@article {10761, title = {Causes of Treatment Failure in Children With Inflammatory Bowel Disease Treated With Infliximab: A Pharmacokinetic Study.}, journal = {J Pediatr Gastroenterol Nutr}, volume = {68}, year = {2019}, month = {2019 Jan}, pages = {37-44}, abstract = {

OBJECTIVES: Anti-tumor necrosis factor antibodies have led to a revolution in the treatment of inflammatory bowel diseases (IBD); however, a sizable proportion of patients does not respond to therapy. There is increasing evidence suggesting that treatment failure may be classified as mechanistic (pharmacodynamic), pharmacokinetic, or immune-mediated. Data regarding the contribution of these factors in children with IBD treated with infliximab (IFX) are still incomplete. The aim was to assess the causes of treatment failure in a prospective cohort of pediatric patients treated with IFX.

METHODS: This observational study considered 49 pediatric (median age 14.4) IBD patients (34 Crohn disease, 15 ulcerative colitis) treated with IFX. Serum samples were collected at 6, 14, 22 and 54 weeks, before IFX infusions. IFX and anti-infliximab antibodies (AIA) were measured using enzyme linked immunosorbent assays. Disease activity was determined by Pediatric Crohn{\textquoteright}s Disease Activity Index or Pediatric Ulcerative Colitis Activity Index.

RESULTS: Clinical remission, defined as a clinical score <10, was obtained by 76.3\% of patients at week 14 and by 73.9\% at week 54. Median trough IFX concentration was higher at all time points in patients achieving sustained clinical remission. IFX levels during maintenance correlated also with C-reactive protein, albumin, and fecal calprotectin. After multivariate analysis, IFX concentration at week 14 >3.11 μg/mL emerged as the strongest predictor of sustained clinical remission. AIA concentrations were correlated inversely with IFX concentrations and directly with adverse reactions.

CONCLUSIONS: Most cases of therapeutic failure were associated with low serum drug levels. IFX trough levels at the end of induction are associated with sustained long-term response.

}, issn = {1536-4801}, doi = {10.1097/MPG.0000000000002112}, author = {Naviglio, Samuele and Lacorte, Doriana and Lucaf{\`o}, Marianna and Cif{\`u}, Adriana and Favretto, Diego and Cuzzoni, Eva and Silvestri, Tania and Pozzi Mucelli, Martina and Radillo, Oriano and Decorti, Giuliana and Fabris, Martina and Bramuzzo, Matteo and Taddio, Andrea and Stocco, Gabriele and Alvisi, Patrizia and Ventura, Alessandro and Martelossi, Stefano} } @article {10436, title = {High-Throughput Sequencing of microRNAs in Glucocorticoid Sensitive Paediatric Inflammatory Bowel Disease Patients.}, journal = {Int J Mol Sci}, volume = {19}, year = {2018}, month = {2018 May 08}, abstract = {

The aim of this research was the identification of novel pharmacogenomic biomarkers for better understanding the complex gene regulation mechanisms underpinning glucocorticoid (GC) action in paediatric inflammatory bowel disease (IBD). This goal was achieved by evaluating high-throughput microRNA (miRNA) profiles during GC treatment, integrated with the assessment of expression changes in GC receptor (GR) heterocomplex genes. Furthermore, we tested the hypothesis that differentially expressed miRNAs could be directly regulated by GCs through investigating the presence of GC responsive elements (GREs) in their gene promoters. Ten IBD paediatric patients responding to GCs were enrolled. Peripheral blood was obtained at diagnosis (T0) and after four weeks of steroid treatment (T4). MicroRNA profiles were analyzed using next generation sequencing, and selected significantly differentially expressed miRNAs were validated by quantitative reverse transcription-polymerase chain reaction. In detail, 18 miRNAs were differentially expressed from T0 to T4, 16 of which were upregulated and 2 of which were downregulated. Out of these, three miRNAs (miR-144, miR-142, and miR-96) could putatively recognize the 3\’UTR of the GR gene and three miRNAs (miR-363, miR-96, miR-142) contained GREs sequences, thereby potentially enabling direct regulation by the GR. In conclusion, we identified miRNAs differently expressed during GC treatment and miRNAs which could be directly regulated by GCs in blood cells of young IBD patients. These results could represent a first step towards their translation as pharmacogenomic biomarkers.

}, keywords = {Adolescent, Biomarkers, Child, Female, Gene Expression Regulation, Glucocorticoids, High-Throughput Nucleotide Sequencing, Humans, Inflammatory Bowel Diseases, Male, MicroRNAs, Receptors, Glucocorticoid, Transcriptome}, issn = {1422-0067}, doi = {10.3390/ijms19051399}, author = {De Iudicibus, Sara and Lucaf{\`o}, Marianna and Vitulo, Nicola and Martelossi, Stefano and Zimbello, Rosanna and De Pascale, Fabio and Forcato, Claudio and Naviglio, Samuele and Di Silvestre, Alessia and Gerdol, Marco and Stocco, Gabriele and Valle, Giorgio and Ventura, Alessandro and Bramuzzo, Matteo and Decorti, Giuliana} } @article {10795, title = {How to predict response to anti-tumour necrosis factor agents in inflammatory bowel disease.}, journal = {Expert Rev Gastroenterol Hepatol}, volume = {12}, year = {2018}, month = {2018 Aug}, pages = {797-810}, abstract = {

