The role of upper gastrointestinal endoscopy in the diagnosis of pediatric inflammatory bowel disease.

OBJECTIVES: Upper gastrointestinal (UGI) tract involvement is frequently reported in pediatric Crohn disease (CD) and ulcerative colitis (UC). Aside from granulomas, most findings are nonspecific. The aims of this study were to review the prevalence of UGI tract findings in pediatric patients with CD or UC at diagnosis and to describe differences in endoscopic and histologic features. METHODS: Patients with CD and UC aged 2 to 17 years diagnosed between 2000 and 2015 who had upper and lower endoscopy at diagnosis were randomly chosen from the BC Children's Hospital inflammatory bowel disease (IBD) registry. Pathology review of the UGI biopsy specimens was blinded to IBD diagnosis. RESULTS: Of the 198 patients, 102 with CD and 96 with UC were included, with a mean age of 11.7 years (range, 2.3-17 years). Patients with CD were more likely to have aphthous ulcers (20.4% vs 3.5%, P = .002) and erosions (16.3% vs 3.5%, P =.018), most commonly affecting the antrum. Macroscopically normal UGI endoscopy was present in 60% of patients. Microscopic disease was reported in 100% of patients with CD and 87% of patients with UC. In both groups, nonspecific inflammation was the most common finding. Chronic deep, superficial, and diffuse inflammation were more frequent among patients with CD than UC (42% vs 4%, P < .001; 60% vs 17%, P < .001; 50% vs 34%, P = .04, respectively). CONCLUSIONS: The UGI tract macroscopic changes were common in pediatric IBD, especially in CD. Despite macroscopically normal endoscopy, histologic abnormalities were frequent. Although chronic inflammation was more often reported in patients with CD, aside from granulomas there were no unique histologic abnormalities unique to CD.

Sharing reference intervals and monitoring patients across laboratories - findings from a likely commutable external quality assurance program.

OBJECTIVES: Laboratory results are increasingly interpreted against common reference intervals (CRIs), published clinical decision limits, or previous results for the same patient performed at different laboratories. However, there are no established systems to determine whether current analytical performance justifies these interpretations. We analysed data from a likely commutable external quality assurance program (EQA) to assess these interpretations. METHODS: The use of CRIs was assessed by evaluating instrument group medians against minimum specifications for bias. The use of clinical decision limits was assessed using specifications from professional bodies, and the monitoring of patients by testing at different laboratories was assessed by comparing all-laboratory imprecision to within-subject biological variation. RESULTS: Five of the 18 analytes with Australasian CRIs did not meet specification for all instrument groups. Among these, calcium and magnesium failed for one instrument group out of seven, while bicarbonate, chloride, and lipase failed for two instrument groups. Of the 18 analytes reviewed currently without CRIs in Australasia, 10 candidates were identified. Among analytes with clinical decision limits, i.e. lipids, glucose, and vitamin D, only triglycerides met both bias and imprecision specifications, while vitamin D met the imprecision specification. Monitoring patients by testing at different laboratories was supported for 15 of the 46 (33 %) analyte-method principles groups that met minimum imprecision specifications. CONCLUSIONS: Analysis of data from commutable EQA programs can provide a mechanism for monitoring whether analytical performance justifies the interpretations made in contemporary laboratory practice. EQA providers should establish systems for routinely providing this information to the laboratory community.

Quality assurance programs for vitamin A and E in serum: are we doing enough to assess laboratory performance?

