Prognosis of pediatric ulcerative colitis after infliximab failure: A multicenter registry-based cohort study.

BACKGROUND AND AIM: Even with increasing numbers of biologic agents available for management of ulcerative colitis (UC), infliximab (IFX) retains an important place in treatment of pediatric patients with this disease. As few reports have addressed outcomes in pediatric UC patients who had to discontinue IFX, we examined clinical course and prognosis after IFX failure in pediatric UC. METHODS: A prospective cohort study of pertinent cases enrolled in the Japanese Pediatric Inflammatory Bowel Disease Registry between 2012 and 2020 was conducted to determine outcomes for pediatric UC patients who received IFX but required its discontinuation during follow-up (IFX failure). RESULTS: Of the 301 pediatric UC patients in the registry, 75 were treated with IFX; in 36 of these, IFX was discontinued during follow-up. Severity of UC at onset and absence of concomitant immunomodulator therapy were significant risk factors for IFX failure (P = 0.005 and P = 0.02, respectively). The cumulative colectomy rate after IFX failure was 41.3% at 1 year and 47.5% at 2 years. Colectomy was significantly more frequent when IFX was discontinued before June 1, 2018, than when IFX was discontinued later (P = 0.013). This difference likely involves availability of additional biologic agents for treatment of UC beginning in mid-2018 (P = 0.005). CONCLUSION: In pediatric UC patients, approximately 50% underwent colectomy during a 2-year interval following IFX failure. Prognosis after IFX failure appeared to improve with availability of new biologic agents and small-molecule drugs in mid-2018.

Evaluation of Deficient Nutrients in Infants and Toddlers Mainly Taking Amino Acid-Based Elemental Formulas: An Exploratory Study.

INTRODUCTION: This study evaluated nutrient deficiencies in infants and toddlers with inflammatory bowel disease (IBD) and eosinophilic gastrointestinal disorders (EGIDs), whose primary nutritional source is elemental formulas (EFs). METHODS: The nutrient status of children with IBD and EGID aged 6 months to 6 years was evaluated. RESULTS: Twenty-one children fed with EFs (EF group) and 25 controls (CL group) were enrolled. The selenium level in the EF group was lower than that in the CL group (2.2 µg/dL vs. 9.3 µg/dL; p < 0.01). Although fat-soluble vitamins were deficient in some EF group participants, no significant differences were observed in their concentration and insufficiency proportion. However, ascorbic acid deficiency was more frequent in the EF group, with significantly lower levels (8.6 µg/mL vs. 12.0 µg/mL; p < 0.01). The triene:tetraene ratio was significantly higher in the EF group (0.046 vs. 0.010; p < 0.01). Asparagine and taurine levels were significantly lower in the EF group (asparagine: p < 0.01; taurine: p < 0.01) and tyrosine and phenylalanine levels were higher in the EF group, resulting in a lower Fisher's ratio (p < 0.01). CONCLUSION: Long-term feeding with EFs can cause deficiencies in essential fatty acids, selenium, and ascorbic acid and also carries a risk of amino acid imbalance in infants and toddlers.

Safety and efficacy of vedolizumab in pediatric patients with ulcerative colitis: multicenter study in Japan.

BACKGROUND: Vedolizumab (VDZ) is a humanized monoclonal antibody that binds to α4ß7 integrin expressed in T-lymphocytes and is gut selective. Few studies have evaluated the safety and efficacy of VDZ in pediatric ulcerative colitis (UC) patients, especially from Asia. METHODS: A longitudinal multicenter retrospective study was conducted at 10 Japanese tertiary medical institutions. Patients aged ≤18 years old who received VDZ for UC between January 2019 and July 2021 were enrolled. Information on the clinical characteristics, prior/concomitant treatment, and safety during the observation period was collected. RESULTS: The data obtained from 48 patients (males, n = 30; females, n = 18) were analyzed. The median age at VDZ induction was 14 (range 4-18) years old. VDZ was indicated in 73% of patients as switching from previous biologics due to primary failure, loss of response, and adverse events (AEs) and was the first biologic in 27%. Remission was achieved or maintained at weeks 14, 30, and 54 in 79.2%, 75.0%, and 65.8% of patients, respectively. There were no significant differences between the number of previous biologics exposures and VDZ effectiveness. The hematocrit, serum albumin concentrations, and erythrocyte sedimentation rate (ESR) at baseline differed significantly by VDZ effectiveness. Nine AEs, including infusion reaction, were noted in seven (14.3%) patients. There were no severe AEs related to VDZ administration. CONCLUSIONS: VDZ was safe and effective in children with UC. The hematocrit, albumin, and ESR at VDZ initiation might be predictors for VDZ effectiveness. VDZ may be an important option for pediatric patients and can be used as an alternative to immunomodulators.

