Pediatric nutritional surgery and its implications: results from a unicentric retrospective analysis.

PURPOSE: Existing guidelines provide weak recommendations on the surgical management of nutritional problems in children. The objective was to design a management pathway to address the best nutritional surgery (NS) procedure in a given patient. METHODS: Retrospective analysis of children treated at our department from January 2015 to December 2019. The sample was divided into two groups according to presence or absence of neurological impairment (NI). Patients with NI (Group 1) were classified in three subgroups based on presenting symptoms: A-Dysphagia without gastroesophageal reflux (GER); B-GER with or without dysphagia; C-Symptoms associated with a delayed gastric emptying. RESULTS: A total of 154 patients were included, 111 with NI. One-hundred-twenty-eight patients underwent only one procedure. Complications and mortality were superior in Group 1. In subgroup A, isolated gastrostomy was the first NS in all patients. In subgroup B most of patients were subjected to a Nissen fundoplication, while in 5 cases total esophagogastric dissociation (TEGD) was the first intervention. Considering the entire sample, 92.3% patients who underwent a TEGD did not require further procedures. CONCLUSION: NS encompasses various procedures depending on presenting symptoms and neurological status. A management flowchart for these patients is proposed.

Diagnosis and management of anemia in pediatric inflammatory bowel diseases: Clinical practice guidelines on behalf of the SIGENP IBD Working group.

Anemia is one of the most frequent extra-intestinal manifestations of inflammatory bowel disease. Insidious onset, variability of symptoms and lack of standardized screening practices may increase the risk of underestimating its burden in children with IBD. Despite its relevance and peculiarity in everyday clinical practice, this topic is only dealt with in a few documents specifically for the pediatric field. The aim of the current guidelines is therefore to provide pediatric gastroenterologists with a practical update to support the clinical and therapeutic management of children with IBD and anemia. A panel of 19 pediatric gastroenterologists and 1 pediatric hematologist with experience in the field of pediatric IBD was agreed by IBD Working group of the Italian Society of Gastroenterology, Hepatology and Nutrition (SIGENP) to produce the present article outlining practical clinical approaches to the pediatric patient with IBD and anemia. The levels of evidence and recommendations have been defined for each part of the statement according to the GRADE system.

Non-interventional, 5-year retrospective data of home parenteral nutrition in patients with benign chronic intestinal failure: Analysis of an Italian nurse registry (SERECARE II).

OBJECTIVE: This study is an assessment of home parenteral nutrition service performance and safety and efficacy outcomes in patients with benign chronic intestinal failure. METHODS: This is a retrospective, non-interventional, and multicenter study. Data were collected by trained nurses and recorded in a dedicated registry (SERECARE). RESULTS: From January 1, 2013 to June 30, 2018, data from a total of 683 patients with benign chronic intestinal failure were entered in the registry. Patients included 208 pediatric (53.8% male; median age = 4.0 y) and 475 adult (47.6% male; median age = 59.0 y) participants. On average, patients were visited 5.4 ± 4.5 times and received 1.4 ± 0.8 training sessions. Retraining was not common and mostly due to change of therapy or change of caregiver. Of 939 complications, 40.9% were related to the central venous catheter and were mostly infectious (n = 182) and mechanical (n = 187). The rate of infectious and mechanical complications per 1000 catheter days decreased over 5 y (0.30-0.15 and 0.33 -0.19, respectively). The rate of complications per 1000 catheter days and the mean complications per patient were higher in pediatric than in adult patients. The hospitalization rate was 1.01 per patient throughout the study period. These data were similar to those registered in a previous study period (2002-2011) (n = 1.53 per patient). Changes over time in the efficacy variables were mostly small and non-significant. CONCLUSIONS: This study confirms the importance of setting up and maintaining structured registries to monitor and improve home parenteral nutrition care. Safety outcomes have improved over the years, most likely due to the underlying efficient nursing service.

Major Abdominal Surgery for Pediatric Crohn's Disease in the Anti-TNF Era: 10-Year Analysis of Data From the IBD Registry of Italian Society of Pediatric Gastroenterology, Hepatology, and Nutrition.