OBJECTIVES: Monitoring serum vitamin A (retinol) and vitamin E (α-tocopherol) concentrations is common practice for assessing nutritional status. Measurement of these vitamins can be challenging due to several factors. Whilst the RCPAQAP Vitamins: Serum Program assists participating laboratories in harmonisation, the materials provided do not contain the analogues of retinol and α-tocopherol that may be present in real patient samples. We aimed to assess participants' capacity to accurately report retinol and α-tocopherol in the presence of the vitamin E analogues tocopherol acetate and γ-tocopherol. METHODS: A supplementary series of a control sample and three matched spiked samples were distributed to each laboratory participating in the Program. Retinol and α-tocopherol results for each spiked sample were compared to the results of the control sample submitted by each participant. Acceptability of retinol and α-tocopherol results was determined based on the RCPAQAP allowable performance specifications (APS). RESULTS: Thirteen participants returned results for the supplementary sample series. Interference from α-tocopherol acetate was observed with results below the APS in 30 % (n=4) of laboratories for retinol quantification and in 23 % (n=3) for α-tocopherol quantification. One laboratory returned results above the APS for α-tocopherol when γ-tocopherol was present. CONCLUSIONS: This supplementary sample series has shown that the presence of vitamin E analogues can lead to the over or under estimation of nutritional status by some participants. Affected laboratories are encouraged to review their analytical procedures. To further assess laboratory competence, EQA providers should consider using patient samples or spiked challenge samples.

Characterization of Switch/Sucrose Nonfermenting Complex Proteins and Nestin Expression in a Cohort of Pediatric Central Nervous System Tumors.

Tumors of the central nervous system (CNS) in pediatric patients have undergone significant diagnostic refinement through the use of immunohistochemistry (IHC) and molecular techniques. The utility of these novel IHC antibodies has been demonstrated with the inactivation of the switch/sucrose nonfermenting (SWI/SNF) chromatin-remodeling complex in the diagnosis of atypical teratoid/rhabdoid tumors, predominantly through the loss of integrase interactor 1 (INI1; SMARCB1 ). Alternatively, these tumors may have inactivation of brahma-related gene 1 (BRG1; SMARCA4 ) in a subset of cases. The role of other SWI/SNF component proteins and their expression in pediatric brain tumors is not well established. Nestin, an intermediate filament, has been shown to be present in some pediatric CNS tumors, but of uncertain diagnostic and prognostic significance. We sought to explore the immunohistochemical expression profile for common SWI/SNF subunits and nestin in a pediatric CNS tumor cohort. Using a 118-sample tissue microarray, we performed IHC for INI1, BRG1, brahma (BRM), ARID1A, ARID1B, polybromo 1, and nestin. In 19 cases, INI1 was lost and BRG1 was lost in 2 cases. Interestingly, 6 cases originally diagnosed as primitive neuroectodermal tumors showed isolated loss of BRM. Other SWI/SNF proteins did not provide further diagnostic resolution. Nestin was positive in 76.2% of INI1/BRG1-deficient tumors, compared with 29.1% in INI1/BRG1-intact tumors yielding a sensitivity of 76.2%, specificity of 68.0%, and a P value of <0.001, but nestin positivity did not correlate specifically with poor outcomes. In conclusion, we confirm the utility of BRG1 IHC in the workup of pediatric CNS tumors, which may facilitate a difficult diagnosis when conventional markers are inconclusive, or as a first-line marker in cases where intraoperative smears are suggestive of atypical teratoid/rhabdoid tumor. Although nestin expression was associated with SWI/SNF inactivation, it did not yield statistically significant diagnostic or prognostic information in our study. Interestingly, we identified 6 tumors with isolated BRM IHC loss, the significance of which is uncertain but warrants further investigation.

ASAP─Automated Sonication-Free Acid-Assisted Proteomes─from Cells and FFPE Tissues.

Formalin-fixed, paraffin-embedded (FFPE) tissues are an invaluable resource for retrospective studies, but protein extraction and subsequent sample processing steps have been shown to be challenging for mass spectrometry (MS) analysis. Streamlined high-throughput sample preparation workflows are essential for efficient peptide extraction from complex clinical specimens such as fresh frozen tissues or FFPE. Overall, proteome analysis has gained significant improvements in the instrumentation, acquisition methods, sample preparation workflows, and analysis pipelines, yet even the most recent FFPE workflows remain complex and are not readily scalable. Here, we present an optimized workflow for automated sonication-free acid-assisted proteome (ASAP) extraction from FFPE sections. ASAP enables efficient protein extraction from FFPE specimens, achieving similar proteome coverage as established methods using expensive sonicators, resulting in reduced sample processing time. The broad applicability of ASAP on archived pediatric tumor FFPE specimens resulted in high-quality data with increased proteome coverage and quantitative reproducibility. Our study demonstrates the practicality and superiority of the ASAP workflow as a streamlined, time- and cost-effective pipeline for high-throughput FFPE proteomics of clinical specimens.