Low billing rates for pediatric sedation fee on magnetic resonance imaging.

BACKGROUND: The 2018 revision of social insurance in Japan allows additional fees to be calculated for pediatric magnetic resonance imaging (MRI) that must be performed under sedation. The number and trend of actual claims since this revision was established is unknown. The aim of this study to investigate the use of the additional fees and any regional differences in the use. METHODS: To analyze the claims of additional fees for pediatric sedated MRI after the fiscal year (FY) 2018, the actual claims in inpatient and outpatient practice was analyzed using publicly-available data from the Ministry of Health, Labour and Welfare (MHLW). We analyzed the calculation rate for all MRI scans. Annual changes in the actual number and calculation rate were analyzed. The ratio of the number of additional fees to the overall number of pediatric radiological procedures was used to examine the geographic disparity. RESULTS: The number of calculations from FY 2018 to FY 2020 was available. In FY 2020, only 1347 additional fees were calculated, corresponding to 0.35% of the total number of MRI scans. The number of fees showed a decreasing trend. Most cases were in the 0-4 year age group; however, there were a few cases in the 10-14 year age group without such a decrease. The relative number of calculations by prefecture showed an up to 14-fold disparity. CONCLUSIONS: The requirements for sedation for pediatric MRI are strict, but they are not fully utilized. Measures such as relaxing the requirements for the fee are needed to make MRI-related sedation safer.

Small bowel endoscopy for children: Collaboration of capsule endoscopy and device-assisted enteroscopy.

Capsule endoscopy (CE) and balloon-assisted enteroscopy (BAE) have become indispensable techniques for the diagnosis and management of small bowel disease in both adult and pediatric cases. However, relevant differences exist in the indications between these cohorts, with body weight and age having particular relevance in decisions for the latter. Both CE and BAE are designed for adult physique and they were not widely used among children. In addition, the types of small intestinal diseases differ between adults and children, and consequently, the indications also differ between them. This review focuses on the issues relevant to pediatric cases and describes the practical application of endoscopy in clinical practice. In conclusion, although there are age and weight restrictions, both CE and BAE are safe and useful devices for use in children, and their indications for use in children are likely to expand in the future.

Incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation.

OBJECTIVES: To describe the incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation. METHODS: We included 45 patients with perianal inflammation who underwent ultrasonography. To demonstrate the diagnostic performance of ultrasound for fistula-in-ano, a definite diagnosis of perianal abscess, and fistula-in-ano was determined as that proven through magnetic resonance imaging (MRI) or computed tomography (CT). The absence or presence of perianal abscess and fistula-in-ano on ultrasonography was recorded. RESULTS: Among the 45 patients, on ultrasound, perianal abscess and fistula-in-ano were detected in 22 (48.9%) and 30 (68.2%) patients, respectively. Nine patients had MRI or CT and a definite diagnosis of perianal abscess or fistula-in-ano; accuracy, negative predictive value, and positive predictive value of ultrasound for perianal abscess were 77.8% (7/9; 95% confidence interval [CI]: 40.0%-97.1%), 66.7% (2/3; 95% CI: 9.4%-99.2%), 83.3% (5/6; 95% CI: 35.9%-99.6%), and those of fistula-in-ano were 100% (9/9; 95% CI: 66.4%-100%), 100% (8/8; 95% CI: 63.1%-100%), and 100% (1/1; 95% CI: 2.5%-100%), respectively. CONCLUSIONS: Perianal abscess and fistula-in-ano were detected by ultrasound in half of the patients with perianal inflammation. Accordingly, ultrasound has an acceptable diagnostic performance for perianal abscess and fistula-in-ano.

A Systematic Review of Monogenic Inflammatory Bowel Disease.

