One year of experience with combined pharmacokinetic/pharmacogenetic monitoring of anti-TNF alpha agents: a retrospective study.

Anti-tumor necrosis factor alpha (anti-TNFα) inhibitors are used extensively for the management of moderate to severe inflammatory bowel disease (IBD) in both adult and pediatric patients. Unfortunately, not all patients show an optimal response to induction therapy, while others lose their response over time for reasons yet poorly understood. We report on a pharmacokinetic/pharmacogenetic approach to monitor the therapy with anti-TNFα in a real-world cohort of seventy-nine pediatric patients affected by IBD that was analyzed retrospectively. We evaluated plasma concentrations of infliximab, adalimumab, and related anti-drug antibodies (ADAs), and single nucleotide polymorphisms (SNPs) in genes involved in immune processes and inflammation on the anti-TNFα response. We found a significant association between the SNP in TNFα promoter (-308G>A) and clinical remission without steroids in patients on infliximab therapy. Additionally, a potential connection between HLA-DQA1*05 genetic variant carriers and a higher risk of anti-TNFα immunogenicity emerged.

Dual biological therapy and small molecules in pediatric inflammatory bowel disease.

Inflammatory bowel diseases (IBDs) including Crohn's disease (CD), ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBD-U) are chronic inflammatory disorders which can affect the gastrointestinal tract. Anti-tumor necrosis factors antibodies (anti-TNFα) such as infliximab (IFX) and adalimumab (ADA) are the first line biological therapy for severe or complicated IBDs in pediatric age. Second line therapeutic options as vedolizumab (VDZ) and ustekinumab (UST) are currently used off-label in pediatric age. Furthermore, despite optimization of biologics, a great proportion of patients may fail to respond to biologic agents (up to 30%) or lose response over the time (around 50%) hence these patients may be left without another valid therapeutic option. Consequently, several efforts have been made in the last years in order to develop new drugs and to contrive new therapeutic strategies. Small molecule drugs (SMDs) and combination therapy with either two biologic agents or with a SMD and a biological agent have recently been proposed. Data on safety and efficacy of these new therapeutic options are limited. The objective of the present review is to summarize the most up-to-date available literature in pediatric IBD.

Predictive Fat Mass Equations for Children With Inflammatory Bowel Disease.

OBJECTIVE: Evaluate accuracy of skinfold thicknesses and body mass index (BMI) for the prediction of fat mass percentage (FM%) in paediatric inflammatory bowel disease (IBD) and to develop population-specific formulae based on anthropometry for estimation of FM%. METHODS: IBD children (n = 30) and healthy controls (HCs, n = 144) underwent anthropometric evaluation and dual-energy X-ray absorptiometry (DEXA) scan, as the clinical reference for measurement of body composition. Body FM% estimated with skinfolds thickness was compared with FM% measured with DEXA. By means of 4 prediction models, population specific formulae for estimation of FM% were developed. RESULTS: No significant difference in terms of FM% measured by DEXA was found between IBD population and HCs (FM% 29.6% vs 32.2%, P = 0.108). Triceps skinfold thickness (TSF, Model 2) was better than BMI (Model 1) at predicting FM% (82% vs 68% of variance). The sum of 2 skinfolds (biceps + triceps; SF2, Model 3) showed an improvement in the prediction of FM% as compared with TSF, Model 2 (86% vs 82% of variance). The sum of 4 skinfolds (biceps + triceps + suprailiac + subscapular; Model 4) showed further improvement in the prediction of FM% as compared with SF2 (88% vs 86% of variance). CONCLUSIONS: The sum of 4 skinfolds is the most accurate in predicting FM% in paediatric IBD. The sum of 2 skinfolds is less accurate but more feasible and less prone to error. The newly developed population-specific formulae could be a valid tool for estimation of body composition in IBD population and an alternative to DEXA measurement.

Ruxolitinib in Aicardi-Goutières syndrome.

Aicardi-Goutières Syndrome (AGS) is a monogenic leukodystrophy with pediatric onset, clinically characterized by a variable degree of neurologic impairment. It belongs to a group of condition called type I interferonopathies that are characterized by abnormal overproduction of interferon alpha, an inflammatory cytokine which action is mediated by the activation of two of the four human Janus Kinases. Thanks to an ever-increasing knowledge of the molecular basis and pathogenetic mechanisms of the disease, Janus Kinase inhibitors (JAKIs) have been proposed as a treatment option for selected interferonopathies. Here we reported the 24 months follow-up of the fifth AGS patient treated with ruxolitinib described so far in literature. The treatment was globally well tolerated; clinical examinations and radiological images demonstrated a progressively improving course. It is however to note that patients presenting with mild and spontaneously improving course have been reported. Large natural history studies on AGS spectrum are strongly required in order to get a better understanding of the results emerging from ongoing therapeutic trials on such rare disease.