Multi-omic profiling of the leukemic microenvironment shows bone marrow interstitial fluid is distinct from peripheral blood plasma.

BACKGROUND: The bone marrow is the place of hematopoiesis with a microenvironment that supports lifelong maintenance of stem cells and high proliferation. It is not surprising that this environment is also favourable for malignant cells emerging in the bone marrow or metastasizing to it. While the cellular composition of the bone marrow microenvironment has been extensively studied, the extracellular matrix and interstitial fluid components have received little attention. Since the sinusoids connect the bone marrow interstitial fluid to the circulation, it is often considered to have the same composition as peripheral blood plasma. Stark differences in the cellular composition of the bone marrow and peripheral blood with different secretory capacities would however suggest profound differences. METHODS: In this study we set out to better define if and how the bone marrow interstitial fluid (BMIF) compares to the peripheral blood plasma (PBP) and how both are remodeled during chemotherapy. We applied a multi-omic strategy to quantify the metabolite, lipid and protein components as well as the proteolytic modification of proteins to gain a comprehensive understanding of the two compartments. RESULTS: We found that the bone marrow interstitial fluid is clearly distinct from peripheral blood plasma, both during active pediatric acute lymphoblastic leukemia and following induction chemotherapy. Either compartment was shaped differently by active leukemia, with the bone marrow interstitial fluid being rich in extracellular vesicle components and showing protease dysregulation while the peripheral blood plasma showed elevation of immune regulatory proteins. Following chemotherapy, the BMIF showed signs of cellular remodeling and impaired innate immune activation while the peripheral blood plasma was characterized by restored lipid homeostasis. CONCLUSION: This study provides a comprehensive examination of the fluid portion of the acute lymphoblastic leukemia microenvironment and finds the contribution of either microenvironment to tumourigenesis.

Application of the Eosinophilic Esophagitis Histology Scoring System Grade Scores in Patients at British Columbia Children's Hospital.

INTRODUCTION: Histologic diagnosis of eosinophilic esophagitis (EoE) involves peak eosinophil counts (PEC) being greater than 15 per high power field. The EoE Histology Scoring System (EoEHSS) was developed to comprehensively evaluate biopsies to better predict symptom and endoscopy response; we aimed to validate the EoEHSS in our provincial registry, where EoEHSS had not been employed. METHODS: We reviewed 186 esophageal biopsies from 16 patients at diagnosis and follow-up. Statistical analyses were conducted to quantify how grade scores correlate with active EoE status and PEC counts, and each feature's ability to predict active disease. RESULTS: Nearly all EoEHSS variables were associated with active EoE and high PEC, with basal zone hyperplasia, eosinophil abscesses, and surface epithelial alteration being most predictive in identifying active EoE. CONCLUSIONS: We validated and demonstrated each EoEHSS variable's strength in tracking traditional PEC counts, resulting in its adoption as a standard reporting element for our research registry.

Quantifying Proximal Collecting Tubule Deficiency in Angiotensin-Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker Fetopathy.

INTRODUCTION: Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers (AAs) are used for several indications, with cessation recommended in pregnancy due to toxic effects. AA fetopathy phenotype is similar to renal tubular dysgenesis including reduced proximal convoluted tubules (PCTs). Our study aimed to quantify the reduction of PCTs in fetuses and infants with prenatal exposure to AAs. MATERIALS AND METHODS: We identified 5 fetal AA exposure cases that underwent autopsy at our institution between 2011 and 2018 and compared with 5 gestational age-matched controls. Immunohistochemistry with CD10 and epithelial membrane antigen (EMA) was utilized. RESULTS: CD10 and EMA identified a median PCT density of 19.0% ± 12.3% in AA fetopathy patients, significantly less than controls (52.8% ± 4.4%; p < 0.0001). One case with in utero cessation had a PCT density of 34.2% ± 0.2%. Among other AA fetopathy findings, 1 case demonstrated unilateral renal vein thrombosis and 4 had hypocalvaria. CONCLUSIONS: We have quantified the reduction in AA fetopathy PCT density, and demonstrated in utero cessation may recover PCT differentiation. Future studies may benefit from calculating PCT percentage as a potential biomarker to correlate with post-natal renal function and maternal factors including medication type, dosage, duration, and time from medication cessation.