BACKGROUND & AIMS: Advances in genomic technologies have led to increasing reports of monogenic inflammatory bowel disease (IBD). Here, we systematically review the literature to determine the clinical features, genetic profile, and previously used treatment strategies in monogenic IBD. METHODS: A systematic review of MEDLINE articles published between January 2000 and December 2020 was conducted. A total of 750 individual monogenic IBD cases were identified from 303 eligible articles. RESULTS: The most frequently reported monogenic IBD genes were IL10RA/B, XIAP, CYBB, LRBA, and TTC7A. In total, 63.4% of patients developed IBD before 6 years of age, 17.4% developed IBD between ages 10 and 17.9 years, and 10.9% developed IBD after age 18. There was a substantial difference between these age groups and the underlying monogenic disorders. Only 31.7% had any history of extraintestinal comorbidity (EIC) before IBD onset, but 76.0% developed at least 1 EIC during their clinical course. The most common EICs were atypical infection (44.7%), dermatologic abnormality (38.4%), and autoimmunity (21.9%). Bowel surgery, biologic therapy, and hematopoietic stem cell transplantation were performed in 27.1%, 32.9%, and 23.1% of patients, respectively. CONCLUSIONS: Monogenic IBD cases, although rare, have varied extraintestinal comorbidities and limited treatment options including surgery and transplant. Early identification and improved understanding of the characteristics of the genes and underlying disease processes in monogenic IBD is important for effective management.

Serum matrix metalloproteinase-7 in biliary atresia: A Japanese multicenter study.

BACKGROUND: Biliary atresia (BA) is among the commonest indications for liver transplantation (LT) in children. We examined whether serum matrix metalloproteinase-7 (MMP-7) is useful for diagnosis of BA in Japanese infants, and whether serum MMP-7 concentrations before and after Kasai portoenterostomy (KP) predicted LT within a year. METHODS: Subjects under 6 months old at eight pediatric centers in Japan were enrolled retrospectively, including patients with cholestasis and normal controls (NC) without liver disease. Patients with cholestasis were divided into groups representing BA versus cholestasis from other causes (non-BA). Serum samples were collected from patients with BA at diagnosis and 1 and 4 weeks after KP, as well as from non-BA and NC. RESULTS: Serum MMP-7 concentrations were significantly higher in BA at diagnosis (median, 89.1 ng/ml) than in non-BA (11.0; p < 0.001) or NC (10.3; p < 0.001). Receiver operating characteristic (ROC) analysis of MMP-7 for BA versus non-BA yielded an area under the ROC curve of 0.99 (95% confidence interval, 0.96-1.00). An optimal cut-off value of 18.6 ng/ml for serum MMP-7 in diagnosing BA demonstrated sensitivity and specificity of 100% and 90%, respectively. Serum MMP-7 before and 1 week and 4 weeks after KP did not differ significantly between BA requiring only KP and BA requiring LT after KP. CONCLUSION: Serum MMP-7 is a useful marker for diagnosis of BA in Japanese infants, but it could not predict LT within a year.

Diagnostic Accuracy of Ultrasound for Detecting Gastric or Duodenal Ulcers in Pediatric Patients.

OBJECTIVE: Direct ultrasound imaging findings alone have low sensitivity for diagnosing duodenal (65%) and gastric ulcers (40%). This retrospective study evaluated the efficiency of ultrasound in detecting gastric/duodenal ulcers in pediatric patients through direct and indirect findings. METHODS: We evaluated 244 children who underwent ultrasound and subsequent endoscopy within 4 weeks for direct and indirect imaging findings indicative of gastric/duodenal ulcers. Positive direct imaging findings revealed gastric or duodenal wall thickness >8 or 5 mm, respectively, and indirect findings revealed inflammatory changes, hyperechogenicity, and presence of lymph node around ulcers. Correspondingly, we calculated the sensitivity and specificity for diagnosing gastric/duodenal ulcers and used the Fisher's exact and Mann-Whitney U tests to compare the frequency of findings and gastroduodenal wall thicknesses in pediatric patients with gastric/duodenal ulcers. RESULTS: Overall, 6 and 24 were diagnosed with gastric and duodenal ulcers, respectively. The sensitivities of direct and indirect findings were 60.0% (18/30) and 80.0% (24/30), respectively; the corresponding specificities were 98.1% (210/214) and 97.2% (208/214). The frequency of direct and indirect sonographic findings differed significantly between patients with gastric or duodenal ulcers (18/30 versus 24/30, P = .002). Gastric and duodenal wall thicknesses were greater in patients with gastric (6.6 ± 2.6 mm versus 3.6 ± 1.4 mm; P = .003) or duodenal ulcer (5.0 ± 1.4 mm versus 2.2 ± 1.0 mm; P <.0001), respectively, than in those without. CONCLUSIONS: The frequency of indirect finding was greater than that of direct finding in pediatric patients with gastric/duodenal ulcers. Therefore, sonographers should carefully evaluate indirect findings around the stomach or duodenum.