INTRODUCTION: Anti-tumor necrosis factor (TNF) agents have changed the therapeutic approach to inflammatory bowel disease (IBD). However, a considerable proportion of patients either do not primarily respond or lose response to treatment. Despite the long-standing experience in the use of these drugs, still there is the need of identifying the possible predictors of efficacy. Areas covered: We critically review the current knowledge on predictors of response to anti-TNF therapy - both those available in clinical practice and those still under investigation. Multiple factors are involved in treatment success, including disease phenotype and severity, adherence to medications, and pharmacogenomic, pharmacokinetic, and immunologic factors. Literature search was conducted in PubMed using keywords {\textquoteright}inflammatory bowel disease,{\textquoteright} {\textquoteright}Crohn{\textquoteright}s disease,{\textquoteright} and {\textquoteright}ulcerative colitis,{\textquoteright} matched with {\textquoteright}antitumor necrosis factor,{\textquoteright} {\textquoteright}biologic therapy,{\textquoteright} {\textquoteright}clinical response,{\textquoteright} {\textquoteright}predictors,{\textquoteright} and {\textquoteright}efficacy,{\textquoteright} Relevant articles were selected for review. Expert commentary: While the role of several factors in clinical practice is clearly established, other investigational markers have been proposed, mostly in small studies, yet for many of them little external validation exists. Therapeutic drug monitoring is emerging as a pivotal strategy to guide decisions in clinical practice. In the near future, novel markers could improve our ability to direct treatment and personalize therapy.

}, keywords = {Antibodies, Monoclonal, Biological Therapy, Gastrointestinal Agents, Humans, Inflammatory Bowel Diseases, Patient Selection, Prognosis, Treatment Outcome, Tumor Necrosis Factor-alpha}, issn = {1747-4132}, doi = {10.1080/17474124.2018.1494573}, author = {Naviglio, Samuele and Giuffrida, Paolo and Stocco, Gabriele and Lenti, Marco Vincenzo and Ventura, Alessandro and Corazza, Gino Roberto and Di Sabatino, Antonio} } @article {10831, title = {Pharmacogenetics of treatments for inflammatory bowel disease.}, journal = {Expert Opin Drug Metab Toxicol}, volume = {14}, year = {2018}, month = {2018 Dec}, pages = {1209-1223}, abstract = {

INTRODUCTION: Inflammatory bowel disease is a chronic inflammation of the gut whose pathogenesis is still unclear. Although no curative therapy is currently available, a number of drugs are used in induction and maintenance therapy; however, for most of these drugs, a high inter-individual variability in response is observed. Among the factors of this variability, genetics plays an important role. Areas covered: This review summarizes the results of pharmacogenetic studies, considering the most important drugs used and in particular aminosalycilates, glucocorticoids, thiopurines, monoclonal antibodies and thalidomide. Most studies used a candidate gene approach, even if significant breakthroughs have been obtained recently from applying genome-wide studies. When available, also investigations considering epigenetics and pharmacogenetic dosing guidelines have been included. Expert opinion: Only for thiopurines, genetic markers identified as predictors of efficacy or adverse events have allowed the development of dosing guidelines. For the other drugs, encouraging results are available and great expectations rely on the study of epigenetics and integration with pharmacokinetic information, especially useful for biologics. However, to improve therapy of IBD patients with these drugs, for implementation in the clinics of pharmacogenetics, informatic clinical decision support systems and training about pharmacogenetics of health providers are needed.

}, keywords = {Dose-Response Relationship, Drug, Epigenesis, Genetic, Gastrointestinal Agents, Genetic Markers, Genetic Predisposition to Disease, Humans, Inflammatory Bowel Diseases, Pharmacogenetics}, issn = {1744-7607}, doi = {10.1080/17425255.2018.1551876}, author = {Lucaf{\`o}, Marianna and Franca, Raffaella and Selvestrel, Davide and Curci, Debora and Pugnetti, Letizia and Decorti, Giuliana and Stocco, Gabriele} } @article {10510, title = {Role of the Long Non-Coding RNA Growth Arrest-Specific 5 in Glucocorticoid Response in Children with Inflammatory Bowel Disease.}, journal = {Basic Clin Pharmacol Toxicol}, volume = {122}, year = {2018}, month = {2018 Jan}, pages = {87-93}, abstract = {

Glucocorticoids (GCs) are widely employed in inflammatory, autoimmune and neoplastic diseases, and, despite the introduction of novel therapies, remain the first-line treatment for inducing remission in inflammatory bowel disease (IBD). Given the high incidence of suboptimal response, associated with a significant number of side-effects, that are particularly severe in paediatric patients, the identification of subjects that are most likely to respond poorly to GCs is extremely important. Recent evidence suggests that the long non-coding RNA (lncRNA) GAS5 could be a potential marker of GC resistance. To address this issue, we evaluated the association between the lncRNA GAS5 and the efficacy of steroids, in terms of inhibition of proliferation, in two cell lines derived from colon and ovarian cancers, to confirm the sensitivity and specificity of these lncRNAs. These cells showed a different sensitivity to GCs and revealed differential expression of GAS5 after treatment. GAS5 was up-regulated in GC-resistant cells and accumulated more in the cytoplasm compared to the nucleus in response to the drug. The functions of GAS5 were assessed by silencing, and we found that GAS5 knock-down reduced the proliferation during GC treatment. Furthermore, for the first time, we measured GAS5 levels in 19 paediatric IBD patients at diagnosis and after the first cycle of GCs, and we demonstrated an up-regulation of the lncRNA in patients with unfavourable steroid response. Our preliminary results indicate that GAS5 could be considered a novel pharmacogenomic marker useful for the personalization of GC therapy.