SMARCA4-deficient rhabdoid tumours show intermediate molecular features between SMARCB1-deficient rhabdoid tumours and small cell carcinomas of the ovary, hypercalcaemic type.

Extracranial rhabdoid tumours (ECRTs) are an aggressive malignancy of infancy and early childhood. The vast majority of cases demonstrate inactivation of SMARCB1 (ECRTSMARCB1 ) on a background of a remarkably stable genome, a low mutational burden, and no other recurrent mutations. Rarely, ECRTs can harbour the alternative inactivation of SMARCA4 (ECRTSMARCA4 ) instead of SMARCB1. However, very few ECRTSMARCA4 cases have been published to date, and a systematic characterization of ECRTSMARCA4 is missing from the literature. In this study, we report the clinical, pathological, and genomic features of additional cases of ECRTSMARCA4 and show that they are comparable to those of ECRTSMARCB1. We also assess whether ECRTSMARCB1 , ECRTSMARCA4 , and small cell carcinomas of the ovary, hypercalcaemic type (SCCOHT) represent distinct or overlapping entities at a molecular level. Using DNA methylation and transcriptomics-based tumour classification approaches, we demonstrate that ECRTSMARCA4 display molecular features intermediate between SCCOHT and ECRTSMARCB1 ; however, ECRTSMARCA4 appear to be more closely related to SCCOHT by DNA methylation. Conversely, both transcriptomics and DNA methylation show a larger gap between SCCOHT and ECRTSMARCB1 , potentially supporting their continuous separate classification. Lastly, we show that ECRTSMARCA4 display concomitant lack of SMARCA4 (BRG1) and SMARCA2 (BRM) expression at the protein level, similar to what is seen in SCCOHT. Overall, these results expand our knowledge on this rare tumour type and explore the similarities and differences among entities from the 'rhabdoid tumour' spectrum. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Atypical teratoid/rhabdoid tumors (ATRTs) with SMARCA4 mutation are molecularly distinct from SMARCB1-deficient cases.

Atypical teratoid/rhabdoid tumors (ATRTs) are very aggressive childhood malignancies of the central nervous system. The underlying genetic cause are inactivating bi-allelic mutations in SMARCB1 or (rarely) in SMARCA4. ATRT-SMARCA4 have been associated with a higher frequency of germline mutations, younger age, and an inferior prognosis in comparison to SMARCB1 mutated cases. Based on their DNA methylation profiles and transcriptomics, SMARCB1 mutated ATRTs have been divided into three distinct molecular subgroups: ATRT-TYR, ATRT-SHH, and ATRT-MYC. These subgroups differ in terms of age at diagnosis, tumor location, type of SMARCB1 alterations, and overall survival. ATRT-SMARCA4 are, however, less well understood, and it remains unknown, whether they belong to one of the described ATRT subgroups. Here, we examined 14 ATRT-SMARCA4 by global DNA methylation analyses. We show that they form a separate group segregating from SMARCB1 mutated ATRTs and from other SMARCA4-deficient tumors like small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) or SMARCA4 mutated extra-cranial malignant rhabdoid tumors. In contrast, medulloblastoma (MB) samples with heterozygous SMARCA4 mutations do not group separately, but with established MB subgroups. RNA sequencing of ATRT-SMARCA4 confirmed the clustering results based on DNA methylation profiling and displayed an absence of typical signature genes upregulated in SMARCB1 deleted ATRT. In summary, our results suggest that, in line with previous clinical observations, ATRT-SMARCA4 should be regarded as a distinct molecular subgroup.

