PACSIN2 rs2413739 influence on thiopurine pharmacokinetics: validation studies in pediatric patients.

The aim of the study was to validate the impact of the single-nucleotide polymorphism rs2413739 (T > C) in the PACSIN2 gene on thiopurines pharmacological parameters and clinical response in an Italian cohort of pediatric patients with acute lymphoblastic leukemia (ALL) and inflammatory bowel disease (IBD). In ALL, PACSIN2 rs2413739 T allele was associated with a significant reduction of TPMT activity in erythrocytes (p = 0.0094, linear mixed-effect model, multivariate analysis considering TPMT genotype) and increased severe gastrointestinal toxicity during consolidation therapy (p = 0.049). A similar trend was present also for severe hematological toxicity during maintenance. In IBD, no significant effect of rs2413739 could be found on TPMT activity, however azathioprine effectiveness was reduced in patients carrying the T allele (linear mixed effect, p = 0.0058). In PBMC from healthy donors, a positive correlation between PACSIN2 and TPMT protein concentration could be detected (linear mixed effect, p = 0.045). These results support the role of PACSIN2 polymorphism on TPMT activity and mercaptopurine adverse effects in patients with ALL. Further evidence on PBMC and pediatric patients with IBD supports an association between PACSIN2 variants, TPMT activity, and thiopurines effects, even if more studies are needed since some of these effects may be tissue specific.

Infections and malignancies risks related to TNF-α-blocking agents in pediatric inflammatory bowel diseases.

Introduction: Tumor necrosis factor-α (TNF-α)-blocking agents are drugs approved for the treatment of inflammatory bowel diseases (IBDs). Infliximab and adalimumab are approved for the treatment of IBD in the pediatric setting with the improvement of therapeutic management. Biological agents, also in the pediatric population, can be administered either alone or in combination with immunomodulators. Their use has raised safety concerns regarding the risk of infections and malignancies.Areas covered: A broad review of the safety concerns for the use of anti-TNF-α drugs in children with IBD was performed, and information regarding the risk of infections and malignancies were updated, also in comparison with the safety of traditional drugs such as steroids and/or immunosuppressants.Expert commentary: Anti-TNF-α drugs have shown favorable safety profiles, and adalimumab treatment is associated with lower immunogenicity compared with infliximab. Heightened awareness and vigilant surveillance leading to prompt diagnosis and treatment are important for optimal management.

Pediatric gastrointestinal bleeding: Perspectives from the Italian Society of Pediatric Gastroenterology.

There are many causes of gastrointestinal bleeding (GIB) in children, and this condition is not rare, having a reported incidence of 6.4%. Causes vary with age, but show considerable overlap; moreover, while many of the causes in the pediatric population are similar to those in adults, some lesions are unique to children. The diagnostic approach for pediatric GIB includes definition of the etiology, localization of the bleeding site and determination of the severity of bleeding; timely and accurate diagnosis is necessary to reduce morbidity and mortality. To assist medical care providers in the evaluation and management of children with GIB, the "Gastro-Ped Bleed Team" of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) carried out a systematic search on MEDLINE via PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) to identify all articles published in English from January 1990 to 2016; the following key words were used to conduct the electronic search: "upper GIB" and "pediatric" [all fields]; "lower GIB" and "pediatric" [all fields]; "obscure GIB" and "pediatric" [all fields]; "GIB" and "endoscopy" [all fields]; "GIB" and "therapy" [all fields]. The identified publications included articles describing randomized controlled trials, reviews, case reports, cohort studies, case-control studies and observational studies. References from the pertinent articles were also reviewed. This paper expresses a position statement of SIGENP that can have an immediate impact on clinical practice and for which sufficient evidence is not available in literature. The experts participating in this effort were selected according to their expertise and professional qualifications.

Influence of urine volume on the assessment of intestinal permeability in affected children by multiple sugar probes.

BACKGROUND: In this study we have looked at the reliability of a multi-sugar test in a pediatric patient population and its accuracy at small urine volumes to evaluate intestinal permeability. METHODS: Out of 117 subjects enrolled, 31 were healthy and 86 were sick. A solution containing lactulose, rhamnose, sucrose, and sucralose was administered to subjects who were on fasting; the urine excreted during 5 h was collected and measured. Samples were analyzed by gas chromatography-tandem mass spectrometry and results were expressed as percentage of sugar recoveries and lactulose/rhamnose (L/R) ratio. RESULTS: The analyses showed a clear effect of low urinary volumes (≤240 mL) particularly affecting rhamnose excretion in healthy subjects and sucrose and sucralose recovery in diseased children. Despite the low rhamnose recovery, as lactulose is not similarly affected, the diagnostic reliability of L/R ratio is well preserved at low diuresis conditions. However, this ratio can be useful to discriminate acute conditions vs. clinical remissions only at high urine volumes. Data also suggest potential diagnostic applicability of sucrose and sucralose in children at high urine volumes. CONCLUSIONS: In conclusion, the multi-sugar test has a good predictivity in pediatric subjects but results must be carefully interpreted in the face of reduced diuresis.

A common genetic background could explain early-onset Crohn's disease.

Crohn's disease (CD) is a multifactorial disease, in which environmental, microbial and genetic factors play important roles. CD is characterized by a chronic granulomatous inflammation by necrotic scarring with aspects of full-thickness wall. In spite of affecting mainly young adults, sometimes, CD can be present in the first year of life (early onset Crohn disease, EOCD) showing an unpredictable course and being often more severe than at older ages. In this paper we propose the hypothesis that EOCD patients should be analyzed using a Mendelian approach with family studies aimed to identify new loci directly involved in the early onset Crohn's disease. So we will leave the classic association study approach used until now for the identification of genes responsible for susceptibility to CD and propose linkage family analysis as alternative and powerful tool for the identification of new genetic variants associated with familiar cases of EOCD.