BACKGROUND: The natural history of Crohn's disease (CD) can result in complications requiring surgery. Pediatric data are scarce about major abdominal surgery. The IBD Registry from the Italian Society of Pediatric Gastroenterology, Hepatology, and Nutrition has been active since 2008 and collects data from major pediatric IBD centers in Italy. The aim of the present report was to explore the prevalence of major abdominal surgery among children affected by CD in an era when antitumor necrosis factor (anti-TNF-α) agents were already used so that we might appraise the incidence of surgical-related complications and identify the factors associated with postoperative disease recurrence. METHODS: We retrospectively analyzed data from patients enrolled in the registry from January 2009 to December 2018. Patients with monogenic IBD and patients undergoing surgery for perianal disease were excluded. RESULTS: In total, 135 of 1245 patients were identified. We report the prevalence of major abdominal surgery of 10.8%. Pediatric surgeons performed the procedure in 54.1% of cases, and a laparoscopic approach was used in 47.4% of surgical procedures. Seventeen patients (12.6%) experienced a total of 21 early postoperative complications, none of which was severe. A laparoscopic approach was the only factor negatively associated with the occurrence of postoperative complications (odds ratio, 0.22; 95% confidence interval, 0.06-0.8; P = .02). Fifty-four (40%) patients experienced postoperative endoscopic recurrence, and 33 (24.4%) of them experienced postoperative clinical recurrence. The postoperative treatment with anti-TNF-α drugs was significantly associated with a reduced risk of endoscopic recurrence (odds ratio, 0.19; 95% confidence interval, 0.05-0.79; P = .02). CONCLUSION: In our cohort, the overall prevalence of major abdominal surgery was low, as well as the rate of surgical-related complications. Postoperative anti-TNF-α therapy seems be protective against endoscopic recurrence.

Data from the IBD SIGENP registry show that the prevalence of major abdominal surgery is 10.8%, with a relatively low occurrence of short-term postoperative complications. The administration of anti-TNF-α drugs after surgery seems to effectively prevent postoperative endoscopic recurrence of disease.

Disease course of ulcerative proctitis in children: A population-based study on behalf of the SIGENP IBD Group.

BACKGROUND: The natural history of ulcerative proctitis (UP) has been poorly investigated in children. AIMS: We aimed to compare the disease course of children with UP at diagnosis to the other locations and to identify extension predictors. METHODS: This was a multicenter, observational study carried out from data prospectively entered in the SIGENP-IBD-Registry. Children with ulcerative colitis (UC) diagnosis and at least 1-year follow-up were included. On the basis of Paris classification UP patients were identified and compared with the other locations. RESULTS: 872 children were enrolled (median age at diagnosis: 11.2 years; M/F: 426/446), of whom 78 (9%) with UP. Kaplan-Meier analysis demonstrated increased cumulative probabilities of disease extension in the E1 group [1 year: 20.3%; 5 years: 52.7%; 10 years: 72.4%] compared to E3 group [1 year: 8.5%; 5 years: 24.9% and 10 years: 60.1%, p=0.001]. No differences were observed comparing E1 and E2 groups [p=0.4]. Cumulative probabilities of surgery at 1, 5 and 10 years were 1.3, 2.8 and 2.8% in the E1 group and 2.5, 8 and 12.8% in the E2-E3-E4 group, respectively (p=0.1). Cox regression analysis demonstrated that PUCAI>35 at diagnosis was associated with endoscopic extension (HR=4.9; CI 95% 1.5-15.2, p=0.006). CONCLUSIONS: UP is associated with similar short and long-term outcomes compared to other locations.

Diagnostic accuracy of upper gastrointestinal series in children with suspected intestinal malrotation.

Intestinal malrotation (IM) results from an altered or incomplete rotation of the fetal midgut around the superior mesenteric artery axis. The abnormal anatomy of IM is associated with risk of acute midgut volvulus which can lead to catastrophic clinical consequences. The upper gastro-intestinal series (UGI) is addressed as the gold standard diagnosis procedure, but a variable failure degree has been described in literature. The aim of the study was to analyze the UGI exam and describe which features are the most reproducible and reliable in diagnosing IM. Medical records of patients surgically treated for suspected IM between 2007 and 2020 at a single pediatric tertiary care center were retrospectively reviewed. UGI inter-observer agreement and diagnostic accuracy were statistically calculated. Images obtained with antero-posterior (AP) projections were the most significant in terms of IM diagnosis. Duodenal-Jejunal Junction (DJJ) abnormal position resulted to be the most reliable parameter (Se = 0.88; Sp = 0.54) as well as the most readable, with an inter-reader agreement of 83% (k = 0.70, CI 0.49-0.90). The First Jejunal Loops (FJL), caecum altered position and duodenal dilatation could be considered additional data. Lateral projections demonstrated an overall low sensitivity (Se = 0.80) and specificity (Sp = 0.33) with a PPV of 0.85 and a NPV of 0.25. UGI on the sole AP projections ensures a good diagnostic accuracy. The position of the third portion of the duodenum on lateral views showed an overall low reliability, therefore it was not helpful but rather deceiving in diagnosing IM.