Loss of BRG1 (SMARCA4) Immunoexpression in a Pediatric Non-Central Nervous System Tumor Cohort.

Malignant rhabdoid tumors and atypical teratoid/rhabdoid tumors of the central nervous system are primitive malignancies associated with a poor prognosis. These tumors have previously been characterized by inactivation of the switch/sucrose nonfermenting (SWI/SNF) chromatin remodeling complex protein integrase interactor 1 (INI1), encoded by the SMARCB1 gene. In the last decade, sporadic publications have shown that a different SWI/SNF protein, brahma-related gene 1 (BRG1), encoded by the SMARCA4 gene, is associated with a similar rhabdoid phenotype and possible germline mutation termed rhabdoid tumor predisposition syndrome type 2. We sought to determine the presence of BRG1 expression in pediatric embryonal tumors. Using a local tissue microarray consisting of 28 tumors diagnosed as having an undifferentiated, polyphenotypic, or rhabdoid morphology, expression of BRG1 by immunohistochemistry was performed. Four cases showed loss of INI1, while 3 of the remaining 24 cases demonstrated loss of BRG1. Two cases were diagnosed as soft tissue sarcomas, and 1 case was diagnosed as a small cell carcinoma of the ovary, hypercalcemic type. Survival ranged from less than 6 months after diagnosis to more than 5 years at the time of last follow-up. In conclusion, we demonstrate that BRG1 immunohistochemistry is a useful second-line immunostain for the workup of undifferentiated, polyphenotypic or rhabdoid pediatric tumors that demonstrate retained expression of INI1.

Poor Correlation of Oral Swabs with Esophageal Eosinophil Counts.

Eosinophilic esophagitis (EoE) is a chronic condition that requires repeated endoscopies/biopsies to track the disease and treatment response. This invasive procedure involves risk to the patient and has significant costs. We studied whether the detection of specific proteins (cytokines and eosinophil degranulation products) from oral swabs could serve as a minimally invasive test for EoE. Swabs of the oral cavity (buccal and oropharyngeal) were obtained prior to endoscopy/biopsies in patients with EoE, possible EoE, and non-EoE patients in addition to obtaining additional esophageal biopsy tissue. ELISAs measuring the levels of cytokines IL-5, IL-8, IL-13, and eosinophil degranulation products including major basic protein (MBP), eosinophil derived neurotoxin (EDN), and eosinophil peroxidase (EPO) were performed on the samples. Comparisons were made to peak esophageal eosinophil counts. Tolerability of the swabs was evaluated. 43 patients, 4-17 years old, participated in the study. Swabs were well tolerated and all showed measurable protein. 26 patients had EoE [14 active (> 15 eosinophils/high power field), 12 non-active], 17 patients did not have EoE. Results obtained from oral swabs showed poor correlation with those from esophageal tissue. Only measurement of eosinophil degranulation products EDN and EPO from esophageal tissues showed strong correlations with eosinophil counts. In this study, the levels of cytokines and eosinophil degranulation products detected from oral swabs did not correlate with esophageal eosinophilia, and their detection would be insufficient to displace endoscopy/biopsies.

Spindle Epithelial Tumor with Thymus-Like Differentiation (SETTLE): A Case Report.

Background: Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a tumor with an indolent disease course and late metastatic potential. It occurs primarily in children and adolescents, although it can present later in life. It was first described by Chan and Rosai [Tumors of the neck showing thymic or related branchial pouch differentiation: a unifying concept. Hum Pathol. 1991;22(4):349-67. doi:10.1016/0046-8177(91)90083-2], and there have been approximately 46 cases published in the English literature. Case report: We present an 8-year-old female with a SETTLE, undergoing an initial fine-needle aspiration and later a diagnostic biopsy. There is no evidence of disease recurrence at 3.5 years of follow-up. Conclusion: Though fine-needle aspirate biopsy is useful in directing the diagnostic workup of SETTLE by indicating concerning pathology, the broad differential diagnosis associated with it requires histology in conjunction with a limited immunohistochemical panel and unremarkable cytogenetics workup. Surgical resection is the main stay of treatment, and long-term follow-up is important in these patients.