}, keywords = {Biomarkers, Cell Line, Tumor, Cell Proliferation, Child, Drug Resistance, Female, Gene Knockdown Techniques, Glucocorticoids, Humans, Inflammatory Bowel Diseases, Male, Patient Selection, Pharmacogenomic Testing, Precision Medicine, RNA, Long Noncoding, RNA, Small Interfering, Treatment Outcome, Up-Regulation}, issn = {1742-7843}, doi = {10.1111/bcpt.12851}, author = {Lucaf{\`o}, Marianna and Di Silvestre, Alessia and Romano, Maurizio and Avian, Alice and Antonelli, Roberta and Martelossi, Stefano and Naviglio, Samuele and Tommasini, Alberto and Stocco, Gabriele and Ventura, Alessandro and Decorti, Giuliana and De Iudicibus, Sara} } @article {10460, title = {Epratuzumab and Blinatumomab as Therapeutic Antibodies for Treatment of Pediatric Acute Lymphoblastic Leukemia: Current Status and Future Perspectives.}, journal = {Curr Med Chem}, volume = {24}, year = {2017}, month = {2017}, pages = {1050-1065}, abstract = {

BACKGROUND: More than 85\% of children affected by acute lymphoblastic leukemia (ALL) are successfully treated; however relapse remains a remarkable clinical concern, with 50-60\% of relapsing patients facing a fatal outcome. Management of relapsed patients includes standardized intensive risk-adapted regimens based on conventional drugs, and hematopoietic stem cells transplantation for patients with unfavourable features. Biological drugs, in particular the monoclonal antibody epratuzumab and the bi-functional recombinant single chain peptide blinatumomab, have been recently recognized as novel potential agents to be integrated in salvage ALL therapy to further improve rescue outcome.

METHODS: A systematic search of peer-reviewed scientific literature and clinical trials in public databases has been carried out. Both clinical and pre-clinical studies have been included to summarize recent evidence on epratuzumab and blinatumomab for salvage ALL therapy.

RESULTS: Sixty-two papers and 25 clinical trials were included. Although not all patients responded properly to these agents, their use in relapsed and refractory pediatric ALL seems promising.

CONCLUSION: Phase 3 studies have recently begun and more consistent results about epratuzumab and blinatumomab safety and efficacy in comparison to conventional therapies are expected in the next years. Epratuzumab seems safe in the dosing scheme proposed in ALL, but its efficacy over the conventional chemotherapy is still questionable. Blinatumomab has shown promising results in high risk cases such as elder adult patients and conclusive studies on pediatric ALL are needed. Patient inter-individual variability to these agents has not been investigated in depth, but this issue needs to be addressed, in particular for blinatumomab.

}, keywords = {Antibodies, Bispecific, Antibodies, Monoclonal, Antibodies, Monoclonal, Humanized, Antineoplastic Agents, Child, Clinical Trials as Topic, Half-Life, Humans, Precursor Cell Lymphoblastic Leukemia-Lymphoma, Sialic Acid Binding Ig-like Lectin 2}, issn = {1875-533X}, doi = {10.2174/0929867324666170113105733}, author = {Franca, Raffaella and Favretto, Diego and Granzotto, Marilena and Decorti, Giuliana and Rabusin, Marco and Stocco, Gabriele} } @article {10504, title = {Multicentric Case-Control Study on Azathioprine Dose and Pharmacokinetics in Early-onset Pediatric Inflammatory Bowel Disease.}, journal = {Inflamm Bowel Dis}, volume = {23}, year = {2017}, month = {2017 04}, pages = {628-634}, abstract = {

BACKGROUND: Early-onset inflammatory bowel disease (IBD) is generally aggressive, with a high probability of complications and need of surgery. Despite the introduction of highly effective biological drugs, treatment with azathioprine continues to be important even for early-onset IBD; however, in these patients azathioprine response seems to be reduced. This study evaluated azathioprine doses, metabolite concentrations, and their associations with patients{\textquoteright} age in children with IBD treated at 6 tertiary pediatric referral centers.

METHODS: Azathioprine doses, metabolites, and clinical effects were assessed after at least 3 months of therapy in 17 early-onset (age < 6 yr, cases) and 51 nonearly-onset (aged > 12 and <18 yrs, controls) patients with IBD. Azathioprine dose was titrated on therapeutic efficacy (response and adverse effects). Azathioprine metabolites and thiopurine methyltransferase activity were determined by high-performance liquid chromatography with ultra violet-vis detection (HPLC-UV) methods.