Efficacy and Tolerance of Thalidomide in Patients With Very Early Onset Inflammatory Bowel Disease.

BACKGROUND: Few drugs have been studied for patients with very early onset inflammatory bowel disease (VEOIBD). This study aimed to evaluate the efficacy and tolerance of thalidomide in children with VEOIBD compared with children with pediatric-onset IBD (pIBD). METHODS: A retrospective cohort study with a control group was conducted. Propensity score 1:1 matching was used to identify control subjects. The treatment persistence; the causes of drug withdrawal; the rate of clinical remission and mucosal healing at 1, 2, and 3 years; and adverse events (AEs) were evaluated in children with VEOIBD treated with thalidomide and compared with children with pIBD. RESULTS: Thirty-nine courses of treatment with thalidomide in VEOIBD and pIBD patients were compared. The treatment persistence at 1, 2, and 3 years was 68.2% (95% confidence interval [CI], 50.8%-80.6%), 57.0% (95% CI, 39.6%-71.1%), and 50.9% (95% CI, 33.7%-65.8%) for VEOIBD patients and 81.7% (95% CI, 65.3%-90.9%), 60.0% (95% CI, 41.7%-74.3%) and 33.0% (95% CI, 17.4%-49.5%) for pIBD patients, respectively (P = .12). A significantly higher proportion of VEOIBD patients discontinued therapy due to lack of efficacy (48.2% vs 17.2%; P = .03), while AEs were the main reason for discontinuation in pIBD patients. Clinical remission and mucosal healing rates did not significantly differ between VEOIBD and pIBD patients. A significatively lower number of VEOIBD patients experienced AEs compared with pIBD patients (14 [35.9%] vs 30 [76.9%]; P = .0005). CONCLUSIONS: Thalidomide is an effective and tolerated treatment in children with VEOIBD. Discontinuation due to lack of efficacy is more frequent, but AEs are less common than in children with pIBD.

Thalidomide is a valid therapeutic option in children with very early onset inflammatory bowel diseases unresponsive to conventional therapies. Discontinuation due to lack of efficacy is more frequent, but adverse events are less common than in children with pediatric-onset inflammatory bowel disease.

Transition care in patients with IBD: The pediatric and the adult gastroenterologist's perspective. Results from a national survey.

BACKGROUND: Transition is a crucial process in the care of IBD patients, although it remains largely heterogeneous. AIMS: To provide an overview of the transition process in Italy and to investigate the perspective of the paediatric and adult physicians. METHODS: An online survey was developed by the Italian Group for Inflammatory Bowel Diseases (IG-IBD) and the Italian Society of Paediatric Gastroenterology, Hepatology and Nutrition (SIGENP). RESULTS: 104 physicians (62 paediatric and 42 adult gastroenterologists) participated to the survey. The disease status was ranked with the highest priority among the key elements of the transition process. The age of the patient was perceived with a higher priority by paediatric gastroenterologists than by adult ones (p < 0.01). In most cases, the transition was organized through one or more joint meetings. Only less than 25 % of responders reported to involve other professions during transition. The struggle in leaving paediatric setting was perceived as the main obstacle to an effective transition process. Paediatric IBD gastroenterologists ranked the struggle in leaving the paediatric setting and the attending physician as higher critical point than adult gastroenterologists. CONCLUSIONS: The current survey provided a snapshot of the IBD transition process in Italy. The present findings highlight the need to embed transitional care in healthcare policy.

Institution of an interdisciplinary IBD centre is associated with improved healthcare utilisation.

Despite the institution of an interdisciplinary Inflammatory Bowel Disease (IBD) centre is encouraged, how it may improve patient care is still unknown. In a 5-year period following organisation of an IBD centre, hospitalisations per patient/year decreased (0.41-0.17) and patients on biologics increased (7.7%-26.7%). Total number of hospitalisations (-18.4%) and length of hospitalisation (-29.4%) improved compared with a preceding 5-year period. These findings suggest that institution of an interdisciplinary IBD centre is associated with improved healthcare utilisation.