Systematic testing and specificity mapping of alloantigen-specific chimeric antigen receptors in regulatory T cells.

Chimeric antigen receptor (CAR) technology can be used to engineer the antigen specificity of regulatory T cells (Tregs) and improve their potency as an adoptive cell therapy in multiple disease models. As synthetic receptors, CARs carry the risk of immunogenicity, particularly when derived from nonhuman antibodies. Using an HLA-A*02:01-specific CAR (A2-CAR) encoding a single-chain variable fragment (Fv) derived from a mouse antibody, we developed a panel of 20 humanized A2-CARs (hA2-CARs). Systematic testing demonstrated variations in expression, and ability to bind HLA-A*02:01 and stimulate human Treg suppression in vitro. In addition, we developed a new method to comprehensively map the alloantigen specificity of CARs, revealing that humanization reduced HLA-A cross-reactivity. In vivo bioluminescence imaging showed rapid trafficking and persistence of hA2-CAR Tregs in A2-expressing allografts, with eventual migration to draining lymph nodes. Adoptive transfer of hA2-CAR Tregs suppressed HLA-A2+ cell-mediated xenogeneic graft-versus-host disease and diminished rejection of human HLA-A2+ skin allografts. These data provide a platform for systematic development and specificity testing of humanized alloantigen-specific CARs that can be used to engineer specificity and homing of therapeutic Tregs.

Pediatric Eosinophilic Esophagitis Is Associated With Increased Lamina Propria Immunoglobulin G4-Positive Plasma Cells.

OBJECTIVE: Eosinophilic esophagitis (EoE) is considered a TH2-mediated food allergy disease that leads to submucosal esophageal fibrosis and strictures. Recent studies focused on adults with EoE identified a strong association with elevated esophageal IgG4 immunostaining. Our study aimed to determine the association of IgG4 with EoE in pediatric patients. METHODS: Using our local EoE research registry, we identified 41 adequate biopsies from EoE patients. We used 10 age- and sex-matched patients with no diagnostic abnormalities at endoscopy or on biopsy. Using a monoclonal antibody to Immunoglobulin G4 (IgG4), we determined the maximum density of IgG4-positive plasma cells (IgG4-PC) per high-power field (hpf). Using a semi-quantitative assessment, we also graded the noncellular staining of the lamina propria and epithelium. RESULTS: Our EoE cohort consisted predominantly of boys with an average age of 5.9 years and 63% had a documented IgE-based food allergy. Median peak eosinophilia was 40 eosinophils/hpf and the median IgG4-PC density was 39/hpf in the active esophagitis patients, compared with a median of 0 IgG4-PC/hpf in the non-EoE patients (P = 0.0001). EoE patients with a food allergy showed a significantly higher IgG4-PC density (44.5/hpf) than those without a food allergy (8/hpf; P = 0.0385). There was no significant association between IgG4-PC density and peak eosinophilia (r = 0.0011). CONCLUSIONS: We demonstrate that active esophagitis in pediatric EoE patients is associated with elevated levels of IgG4-positive plasma cells, which was more significant in EoE patients with a documented food allergy. Our study also adds to the growing literature that EoE may involve more than just an exaggerated TH2 immune response.

Pediatric Pathology Fellowship Recruitment-Report of a Survey Conducted by the Fellowship Committee of the Society for Pediatric Pathology.