RESULTS: Frequency of patients in remission was similar among early-onset and control groups, respectively (82\% and 84\%, P value = 0.72). Early-onset patients required higher doses of azathioprine (median 2.7 versus 2.0 mg{\textperiodcentered}kg{\textperiodcentered}d, P value = 1.1 {\texttimes} 10). Different doses resulted in comparable azathioprine active thioguanine nucleotide metabolite concentrations (median 263 versus 366 pmol/8 {\texttimes} 10 erythrocytes, P value = 0.41) and methylmercaptopurine nucleotide concentrations (median 1455 versus 1532 pmol/8 {\texttimes} 10 erythrocytes, P value = 0.60). Lower ratios between thioguanine nucleotide metabolites and azathioprine doses were found in early-onset patients (median 98 versus 184 pmol/8 {\texttimes} 10 erythrocytes{\textperiodcentered}mg{\textperiodcentered}kg{\textperiodcentered}d, P value = 0.017). Interestingly, early-onset patients presented also higher thiopurine methyltransferase activity (median 476 versus 350 nmol methylmercaptopurine/mg hemoglobin/h, P-value = 0.046).

CONCLUSIONS: This study demonstrated that patients with early-onset IBD present increased inactivating azathioprine metabolism, likely because of elevated activity of the enzyme thiopurine methyltransferase.

}, keywords = {Adolescent, Age of Onset, Antimetabolites, Azathioprine, Case-Control Studies, Child, Child, Preschool, Chromatography, High Pressure Liquid, Dose-Response Relationship, Drug, Erythrocytes, Female, Guanine Nucleotides, Humans, Inflammatory Bowel Diseases, Male, Mercaptopurine, Methyltransferases, Thioguanine}, issn = {1536-4844}, doi = {10.1097/MIB.0000000000001051}, author = {Stocco, Gabriele and Martelossi, Stefano and Arrigo, Serena and Barabino, Arrigo and Aloi, Marina and Martinelli, Massimo and Miele, Erasmo and Knafelz, Daniela and Romano, Claudio and Naviglio, Samuele and Favretto, Diego and Cuzzoni, Eva and Franca, Raffaella and Decorti, Giuliana and Ventura, Alessandro} } @article {8512, title = {Carbamazepine-induced thrombocytopenic purpura in a child: Insights from a genomic analysis.}, journal = {Blood Cells Mol Dis}, volume = {59}, year = {2016}, month = {2016 Jul}, pages = {97-9}, issn = {1096-0961}, doi = {10.1016/j.bcmd.2016.05.001}, author = {Abate, Maria Valentina and Stocco, Gabriele and Devescovi, Raffaella and Carrozzi, Marco and Pierobon, Chiara and Valencic, Erica and Lucaf{\`o}, Marianna and Di Silvestre, Alessia and d{\textquoteright}Adamo, Pio and Tommasini, Alberto and Decorti, Giuliana and Ventura, Alessandro} } @article {8319, title = {Thiopurine Biotransformation and Pharmacological Effects: Contribution of Oxidative Stress.}, journal = {Curr Drug Metab}, volume = {17}, year = {2016}, month = {2016}, pages = {542-9}, abstract = {

BACKGROUND: Thiopurine antimetabolites are important agents for the treatment of severe diseases, such as acute lymphoblastic leukemia and inflammatory bowel disease. Their pharmacological actions depend on biotransformation into active thioguanine-nucleotides; intracellular metabolism is mediated by enzymes of the salvage pathway of nucleotide synthesis and relies on polymorphic enzymes involved in thiopurines{\textquoteright} catabolism such as thiopurine-S-methyl transferase. Given the enzymes involved in thiopurines{\textquoteright} metabolism, it is reasonable to hypothesize that these drugs are able to induce significant oxidative stress conditions, possibly altering their pharmacological activity.

METHODS: A systemic search of peer-reviewed scientific literature in bibliographic databases has been carried out. Both clinical and preclinical studies as well as mechanistic studies have been included to shed light on the role of oxidative stress in thiopurines{\textquoteright} pharmacological effects.

RESULTS: Sixty-nine papers were included in our review, allowing us to review the contribution of oxidative stress in the pharmacological action of thiopurines. Thiopurines are catabolized in the liver by xanthine oxidase, with potential production of reactive oxidative species and azathioprine is converted into mercaptopurine by a reaction with reduced glutathione, that, in some tissues, may be facilitated by glutathione- S-transferase (GST). A clear role of GSTM1 in modulating azathioprine cytotoxicity, with a close dependency on superoxide anion production, has been recently demonstrated. Interestingly, recent genome-wide association studies have shown that, for both azathioprine in inflammatory bowel disease and mercaptopurine in acute lymphoblastic leukemia, treatment effects on patients{\textquoteright} white blood cells are related to variants of a gene, NUDT15, involved in biotransformation of oxidated nucleotides.

CONCLUSIONS: Basing on previous evidences published in literature, oxidative stress may contribute to thiopurine effects in significant ways that, however, are still not completely elucidated.

