Raffi Lev‐Tzion

ORCID: 0000-0001-5193-9577
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About
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Research Areas
  • Inflammatory Bowel Disease
  • Microscopic Colitis
  • Pharmaceutical studies and practices
  • Immunodeficiency and Autoimmune Disorders
  • Adolescent and Pediatric Healthcare
  • Eosinophilic Esophagitis
  • Autoimmune and Inflammatory Disorders Research
  • Celiac Disease Research and Management
  • Acute Lymphoblastic Leukemia research
  • Childhood Cancer Survivors' Quality of Life
  • Pancreatitis Pathology and Treatment
  • Viral gastroenteritis research and epidemiology
  • Chronic Lymphocytic Leukemia Research
  • Esophageal and GI Pathology
  • Digestive system and related health
  • Liver Diseases and Immunity
  • Helicobacter pylori-related gastroenterology studies
  • Clostridium difficile and Clostridium perfringens research
  • Gastrointestinal disorders and treatments
  • Urticaria and Related Conditions
  • Nutrition and Health in Aging
  • Thyroid and Parathyroid Surgery
  • Pregnancy and Medication Impact
  • Machine Learning in Healthcare
  • Medical Coding and Health Information

Hebrew University of Jerusalem
2019-2025

Shaare Zedek Medical Center
2014-2025

Ben-Gurion University of the Negev
2015

Washington University in St. Louis
2011-2012

Soroka Medical Center
2007

Abstract Infliximab (IFX) is administered intravenously using weight-based dosing (5 mg/kg) in inflammatory bowel disease (IBD) patients. Our hypothesis that especially young children need a more intensive treatment regimen than the current dose administration. We aimed to assess IFX pharmacokinetics (PK), based on existing therapeutic drug monitoring (TDM) data IBD patients < 10 years. TDM were collected retrospectively 14 centres. Children treated with included if was started as at age...

10.1007/s00431-020-03750-0 article EN cc-by European Journal of Pediatrics 2020-08-19

Abstract Background Alterations in the microbiome have been postulated to drive inflammation IBD. In this pilot randomized controlled trial, we evaluated effectiveness of quadruple antibiotic cocktail addition intravenous-corticosteroids (IVCSs) acute severe colitis (ASC). Methods Hospitalized children with ASC (pediatric ulcerative activity index [PUCAI] ≥65) were into 2 arms: first received antibiotics IVCS (amoxicillin, vancomycin, metronidazole, doxycycline/ciprofloxacin [IVCS+AB]),...

10.1093/ibd/izz298 article EN Inflammatory Bowel Diseases 2019-12-13

Myosin Vb (MYO5B) is a motor protein that facilitates trafficking and recycling in polarized cells by RAB11- RAB8-dependent mechanisms. Biallelic MYO5B mutations are identified the majority of patients with microvillus inclusion disease (MVID). MVID an intractable diarrhea infantile onset characteristic histopathologic findings requires life-long parenteral nutrition or intestinal transplantation. A large number such eventually develop cholestatic liver disease. Bi-allelic also subset...

10.3390/jcm10030481 article EN Journal of Clinical Medicine 2021-01-28

Abstract Background Loss of response (LOR) to first biologic agent is not uncommon. One the most challenging mechanisms LOR pharmacodynamic (inflammatory activity in presence adequate trough concentrations, TC). We aimed explore outcomes pediatric patients with Crohn’s disease following adalimumab failure. Methods conducted a retrospective longitudinal cohort study 6 Israeli centers. Data who experienced (as agent) TC (>7.5 mcg/ml) and switched either infliximab or ustekinumab were...

10.1093/ecco-jcc/jjae190.1121 article EN Journal of Crohn s and Colitis 2025-01-01

Abstract Background Sigmoidoscopy is a less invasive procedure than full colonoscopy, demands simpler preparation, requires shorter time, and may be conducted with lighter sedation. Despite these advantages the continuous nature of inflammation in ulcerative colitis (UC), which typically decreases from distal to proximal colon, FDA recently requests colonoscopy assess UC clinical trials (i.e. 3 colonoscopies 54 weeks). Data support this requirement are scarce children. We, thus, aimed...

10.1093/ecco-jcc/jjae190.0979 article EN Journal of Crohn s and Colitis 2025-01-01

Abstract Background Identifying biological pathways that are associated with poor disease course in IBD may improve early risk stratification and guide targeted therapeutic approaches. We therefore aimed to integrate multiomics data determined at onset explore pediatric IBD, focusing on both microbial host-derived signals. Methods Children were enrolled followed prospectively for18 months. Samples for whole exome sequencing (WES), serum metabolomics, stool microbiome analyzed using MaAsLin2...