Biological therapy in pediatric age.

Biological therapies, especially blocking tumor necrosis factor-α (TNFα) agents have radically changed the therapeutic approach and disease course of pediatric inflammatory bowel disease (IBD). In particular, drugs such as infliximab (IFX) and adalimumab (ADA) have been demonstrated to be effective in inducing and maintaining corticosteroid-free remission in both adult and pediatric patients with Crohns Disease (CD) and Ulcerative colitis (UC). Biosimilar biological (BioS) therapy is increasingly being used in pediatric age even though most knowledge on the safety and efficacy of these agents is based on IFX in adult IBD data. Studies show high rates of clinical response and remission in both IFX naïve patients and in patients switched from originator to BioS with similar risks of adverse events (AEs) as those reported with IFX originator. In the present review indications, efficacy and AEs of biological therapy in pediatric IBD will be discussed, as well as the role of other biological agents such as Golimumab, Vedolizumab and Ustekinumab, the role of BioS biological therapy and utility of therapeutic drug monitoring in clinical practice.

Noninvasive testing in the management of children with suspected inflammatory bowel disease.

Objective: To assess the accuracy of noninvasive parameters, fecal calprotectin (FC), increased bowel wall thickening (BWT) at intestinal ultrasound (IUS) and blood inflammatory indexes (BII), alone or in combination, as diagnostic tools for inflammatory bowel disease (IBD) in pediatric patients. Methods: Retrospective data were collected on consecutive children (age 2-18 years) referred to our pediatric gastroenterology clinic, for recurrent abdominal pain and/or altered bowel habit from 2007 to 2013. Subjects who had diagnostic workup: laboratory tests (FC, BII, white blood cell (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)) and IUS as initial assessment were eligible. Subjects with known gastrointestinal (GI) diseases, or signs or symptoms highly suggestive for organic diseases necessitating prompt endoscopy (e.g., perianal disease or rectal bleeding), or who had recently performed endoscopy were excluded. The accuracy of noninvasive tests for detecting IBD was assessed using endoscopic and/or radiological investigations, performed in subsequent clinical follow up, as reference gold standard. Results: Seventy-seven patients (mean age 11.3, 44 males) were included, 23 (29.9%) with a final diagnosis of IBD. As single tests, FC gave the highest sensitivity (96%) but lower specificity (72%) and IUS highest specificity (96%) with lower sensitivity (70%). The combination of FC + IUS showed excellent accuracy for detecting children with IBD with positive predictive value: 100%; negative predictive value: 88.5%. The probability of IBD in children with normal FC, BII and IUS was 0.09%. Conclusions: FC and increased BWT at IUS are accurate to guide reassurance or proceeding with further invasive procedures for detecting IBD in children with mild GI symptoms.

Brain abscess in pediatric age: a review.

OBJECTIVE: The purpose of the paper is to examine the current state of the art about epidemiology, diagnosis, and treatment of this infection. METHODS: A review of the literature was performed through a PubMed search of original articles, case reports, and reviews using the key words "brain abscess," "cerebral abscess," "brain infection," "intracranial suppuration," "otogenic brain abscess," "otitis complications," and "sinusitis complications." RESULTS: Pediatric brain abscess is a rare but serious infection, often involving patients with specific risk factors and burdened by a high risk of morbidity and mortality. Brain abscess incidence and mortality decreased over the years, thanks to improved antibiotic therapy, new neurosurgical techniques, and the wide spread of vaccinations. There are no guidelines for the adequate diagnostic-therapeutic pathway in the management of brain abscesses; therefore, conflicting data emerge from the literature. In the future, multicentric prospective studies should be performed in order to obtain stronger evidences about brain abscesses management. Over the next few years, changes in epidemiology could be observed because of risk factors changes.

Accuracy in Diagnosis of Celiac Disease Without Biopsies in Clinical Practice.