Pediatric pathology (PP) is a subspecialty of pathology encompassing disease states during human development from the fetus to the young adult. Despite the existence of ACGME-accredited fellowship programs and opportunity for pediatric pathology subspecialty board certification, many pediatric pathology fellowship positions remain unfilled in North America. We sought to understand the difficulties in recruitment to the PP training programs by conducting a survey. A 3-pronged survey targeting pathology residents (PR), PP fellows and recent fellowship graduates (F&G), and PP training programs was conducted. Three separate questionnaires were prepared, one for each group; and administered online via SurveyMonkey. There were 175 responses to PR survey, 29 to F&G and 19 to programs survey. The results of the PR and F&G survey revealed that trainees select a subspecialty early in their residency training, primarily based on their interest, followed by prospects of employment. Nearly half of resident respondents had discounted pediatric pathology subspecialty training without prior exposure to the specialty. Senior residents and faculty members were reported as the main source for fellowship information for residents choosing subspecialty training and the choice of the training program was mostly dictated by geographic location. Most fellow recruits are racially diverse, female, and American medical graduates. Pathology residents decide on subspecialty training based on their interest; however, many are not exposed to pediatric pathology early on in training. The survey results suggest that existing PP fellowship positions likely will continue to exceed demand for subspecialty training. The results of the study could aid in developing strategies to boost recruitment to PP.

Eosinophilic density in graft biopsies positive for rejection and blood eosinophil count can predict development of post-transplant digestive tract eosinophilia.

EGID is a known post-transplant complication. Its etiology has been related to antirejection medication, but other factors may also play a role as only few transplant recipients develop EGID despite standardized treatment. This study aimed to determine whether EGID is associated with rejection events and with a specific phenotype of the rejection-positive graft biopsies in children with solid organ transplant. All patients with liver, heart, and kidney transplant followed at our institution were included in the study. Digestive tract eosinophilia was more common in heart and liver recipients and was a rare event after renal transplantation. Subjects with EGID had higher incidence of rejection and elevated peripheral blood AEC. The first rejection event and high AEC values preceded EGID diagnosis in the majority of patients. Histologically, the initial rejection-positive graft biopsy revealed accentuated eosinophilia in EGID patients compared with non-EGID cohort, which correlated with higher blood eosinophil counts at the time of first rejection episode. Prominent graft tissue and peripheral blood eosinophilia prior to EGID diagnosis suggests a predisposition for eosinophil activation in patients with post-transplant digestive eosinophilic disorder. These parameters can be used as markers for subsequent development of EGID.

Treatment of neuroblastoma in congenital central hypoventilation syndrome with a PHOX2B polyalanine repeat expansion mutation: New twist on a neurocristopathy syndrome.

Neuroblastoma in patients with congenital central hypoventilation syndrome (CCHS) as part of a neurocristopathy syndrome is a rare finding and has only been associated with paired-like homeobox 2b (PHOX2B) non-polyalanine-repeat-expansion mutations. To the best of our knowledge, we report the first case of a child with CCHS and Hirschsprung disease who had a PHOX2B polyalanine-repeat-expansion mutation (PARM) (genotype 20/33) and developed high-risk neuroblastoma. We further describe his treatment including chemotherapy and therapeutic I(131) -metaiodobenzylguanidine. This case highlights the need to consider neuroblastoma in patients with CCHS and the longest PHOX2B PARMs and to individualize treatment based on co-morbidities.

Combined robotic and open approach to excision of accessory bladder and urethral triplication.

BACKGROUND: Management of urethral and bladder duplication anomalies centers on prevention of recurrent infections and preservation of renal function. We present a surgical approach to urethral triplication and bladder duplication utilizing a combined robotic and open approach. METHODS: A 17-year-old male presenting with fevers and abdominal pain was found to have two accessory urethras dorsal to a normal orthotopic ventral meatus. A large cavity anterior to the bladder was identified on a computed tomography scan and drained of purulent fluid. After improvement with antibiotics, endoscopic evaluation revealed no distinct connection between the cavities. The patient subsequently underwent open excision of the urethral triplication followed by robotic excision of the accessory bladder. RESULTS: Total console time for the robotic portion was 2 hours 18 minutes and estimated blood loss was 30mL. The dissection was difficult due to reaction from prior infections, but the accessory bladder was able to be dissected off without opening the native bladder. The accessory bladder specimen was consistent with a urothelial lining exhibiting reactive changes. CONCLUSION: To our knowledge, robotic excision of a urethral/bladder duplication anomaly has not yet been described in the literature. The robotic approach allowed for excellent visualization and is technically feasible.