10.1093/ecco-jcc/jjae190.0731 article EN Journal of Crohn s and Colitis 2025-01-01

Abstract Background Data regarding burden of depression and anxiety in pediatric-onset inflammatory bowel diseases (PIBD) are limited. We aimed to study the prevalence a nationwide cohort PIBD Methods were retrieved from epi-IIRN, 4 Israeli Health Maintenance Organizations covering 98% population 2005. matched children non-IBD controls for calculating time depression/anxiety. Patients with depression/anxiety prior IBD diagnosis excluded. Poor disease course (PDC) was defined as IBD-related...

10.1093/ecco-jcc/jjae190.0125 article EN Journal of Crohn s and Colitis 2025-01-01

Objective. Accumulating evidence links juvenile idiopathic arthritis (JIA) to nonhost factors such as gut microbes. We hypothesize that children with new-onset JIA have increased intestinal bacterial translocation and circulating lipopolysaccharide (LPS). Methods. studied systemic treatment-naive patients [polyarticular JIA, n = 22, oligoarticular 31, spondyloarthropathies (SpA), 16], established inflammatory bowel disease–related (IBD-RA, 11), 34 healthy controls. determined IgG reactivity...

10.3899/jrheum.161589 article EN The Journal of Rheumatology 2017-09-15

Summary Background Patients enrolled in randomised controlled trials (RCTs) may differ from the target population due to restricted eligibility criteria. Aim To compare treatment response biologics routine practice for children with inflammatory bowel diseases (IBD) who would and not have been eligible enrolment regulatory RCT of same drug. Methods We IBD initiated adalimumab, infliximab, vedolizumab or ustekinumab. The criteria as defined corresponding biologic were applied each patient....

10.1111/apt.17092 article EN Alimentary Pharmacology & Therapeutics 2022-06-23

<b><i>Background:</i></b> The pathogenesis of inflammatory bowel disease (IBD) is complex and involves the contribution genetic environmental factors. Many patients with very early onset IBD are difficult to treat. current antibiotic medication that targets gram-negative anaerobic bacteria provides only moderate efficacy in subsets IBD. <b><i>Methods:</i></b> We report a case series 5 children mean age 1.6 years (range 6 months 2.7 years)...

10.1159/000475660 article EN Digestion 2017-01-01

BACKGROUND: Studies have increasingly challenged the traditional management of acute pancreatitis (AP) with bowel rest. However, these studies used a low-fat diet or transgastric feeding and only included adults. Aiming to generate higher-quality prospective pediatric data, we compared approach fasting intravenous fluids early enteral standard formula. METHODS: Randomized controlled trial children (2–18 years) mild-moderate AP. Patients were randomly assigned 1:1 initial an immediate,...

10.1542/peds.2020-1149 article EN PEDIATRICS 2020-08-12

Several studies have proposed models to predict disease outcomes in paediatric ulcerative colitis (UC), notably PROTECT, Schechter and PIBD-ahead, but none has been validated by external cohorts AIM: To explore these a prospective multicentre inception cohort METHODS: Children newly diagnosed with UC 17 centres were followed at onset 3 12 months thereafter, as well last visit. Outcomes included steroid-free remission (SFR) acute severe (ASC).Of the 223 children, 74 (34%), 97 (43%) 52 (23%)...

10.1111/apt.17544 article EN cc-by-nc Alimentary Pharmacology & Therapeutics 2023-05-29

ABSTRACT Objectives: Use of thiopurines for inflammatory bowel diseases (IBDs) is declining in some parts the world. We aimed to explore outcomes and predictors response a real‐world prospective cohort children with dose optimization. Methods: Children IBD treated without biologics were enrolled. Dosing was guided by thiopurine S‐methyltransferase‐activity at baseline clinical toxicity 4 months; 1 year into study, therapeutic drug monitoring months also considered decision making. The...

10.1097/mpg.0000000000002566 article EN Journal of Pediatric Gastroenterology and Nutrition 2019-11-25

Thiopurines are effective for maintenance of remission in inflammatory bowel disease (IBD) only about half patients. Predictors response may assist selecting the most appropriate patients thiopurine therapy. inhibit Rac1, a GTPase that exerts an antiapoptotic effect on T-lymphocytes. A genetic association was recently demonstrated between Rac1 single nucleotide polymorphism (SNP) and poorer to thiopurines adult with Crohn disease. We aimed determine whether SNPs associated children...

10.1097/mpg.0000000000000820 article EN Journal of Pediatric Gastroenterology and Nutrition 2015-04-16

Abstract Background We previously reported the effectiveness of vedolizumab (VDZ) to induce remission in children with CD and UC enrolled prospective,multicenter VEDOKIDS study.In this extended analysis,we aimed explore safety VDZ maintain through week 30 Methods Children or commenced on at any stage disease were followed baseline 2, 6, 14 weeks thereafter.Explicit demographic,clinical data prospectively recorded.The primary outcome was steroid-and EEN-free clinical (SFR) weeks,analyzed...

10.1093/ecco-jcc/jjac190.0904 article EN Journal of Crohn s and Colitis 2023-01-30
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