BACKGROUND & AIMS: The guidelines of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition allow for diagnosis of celiac disease without biopsies in children with symptoms and levels of immunoglobulin A against tissue-transglutaminase (TGA-IgA) 10-fold or more the upper limit of normal (ULN), confirmed by detection of endomysium antibodies (EMA) and positivity for HLA-DQ2/DQ8. We performed a large, international prospective study to validate this approach. METHODS: We collected data from consecutive pediatric patients (18 years or younger) on a gluten-containing diet who tested positive for TGA-IgA from November 2011 through May 2014, seen at 33 pediatric gastroenterology units in 21 countries. Local centers recorded symptoms; measurements of total IgA, TGA, and EMA; and histopathology findings from duodenal biopsies. Children were considered to have malabsorption if they had chronic diarrhea, weight loss (or insufficient gain), growth failure, or anemia. We directly compared central findings from 16 antibody tests (8 for TGA-IgA, 1 for TGA-IgG, 6 for IgG against deamidated gliadin peptides, and 1 for EMA, from 5 different manufacturers), 2 HLA-DQ2/DQ8 tests from 2 manufacturers, and histopathology findings from the reference pathologist. Final diagnoses were based on local and central results. If all local and central results were concordant for celiac disease, cases were classified as proven celiac disease. Patients with only a low level of TGA-IgA (threefold or less the ULN) but no other results indicating celiac disease were classified as no celiac disease. Central histo-morphometry analyses were performed on all other biopsies and cases were carefully reviewed in a blinded manner. Inconclusive cases were regarded as not having celiac disease for calculation of diagnostic accuracy. The primary aim was to determine whether the nonbiopsy approach identifies children with celiac disease with a positive predictive value (PPV) above 99% in clinical practice. Secondary aims included comparing performance of different serological tests and to determine whether the suggested criteria can be simplified. RESULTS: Of 803 children recruited for the study, 96 were excluded due to incomplete data, low level of IgA, or poor-quality biopsies. In the remaining 707 children (65.1% girls; median age, 6.2 years), 645 were diagnosed with celiac disease, 46 were found not to have celiac disease, and 16 had inconclusive results. Findings from local laboratories of TGA-IgA 10-fold or more the ULN, a positive result from the test for EMA, and any symptom identified children with celiac disease (n = 399) with a PPV of 99.75 (95% confidence interval [CI], 98.61-99.99); the PPV was 100.00 (95% CI, 98.68-100.00) when only malabsorption symptoms were used instead of any symptom (n = 278). Inclusion of HLA analyses did not increase accuracy. Findings from central laboratories differed greatly for patients with lower levels of antibodies, but when levels of TGA-IgA were 10-fold or more the ULN, PPVs ranged from 99.63 (95% CI, 98.67-99.96) to 100.00 (95% CI, 99.23-100.00). CONCLUSIONS: Children can be accurately diagnosed with celiac disease without biopsy analysis. Diagnosis based on level of TGA-IgA 10-fold or more the ULN, a positive result from the EMA tests in a second blood sample, and the presence of at least 1 symptom could avoid risks and costs of endoscopy for more than half the children with celiac disease worldwide. HLA analysis is not required for accurate diagnosis. Clinical Trial Registration no: DRKS00003555.

Therapeutic Drug Monitoring of Anti-TNFα Inhibitors: A Matter of Cut-Off Ranges.

Therapeutic drug monitoring (TDM) is a useful tool for optimising the use of anti-TNFα inhibitors in patients with inflammatory bowel diseases (IBDs). Recently, point-of-care methods for the quantification of drug levels and anti-drug antibodies (ADAs) have been developed to overcome the limitations of conventional enzyme-linked immunoabsorbent assays (ELISAs). Here, we evaluated the performance, interchangeability, and agreement between an automated ELISA-based immunoassay (CHORUS Promonitor) and the lateral flow assay (RIDA®QUICK) for the quantification of infliximab (IFX, n = 65) and adalimumab (ADM, n = 58) plasma levels in IBD patients. Thirty-two samples for IFX and twenty-three samples for ADM that tested positively for the presence of ADAs were also used. Overall, data analysis showed a good agreement of ADM trough concentrations (R2 = 0.75) between the two assays as well as for ADA measurement (K > 0.8). However, IFX levels highlighted a weak correlation (R2 = 0.58) between the two kits, with the RIDA®QUICK assay overestimating IFX plasma values by 30% when compared to the CHORUS Promonitor kit. Results from this study show that the two assays are not quantitatively and qualitatively interchangeable due to substantial discrepancies in some results. Accordingly, the same assay should be used for the longitudinal follow-up of IBD patients.

Resting energy expenditure in children and adolescents with cerebral palsy: accuracy of available prediction formulas and development of population-specific methods.