}, issn = {1875-5453}, author = {Pelin, Marco and De Iudicibus, Sara and Londero, Margherita and Spizzo, Riccardo and Dei Rossi, Sveva and Martelossi, Stefano and Ventura, Alessandro and Decorti, Giuliana and Stocco, Gabriele} } @article {3592, title = {5-Aminoimidazole-4-carboxamide ribonucleotide-transformylase and inosine-triphosphate-pyrophosphatase genes variants predict remission rate during methotrexate therapy in patients with juvenile idiopathic arthritis.}, journal = {Rheumatol Int}, volume = {35}, year = {2015}, month = {2015 Apr}, pages = {619-27}, abstract = {

For children with juvenile idiopathic arthritis (JIA) who fail to respond to methotrexate, the delay in identifying the optimal treatment at an early stage of disease can lead to long-term joint damage. Recent studies indicate that relevant variants to predict methotrexate response in JIA are those in 5-aminoimidazole-4-carboxamide ribonucleotide-transformylase (ATIC), inosine-triphosphate-pyrophosphatase (ITPA) and solute-liquid-carrier-19A1 genes. The purpose of the study was, therefore, to explore the role of these candidate genetic factors on methotrexate response in an Italian cohort of children with JIA. Clinical response to methotrexate was evaluated as clinical remission stable for a 6-month period, as ACRPed score and as change in Juvenile Arthritis Disease score. The most relevant SNPs for each gene considered were assayed on patients{\textquoteright} DNA. ITPA activity was measured in patients{\textquoteright} erythrocytes. Sixty-nine patients with JIA were analyzed: 52.2 \% responded to therapy (ACRPed70 score), while 37.7 \% reached clinical remission stable for 6 months. ATIC rs2372536 GG genotype was associated with improved clinical remission (adjusted p value = 0.0090). For ITPA, rs1127354 A variant was associated with reduced clinical remission: (adjusted p value = 0.028); this association was present even for patients with wild-type ITPA and low ITPA activity. These preliminary results indicate that genotyping of ATIC rs2372536 and ITPA rs1127354 variants or measuring ITPA activity could be useful to predict methotrexate response in children with JIA after validation by further prospective studies on a larger patient cohort.

}, issn = {1437-160X}, doi = {10.1007/s00296-014-3131-y}, author = {Pastore, Serena and Stocco, Gabriele and Moressa, Valentina and Zandon{\`a}, Luigi and Favretto, Diego and Malus{\`a}, Noelia and Decorti, Giuliana and Lepore, Loredana and Ventura, Alessandro} } @article {7762, title = {Genetic determinants for methotrexate response in juvenile idiopathic arthritis.}, journal = {Front Pharmacol}, volume = {6}, year = {2015}, month = {2015}, pages = {52}, abstract = {

Juvenile idiopathic arthritis (JIAs) is the most common chronic rheumatic disease of childhood and is an important cause of disability. The folic acid analog methotrexate is the first choice disease-modifying anti-rheumatic drug in this disease, however, 35-45\% of patients fail to respond. Molecular elements, such as variants in genes of pharmacological relevance, influencing response to methotrexate in JIA, would be important to individualize treatment strategies. Several studies have evaluated the effects of candidate genetic variants in the complex pathway of genes involved in methotrexate pharmacodynamics and pharmacokinetics, however, results are still contrasting and no definitive genetic marker of methotrexate response useful for the clinician to tailor therapy of children with JIA has been identified. Recently, genome-wide approaches have been applied, identifying new potential biological processes involved in methotrexate response in JIA such as TGF-beta signaling and calcium channels. If these genomic results are properly validated and integrated with innovative analyses comprising deep sequencing, epigenetics, and pharmacokinetics, they will greatly contribute to personalize therapy with methotrexate in children with JIA.

}, issn = {1663-9812}, doi = {10.3389/fphar.2015.00052}, author = {Pastore, Serena and Stocco, Gabriele and Favretto, Diego and De Iudicibus, Sara and Taddio, Andrea and d{\textquoteright}Adamo, Pio and Malus{\`a}, Noelia and Addobbati, Riccardo and Decorti, Giuliana and Lepore, Loredana and Ventura, Alessandro} } @article {8065, title = {Glucocorticoid pharmacogenetics in pediatric idiopathic nephrotic syndrome.}, journal = {Pharmacogenomics}, volume = {16}, year = {2015}, month = {2015 Sep}, pages = {1631-48}, abstract = {

Idiopathic nephrotic syndrome represents the most common type of primary glomerular disease in children: glucocorticoids (GCs) are the first-line therapy, even if considerable interindividual differences in thepir efficacy and side effects have been reported. Immunosuppressive and anti-inflammatory effects of these drugs are mainly due to the GC-mediated transcription regulation of pro- and anti-inflammatory genes. This mechanism of action is the result of a complex multistep pathway that involves the glucocorticoid receptor and several other proteins, encoded by polymorphic genes. Aim of this review is to highlight the current knowledge on genetic variants that could affect GC response, particularly focusing on children with idiopathic nephrotic syndrome.

}, issn = {1744-8042}, doi = {10.2217/pgs.15.101}, author = {Cuzzoni, Eva and De Iudicibus, Sara and Franca, Raffaella and Stocco, Gabriele and Lucaf{\`o}, Marianna and Pelin, Marco and Favretto, Diego and Pasini, Andrea and Montini, Giovanni and Decorti, Giuliana} } @article {8075, title = {Patients{\textquoteright} Induced Pluripotent Stem Cells to Model Drug Induced Adverse Events: A Role in Predicting Thiopurine Induced Pancreatitis?}, journal = {Curr Drug Metab}, volume = {17}, year = {2015}, month = {2015}, pages = {91-8}, abstract = {