Clusters of Disease Activity and Early Risk Factors of Clinical Course of Pediatric Crohn's Disease.

BACKGROUND: This study aimed to define clusters of disease activity and prognostic factors of disease course in a well-characterized cohort of children with Crohn's disease (CD). METHODS: All patients from the SIGENP IBD (Italian Society of Pediatric Gastroenterology Hepatology and Nutrition Inflammatory Bowel Disease) registry with a 5-year follow-up and 6-monthly evaluation were included. Active disease was defined for each semester as follows: clinical activity (weighted Pediatric Crohn's Disease Activity Index ≥12.5 or Mucosal Inflammation Noninvasive Index ≥8) and active disease on endoscopy (Simple Endoscopic Score for Crohn's Disease >3 or fecal calprotectin >250 µg/g) or imaging. Formula-based clusters were generated based on previously published patterns in adults. RESULTS: Data from 332 patients were analyzed. A total of 105 (32%) experienced a quiescent disease course; 49 (15%) and 31 (9%) a moderate-to-severe chronically active and chronic intermittent disease, respectively; 104 (31%) and 43 (13%) had active disease in the first 2 years after diagnosis and remission thereafter and vice versa, respectively. Surgery at diagnosis was significantly associated with a quiescent course (odds ratio [OR], 10.05; 95% confidence interval [CI], 3.05-25.22; P=.0005), while growth impairment at the diagnosis and active disease requiring corticosteroids at 6 months were inversely related to the quiescent group (OR, 0.48; 95% CI, 0.27-0.81; P= .007; and OR, 0.35; 95% CI, 0.16-0.71; P= .005, respectively). Perianal involvement at diagnosis and moderate-severe activity at 6 months correlated with disease progression (OR, 3.85; 95% CI, 1.20-12.85; P=.02). CONCLUSIONS: During the first 5 years of follow-up, one-third of children with CD experience a quiescent course. However, another one-third have a moderate-to-severe disease course. Surgery at the diagnosis is related to a quiescent course, while growth impairment and lack of response to induction therapy correlate with more severe disease activity during follow-up.

We aimed to define clusters of disease activity and prognostic factors of disease course in pediatric Crohn's disease. One-third of patients have a quiescent course; however, half of them have an active disease by the end of the 5-year follow-up.

Dose escalation of adalimumab as a strategy to overcome anti-drug antibodies: A case report of infantile-onset inflammatory bowel disease.

BACKGROUND: Treatment of infantile-onset inflammatory bowel disease (IO-IBD) is often challenging due to its aggressive disease course and failure of standard therapies with a need for biologics. Secondary loss of response is frequently caused by the production of anti-drug antibodies, a well-known problem in IBD patients on biologic treatment. We present a case of IO-IBD treated with therapeutic drug monitoring (TDM)-guided high-dose anti-tumor necrosis factor therapy, in which dose escalation monitoring was used as a strategy to overcome anti-drug antibodies. CASE SUMMARY: A 5-mo-old boy presented with a history of persistent hematochezia from the 10th d of life, as well as relapsing perianal abscess and growth failure. Hypoalbuminemia, anemia, and elevated inflammatory markers were also present. Endoscopic assessment revealed skip lesions with deep colic ulcerations, inflammatory anal sub-stenosis, and deep fissures with persistent abscess. A diagnosis of IO-IBD Crohn-like was made. The patient was initially treated with oral steroids and fistulotomy. After the perianal abscess healed, adalimumab (ADA) was administered with concomitant gradual tapering of steroids. Clinical and biochemical steroid-free remission was achieved with good trough levels. After 3 mo, antibodies to ADA (ATA) were found with undetectable trough levels; therefore, we optimized the therapy schedule, first administering 10 mg weekly and subsequently up to 20 mg weekly (2.8 mg/kg/dose). After 2 mo of high-dose treatment, ATA disappeared, with concomitant high trough levels and stable clinical and biochemical remission of the disease. CONCLUSION: TDM-guided high-dose ADA treatment as a monotherapy overcame ATA production. This strategy could be a good alternative to combination therapy, especially in very young patients.

Posterior Tracheopexy for Tracheomalacia: A Study of Clinical and Radiological Consequences on Esophagus.