Introduction: Energy requirements are difficult to estimate in children with cerebral palsy (CP). Resting energy expenditure (REE), necessary to implement personalized nutritional interventions, is most commonly estimated using prediction formulae since indirect calorimetry, the reference method, is not available in all nutrition units. The aims of the present study were: (1) to evaluate the accuracy of the most commonly used REE prediction formulae developed for healthy children, in children with CP; (2) to assess the accuracy of the REE population-specific formula for CP children proposed in our preliminary report; (3) to develop new population-specific methods. Methods: REE was measured by indirect calorimetry in 100 children and adolescents with spastic quadriplegic cerebral palsy (SQCP) and estimated on the basis of predictive formulas selected by the clinicians [World Health Organization (WHO), Harris-Benedict, Schofield weight, Schofield weight & height, Oxford, Mifflin formulae and a population-specific formula for CP children developed in our preliminary report]. Results: 100 children with SQCP (35 girls, 35%) classified as level V according to gross motor function classification system (GMFCS-V); 64% with oral nutrition, 29% total enteral nutrition (nasogastric tube feeding, percutaneous endoscopic gastrostomy, percutaneous endoscopic transgastric jejunostomy) and 7% mixed nutrition. The median (IQR) REE was 41.96 (17.5) kcal/kg/day.Statistical analysis highlighted a proportional bias between the indirect calorimetry and all considered predictive formulae for REE determination. By studying the relationship between the bias and the mean values of REE, specific conversion equations were obtained. With a pre-specified model having as predictors the variable weight and the variable Triceps Skinfold (TSF) and, as response the variable REE measured by indirect calorimetry, a predictive nomogram was developed to estimate the REE in this population of children. Conclusions: We suggest using predictive formulae for healthy children with caution, and where possible carrying out indirect calorimetry to assess REE in children with CP. However, we propose a new tool which could be developed to become an additional help for assessment of REE in the clinical practice.Future objectives will be to obtain a larger sample size, in a multicenter perspective study, to build a specific predictive model for the REE of the studied population.

Prevalence and detection rate of celiac disease in Italy: Results of a SIGENP multicenter screening in school-age children.

BACKGROUND: Celiac disease is a common lifelong disorder. Recent studies indicate that the number of clinically detected cases has increased over the last decades, however little is known about changes in the prevalence and the detection rate of celiac disease. AIM: To evaluate the current prevalence and detection rate of celiac disease in Italy by a multicenter, mass screening study on a large sample of school-age children. METHODS: children aged 5-11 years were screened at school by HLA-DQ2 and -DQ8 determination on a drop of blood in six Italian cities; total serum IgA and IgA anti-transglutaminase were determined in children showing HLA-DQ2 and/or -DQ8 positivity. Diagnosis of celiac disease was confirmed according to the European guidelines. RESULTS: 5994 children were eligible, 4438 participated and 1873 showed predisposing haplotypes (42.2%, 95% CI=40.7-43.7). The overall prevalence of celiac disease was 1.65% (95% CI, 1.34%-2.01%). Only 40% of celiac children had been diagnosed prior to the school screening. Symptoms evoking celiac disease were as common in celiac children as in controls. CONCLUSION: In this multicenter study the prevalence of celiac disease in school-age Italian children was one of the highest in the world. Determination of HLA predisposing genotypes is an easy and fast first-level screening test for celiac disease. Without a mass screening strategy, 60% of celiac patients remain currently undiagnosed in Italy.

Self-Perceived Physical Level and Fitness Performance in Children and Adolescents with Inflammatory Bowel Disease.

Background: Inflammatory bowel disease (IBD) patients show a higher risk of developing metabolic and cardiovascular diseases due to the presence of systemic low-grade chronic inflammation. Exercise can improve cardiovascular fitness and modulate the inflammatory processes. We evaluated the physical activity (PA) level and the fitness performance of children and adolescents with IBD. Patients and methods: We considered 54 pediatric patients with IBD (14.6 ± 2.2; 22 M), including CD (n = 27) UC (n = 24) and IBD unclassified (n = 3), and 70 healthy children. In all children, the Physical Activity Questionnaire (PAQ-C) and the International Fitness Enjoyment Scale were self-reported and recorded. Results: PAQ-C showed significant difference in PA levels in patients with IBD compared to controls (p < 0.001). A decrease in general fitness (p = 0.003), cardiorespiratory fitness (p = 0.002), strength (p = 0.01), speed agility (p = 0.003), and flexibility (p = 0.01) were also detected between patients and controls. Speed agility was related to age (p = 0.02) and BMI z-score (p = 0.01), and flexibility to BMI z-score (p = 0.05). We noted a correlation between PA levels and physician global assessment (p = 0.021) and activity disease severity (p = 0.025). Conclusions: A poorer PA level and poor physical competence were found in patients with IBD compared to healthy children and adolescents. Monitored exercise could provide multiple benefits at both physical and psychological levels.