Induced pluripotent stem cells (iPSC) can be produced from adult cells by transfecting them with a definite set of pluripotency-associated genes. Under adequate growth conditions and stimulation iPSC can differentiate to almost every somatic lineage in the body. Patients{\textquoteright} derived iPSC are an innovative model to study mechanisms of adverse drug reactions in individual patients and in cell types that cannot be easily obtained from human subjects. Proof-of concept studies with known toxicants have been performed for liver, cardiovascular and central nervous system cells: neurons obtained from iPSC have been used to elucidate the mechanism of chemotherapy-induced peripheral neuropathy by evaluating the effects of neurotoxic drugs such as vincristine. However, no study has been performed yet on pancreatic tissue and drug induced pancreatitis. Thiopurines (azathioprine and mercaptopurine) are immunosuppressive antimetabolite drugs, commonly used to treat Crohn{\textquoteright}s disease. About 5\% of Crohn{\textquoteright}s disease patients treated with thiopurines develop pancreatitis, a severe idiosyncratic adverse event; these patients have to stop thiopurine administration and may require medical treatment, with significant personal and social costs. Molecular mechanism of thiopurine induced pancreatitis (TIP) is currently unknown and no fully validated biomarker is available to assist clinicians in preventing this adverse event. Hence, in this review we have reflected upon the probable research applications of exocrine pancreatic cells generated from patient specific iPS cells. Such pancreatic cells can provide excellent insights into the molecular mechanism of TIP. In particular three hypotheses on the mechanism of TIP could be explored: drug biotransformation, innate immunity and adaptative immunity.

}, issn = {1875-5453}, author = {Stocco, Gabriele and Lanzi, Gaetana and Yue, Fengming and Giliani, Silvia and Sasaki, Katsunori and Tommasini, Alberto and Pelin, Marco and Martelossi, Stefano and Ventura, Alessandro and Decorti, Giuliana} } @article {7779, title = {Role of oxidative stress mediated by glutathione-s-transferase in thiopurines{\textquoteright} toxic effects.}, journal = {Chem Res Toxicol}, volume = {28}, year = {2015}, month = {2015 Jun 15}, pages = {1186-95}, abstract = {

Azathioprine (AZA), 6-mercaptopurine (6-MP), and 6-thioguanine (6-TG) are antimetabolite drugs, widely used as immunosuppressants and anticancer agents. Despite their proven efficacy, a high incidence of toxic effects in patients during standard-dose therapy is recorded. The aim of this study is to explain, from a mechanistic point of view, the clinical evidence showing a significant role of glutathione-S-transferase (GST)-M1 genotype on AZA toxicity in inflammatory bowel disease patients. To this aim, the human nontumor IHH and HCEC cell lines were chosen as predictive models of the hepatic and intestinal tissues, respectively. AZA, but not 6-MP and 6-TG, induced a concentration-dependent superoxide anion production that seemed dependent on GSH depletion. N-Acetylcysteine reduced the AZA antiproliferative effect in both cell lines, and GST-M1 overexpression increased both superoxide anion production and cytotoxicity, especially in transfected HCEC cells. In this study, an in vitro model to study thiopurines{\textquoteright} metabolism has been set up and helped us to demonstrate, for the first time, a clear role of GST-M1 in modulating AZA cytotoxicity, with a close dependency on superoxide anion production. These results provide the molecular basis to shed light on the clinical evidence suggesting a role of GST-M1 genotype in influencing the toxic effects of AZA treatment.

}, issn = {1520-5010}, doi = {10.1021/acs.chemrestox.5b00019}, author = {Pelin, Marco and De Iudicibus, Sara and Fusco, Laura and Taboga, Eleonora and Pellizzari, Giulia and Lagatolla, Cristina and Martelossi, Stefano and Ventura, Alessandro and Decorti, Giuliana and Stocco, Gabriele} } @article {7737, title = {Role of Pharmacogenetics in Hematopoietic Stem Cell Transplantation Outcome in Children.}, journal = {Int J Mol Sci}, volume = {16}, year = {2015}, month = {2015}, pages = {18601-27}, abstract = {

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic procedure for several congenital and acquired disorders, both malignant and nonmalignant. Despite the great improvements in HSCT clinical practices over the last few decades, complications, such as graft vs. host disease (GVHD) and sinusoidal obstructive syndrome (SOS), are still largely unpredictable and remain the major causes of morbidity and mortality. Both donor and patient genetic background might influence the success of bone marrow transplantation and could at least partially explain the inter-individual variability in HSCT outcome. This review summarizes some of the recent studies on candidate gene polymorphisms in HSCT, with particular reference to pediatric cohorts. The interest is especially focused on pharmacogenetic variants affecting myeloablative and immunosuppressive drugs, although genetic traits involved in SOS susceptibility and transplant-related mortality are also reviewed.