Qing-Dai for pediatric ulcerative colitis multicenter survey and systematic review.

BACKGROUND: Pediatric ulcerative colitis (UC) is more challenging to treat than adult UC. Qing-Dai therapy is effective in adults but reports of its efficacy in children are unavailable. We conducted a questionnaire survey on Qing-Dai use among pediatric patients with UC in Japan to determine its efficacy and safety. METHODS: Questionnaires were sent to 31 high-volume centers treating pediatric patients with inflammatory bowel disease. The number of patients using Qing-Dai, short-term and long-term effects, and adverse events were assessed. A systematic review of studies on the efficacy and safety of Qing-Dai usage for UC was also performed. RESULTS: Overall, 29/31 facilities (93.5%) responded, Qing-Dai was used in 107 patients with UC, and 84/107 patients (78.5%) initiated treatment. Within 6 months, 81/101 (80.2%) patients had clinical remission, while 59/92 (64.1%) patients had no relapse and 29/92 (31.5%) experienced only one to two relapses yearly. Eighty-seven percent of the patients underwent regular follow ups for adverse events, among whom one patient was diagnosed with pulmonary arterial hypertension (PAH), five with enteritis, and one with headache. In the systematic review, the clinical remission rate was 50-80%, and PAH was observed in 14 of 1,158 patients (1.2%). CONCLUSIONS: Qing-Dai is highly effective in treating pediatric UC. However, Qing-Dai should be administered with caution as it may cause adverse events such as PAH.

A consensus statement on health-care transition for childhood-onset inflammatory bowel disease patients.

Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder of the intestine. The incidence of IBD is increasing worldwide, including Japan, and in approximately 25% of all affected patients it is diagnosed before 18 years of age. For the health maintenance of such patients, planned transition to adult care systems is essential. Previous Japanese surveys have revealed gaps between adult and pediatric gastroenterologists with regard to their knowledge and perception of health-care transition for patients with childhood-onset IBD. In 2021-2022, several Web workshops to discuss issues related to the transitional care of IBD patients were held by the Ministry of Health, Labour and Welfare of Japan as part of their program for research on intractable diseases. Clinicians experienced in IBD treatment for pediatric and adult patients participated. As a result, this panel of adult and pediatric gastroenterologists developed five consensus statements on the issue of "transfer from pediatric to adult care" and nine statements on the issue of "addressing transitional care (transition program)." To address current gaps in health-care transition for childhood-onset IBD patients, a programmed approach to transition, and better partnerships between pediatric and adult gastroenterologists are indicated. It is hoped that this consensus statement will provide a basis for the development of appropriate guidelines for clinical practice.

Safety and efficacy of the endoscopic delivery of capsule endoscopes in adult and pediatric patients: Multicenter Japanese study (AdvanCE-J study).

BACKGROUND AND AIM: We retrospectively determined the safety and efficacy of the endoscopic delivery (ED) of capsule endoscopes. METHODS: We enrolled 10,156 patients who underwent small bowel capsule endoscopy (SBCE), 3182 who underwent patency capsule (PC), and 1367 who underwent colon capsule endoscopy (CCE), at 11 gastroenterological and nine pediatric centers. RESULTS: Small bowel capsule endoscopies, PCs, and CCEs were endoscopically delivered to 546 (5.4%), 214 (6.7%), and 14 (1.0%) patients, respectively. Only mild complications occurred for 21.6% (167/774), including uneventful mucosal damage, bleeding, and abdominal pain. Successful ED of SBCE to the duodenum or jejunum occurred in 91.8% and 90.7% of patients aged <16 years and ≥16 years, respectively (P = 0.6661), but the total enteroscopy rate was higher in the first group (91.7%) than in the second (76.2%, P < 0.0001), for whom impossible ingestion (87.3%) was significantly more common than prolonged lodging in the stomach (64.2%, P = 0.0010). Successful PC and CCE delivery to the duodenum occurred in 84.1% and 28.6%, thereafter the patency confirmation rate and total colonoscopy rate was 100% and 61.5%, respectively. The height, weight, and age cutoff points in predicting spontaneous ingestion were 132 cm, 24.8 kg, and 9 years 2 months, respectively, in patients aged <16 years. Patients aged ≥16 years could not swallow the SBCEs mainly due to dysphagia (75.0%); those who retained it in the esophagus due to cardiac disease (28.6%), etc. and in the stomach due to diabetes mellitus (15.7%), etc. CONCLUSIONS: This large-scale study supports the safety and efficacy of ED in adult and pediatric patients. UMIN000042020.