INTRODUCTION: Posterior tracheopexy (PT) directly addresses the posterior trachealis membrane intrusion in severe tracheomalacia. During PT, the esophagus is mobilized and membranous trachea is sutured to the prevertebral fascia. Although dysphagia has been reported as a possible complication of PT, in the literature there are no data investigating postoperative esophageal anatomy and digestive symptoms. Our aim was to study clinical and radiological consequences of PT on esophagus. METHODS: Patients with symptomatic tracheobronchomalacia scheduled for PT between May 2019 and November 2022 underwent pre- and postoperative esophagogram. For each patient, we analyzed radiological images and measured esophageal deviation providing new radiological parameters. RESULTS: All 12 patients underwent thoracoscopic PT (n = 3) or robot-assisted thoracoscopic PT (n = 9). For all patients, the postoperative esophagogram showed a right dislocation of the thoracic esophagus (median postoperative deviation = 27.5 mm). We report an esophageal perforation at postoperative day 7 in a patient affected by esophageal atresia, who underwent several surgical procedures before. A stent was placed and esophagus healed. Another patient with severe right dislocation referred transient dysphagia to solids, which resolved gradually in the first postoperative year. All the other patients did not present any esophageal symptoms. CONCLUSION: For the first time, we demonstrate the right dislocation of the esophagus after PT and we propose an objective method to measure it. In most patients, PT is a procedure not affecting esophageal function, but dysphagia can occur if dislocation is important. Esophagus mobilization during PT should be cautious, especially in patients who underwent previous thoracic procedures.

The Influence of SARS-CoV-2 Pandemic on the Diagnosis of Celiac Disease and Clinical Practice in Pediatric Gastroenterology.

Celiac disease (CD) has a high prevalence but remains largely underdiagnosed. Although extensive studies have confirmed that children with CD do not have an increased risk of severe COVID-19, public health regulations associated with the SARS-CoV-2 pandemic may have exacerbated this problem. The aim of this study was to assess the effect of SARS-CoV-2 on the number of new-onset CD cases. Additionally, the role of SARS-CoV-2 in autoimmune diseases and its influence on clinical practice in pediatric gastroenterology were briefly reviewed. We described the data from the hospital electronic registry of new-onset CD, during the COVID-19 pandemic and 2 years before. A total of 423 children were diagnosed with CD between March 2018 and February 2022: 228 in the 2-year pre-COVID-19 period and 195 during the pandemic. The number of patients during the COVID-19 pandemic was 14.5% lower than in the previous years. The quarterly comparison of CD diagnoses showed a reduction in all quarters. A reduction in diagnoses during the lockdown and in the following months was evident and not compensated thereafter. This is the first study to evaluate the impact of SARS-CoV-2 on the diagnosis of CD in children. Further studies are necessary to improve the system of biopsy-sparing diagnosis and to evaluate the effect of the diagnostic delay. Special attention should be given to the implementation of telemedicine services.

Clinical Course of Very Early-Onset Inflammatory Bowel Disease.

OBJECTIVES: Data on the phenotypes and disease outcomes of very early-onset inflammatory bowel disease (VEO-IBD) are limited. The aims of this study were to describe the clinical features, outcomes, and treatment response of VEO-IBD patients and to compare them with later-onset pediatric inflammatory bowel disease (P-IBD) patients. METHODS: All consecutive patients aged 0-6 years who were diagnosed with Crohn disease (CD), ulcerative colitis, or IBD unclassified (IBD-U) at 2 academic hospitals from 2010 to March 2021 were included. They were compared to sex-matched IBD patients aged 6-17 years. RESULTS: Two hundred thirty-two patients were included, 78 (34%) with VEO-IBD and 154 (66%) with P-IBD. IBD-U was the most common diagnosis in the VEO-IBD group compared to P-IBD (28% vs 3%, P < 0.001), while CD was predominant in older children (27% vs 52%, P < 0.001). The VEO-IBD group showed lower rates of clinical remission after induction with steroids compared to older children (82% vs 93%, P = 0.01), higher rates of steroid resistance (14% vs 5%, P = 0.02), and steroid dependence (27% vs 8%, P < 0.001). The number of patients who started anti-tumor necrosis factor (TNF)-α agents was similar between the groups. Anti-TNF-α retention was lower in the VEO-IBD group at 1 and 2 years (59% vs 85%, P = 0.003; 16% vs 55%, P < 0.001, respectively). Surgical risk appeared to be higher for VEO-IBD (32% vs 14%, P < 0.001). CONCLUSIONS: When compared to P-IBD patients, patients with VEO-IBD may have a more severe disease course, a poorer response to steroids and anti-TNF-α agents, and require more frequent surgical procedures.