}, issn = {1422-0067}, doi = {10.3390/ijms160818601}, author = {Franca, Raffaella and Stocco, Gabriele and Favretto, Diego and Giurici, Nagua and Decorti, Giuliana and Rabusin, Marco} } @article {3516, title = {Pharmacogenetics of azathioprine in inflammatory bowel disease: a role for glutathione-S-transferase?}, journal = {World J Gastroenterol}, volume = {20}, year = {2014}, month = {2014 Apr 7}, pages = {3534-41}, abstract = {

Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

}, keywords = {6-Mercaptopurine, Animals, Apoptosis, Azathioprine, Glutathione, Glutathione Transferase, Humans, Immunosuppressive Agents, Inflammatory Bowel Diseases, Oxidative Stress, Pharmacogenetics, Polymorphism, Genetic}, issn = {2219-2840}, doi = {10.3748/wjg.v20.i13.3534}, author = {Stocco, Gabriele and Pelin, Marco and Franca, Raffaella and De Iudicibus, Sara and Cuzzoni, Eva and Favretto, Diego and Martelossi, Stefano and Ventura, Alessandro and Decorti, Giuliana} } @article {1933, title = {Personalized therapies in pediatric inflammatory and autoimmune diseases.}, journal = {Curr Pharm Des}, volume = {18}, year = {2012}, month = {2012}, pages = {5766-75}, abstract = {

Pediatric inflammatory and autoimmune diseases are a wide array of systemic or organ-specific conditions, characterized by an exaggerated immune reactivity, which generally occurs in immunogenetically predisposed children. Among the most important ones, in terms of their diffusion and morbidity in the population worldwide, pediatric inflammatory bowel disease (IBD) and juvenile rheumatoid arthritis (JRA) have to be considered. The aim of personalized therapy is to give to each patient the most appropriate drug and dose regimen, in order to maximize treatment response and reduce the risk of adverse events. In general, several therapeutic options exist for pediatric inflammatory and autoimmune conditions, therefore the perspective of pharmacological tools that allow identification of patients with increased risk of treatment issues related to a particular medication, in terms of lack of efficacy or increased probability of adverse events, is particularly desirable and promising. The present review will be focused on the personalized therapy approaches already available or in development for pediatric patients with IBD or JRA, comprising pharmacokinetic, pharmacodynamic and pharmacogenetic assays.

}, keywords = {Arthritis, Rheumatoid, Autoimmune Diseases, Child, Genetic Predisposition to Disease, Humans, Immunogenetic Phenomena, Individualized Medicine, Inflammation, Inflammatory Bowel Diseases, Pharmacogenetics}, issn = {1873-4286}, author = {Stocco, Gabriele and De Iudicibus, Sara and Franca, Raffaella and Addobbati, Riccardo and Decorti, Giuliana} } @article {1652, title = {Genetic predictors of glucocorticoid response in pediatric patients with inflammatory bowel diseases.}, journal = {J Clin Gastroenterol}, volume = {45}, year = {2011}, month = {2011 Jan}, pages = {e1-7}, abstract = {

BACKGROUND: Glucocorticoids (GCs) are used in moderate-to-severe inflammatory bowel diseases (IBD) but their effect is often unpredictable.

AIM: To determine the influence of 4 polymorphisms in the GC receptor [nuclear receptor subfamily 3, group C, member 1 (NR3C1)], interleukin-1β (IL-1β), and NACHT leucine-rich-repeat protein 1 (NALP1) genes, on the clinical response to steroids in pediatric patients with IBD.

METHODS: One hundred fifty-four young IBD patients treated with GCs for at least 30 days and with a minimum follow-up of 1 year were genotyped. The polymorphisms considered are the BclI in the NR3C1 gene, C-511T in IL-1β gene, and Leu155His and rs2670660/C in NALP1 gene. Patients were grouped as responder, dependant, and resistant to GCs. The relation between GC response and the genetic polymorphisms considered was examined using univariate, multivariate, and Classification and Regression Tree (CART) analysis.

RESULTS: Univariate analysis showed that BclI polymorphism was more frequent in responders compared with dependant patients (P=0.03) and with the combined dependant and resistant groups (P=0.02). Moreover, the NALP1 Leu155His polymorphism was less frequent in the GC responsive group compared with resistant (P=0.0059) and nonresponder (P=0.02) groups. Multivariate analysis comparing responders and nonresponders confirmed an association between BclI mutated genotype and steroid response (P=0.030), and between NALP1 Leu155His mutant variant and nonresponders (P=0.033). An association between steroid response and male sex was also observed (P=0.034). In addition, Leu155His mutated genotype was associated with steroid resistance (P=0.034). Two CART analyses supported these findings by showing that BclI and Leu155His polymorphisms had the greatest effect on steroid response (permutation P value=0.046). The second CART analysis also identified age of disease onset and male sex as important variables affecting response.

CONCLUSIONS: These results confirm that genetic and demographic factors may affect the response to GCs in young patients with IBD and strengthen the importance of studying high-order interactions for predicting response.

}, keywords = {Adolescent, Child, Drug Resistance, Female, Follow-Up Studies, Genotype, Glucocorticoids, Humans, Inflammatory Bowel Diseases, Male, Multivariate Analysis, Polymorphism, Genetic, Receptors, Glucocorticoid, Regression Analysis, Retrospective Studies, Sex Factors, Treatment Outcome}, issn = {1539-2031}, doi = {10.1097/MCG.0b013e3181e8ae93}, author = {De Iudicibus, Sara and Stocco, Gabriele and Martelossi, Stefano and Londero, Margherita and Ebner, Egle and Pontillo, Alessandra and Lionetti, Paolo and Barabino, Arrigo and Bartoli, Fiora and Ventura, Alessandro and Decorti, Giuliana} } @article {1705, title = {Genetic polymorphism of inosine-triphosphate-pyrophosphatase influences mercaptopurine metabolism and toxicity during treatment of acute lymphoblastic leukemia individualized for thiopurine-S-methyl-transferase status.}, journal = {Expert Opin Drug Saf}, volume = {9}, year = {2010}, month = {2010 Jan}, pages = {23-37}, abstract = {