Antiretroviral drugs in HIV-infected children.

Availability of highly active antiretroviral therapy has dramatically increased survival rates and substantially modified the course of HIV infection, which has now become a chronic disease both in adults and in children. Treatment strategies in paediatric patients have to face with specific challenges associated with selection of a successful antiretroviral drug regimen, long-lasting maintenance of adherence to therapy, short and long-term drug-related toxicities and emerging of extensive drug resistance. This review shows an up-to-date picture of the ultimate advances of antiretroviral therapy in HIV-infected children.

The Role of Carrageenan in Inflammatory Bowel Diseases and Allergic Reactions: Where Do We Stand?

Carrageenan (CGN) is a high molecular weight polysaccharide extracted from red seaweeds, composed of D-galactose residues linked in ß-1,4 and α-1,3 galactose-galactose bond, widely used as a food additive in processed foods for its properties as a thickener, gelling agent, emulsifier, and stabilizer. In recent years, with the spread of the Western diet (WD), its consumption has increased. Nonetheless, there is a debate on its safety. CGN is extensively used as an inflammatory and adjuvant agent in vitro and in animal experimental models for the investigation of immune processes or to assess the activity of anti-inflammatory drugs. CGN can activate the innate immune pathways of inflammation, alter the gut microbiota composition and the thickness of the mucus barrier. Clinical evidence suggests that CGN is involved in the pathogenesis and clinical management of inflammatory bowel diseases (IBD), indeed food-exclusion diets can be an effective therapy for disease remission. Moreover, specific IgE to the oligosaccharide α-Gal has been associated with allergic reactions commonly referred to as the "α-Gal syndrome". This review aims to discuss the role of carrageenan in inflammatory bowel diseases and allergic reactions following the current evidence. Furthermore, as no definitive data are available on the safety and the effects of CGN, we suggest gaps to be filled and advise to limit the human exposure to CGN by reducing the consumption of ultra-processed foods.

Strictureplasties performed by laparoscopic approach for complicated Crohn's disease. A prospective, observational, cohort study.

BACKGROUND: Laparoscopy is considered the best surgical approach for Crohn's Disease (CD), and strictureplasty a reliable alternative to intestinal resection. Nevertheless, their association has never been evaluated. AIM: To investigate feasibility and safety of conventional (SP) and non-conventional (NCSP) strictureplasties, using laparoscopy, for complicated CD. METHODS: Starting January 2008, a prospective cohort study was performed, in consecutive, unselected patients, undergoing primary surgery for CD (Group-A). The residential database (CD-CARD) was used for the retrospective extraction of control patients (Group-B). Univariate and multi-variate analysis of pre-operative characteristics, intra-operative findings, morbidity, and intra-abdominal septic complications (IASCs) was performed. RESULTS: Between January 2008 and December 2019, 331 patients received 162 SPs, 138 NCSPs, and 373 resections (Group-A). From the CD-CARD, 227 control patients received 159 SPs, 117 NCSPs, and 271 resections (Group-B) (ns). Preoperatively, Group-A presented batter nutritional status and received more biological therapies, Group-B more steroids. Group-A presented less abdominal abscesses, planned ostomies, minor complications, shorter operating time and hospitalization than Group-B, but similar major complications, IASCs and anastomotic leaks. IASCs were related to older age, elevated inflammatory indices, and preoperative treatment with high-risk drugs. CONCLUSIONS: SP and NCSP are feasible by laparoscopy, with low morbidity rate, confirming the advantages of both minimally invasive and conservative surgery.

A Multivariate Pattern Analysis of Metabolic Profile in Neurologically Impaired Children and Adolescents.