Intrasphincteric Botox injections in Hirschsprung's disease: indications and outcome in 64 procedures over a ten-year period.

BACKGROUND: Intrasphincteric botulinum toxin (Botox) injection for symptomatic postoperative anal achalasia in Hirschsprung's disease (HSCR) has found wide application in the last twenty years. The aim of this study was to describe effectiveness and functional outcome of a series of patients treated over a 10-year period. METHODS: All consecutive HSCR patients who received intrasphincteric Botox injections between January 2007 and December 2016 were included. Demographic data and clinical features were collected. A detailed questionnaire focusing on outcome in the medium and long-term was administered to all families. RESULTS: In the study period 64 intrasphincteric Botox injections were performed in 31 patients. Completed questionnaires were returned by 27 out of 28 eligible patients (96%) reporting improvement or symptoms resolution in 16 (59%). The highest success rates were experienced by patients younger than 4, with long HSCR forms and with recurrent enterocolitis (75%, 100% and 100% of success rates, respectively). No major complications occurred. Minor complications were described by 7 patients (26%). CONCLUSIONS: Intrasphincteric Botox injection proved to be feasible, safe and reasonably effective in children with HSCR and postoperative anal achalasia. Infants and toddlers with long HSCR forms and recurrent bouts of enterocolitis are those who would benefit most from this treatment.

Enterostomy-related complications in Hirschsprung's disease in a single cohort.

BACKGROUND: Hirschsprung's disease (HSCR) is a frequent cause of intestinal obstruction in children and may require an enterostomy. The study aimed to describe the most common enterostomy-related complications in a series of patients treated in a single center. METHODS: A series of consecutive HSCR patients treated or followed-up at our institution between January 1993 and December 2016 were included. Data about HSCR type, enterostomy site, duration and complications of the stoma were recorded. RESULTS: Three hundred one patients with HSCR were followed-up. Sixty-one had ultralong forms (TCSA/TIA), 21 had long forms (L-HSCR) and 219 had classic short forms (S-HSCR). One hundred thirty-seven patients required a stoma (100% of patients with TCSA/TIA, 66.7% with L-HSCR and 28.3% with S-HSCR). We observed 64 stoma-related complications: 36 major complications and 28 minor complications. Major complications occurred more often in long forms (P=0.037). The presence of an ileostomy was statistically associated with an increased rate of complications compared to colostomy. The longer the stoma was in site, the higher the complication rate was. CONCLUSIONS: Long and ultra-long forms are associated with a longer duration of the stoma and to a major risk of stoma-related complications.

DNA methylation of the TPMT gene and azathioprine pharmacokinetics in children with very early onset inflammatory bowel disease.

BACKGROUND: Thiopurine methyltransferase (TPMT) is a crucial enzyme for azathioprine biotransformation and its activity is higher in very early onset inflammatory bowel disease (VEO-IBD) patients than in adolescents with IBD (aIBD). AIMS: The aims of this pharmacoepigenetic study were to evaluate differences in peripheral blood DNA methylation of the TPMT gene and in azathioprine pharmacokinetics in patients with VEO-IBD compared to aIBD. METHODS: The association of age with whole genome DNA methylation profile was evaluated in a pilot group of patients and confirmed by a meta-analysis on 3 cohorts of patients available on the public functional genomics data repository. Effects of candidate CpG sites in the TPMT gene were validated in a larger cohort using pyrosequencing. TPMT activity and azathioprine metabolites (TGN) were measured in patients' erythrocytes by HPLC and associated with patients' age group and TPMT DNA methylation. RESULTS: Whole genome DNA methylation pilot analysis, combined with the meta-analysis revealed cg22736354, located on TPMT downstream neighboring region, as the only statistically significant CpG whose methylation increases with age, resulting lower in VEO-IBD patients compared to aIBD (median 9.6% vs 12%, p = 0.029). Pyrosequencing confirmed lower cg22736354 methylation in VEO-IBD patients (median 4.0% vs 6.0%, p = 4.6 ×10-5). No differences in TPMT promoter methylation were found. Reduced cg22736354 methylation was associated with lower TGN concentrations (rho = 0.31, p = 0.01) in patients with VEO-IBD and aIBD. CONCLUSION: Methylation of cg22736354 in TPMT gene neighborhood is lower in patients with VEO-IBD and is associated with reduced azathioprine inactivation and increased TGN concentrations.