IMPORTANCE OF THE FIELD: Although genetic polymorphisms in the gene encoding human thiopurine methyltransferase (TPMT) are known to have a marked effect on mercaptopurine metabolism and toxicity, there are many patients with wild-type TPMT who develop toxicity. Furthermore, when mercaptopurine dosages are adjusted in patients who are heterozygous at the TPMT locus, there are still some patients who develop toxicity for reasons that are not fully understood. Therefore, we recently studied the effects of a common polymorphism in another gene encoding an enzyme involved in mercaptopurine metabolism (SNP rs1127354 in inosine-triphospate-pyrophosphatase, ITPA), showing that genetic polymorphism of ITPA is a significant determinant of mercaptopurine metabolism and of febrile neutropenia following combination chemotherapy of acute lymphoblastic leukemia (ALL) in which mercaptopurine doses are individualized based on TPMT genotype.

AREA COVERED IN THIS REVIEW: In this review, we summarize the knowledge available about the effect and clinical relevance of TPMT and ITPA on mercaptopurine pharmacogenomics, with a particular focus on the use of this medication in pediatric patients with ALL.

WHAT THE READER WILL GAIN: Reader will gain insights into: i) the effects of pharmacogenomic traits on mercaptopurine toxicity and efficacy for the treatment of ALL and ii) individualization strategies that can be used to mitigate toxicity without compromising efficacy in pediatric patients with ALL.

TAKE HOME MESSAGE: Mercaptopurine dose can be adjusted on the basis of TPMT genotype to mitigate toxicity in pediatric patients with ALL. As treatment is individualized in this way for the most relevant genetic determinant of drug response (i.e., for mercaptopurine, TPMT), the importance of other genetic polymorphisms emerges (e.g., ITPA).

}, keywords = {6-Mercaptopurine, Antineoplastic Combined Chemotherapy Protocols, Child, Humans, Individualized Medicine, Methyltransferases, Models, Biological, Neutropenia, Nucleotide Transport Proteins, Polymorphism, Genetic, Precursor Cell Lymphoblastic Leukemia-Lymphoma, Pyrophosphatases}, issn = {1744-764X}, doi = {10.1517/14740330903426151}, author = {Stocco, Gabriele and Crews, Kristine R and Evans, William E} } @article {1686, title = {Pharmacogenomics in pediatric leukemia.}, journal = {Curr Opin Pediatr}, volume = {22}, year = {2010}, month = {2010 Dec}, pages = {703-10}, abstract = {

PURPOSE OF REVIEW: The therapeutic index of many medications, especially in children, is very narrow with substantial risk for toxicity at doses required for therapeutic effects. This is particularly relevant to cancer chemotherapy, when the risk of toxicity must be balanced against potential suboptimal (low) systemic exposure that can be less effective in patients with higher rates of drug clearance. The purpose of this review is to discuss genetic factors that lead to interpatient differences in the pharmacokinetics and pharmacodynamics of these medications.

RECENT FINDINGS: Genome-wide agonistic studies of pediatric patient populations are revealing genome variations that may affect susceptibility to specific diseases and that influence the pharmacokinetic and pharmacodynamic characteristics of medications. Several genetic factors with relatively small effect may be combined in the determination of a pharmacogenomic phenotype and considering these polygenic models may be mandatory in order to predict the related drug response phenotypes. These findings have potential to yield new insights into disease pathogenesis, and lead to molecular diagnostics that can be used to optimize the treatment of childhood cancers.

SUMMARY: Advances in genome technology, and their comprehensive and systematic deployment to elucidate the genomic basis of interpatient differences in drug response and disease risk, hold great promise to ultimately enhance the efficacy and reduce the toxicity of drug therapy in children.

}, keywords = {Antineoplastic Agents, Child, Genetic Predisposition to Disease, Genetic Testing, Humans, Individualized Medicine, Pharmacogenetics, Phenotype, Precursor Cell Lymphoblastic Leukemia-Lymphoma}, issn = {1531-698X}, doi = {10.1097/MOP.0b013e32833fde85}, author = {Paugh, Steven W and Stocco, Gabriele and Evans, William E} } @article {1706, title = {Usefulness of the measurement of azathioprine metabolites in the assessment of non-adherence.}, journal = {J Crohns Colitis}, volume = {4}, year = {2010}, month = {2010 Nov}, pages = {599-602}, abstract = {

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.

}, keywords = {6-Mercaptopurine, Adolescent, Azathioprine, Child, Child, Preschool, Female, Guanine Nucleotides, Hepatitis, Autoimmune, Humans, Immunosuppressive Agents, Inflammatory Bowel Diseases, Male, Medication Adherence, Thionucleotides, Young Adult}, issn = {1876-4479}, doi = {10.1016/j.crohns.2010.04.003}, author = {Stocco, Gabriele and Londero, Margherita and Campanozzi, Angelo and Martelossi, Stefano and Marino, Sara and Malus{\`a}, Noelia and Bartoli, Fiora and Decorti, Giuliana and Ventura, Alessandro} }