BACKGROUND: The prevalence of pediatric metabolic syndrome is usually closely linked to overweight and obesity; however, this condition has also been described in children with disabilities. We performed a multivariate pattern analysis of metabolic profiles in neurologically impaired children and adolescents in order to reveal patterns and crucial biomarkers among highly interrelated variables. PATIENTS AND METHODS: We retrospectively reviewed 44 cases of patients (25M/19F, mean age 12.9 ± 8.0) with severe disabilities. Clinical and anthropometric parameters, body composition, blood pressure, and metabolic and endocrinological assessment (fasting blood glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, glutamic oxaloacetic transaminase, glutamate pyruvate transaminase, gamma-glutamyl transpeptidase) were recorded in all patients. As a control group, we evaluated 120 healthy children and adolescents (61M/59F, mean age 12.9 ± 2.7). RESULTS: In the univariate analysis, the children-with-disabilities group showed a more dispersed distribution, thus with higher variability of the features related to glucose metabolism and insulin resistance (IR) compared to the healthy controls. The principal component (PC1), which emerged from the PC analysis conducted on the merged dataset and characterized by these variables, was crucial in describing the differences between the children-with-disabilities group and controls. CONCLUSION: Children and adolescents with disabilities displayed a different metabolic profile compared to controls. Metabolic syndrome (MetS), particularly glucose metabolism and IR, is a crucial point to consider in the treatment and care of this fragile pediatric population. Early detection of the interrelated variables and intervention on these modifiable risk factors for metabolic disturbances play a central role in pediatric health and life expectancy in patients with a severe disability.

Factors associated with quality of life in Italian children and adolescents with IBD.

Improving the quality of life (QoL) is crucial in the management of pediatric inflammatory bowel disease (IBD). We aimed to (1) Validate the IMPACT-III questionnaire in Italian IBD children; (2) explore factors associated to QoL in pediatric IBD. Internal consistency, concurrent validity, discriminant validity and reproducibility of the Italian version of the IMPACT-III questionnaire was measured in IBD children/adolescents in 8 centers. Associations between patient and disease characteristics and the IMPACT-III domains were analyzed through quantile regression analysis. The IMPACT-III questionnaire, collected in 282 children with IBD (median age: 14.8 years; IQR 12.4-16.4) showed a median total score of 76 (IQR 67-83). Female gender, active disease and age were negatively associated with the total IMPACT-III score. Specifically, female gender was negatively associated with the Bowel/Systemic Symptoms, Emotional and Treatment domain scores, while disease activity was significantly associated with Bowel Symptoms and Treatment/Interventions reported QoL. The IMPACT- III showed good internal consistency (Cronbach's alpha coefficient = 0.87, 95% CI 0.85-0.89) and reproducibility (Concordance Correlation Coefficient = 0.66, 95% CI 0.57-0.74). In Italian children with IBD active disease, female gender and adolescence are associated to a worse QoL, indicating the need of more attention in this subgroup of young patients. IMPACT-III questionnaire is a reliable instrument to measure QoL in Italian children.

Efficacy of the gluten free diet in the management of functional gastrointestinal disorders: a systematic review on behalf of the Italian Society of Paediatrics.

BACKGROUND: Functional gastrointestinal disorders (FGIDs) are characterized by chronic/recurrent gastrointestinal symptoms not related to organic disorders. Due to the limited treatment options and to the perception of subjects with FGIDs suffering from a food intolerance, in recent years there has been an increase in the self-prescription of elimination diets, especially gluten free diet (GFD), for the treatment of these disorders. For this reason, we decided to perform this systematic review with the aim to evaluate the available evidence on the effects of a GFD on gastrointestinal symptoms, in subjects with FGIDs. METHODS: Cochrane Library and MEDLINE (via PubMed) databases were searched, from inception to March 2018, using the MeSH terms "functional gastrointestinal disorder OR irritable bowel syndrome AND gluten". We included all the clinical trials published in English and evaluating the effects of a GFD in subjects with FGIDs diagnosed according to the Rome II, III, and IV criteria. RESULTS: Eleven trials were eligible (3 prospective trials, 8 single or double-blind placebo-controlled trials), with 10/11 trials including adult subjects with irritable bowel syndrome (IBS) or FGIDs. Most of the prospective studies found an effect of GFD on gastrointestinal symptoms control. Nevertheless, 1 trial failed to find an association between gluten and GI symptoms when FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) content was simultaneously reduced in the diet, and 2 trials reported a worsening of symptoms during placebo administration. The results of the different trials are difficult to compare due to discrepancies in the study protocols regarding the amount and type of gluten administered, the duration of the gluten challenge, the type of placebo used, and the duration of the challenge itself. CONCLUSIONS: According to our results, gluten may contribute to the occurrence of gastrointestinal symptoms in patients with FGIDs, particularly in those with IBS. Nevertheless, the results of the currently available trials are difficult to compare due to the lack of standardization in the study designs. For this reason, it is still not possible to recommend the use of the GFD in the routine management of FGIDs.