema use and/or medication changes between consecutive samples. The microbial composition was assessed by 16S rDNA pyrosequencing. RESULTS: After quality control, 6,194-11,030 sequences per sample were available for analysis. Patient-specific shifts in bacterial composition and diversity were observed during exacerbation compared to remission, but overarching shifts within UC or CD were not observed. Changes in the bacterial community composition between remission and exacerbation as assessed by Bray-Curtis dissimilarity, were significantly larger in CD versus UC patients (0.59 vs. 0.42, respectively; p = 0.025). Thiopurine use was found to be a significant cause of clustering as shown by Principal Coordinate Analysis and was associated with decreases in bacterial richness (Choa1 501.2 vs. 847.6 in non-users; p<0.001) and diversity (Shannon index: 5.13 vs. 6.78, respectively; p<0.01). CONCLUSION: Shifts in microbial composition in IBD patients with changing disease activity over time seem to be patient-specific, and are more pronounced in CD than in UC patients. Furthermore, thiopurine use was found to be associated with the microbial composition and diversity, and should be considered when studying the intestinal microbiota in relation to disease course.

Usefulness of thiopurine metabolites in predicting azathioprine resistance in pediatric IBD patients.

Few data on azathioprine (AZA) therapy for inflammatory bowel disease (IBD) exist for children. We evaluated whether the 6-thioguanine nucleotides (6-TGN) level predicts AZA refractoriness in children with IBD and whether children benefit an AZA dose escalation. Seventy-eight children with IBD initially treated with an AZA dose of 1.5-2.5 mg/kg/day were retrospectively included. The dose was adjusted based on the clinical status. The receiver operating characteristic curve and logistic regression were used to determine predictors for AZA resistance. Initially, 18 of 40 (45%) patients receiving a dose of <2 mg/kg/day and 11 of 38 (28.9%) patients receiving a dose of 2-2.5 mg/kg/day achieved remission. The 6-TGN level above 250 pmol/8.10(8) RBCs was associated with a higher remission rate, though non-significant. Among 35 patients with a dose escalation due to treatment failure, 12 (34.3%) achieved remission (the median 6-TGN level increased from 260 to 394 pmol/8.10(8) RBCs [P = .002]), 23 (67.6%) were AZA refractory. A 6-TGN level above 405 pmol/8.10(8) RBCs was the only predictor for AZA resistance (sensitivity 78.3%, specificity 75%, OR 10.8 [95% CI: 2.1-55.7, P = .004]). Serial metabolite monitoring is useful to identify children with IBD resistant to AZA. Children who cannot achieve remission despite a 6-TGN level above 405 pmol/8.10(8) RBCs should receive alternative therapies than dose increase.