Association between the corrosion of ingested lithium button battery in the esophagus and its complications in pediatric patients.

PURPOSE: The incidence of lithium button battery ingestion has been increasing recently, which results in severe complications. We aimed to demonstrate the association between the corrosion of lithium button batteries in the esophagus on radiographs and their complications. METHODS: The nine pediatric patients included in this study were classified into two groups based on the presence of severe complications. The presence and degree of corrosion on plain radiographs were evaluated. The degree of corrosion was classified into the following three grades; none: 0%; moderate: 1-50%; severe: 51-100%. Fisher's exact test was used for statistical analyses. RESULTS: Of the nine patients, five showed complications. The number of patients who had grade none, moderate, and severe degrees of corrosion was three, four, and two, respectively. The incidence of severe complications differed significantly between the incidence of lithium button batteries' contour (without vs. with severe complications [presence/absence of corrosion] = 1/3 vs. 5/0, respectively; P = 0.0476). In cases with "none" degree of corrosion, all three cases had no complication, and in cases with a "severe" degree of corrosion, all two cases had complications. CONCLUSION: The cases with the presence of corrosion of lithium button batteries had a higher tendency to have severe complications. Therefore, physicians should anticipate the presence of severe complications in pediatric patients with corrosion more than those without corrosion.

Current role of colonoscopy in infants and young children: a multicenter study.

BACKGROUND: To evaluate the role of colonoscopy in infants and young children and clarify the distribution of colonoscopy-requiring diseases in this age group. METHODS: Cohorts of colonoscopies performed at three children's hospitals in Japan between April 2011 and March 2016 including infants and children younger than six years of age were retrospectively reviewed. RESULTS: In total, 453 colonoscopies were performed in 276 infants and young children. Of these 275 (60.8%) were for diagnostic purposes, 177 (39.2%) were performed as follow-up, and one case was performed for treatment. The median patient age at the time of diagnostic colonoscopy was 2.49 years, and there was a male-to-female ratio of 1.72:1. Abnormal macroscopic and/or histopathological findings were noted in 212 (77.1%) cases. Of these, definite diagnoses were established for the presence of eosinophilic gastrointestinal disorders (EGIDs), inflammatory bowel disease (IBD), and polyp/polyposis in 23, 18.5, and 14% of patients, respectively. Among 51 IBD cases, ulcerative colitis, Crohn's disease, and IBD-unclassified were identified in 47.1, 33.3, and 7.8%, retrospectively via endoscopic examination. Of these, 11 (22%) were eventually diagnosed with monogenic diseases via genetic testing. Of those with rectal bleeding, EGIDs, polyps/polyposis, and IBD were found in 27, 19, and 18%, retrospectively. There were significantly more cases of EGIDs and fewer ones of IBD and polyps/polyposis in patients with rectal bleeding younger than two years of age. Furthermore, 68% of all follow-up colonoscopies were performed in children with IBD. There were no serious complications in our study cohort. CONCLUSION: We determined the role of colonoscopy in infants and young children. Diseases diagnosed using colonoscopy in this age group included IBD, EGIDs, and polyps/polyposis. The increasing trend of patients with IBD and EGIDs worldwide means that the role of colonoscopy in infants and younger children will be more important in the future.

Clinical Safety and Utility of Pediatric Balloon-assisted Enteroscopy: A Multicenter Prospective Study in Japan.

OBJECTIVES: The benefit of balloon-assisted enteroscopy (BAE) had been recently documented in pediatric patients, but previous reports are based on single institution experiences. We evaluated the feasibility of pediatric BAE in 8 tertiary referral hospitals throughout Japan. METHODS: This was a prospective, multi-institutional study. Patients younger than 18 years were enrolled between April 2014 and March 2017 to undergo double-balloon or single-balloon enteroscopy. Data were collected prospectively using a standardized questionnaire. RESULTS: We enrolled 79 pediatric patients (96 procedures, 70 boys, 26 girls; median age 12.7 years, range 1-17 years). Antegrade (oral-route) BAE was performed in 20 procedures (lowest body weight 12.9 kg, youngest age 3.7 years), and retrograde (anal-route) BAE in 76 (lowest body weight 10.8 kg, youngest age 1.6 years). Severe adverse events were associated with BAE in 2 patients: 1 with hemorrhage due to polypectomy and 1 with pancreatitis after double-balloon endoscopic retrograde cholangioscopy. No intestinal perforation was reported. Procedure duration of oral-route BAE for diagnosis was significantly longer than anal-route for diagnosis (P < 0.001). The overall diagnostic yield for rectal bleeding/positive fecal occult blood test and abdominal pain was 48%. Among 40 patients referred for diagnosis who did not undergo capsule endoscopy, diagnoses were confirmed in 17 (42.5%) patients after BAE. CONCLUSIONS: This prospective multicenter observational study documents the efficacy of BAE in pediatric patients.

Diagnostic performance of ultrasound without any colon preparation for detecting colorectal polyps in pediatric patients.

BACKGROUND: There are limited data on the sensitivity, specificity and accuracy of ultrasound for detecting colorectal polyps in children and young adults. OBJECTIVE: To evaluate the diagnostic accuracy of ultrasound, without any colon preparation, for detecting colorectal polyps in pediatric patients and to determine the causes of false-negative results. MATERIALS AND METHODS: We included 74 children with clinical signs like rectal bleeding, abdominal pain or diarrhea who underwent both ultrasound and colonoscopy. We evaluated the diagnostic performance of ultrasound for detecting colorectal polyps before colonoscopy, which served as the reference standard. We used Fisher exact and Student's t-tests for statistical analyses. RESULTS: Fifteen pediatric patients were diagnosed with colorectal polyps in the transverse (n=3), descending (n=1) and sigmoid (n=6) colon, and rectum (n=5) by colonoscopy. The sensitivity, specificity and accuracy of ultrasound to detect colorectal polyps were 47% (7/15, 95% confidence interval [CI] 21-73%), 100% (59/59, 95% CI 94-100%) and 89% (66/74, 95% CI 80-95%), respectively. The volume (mean ± standard deviation) of polyps not detected by ultrasound was significantly smaller than that detected (270±380 mm3 vs. 4,600±3,900 mm3, P=0.0124). We observed a significant difference in the location between the polyps detected and not detected by ultrasound (rectal/non-rectal=0/7 vs. 5/3, P=0.0256). No significant age or gender difference was observed. CONCLUSION: The accuracy for detecting colorectal polyps by ultrasound was 89% (95% CI, 80-95%) in our cohort. Polyps found in the rectum and relatively smaller polyps accounted for several false-negative cases.

Unilateral Lung Whiteout in Children: Four Cases and a Discussion of Management.

Unilateral lung whiteout is not a common pediatric chest radiograph finding, but when it is encountered, timely and accurate interpretations of the radiograph are required because life-threatening respiratory failure can be associated. Lung whiteout may result from several conditions, and the differential diagnosis has a broad range. We describe 4 pediatric patients with different etiologies of unilateral lung whiteout: a large pleural effusion, mainstem bronchial plugging with a large cast, a mediastinal tumor, and consolidation. The ultimate causal diagnosis may not be initially obvious, but valuable clues can usually be found in the conventional chest radiograph to assist with appropriate early management. Chest ultrasound provides additional information, and we recommend it as the second examination for such patients.

Zinc monotherapy for young children with presymptomatic Wilson disease: A multicenter study in Japan.

BACKGROUND AND AIM: Few studies of zinc monotherapy for presymptomatic Wilson disease have focused on young children. We therefore evaluated long-term efficacy and safety of zinc monotherapy for such children and established benchmarks for maintenance therapy. METHODS: We retrospectively and prospectively examined children under 10 years old with presymptomatic Wilson disease who received zinc monotherapy from time of diagnosis at 12 participating pediatric centers in Japan. RESULTS: Twenty-four patients met entry criteria. Aspartate aminotransferase and alanine aminotransferase decreased significantly beginning 1 month after initiation of treatment and usually remained under 50 U/L from 1 to 8 years of treatment. Twenty four-hour urinary copper decreased significantly at 6 months and usually remained under 75 µg/day and between 1 and 3 µg/kg/day for the remainder of the study. All patients continued to take zinc, and none became symptomatic. In patients under 6 years old who received 50 mg/day of zinc as an initial dose, aspartate aminotransferase and alanine aminotransferase significantly decreased at 1 month after initiation of treatment, as did γ-glutamyltransferase and 24-h urinary copper at 6 months. CONCLUSIONS: To our knowledge, this is the first multicenter study of zinc monotherapy for young children with presymptomatic Wilson disease. Such monotherapy proved highly effective and safe. Maintaining normal transaminase values (or values under 50 U/L when normalization is difficult) and 24-h urinary copper excretion between 1 and 3 µg/kg/day and under 75 µg/day is a reasonable goal. An initial dose of 50 mg/day is appropriate for patients under 6 years old.